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Sample records for biological samples programa

  1. Biological sample collector

    DOEpatents

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  2. Preservation of Liquid Biological Samples

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi (Inventor); Nimmagudda, Ramalingeshwara (Inventor)

    2004-01-01

    The present invention related to the preservation of a liquid biological sample. The biological sample is exposed to a preservative containing at least about 0.15 g of sodium benzoate and at least about 0.025 g of citric acid per 100 ml of sample. The biological sample may be collected in a vessel or an absorbent mass. The biological sample may also be exposed to a substrate and/or a vehicle.

  3. Preservation of Liquid Biological Samples

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi (Inventor); Nimmagudda, Ramalingeshwara R. (Inventor)

    2000-01-01

    The present invention provides a method of preserving a liquid biological sample, comprising the step of: contacting said liquid biological sample with a preservative comprising, sodium benzoate in an amount of at least about 0.15% of the sample (weight/volume) and citric acid in an amount of at least about 0.025% of the sample (weight/volume).

  4. Modular microfluidic system for biological sample preparation

    DOEpatents

    Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

    2015-09-29

    A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

  5. Spectroscopic diagnostics for bacteria in biologic sample

    DOEpatents

    El-Sayed, Mostafa A.; El-Sayed, Ivan H.

    2002-01-01

    A method to analyze and diagnose specific bacteria in a biologic sample using spectroscopy is disclosed. The method includes obtaining the spectra of a biologic sample of a non-infected patient for use as a reference, subtracting the reference from the spectra of an infected sample, and comparing the fingerprint regions of the resulting differential spectrum with reference spectra of bacteria in saline. Using this diagnostic technique, specific bacteria can be identified sooner and without culturing, bacteria-specific antibiotics can be prescribed sooner, resulting in decreased likelihood of antibiotic resistance and an overall reduction of medical costs.

  6. Trace Element Analysis of Biological Samples.

    ERIC Educational Resources Information Center

    Veillon, Claude

    1986-01-01

    Reviews background of atomic absorption spectrometry techniques. Discusses problems encountered and precautions to be taken in determining trace elements in the parts-per-billion concentration range and below. Concentrates on determining chromium in biological samples by graphite furnace atomic absorption. Considers other elements, matrices, and…

  7. Biological Sterilization of Returned Mars Samples

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Albert, F. G.; Combie, J.; Bodnar, R. J.; Hamilton, V. E.; Jolliff, B. L.; Kuebler, K.; Wang, A.; Lindstrom, D. J.; Morris, P. A.

    1999-01-01

    Martian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.

  8. Microfluidic Tools for Biological Sample Preparation

    SciTech Connect

    Visuri, S R; Ness, K; Dzenitis, J; Benett, B; Bettencourt, K; Hamilton, J; Fisher, K; Krulevitch, P

    2002-04-10

    Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. To support detection instruments, we are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. We are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Sample preparation functions are accomplished with acoustic radiation pressure, dielectrophoresis, and solid phase extraction. We are integrating these technologies into packaged systems with pumps and valves to control fluid flow and investigating small-scale detection methods.

  9. [The ethical implications of conserving biological samples].

    PubMed

    Tazzite, A; Roky, R; Avard, D

    2009-09-01

    The conservation and use of biological samples become more and more frequent all around the world. Biobanks of human body substances (blood, urine, DNA, tissues, cells, etc.), and personal data associated with them are created. They have a double character as they are collections of both human biological samples and personal data. In some cases, the gametes, reproductive tissues, embryos, foetal tissue after abortion or even specimens of dead donors are collected and conserved. Although biobanks raise hopes in both the development of new therapies, new drugs and their integration into clinical medicine, they also point to concerns related to ethical questions such as: the principles of information, the consent of the persons concerned, the confidentiality about the personal data, and in some cases discrimination and stigmatisation. Other ethical aspects could raise gradually as research advance. Research being carried out on human sample requires informed free consent from the person who should be able to consent. The donor must be sufficiently informed about the process of research, the purpose, benefits and the risks involved in participating in this research. In the case of persons unable to give consent such minors or persons with mental disabilities, special measures are undertaken. Once the consent was given, the right of withdrawal has been consistently supported by the various declarations and regulations, but some oppose this right for a number of reasons particularly in the case of research on the samples without risk of physical exposure. In this case the notion of human body integrity is different than in research involving therapeutic or clinical intervention. In the case of withdrawal of consent, the samples should be destroyed, but the anonymous results arising from them and their analysis are not affected. What is the case for future uses? Should the researcher obtain again the consent from the donor for a secondary use of the samples? This is a

  10. Atomic force microscopy of biological samples

    SciTech Connect

    Doktycz, Mitchel John

    2010-01-01

    The ability to evaluate structural-functional relationships in real time has allowed scanning probe microscopy (SPM) to assume a prominent role in post genomic biological research. In this mini-review, we highlight the development of imaging and ancillary techniques that have allowed SPM to permeate many key areas of contemporary research. We begin by examining the invention of the scanning tunneling microscope (STM) by Binnig and Rohrer in 1982 and discuss how it served to team biologists with physicists to integrate high-resolution microscopy into biological science. We point to the problems of imaging nonconductive biological samples with the STM and relate how this led to the evolution of the atomic force microscope (AFM) developed by Binnig, Quate, and Gerber, in 1986. Commercialization in the late 1980s established SPM as a powerful research tool in the biological research community. Contact mode AFM imaging was soon complemented by the development of non-contact imaging modes. These non-contact modes eventually became the primary focus for further new applications including the development of fast scanning methods. The extreme sensitivity of the AFM cantilever was recognized and has been developed into applications for measuring forces required for indenting biological surfaces and breaking bonds between biomolecules. Further functional augmentation to the cantilever tip allowed development of new and emerging techniques including scanning ion-conductance microscopy (SICM), scanning electrochemical microscope (SECM), Kelvin force microscopy (KFM) and scanning near field ultrasonic holography (SNFUH).

  11. Quantitative analysis of bisphosphonates in biological samples.

    PubMed

    Lapko, Veniamin N; Miller, Patrick S; Sheldon, Curtis E; Nachi, Ridha; Kafonek, Chris J

    2014-01-01

    Bisphosphonate drugs pose significant challenges for bioanalysis due to various complicating factors. In 2006, a novel approach, utilizing 'on-column' derivatization with diazomethane, was reported that revolutionized the application of liquid-chromatography-tandem mass spectrometry to bisphosphonates bioanalysis. The methodology enables superior biological sample clean-up while transforming bisphosphonates into species amenable to liquid-chromatography-tandem mass spectrometry detection. Since then, the approach has been successfully applied to numerous bisphosphonates. The use of an alternative methylation reagent - trimethylsilyl diazomethane - for on-column derivatization has been reported recently. This review focuses on published methods utilizing on-column derivatization for bioanalysis of major bisphosphonate drugs in biological matrices. Critical points required for successful application of on-column derivatization to the bioanalysis of bisphosphonates will be discussed.

  12. [Ethical aspects of biological sample banks].

    PubMed

    Cambon-Thomsen, A; Rial-Sebbag, E

    2003-02-01

    Numerous activities in the domain of epidemiology require the constitution or the use of biological sample banks. Such biobanks raise ethical issues. A number of recommendations are applicable to this field, in France and elsewhere. Major principles applicable to biobanks include the respect of person's autonomy, the respect of human body, the respect of confidentiality. These principles are translated into practices through the following procedures: relevant information to the persons regarding their sample management prior to informed consent, opinion of an independent ethics committee, actual implementation of conditions for protecting samples and data. However, although those principles may appear quite simple and obvious, in the context of a largely international practice of research and given the large variety of biobanks, it is not always obvious for researchers to find their way. The attitudes vary between countries, there are numerous texts for various types of biobanks, the same texts raise different interpretations in different institutions, there are new ethical opinions expressed, and mainly the novelty of questions raised by the uses of samples that are possible today, especially in genetics, and were not foreseeable at the time of sampling make the field difficult in practice. This article reviews the types of biobanks, the relevant ethical issues. It also underlines the still unclear or ambiguous situations using some examples of practical situations.

  13. Measurement of NO in biological samples.

    PubMed

    Csonka, C; Páli, T; Bencsik, P; Görbe, A; Ferdinandy, P; Csont, T

    2015-03-01

    Although the physiological regulatory function of the gasotransmitter NO (a diatomic free radical) was discovered decades ago, NO is still in the frontline research in biomedicine. NO has been implicated in a variety of physiological and pathological processes; therefore, pharmacological modulation of NO levels in various tissues may have significant therapeutic value. NO is generated by NOS in most of cell types and by non-enzymatic reactions. Measurement of NO is technically difficult due to its rapid chemical reactions with a wide range of molecules, such as, for example, free radicals, metals, thiols, etc. Therefore, there are still several contradictory findings on the role of NO in different biological processes. In this review, we briefly discuss the major techniques suitable for measurement of NO (electron paramagnetic resonance, electrochemistry, fluorometry) and its derivatives in biological samples (nitrite/nitrate, NOS, cGMP, nitrosothiols) and discuss the advantages and disadvantages of each method. We conclude that to obtain a meaningful insight into the role of NO and NO modulator compounds in physiological or pathological processes, concomitant assessment of NO synthesis, NO content, as well as molecular targets and reaction products of NO is recommended.

  14. Measurement of NO in biological samples

    PubMed Central

    Csonka, C; Páli, T; Bencsik, P; Görbe, A; Ferdinandy, P; Csont, T

    2015-01-01

    Although the physiological regulatory function of the gasotransmitter NO (a diatomic free radical) was discovered decades ago, NO is still in the frontline research in biomedicine. NO has been implicated in a variety of physiological and pathological processes; therefore, pharmacological modulation of NO levels in various tissues may have significant therapeutic value. NO is generated by NOS in most of cell types and by non-enzymatic reactions. Measurement of NO is technically difficult due to its rapid chemical reactions with a wide range of molecules, such as, for example, free radicals, metals, thiols, etc. Therefore, there are still several contradictory findings on the role of NO in different biological processes. In this review, we briefly discuss the major techniques suitable for measurement of NO (electron paramagnetic resonance, electrochemistry, fluorometry) and its derivatives in biological samples (nitrite/nitrate, NOS, cGMP, nitrosothiols) and discuss the advantages and disadvantages of each method. We conclude that to obtain a meaningful insight into the role of NO and NO modulator compounds in physiological or pathological processes, concomitant assessment of NO synthesis, NO content, as well as molecular targets and reaction products of NO is recommended. Linked Articles This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6 PMID:24990201

  15. Determination of cadmium in biological samples.

    PubMed

    Klotz, Katrin; Weistenhöfer, Wobbeke; Drexler, Hans

    2013-01-01

    Analyses of cadmium concentrations in biological material are performed using inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS), but also electrochemical methods, neutron activation analysis (NAA), and X-ray fluorescence spectrometry (XRF). The predominant sample matrices include blood, plasma, serum, and urine, as well as hair, saliva, and tissue of kidney cortex, lung, and liver. While cadmium in blood reveals rather the recent exposure situation, cadmium in urine reflects the body burden and is an indicator for the cumulative long term exposure.After chronic exposure, cadmium accumulates in the human body and causes kidney diseases, especially lesions of proximal tubular cells. A tubular proteinuria causes an increase in urinary excretion of microproteins. Excretions of retinol binding protein (RBP), β2-microglobulin (β2-M), and α1-microglobulin are validated biomarkers for analyzing cadmium effects. For this purpose, immunological procedures such as ELISA, and radio- and latex-immunoassays are used.However, proteinuria is not specific to cadmium, but can also occur after exposure to other nephrotoxic agents or due to various kidney diseases. In summary, cadmium in urine and blood are the most specific biomarkers of cadmium exposure. A combination of parameters of exposure (cadmium in blood, cadmium in urine) and parameters of effect (e.g., β2-M, RBP) is required to reveal cadmium-induced nephrological effects. PMID:23430771

  16. COMPARISON OF BIOLOGICAL COMMUNITIES: THE PROBLEM OF SAMPLE REPRESENTATIVENESS

    EPA Science Inventory

    Obtaining an adequate, representative sample of biological communities or assemblages to make richness or compositional comparisons among sites is a continuing challenge. Traditionally, sample size is based on numbers of replicates or area collected or numbers of individuals enum...

  17. How to analyze those messy biological samples

    SciTech Connect

    Barker, S.A. . Dept. of Veterinary Physiology, Pharmacology, and Toxicology)

    1993-03-01

    Extracting drugs, pollutants, or naturally occurring components from tissues is always an analytical challenge. However, there is an increasing need to perform such extractions for the regulation of food safety, the determination of the degree or nature of pollution in various environments, or to isolate a particular class of structural components from cells. The samples may range from blood to whole oysters, milk to fish, calf's liver to crayfish, or beef to bacteria. The author has developed a generic process that greatly simplifies and speeds the isolation of drugs, pollutants, and biomolecules from tissues, bacteria, and processed foods. This process, called matrix solid-phase dispersion (MSPD; patent pending), allows the analyst to perform sample homogenization, cellular disruption, and sample purification in a single step. The methods that they have developed have shown to reduce solvent usage by 90% and analyst time by 95% when compared with classical procedures for drug isolations from tissue.

  18. Rapid Automated Sample Preparation for Biological Assays

    SciTech Connect

    Shusteff, M

    2011-03-04

    Our technology utilizes acoustic, thermal, and electric fields to separate out contaminants such as debris or pollen from environmental samples, lyse open cells, and extract the DNA from the lysate. The objective of the project is to optimize the system described for a forensic sample, and demonstrate its performance for integration with downstream assay platforms (e.g. MIT-LL's ANDE). We intend to increase the quantity of DNA recovered from the sample beyond the current {approx}80% achieved using solid phase extraction methods. Task 1: Develop and test an acoustic filter for cell extraction. Task 2: Develop and test lysis chip. Task 3: Develop and test DNA extraction chip. All chips have been fabricated based on the designs laid out in last month's report.

  19. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... samples of each serial or subserial of a biological product manufactured in the United States or imported... filling operation. (iv) Representative samples of each serial or subserial in each shipment of imported... such samples from each serial and the minimum quantity of product to be provided in each sample...

  20. Observation of biological samples using a scanning microwave microscope.

    PubMed

    Park, Jewook; Hyun, S; Kim, A; Kim, T; Char, K

    2005-01-01

    We present the application of a scanning microwave microscope technique to biological samples. Since dielectric properties of most biological samples originate mainly from the water they contain, we were able to obtain microscope images of biological samples by our scanning microwave microscope technique. As a model system, we have measured the electrical properties of water in the microwave region. The high dielectric constant and the large loss tangent of water were verified. Furthermore, we have measured the properties of water with differing amounts of sodium chloride concentration ranging from de-ionized water to the saturated solution. We have observed a significant change in the resonant frequency and Q value of the resonator as a function of sodium chloride concentration. The concentration dependence of the signals shows that our scanning microwave microscope technique can be useful for investigating the local electric behavior of biological samples with a simple model of ionic conduction.

  1. Advances in imaging secondary ion mass spectrometry for biological samples

    SciTech Connect

    Boxer, Steven G.; Kraft, Mary L.; Weber, Peter K.

    2008-12-16

    Imaging mass spectrometry combines the power of mass spectrometry to identify complex molecules based on mass with sample imaging. Recent advances in secondary ion mass spectrometry have improved sensitivity and spatial resolution, so that these methods have the potential to bridge between high-resolution structures obtained by X-ray crystallography and cyro-electron microscopy and ultrastructure visualized by conventional light microscopy. Following background information on the method and instrumentation, we address the key issue of sample preparation. Because mass spectrometry is performed in high vacuum, it is essential to preserve the lateral organization of the sample while removing bulk water, and this has been a major barrier for applications to biological systems. Furthermore, recent applications of imaging mass spectrometry to cell biology, microbial communities, and biosynthetic pathways are summarized briefly, and studies of biological membrane organization are described in greater depth.

  2. Advances in imaging secondary ion mass spectrometry for biological samples

    DOE PAGES

    Boxer, Steven G.; Kraft, Mary L.; Weber, Peter K.

    2008-12-16

    Imaging mass spectrometry combines the power of mass spectrometry to identify complex molecules based on mass with sample imaging. Recent advances in secondary ion mass spectrometry have improved sensitivity and spatial resolution, so that these methods have the potential to bridge between high-resolution structures obtained by X-ray crystallography and cyro-electron microscopy and ultrastructure visualized by conventional light microscopy. Following background information on the method and instrumentation, we address the key issue of sample preparation. Because mass spectrometry is performed in high vacuum, it is essential to preserve the lateral organization of the sample while removing bulk water, and this hasmore » been a major barrier for applications to biological systems. Furthermore, recent applications of imaging mass spectrometry to cell biology, microbial communities, and biosynthetic pathways are summarized briefly, and studies of biological membrane organization are described in greater depth.« less

  3. Fast X-Ray Fluorescence Microtomography of Hydrated Biological Samples

    PubMed Central

    Lombi, Enzo; de Jonge, Martin D.; Donner, Erica; Kopittke, Peter M.; Howard, Daryl L.; Kirkham, Robin; Ryan, Chris G.; Paterson, David

    2011-01-01

    Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples. PMID:21674049

  4. Fast x-ray fluorescence microtomography of hydrated biological samples.

    PubMed

    Lombi, Enzo; de Jonge, Martin D; Donner, Erica; Kopittke, Peter M; Howard, Daryl L; Kirkham, Robin; Ryan, Chris G; Paterson, David

    2011-01-01

    Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples. PMID:21674049

  5. Efficient Sample Preparation from Complex Biological Samples Using a Sliding Lid for Immobilized Droplet Extractions

    PubMed Central

    2015-01-01

    Sample preparation is a major bottleneck in many biological processes. Paramagnetic particles (PMPs) are a ubiquitous method for isolating analytes of interest from biological samples and are used for their ability to thoroughly sample a solution and be easily collected with a magnet. There are three main methods by which PMPs are used for sample preparation: (1) removal of fluid from the analyte-bound PMPs, (2) removal of analyte-bound PMPs from the solution, and (3) removal of the substrate (with immobilized analyte-bound PMPs). In this paper, we explore the third and least studied method for PMP-based sample preparation using a platform termed Sliding Lid for Immobilized Droplet Extractions (SLIDE). SLIDE leverages principles of surface tension and patterned hydrophobicity to create a simple-to-operate platform for sample isolation (cells, DNA, RNA, protein) and preparation (cell staining) without the need for time-intensive wash steps, use of immiscible fluids, or precise pinning geometries. Compared to other standard isolation protocols using PMPs, SLIDE is able to perform rapid sample preparation with low (0.6%) carryover of contaminants from the original sample. The natural recirculation occurring within the pinned droplets of SLIDE make possible the performance of multistep cell staining protocols within the SLIDE by simply resting the lid over the various sample droplets. SLIDE demonstrates a simple easy to use platform for sample preparation on a range of complex biological samples. PMID:24927449

  6. A large-scale cryoelectronic system for biological sample banking

    NASA Astrophysics Data System (ADS)

    Shirley, Stephen G.; Durst, Christopher H. P.; Fuchs, Christian C.; Zimmermann, Heiko; Ihmig, Frank R.

    2009-11-01

    We describe a polymorphic electronic infrastructure for managing biological samples stored over liquid nitrogen. As part of this system we have developed new cryocontainers and carrier plates attached to Flash memory chips to have a redundant and portable set of data at each sample. Our experimental investigations show that basic Flash operation and endurance is adequate for the application down to liquid nitrogen temperatures. This identification technology can provide the best sample identification, documentation and tracking that brings added value to each sample. The first application of the system is in a worldwide collaborative research towards the production of an AIDS vaccine. The functionality and versatility of the system can lead to an essential optimization of sample and data exchange for global clinical studies.

  7. Cryogenic X-ray Diffraction Microscopy for Biological Samples

    SciTech Connect

    E Lima; L Wiegart; P Pernot; M Howells; J Timmins; F Zontone; A Madsen

    2011-12-31

    X-ray diffraction microscopy (XDM) is well suited for nondestructive, high-resolution biological imaging, especially for thick samples, with the high penetration power of x rays and without limitations imposed by a lens. We developed nonvacuum, cryogenic (cryo-) XDM with hard x rays at 8 keV and report the first frozen-hydrated imaging by XDM. By preserving samples in amorphous ice, the risk of artifacts associated with dehydration or chemical fixation is avoided, ensuring the imaging condition closest to their natural state. The reconstruction shows internal structures of intact D. radiodurans bacteria in their natural contrast.

  8. Analytical methodologies for the determination of benzodiazepines in biological samples.

    PubMed

    Persona, Karolina; Madej, Katarzyna; Knihnicki, Paweł; Piekoszewski, Wojciech

    2015-09-10

    Benzodiazepine drugs belong to important and most widely used medicaments. They demonstrate such therapeutic properties as anxiolytic, sedative, somnifacient, anticonvulsant, diastolic and muscle relaxant effects. However, despite the fact that benzodiazepines possess high therapeutic index and are considered to be relatively safe, their use can be dangerous when: (1) co-administered with alcohol, (2) co-administered with other medicaments like sedatives, antidepressants, neuroleptics or morphine like substances, (3) driving under their influence, (4) using benzodiazepines non-therapeutically as drugs of abuse or in drug-facilitated crimes. For these reasons benzodiazepines are still studied and determined in a variety of biological materials. In this article, sample preparation techniques which have been applied in analysis of benzodiazepine drugs in biological samples have been reviewed and presented. The next part of the article is focused on a review of analytical methods which have been employed for pharmacological, toxicological or forensic study of this group of drugs in the biological matrices. The review was preceded by a description of the physicochemical properties of the selected benzodiazepines and two, very often coexisting in the same analyzed samples, sedative-hypnotic drugs.

  9. Specific fluorogenic probes for ozone in biological and atmospheric samples.

    PubMed

    Garner, Amanda L; St Croix, Claudette M; Pitt, Bruce R; Leikauf, George D; Ando, Shin; Koide, Kazunori

    2009-07-01

    Ozone exposure is a growing global health problem, especially in urban areas. While ozone in the stratosphere protects the earth from harmful ultraviolet light, tropospheric or ground-level ozone is toxic and can damage the respiratory tract. It has recently been shown that ozone may be produced endogenously in inflammation and antibacterial responses of the immune system; however, these results have sparked controversy owing to the use of a non-specific colorimetric probe. Here we report the synthesis of fluorescent molecular probes able to unambiguously detect ozone in both biological and atmospheric samples. Unlike other ozone-detection methods, in which interference from different reactive oxygen species is often a problem, these probes are ozone specific. Such probes will prove useful for the study of ozone in environmental science and biology, and so possibly provide some insight into the role of ozone in cells.

  10. Specific fluorogenic probes for ozone in biological and atmospheric samples

    PubMed Central

    Garner, Amanda L.; St Croix, Claudette M.; Pitt, Bruce R.; Leikauf, George D.; Ando, Shin; Koide, Kazunori

    2010-01-01

    Ozone exposure is a growing global health problem, especially in urban areas. While ozone in the stratosphere protects the earth from harmful ultraviolet light, tropospheric or ground-level ozone is toxic and can damage the respiratory tract. It has recently been shown that ozone may be produced endogenously in inflammation and antibacterial responses of the immune system; however, these results have sparked controversy owing to the use of a non-specific colorimetric probe. Here we report the synthesis of fluorescent molecular probes able to unambiguously detect ozone in both biological and atmospheric samples. Unlike other ozone-detection methods, in which interference from different reactive oxygen species is often a problem, these probes are ozone specific. Such probes will prove useful for the study of ozone in environmental science and biology, and so possibly provide some insight into the role of ozone in cells. PMID:20634904

  11. A low temperature scanning force microscope for biological samples

    SciTech Connect

    Gustafsson, M. G.L.

    1993-05-01

    An SFM has been constructed capable of operating at 143 K. Two contributions to SFM technology are described: a new method of fabricating tips, and new designs of SFM springs that significantly lower the noise level. The SFM has been used to image several biological samples (including collagen, ferritin, RNA, purple membrane) at 143 K and room temperature. No improvement in resolution resulted from 143 K operation; several possible reasons for this are discussed. Possibly sharper tips may help. The 143 K SFM will allow the study of new categories of samples, such as those prepared by freeze-frame, single molecules (temperature dependence of mechanical properties), etc. The SFM was used to cut single collagen molecules into segments with a precision of {le} 10 nm.

  12. Microsystem strategies for sample preparation in biological detection.

    SciTech Connect

    James, Conrad D.; Galambos, Paul C.; Bennett, Dawn Jonita; Manginell, Monica; Okandan, Murat; Acrivos, Andreas; Brozik, Susan Marie; Khusid, Boris

    2005-03-01

    The objective of this LDRD was to develop microdevice strategies for dealing with samples to be examined in biological detection systems. This includes three sub-components: namely, microdevice fabrication, sample delivery to the microdevice, and sample processing within the microdevice. The first component of this work focused on utilizing Sandia's surface micromachining technology to fabricate small volume (nanoliter) fluidic systems for processing small quantities of biological samples. The next component was to develop interfaces for the surface-micromachined silicon devices. We partnered with Micronics, a commercial company, to produce fluidic manifolds for sample delivery to our silicon devices. Pressure testing was completed to examine the strength of the bond between the pressure-sensitive adhesive layer and the silicon chip. We are also pursuing several other methods, both in house and external, to develop polymer-based fluidic manifolds for packaging silicon-based microfluidic devices. The second component, sample processing, is divided into two sub-tasks: cell collection and cell lysis. Cell collection was achieved using dielectrophoresis, which employs AC fields to collect cells at energized microelectrodes, while rejecting non-cellular particles. Both live and dead Staph. aureus bacteria have been collected using RF frequency dielectrophoresis. Bacteria have been separated from polystyrene microspheres using frequency-shifting dielectrophoresis. Computational modeling was performed to optimize device separation performance, and to predict particle response to the dielectrophoretic traps. Cell lysis is continuing to be pursued using microactuators to mechanically disrupt cell membranes. Novel thermal actuators, which can generate larger forces than previously tested electrostatic actuators, have been incorporated with and tested with cell lysis devices. Significant cell membrane distortion has been observed, but more experiments need to be conducted to

  13. Proteomic Challenges: Sample Preparation Techniques for Microgram-Quantity Protein Analysis from Biological Samples

    PubMed Central

    Feist, Peter; Hummon, Amanda B.

    2015-01-01

    Proteins regulate many cellular functions and analyzing the presence and abundance of proteins in biological samples are central focuses in proteomics. The discovery and validation of biomarkers, pathways, and drug targets for various diseases can be accomplished using mass spectrometry-based proteomics. However, with mass-limited samples like tumor biopsies, it can be challenging to obtain sufficient amounts of proteins to generate high-quality mass spectrometric data. Techniques developed for macroscale quantities recover sufficient amounts of protein from milligram quantities of starting material, but sample losses become crippling with these techniques when only microgram amounts of material are available. To combat this challenge, proteomicists have developed micro-scale techniques that are compatible with decreased sample size (100 μg or lower) and still enable excellent proteome coverage. Extraction, contaminant removal, protein quantitation, and sample handling techniques for the microgram protein range are reviewed here, with an emphasis on liquid chromatography and bottom-up mass spectrometry-compatible techniques. Also, a range of biological specimens, including mammalian tissues and model cell culture systems, are discussed. PMID:25664860

  14. Determination of total mercury in biological and geological samples

    USGS Publications Warehouse

    Crock, James G.

    2005-01-01

    The analytical chemist is faced with several challenges when determining mercury in biological and geological materials. These challenges include widespread mercury contamination, both in the laboratory and the environment, possible losses of mercury during sample preparation and digestion, the wide range of mercury values commonly observed, ranging from the low nanogram per gram or per liter for background areas to hundreds of milligrams per kilogram in contaminated or ore-bearing areas, great matrix diversity, and sample heterogeneity1. These factors can be naturally occurring or anthropogenic, but must be addressed to provide a precise and accurate analysis. Although there are many instrumental methods available for the successful determination of mercury, no one technique will address all problems or all samples all of the time. The approach for the determination of mercury used at the U.S. Geological Survey, Crustal Imaging and Characterization Team, Denver Laboratories, utilizes a suite of complementary instrumental methods when approaching a study requiring mercury analyses. Typically, a study could require the analysis of waters, leachates or selective digestions of solids, vegetation, and biological materials such as tissue, bone, or shell, soils, rocks, sediments, coals, sludges, and(or) ashes. No one digestion or sample preparation method will be suitable for all of these matrices. The digestions typically employed at our laboratories include: (i) a closed-vessel microwave method using nitric acid and hydrogen peroxide, followed by digestion/dilution with a nitric acid/sodium dichromate solution, (ii) a robotic open test-tube digestion with nitric acid and sodium dichromate, (iii) a sealed Teflon? vessel with nitric acid and sodium dichromate, (iv) a sealed glass bottle with nitric acid and sodium dichromate, or (v) open test tube digestion with nitric and sulfuric acids and vanadium pentoxide. The common factor in all these digestions is that they are

  15. Application of Acoustic Techniques for Characterization of Biological Samples

    NASA Astrophysics Data System (ADS)

    Tittmann, Bernhard R.; Ebert, Anne

    The atomic force microscope (AFM) is emerging as a powerful tool in cell biology. Originally developed for high-resolution imaging purposes, the AFM also has unique capabilities as a nano-indenter to probe the dynamic viscoelastic material properties of living cells in culture. In particular, AFM elastography combines imaging and indentation modalities to map the spatial distribution of cell mechanical properties, which in turn reflect the structure and function of the underlying cytoskeleton. Such measurements have contributed to our understanding of cell mechanics and cell biology and appear to be sensitive to the presence of disease in individual cells. Examples of applications and considerations on the effective capability of ultrasonic AFM techniques on biological samples (both mammalian and plant) are reported in this chapter. Included in the discussion is scanning near-field ultrasound holography an acoustic technique which has been used to image structure and in particular nanoparticles inside cells. For illustration an example that is discussed in some detail is a technique for rapid in vitro single-cell elastography. The technique is based on atomic force acoustic microscopy (AFAM) but (1) requires only a few minutes of scan time, (2) can be used on live cells briefly removed from most of the nutrient fluid, (3) does negligible harm or damage to the cell, (4) provides semi-quantitative information on the distribution of modulus across the cell, and (5) yields data with 1-10 nm resolution. The technique is shown to enable rapid assessment of physical/biochemical signals on the cell modulus and contributes to current understanding of cell mechanics.

  16. Micro-radiography of biological samples with medical contrast agents

    NASA Astrophysics Data System (ADS)

    Dammer, J.; Weyda, F.; Benes, J.; Sopko, V.; Gelbic, I.

    2013-12-01

    Micro-radiography is an imaging technique that uses X-rays to study the internal structures of objects. This fast and easy imaging tool is based on differential X-ray attenuation by various tissues and structures within biological samples. The experimental setup described is based on the semiconductor pixel X-ray detector Medipix2 and X-ray micro-focus tube. Our micro-radiographic system has been recently used not only for the examination of internal structures of various arthropods and other biological objects but also for tracing some processes in selected model species (we used living larvae of mosquito Culex quinquefasciatus). Low concentrations of iodine, lanthanum or gold particles were used as a tracer (contrast agent). Such contrast agents increase the absorption of X-rays and allow a better visibility of internal structures of model organisms (especially the various cavities, pores, etc.). In addition, the movement of tracers in selected timing experiments demonstrates some physiological functions of digestive and excretory system.

  17. Thin-layer chromatography analysis of fructooligosaccharides in biological samples.

    PubMed

    Reiffová, Katarína; Nemcová, Radomíra

    2006-03-31

    This study presents the application of a rapid, simple and inexpensive thin-layer chromatography (TLC) for the analysis of fructooligosaccharides (FOSs) as feed additives (prebiotics) in complicated biological samples with minimal pre-treatment. Prebiotics have been monitored in different parts of the intestinal tract (jejunum, ileum and colon) of monogastric animals to which commercially available dietetic products containing fructooligosaccharides Raftifeed IPX, Raftilose and polysaccharide maltodextrin have been added into the feed. Thereby it contributes to a clarification of fructooligosaccharides and polysaccharides transformation in the digestive system. Chromatographic separation has been studied on different chromatographic systems (stationary and mobile phases). Optimal separation of fructooligosaccharides in dietetic products as well as in the samples from intestinal tract of monogastric animals has been achieved on glass-backed precoated silica gel layers impregnated with sodium acetate. The layers were developed with butanol-ethanol-water (5:3:2, v/v) in a vertical trough glass chamber with mobile phase vapour saturation. The visualisation of FOSs on chromatograms was performed with mixture of diphenylamine-aniline-phosphoric acid in acetone as primary detection reagent. Coloured spots of FOSs (blue-pink spots) on chromatograms have also been detected by reflectance densitometry at wavelength lambda=370nm. Simultaneously, the concentration of acetic acid, which is one of FOSs fermentation product, was monitored in the intestinal contents from jejunum, ileum and colon by capillary isotachophoresis.

  18. Extractions of pyrroloquinoline quinone from crude biological samples.

    PubMed

    Suzuki, O; Kumazawa, T; Seno, H; Urakami, T; Matsumoto, T

    1990-01-01

    The best conditions for extractions of free pyrroloquinoline quinone (PQQ) from crude biological samples were investigated with various organic solvents and Sep-Pak C18 cartridges. PQQ was measured with use of its native fluorescence in aqueous solution. PQQ was well extracted into n-butanol under acid conditions, and addition of NaCl did not improve the solvent extraction. PQQ, which had been extracted into n-butanol, could be re-extracted into an aqueous phase by addition of either n-heptane or pyridine, or combination of them. PQQ, which had been adsorbed to Sep-Pak C18 cartridges, could be eluted with a mixture of pyridine and water with very excellent recovery. The recovery of 1 micrograms PQQ, which had been added to 1 g human liver, brain and 1 ml plasma and had undergone the n-butanol and the Sep-Pak extractions, was 50, 75 and 105%, respectively. From the blank fluorescence, endogenous levels of free PQQ in human liver, brain and plasma were found not greater than 0.41, 0.08 and 0.13 micrograms/g or ml, respectively, if present.

  19. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    SciTech Connect

    2013-09-01

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and

  20. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  1. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  2. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  3. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Each sample shall be marked for identification by the person making the selection after which they..., Modified Live Virus; (v) Sixteen samples of all other vaccines consisting of live microorganisms; (vi...-dose or 12 multiple-dose samples of all other vaccines consisting of killed microorganisms....

  4. Elemental mapping of biological samples using a scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Watt, F.; Grime, G. W.

    1988-03-01

    Elemental mapping using a scanning proton microprobe (SPM) can be a powerful technique for probing trace elements in biology, allowing complex interfaces to be studied in detail, identifying contamination and artefacts present in the specimen, and in certain circumstances obtaining indirect chemical information. Examples used to illustrate the advantages of the technique include the elemental mapping of growing pollen tubes, honey bee brain section, a mouse macrophage cell, human liver section exhibiting primary biliary cirrhosis, and the attack by a mildew fungus on a pea leaf.

  5. Alteration of biological samples in speciation analysis of metalloproteins.

    PubMed

    Wolf, Christian; Wenda, Nadine; Richter, Andrea; Kyriakopoulos, Antonios

    2007-10-01

    For investigations of metalloproteins by speciation analysis, the integrity of the protein-metal complexes before and during separation is crucial. Knowledge about potential alterations of the samples is thus essential to avoid misinterpretations of the analytical results. Chromatographic element profiles of different cytosolic samples from animal tissues were measured repeatedly to estimate the sample stability. The dependence of the signals on the dwell time of the sample in an autosampling device at 4 degrees C for a period of 10 h was observed. Alterations in the element content of different metal-containing fractions were quantified by means of recovery values. Some metalloprotein fractions (e.g. approximately 27-kDa arsenic, approximately 27-kDa iron and different zinc fractions) were stable or only minor alterations were observed and for their investigation an autosampling device is therefore suitable. However, most of the other metalloprotein fractions, especially nickel-containing proteins, showed major alterations: these samples should therefore be analysed immediately after preparation or directly after thawing.

  6. Determinations of actinides in biological and environmental samples.

    PubMed

    Singh, N P; Wrenn, M E

    1988-03-01

    This paper summarises the radiochemical procedures utilised in our laboratory to determine U, Th and Pu in different sample matrices, including soft tissues, bones, urine, faeces, soil, water, air-filters, lichen, and building materials such as granite, phosphate and concrete. Sample preparation, depending upon the matrix of the sample, includes either dry ashing and/or wet ashing with a mixture of HNO3 and H2SO4 or HNO3 alone with occasional additions of a few drops of HNO3 and H2O2. Uranium, Th and Pu are either co-precipitated with Fe carrier as hydroxides or with Ca as oxalates. Solvent extractions are performed from 2M HNO3, 4M HNO3 or 10M HCl depending upon the actinide or combination of actinides to be determined. The techniques have been very successful for most samples, with radiochemical recoveries exceeding 70%. However, radiochemical recoveries of Th from soil samples have been very poor (10-30%). Attempts are being made to improve these recoveries.

  7. Determination of platinum, palladium, and lead in biological samples by atomic absorption spectrophotometry.

    PubMed Central

    Tillery, J B; Johnson, D E

    1975-01-01

    A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given. PMID:1227857

  8. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma Lei; Wang Yugang; Xue Jianming; Chen Qizhong; Zhang Weiming; Zhang Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat, and tomato coat) with different mass thickness were studied, together with Mylar for comparison. The energy loss and energy straggling of MeV H and He ions after penetrating the biological and Mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions; however, large deviation in energy straggling is observed between the measured results and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicted by the proposed formula.

  9. Energy loss and straggling of MeV ions through biological samples

    SciTech Connect

    Ma, Lie; Wang, Yugang; Xue, Jianming; Chen, Qizhong; Zhang, Weiming; Zhang, Yanwen

    2007-10-15

    Energy loss and energy straggling of energetic ions through natural dehydrated biological samples were investigated using transmission technique. Biological samples (onion membrane, egg coat and tomato coat) with different mass thickness were studied, together with mylar for comparison, in this work. The energy loss and energy straggling of MeV H and He ions after penetrating from the biological and mylar samples were measured. The experimental results show that the average energy losses of MeV ions through the biological samples are consistent with SRIM predictions, however, large deviation in energy straggling is observed between the measured result and the SRIM predictions. Taking into account inhomogeneity in mass density and structure of the biological sample, an energy straggling formula is suggested, and the experimental energy straggling values are well predicated by the proposed formula.

  10. Study of the spectral features of different biological samples

    NASA Astrophysics Data System (ADS)

    Atif, M.

    2015-03-01

    In the present study we have observed and analyzed the fluorescence changes in the fluorescence spectra of four different samples like brilliant sulphaflanine, quinine bisulphate, coumarine 120 and porcine cornea and sclera including the changes in fluorescence spectrum of cornea are also observed after CO2 laser exposure. The preliminary study clearly explains the proof of concept only.

  11. Sampling of vehicle emissions for chemical analysis and biological testing.

    PubMed Central

    Schuetzle, D

    1983-01-01

    Representative dilution tube sampling techniques for particulate and gas phase vehicle emissions are described using Teflon filter media and XAD-2 resin. More than 90% of the total gas (C8-C18) and particulate direct acting Ames assay mutagenicity (TA 98) was found in the particulate phase. The gas and particulate phase material was fractionated by HPLC into nonpolar, moderately polar and highly polar chemical fractions. The moderately polar chemical fraction of the particulates contained more than 50% of the direct acting Ames assay mutagenicity for the total extract. The concentration of oxygenated polynuclear aromatic hydrocarbons (oxy-PAH) and nitrated PAH (nitro-PAH) identified in the moderately polar particulate fractions are given. Nitro-PAH account for most of the direct-acting (TA 98) Ames assay mutagenicity in these moderately polar fractions. Reactions and kinetic expressions for chemical conversion of PAH are presented. Chemical conversion of PAH to nitro-PAH during dilution tube sampling of particulates on Teflon filters and gases on XAD-2 resin is a minor problem (representing 10-20%, on the average, of the 1-nitropyrene found in extracts) at short (46 min) sampling times, at low sampling temperatures (42 degrees C), and in diluted exhaust containing 3 ppm NO2. Particulate emissions collected from dilution tubes on filter media appear to be representative of what is emitted in the environment as based upon a comparison of highway and laboratory studies. PMID:6186484

  12. Soft Robotic Grippers for Biological Sampling on Deep Reefs

    PubMed Central

    Galloway, Kevin C.; Becker, Kaitlyn P.; Phillips, Brennan; Kirby, Jordan; Licht, Stephen; Tchernov, Dan; Gruber, David F.

    2016-01-01

    Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna. PMID:27625917

  13. Soft Robotic Grippers for Biological Sampling on Deep Reefs

    PubMed Central

    Galloway, Kevin C.; Becker, Kaitlyn P.; Phillips, Brennan; Kirby, Jordan; Licht, Stephen; Tchernov, Dan; Gruber, David F.

    2016-01-01

    Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna.

  14. Use of STM for analysis of surfaces of biological samples

    NASA Astrophysics Data System (ADS)

    Permjakov, N. K.; Ananyan, M. A.; Luskinovich, P. N.; Sorokovoi, V. I.; Saveliev, S. V.

    1999-04-01

    Scanning tunnelling microscopy (STM) was used to image the cell surfaces of the olfactory organ of the shark Carcharhinus longimanus and ectoderm of the frog Xenopus laevis blastulae of 1024 stages, as well as human low-density lipoproteins surface. The samples from two of these objects were prepared by using traditional techniques for scanning electron microscopy (SEM). The lipoprotein samples were prepared by drying in the air. A comparison of the STM images with the earlier obtained SEM images indicates that there are some earlier unknown details of the surface structures of receptor microvilli and support cell membranes of the olfactory organ of the shark. There was found a fold of membrane on the surface of the ectodermal frog embryo cells, which covered yolk granules. STM images of the lipoprotein surface were obtained without increasing conductivity treatment.

  15. Experiment kits for processing biological samples inflight on SLS-2

    NASA Technical Reports Server (NTRS)

    Savage, P. D.; Hinds, W. E.; Jaquez, R.; Evans, J.; Dubrovin, L.

    1995-01-01

    This paper describes development of an innovative, modular approach to packaging the instruments used to obtain and preserve the inflight rodent tissue and blood samples associated with hematology experiments on the Spacelab Life Sciences-2 (SLS-2) mission. The design approach organized the multitude of instruments into twelve 5- x 6- x l-in. kits which were each used for a particular experiment. Each kit contained the syringes, vials, microscope slides, etc., necessary for processing and storing blood and tissue samples for one rat on a particular day. A total of 1245 components, packaged into 128 kits and stowed in 17 Zero(registered trademark) boxes, were required. Crewmembers found the design easy to use and laid out in a logical, simple configuration which minimized chances for error during the complex procedures in flight. This paper also summarizes inflight performance of the kits on SLS-2.

  16. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on-off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  17. Determination of Alkali Ions in Biological and Environmental Samples.

    PubMed

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope. PMID:26860298

  18. Determination of Alkali Ions in Biological and Environmental Samples.

    PubMed

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope.

  19. Multiphoton imaging of biological samples during freezing and heating

    NASA Astrophysics Data System (ADS)

    Breunig, H. G.; Uchugonova, A.; König, K.

    2014-02-01

    We applied multiphoton microscopic imaging to observe freezing and heating effects in plant- and animal cell samples. The experimental setups consisted of a multiphoton imaging system and a heating and cooling stage which allows for precise temperature control from liquid nitrogen temperature (-196°C 77 K) up to +600°C (873 K) with heating/freezing rates between 0.01 K/min and 150 K/min. Two multiphoton imaging systems were used: a system based on a modified optical microscope and a flexible mobile system. To illustrate the imaging capabilities, plant leafs as well as animal cells were microscopically imaged in vivo during freezing based on autofluorescence lifetime and intensity of intrinsic molecules. The measurements illustrate the usefulness of multiphoton imaging to investigate freezing effects on animal and plant cells.

  20. Comparative analysis of toxin detection in biological and enviromental samples

    NASA Astrophysics Data System (ADS)

    Ogert, Robert A.; Burans, James; O'Brien, Tom; Ligler, Frances S.

    1994-03-01

    The basic recognition schemes underlying the principles of standard enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) protocols are increasingly being adapted for use with new detection devices. A direct comparison was made using a fiber optic biosensor that employs evanescent wave detection and an ELISA using avidin-biotin. The assays were developed for the detection of Ricinus communis agglutinin II, also known as ricin or RCA60. Detection limits between the two methods were comparable for ricin in phosphate buffered saline (PBS), however results in complex samples differed slightly. In PBS, sensitivity for ricin was 1 ng/ml using the fiber optic device and 500 pg/ml using the ELISA. The fiber optic sensor could not detect ricin directly in urine or serum spiked with 5 ng/ml ricin, however, the ELISA showed detection but at reduced levels to the PBS control.

  1. Broad Consent For Research With Biological Samples: Workshop Conclusions

    PubMed Central

    Grady, Christine; Eckstein, Lisa; Berkman, Ben; Brock, Dan; Cook-Deegan, Robert; Fullerton, Stephanie M.; Greely, Hank; Hansson, Mats G.; Hull, Sara; Kim, Scott; Lo, Bernie; Pentz, Rebecca; Rodriguez, Laura; Weil, Carol; Wilfond, Benjamin S.; Wendler, David

    2016-01-01

    Different types of consent are used to obtain human biospecimens for future research. This variation has resulted in confusion regarding what research is permitted, inadvertent constraints on future research, and research proceeding without consent. The NIH Clinical Center’s Department of Bioethics held a workshop to consider the ethical acceptability of addressing these concerns by using broad consent for future research on stored biospecimens. Multiple bioethics scholars, who have written on these issues, discussed the reasons for consent, the range of consent strategies, gaps in our understanding, and concluded with a proposal for broad initial consent coupled with oversight and, when feasible, ongoing provision of information to donors. The manuscript describes areas of agreement as well as areas that need more research and dialogue. Given recent proposed changes to the Common Rule, and new guidance regarding storing and sharing data and samples, this is an important and timely topic. PMID:26305750

  2. Quantification of sparfloxacin in pharmaceutical dosages and biological samples.

    PubMed

    Shah, Jasmin; Jan, Muhammad Rasul; Khan, Inayatullah; Khan, Muhammad Naeem

    2012-10-01

    A simple and fast method for spectrophotometric determination of sparfloxacin using p-dimethyl-aminobenzaldehyde (DMAB) has been developed. A yellow coloured product formed from reaction between sparfloxacin and DMAB as a result of condensation reaction at room temperature. The maximum absorbance was found at 392 nm with molar absorptivity of 4.9 × 10(3) L mol(-1) cm(-1). All parameters for the reaction, as concentration of DMBA reagent, molarity of sulphuric acid, and reaction temperature were studied. Under the conditions studied, a linear relationship between absorbance of the condensation product and concentration of sparfloxacin in the range of 2.0-80.0 μg mL(-1) was found with good correlation coefficient (0.9997). The limits of detection (LOD) and quantification (LOQ) for the proposed method were found to be 0.22 and 0.75 μg mL(-1) respectively. The repeatability and accuracy (model) of the method was studied at three different concentrations of sparfloxacin and found with value of relative standard deviation less than 2.0%. The method was found selective for determination of sparfloxacin in the presence of commonly used excipients in dosage forms. The developed method was validated statistically and applied successfully to the analysis of the drug in pure form, pharmaceutical preparations, and spiked blood plasma and urine samples with good accuracy (real) and precision. The percentage recovery was found from 99.0-100.0% with relative standard deviation less than 1%. The results of the proposed method were compared statistically with the results of literature HPLC method.

  3. Hybrid molecular probe for nucleic acid analysis in biological samples.

    PubMed

    Yang, Chaoyong James; Martinez, Karen; Lin, Hui; Tan, Weihong

    2006-08-01

    The ability to detect changes in gene expression, especially in real-time and with sensitivity sufficient enough to monitor small variations in a single-cell, will have considerable value in biomedical research and applications. Out of the many available molecular probes for intracellular monitoring of nucleic acids, molecular beacon (MB) is the most frequently used probe with the advantages of high sensitivity and selectivity. However, any processes in which the MB stem-loop structure is broken will result in a restoration of the fluorescence in MB. This brings in a few possibilities for false positive signal such as nuclease degradation, protein binding, thermodynamic fluctuation, solution composition variations (such as pH, salt concentration) and sticky-end pairing. These unwanted processes do exist inside living cells, making nucleic acid monitoring inside living cells difficult. We have designed and synthesized a hybrid molecular probe (HMP) for intracellular nucleic acid monitoring to overcome these problems. HMP has two DNA probes, one labeled with a donor and the other an acceptor. The two DNA probes are linked by a poly(ethylene glycol) (PEG) linker, with each DNA being complementary to adjacent areas of a target sequence. Target binding event brings the donor and acceptor in proximity, resulting in quenching of the donor fluorescence and enhancement of the acceptor emission. The newly designed HMP has high sensitivity, selectivity, and fast hybridization kinetics. The probe is easy to design and synthesize. HMP does not generate any false positive signal upon digestion by nuclease, binding by proteins, forming complexes by sticky-end pairing, or by other molecular interaction processes. HMP is capable of selectively detecting nucleic acid targets from cellular samples.

  4. The effect of sterilization on biological, organic geochemical and morphological information in natural samples

    NASA Technical Reports Server (NTRS)

    Hochstein, L. I.; Kvenvolden, K. A.; Philpott, D. E.

    1974-01-01

    The loss of biological, organic geochemical, and morphological science information that may occur should a Mars surface sample be sterilized prior to return to earth is examined. Results of experimental studies are summarized.

  5. Multielement analysis of micro-volume biological samples by ICP-MS with highly efficient sample introduction system.

    PubMed

    Takasaki, Yuka; Inagaki, Kazumi; Sabarudin, Akhmad; Fujii, Shin-Ichiro; Iwahata, Daigo; Takatsu, Akiko; Chiba, Koichi; Umemura, Tomonari

    2011-12-15

    A method for multielement analysis of micro-volume biological sample by inductively coupled plasma mass spectrometry (ICP-MS) with a highly efficient sample introduction system was presented. The sample introduction system was the combination of (1) an inert loop injection unit and (2) a high performance concentric nebulizer (HPCN) coupled with a temperature controllable cyclone chamber. The loop injection unit could introduce 20 μL samples into the carrier liquid flow of 10 μL min(-1) producing a stable signal for 100s without any dilution. The injection loop is continuously washed with 0.1M HNO(3) carrier solution during the measurement, thereby much improving sample throughput. The HPCN is a triple tube concentric nebulizer, which can generate fine aerosols and provide a stable and highly measurement sensitivity in ICP-MS at a liquid flow rate less than 10 μL min(-1). With the combination of the chamber heating at 60°C, the sensitivity obtained with the proposed sample introduction system at the liquid flow rate of 10 μL min(-1) was almost the same as that with a common concentric nebulizer and cyclone chamber system at the liquid flow rate of 1 mL min(-1), though the sample consumption rate of the HPCN was two orders of the magnitude lower than that of the common nebulizer. The validation of the proposed system was performed by analyzing the NIST SRM 1577b Bovine Liver. The observed values for 12 elements such as Na, P, S, K, Ca, Mn, Fe, Co, Cu, Zn, Mo, Cd were in good agreement with their certified values and information value. Satisfactory analytical results for 14 elements such as Na, Mg, P, S, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Y, Ba in Escherichia coli sample were also obtained. The proposed sample introduction system was quite effective in the cases when only micro-volume of biological sample is available. PMID:22099643

  6. Analysis of low-angle x-ray scattering peaks from lyophilized biological samples

    NASA Astrophysics Data System (ADS)

    Desouky, Omar S.; Elshemey, Wael M.; Selim, Nabila S.; Ashour, Ahmed H.

    2001-08-01

    Low-angle x-ray scattering (LAXS) from lyophilized blood and its constituents is characterized by the presence of two peaks in the forward direction of scattering. These peaks are found to be sensitive to the variations in the molecular structure of a given sample. The present work aims to explore the nature of LAXS from a variety of lyophilized biological samples. It also aims to investigate the possibility that a certain biological macromolecule is responsible of the production of LAXS peaks. This is carried out through measurements of LAXS from complex biological samples and their basic constituents. Among the measured samples are haemoglobin (Hb), globin, haem, packed red blood cells, bovine albumin, egg albumin, milk, casein, glutamine, alanine, fat, muscle and DNA. A table containing some characteristic parameters of the LAXS profiles of these samples is also presented. Analysis of measured profiles shows that all lyophilized samples produce at least one relatively broad peak at a scattering angle around 10.35°. The full width at half maximum (FWHM) of this peak varies considerably among the measured samples. Except for milk and casein, one additional peak at a scattering angle around 4.65° is observed only in the LAXS profiles of proteins or protein-rich samples. This fact strongly suggests protein to be the biological macromolecule from which this characteristic peak originates. The same idea is further strengthened through discussion of some previous observations.

  7. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution

    PubMed Central

    Joens, Matthew S.; Huynh, Chuong; Kasuboski, James M.; Ferranti, David; Sigal, Yury J.; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J.; Curran, Kevin P.; Chalasani, Sreekanth H.; Stern, Lewis A.; Goetze, Bernhard; Fitzpatrick, James A. J.

    2013-01-01

    Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure. PMID:24343236

  8. Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution.

    PubMed

    Joens, Matthew S; Huynh, Chuong; Kasuboski, James M; Ferranti, David; Sigal, Yury J; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J; Curran, Kevin P; Chalasani, Sreekanth H; Stern, Lewis A; Goetze, Bernhard; Fitzpatrick, James A J

    2013-12-17

    Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

  9. Toward the realization of reproducible Atomic Force Microscopy measurements of elastic modulus in biological samples.

    PubMed

    Demichelis, A; Divieto, C; Mortati, L; Pavarelli, S; Sassi, G; Sassi, M P

    2015-04-13

    The validation of the AFM method for elastic modulus E measurement in soft materials (E <5 MPa) is still missing. The interest of measurements in materials with E <5 MPa is mainly biological, including soft tissues and single cells. For the diagnosis of malignant human tumors, a change in cell elasticity, within tissues, has recently been recognized as a marker of metastatic potential. To measure a cell elasticity difference, reproducible E measurements in biological samples are needed. In this work a robust method for a metrological validation of E measurements in the range 500-5000 kPa was developed, based on the realization of thick E standard samples and on the study of the interactions between the measurement process and the sample at micro- and nano-scale. E measurement reproducibility limit of 4% has been reached. This allows designing a very sensitive and reproducible measurement of E in biological samples representing thus a powerful diagnostic tool for cancer detection.

  10. Improved Butanol-Methanol (BUME) Method by Replacing Acetic Acid for Lipid Extraction of Biological Samples.

    PubMed

    Cruz, Mutya; Wang, Miao; Frisch-Daiello, Jessica; Han, Xianlin

    2016-07-01

    Extraction of lipids from biological samples is a critical step in lipidomics, especially for shotgun lipidomics where lipid extracts are directly infused into a mass spectrometer. The butanol-methanol (BUME) extraction method was originally developed to extract lipids from plasma samples with 1 % acetic acid. Considering some lipids are sensitive to acidic environments, we modified this protocol by replacing acetic acid with lithium chloride solution and extended the modified extraction to tissue samples. Although no significant reduction of plasmalogen levels in the acidic BUME extracts of rat heart samples was found, the modified method was established to extract various tissue samples, including rat liver, heart, and plasma. Essentially identical profiles of the majority of lipid classes were obtained from the extracts of the modified BUME and traditional Bligh-Dyer methods. However, it was found that neither the original, nor the modified BUME method was suitable for 4-hydroxyalkenal species measurement in biological samples. PMID:27245345

  11. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    NASA Astrophysics Data System (ADS)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  12. Absorption and Diffusion Measurements of Biological Samples using a THz Free Electron Laser.

    PubMed

    Giovenale, E; D'Arienzo, M; Doria, A; Gallerano, G P; Lai, A; Messina, G; Piccinelli, D

    2003-06-01

    A compact THz Free Electron Laser (FEL) isbeing used to perform irradiation ofbiological samples to investigate possiblegenotoxic effects. In order to evaluate theexact radiation dose absorbed by the singlecomponents of the samples it is necessaryto study the optical properties of thesamples, separating the contributions tothe radiation attenuation coefficientcoming from absorption and from diffusion.Spectroscopic measurements have beenperformed on different biological samples, comparing the experimental results withtheoretical models. PMID:23345832

  13. Determination of selenium in biological samples with an energy-dispersive X-ray fluorescence spectrometer.

    PubMed

    Li, Xiaoli; Yu, Zhaoshui

    2016-05-01

    Selenium is both a nutrient and a toxin. Selenium-especially organic selenium-is a core component of human nutrition. Thus, it is very important to measure selenium in biological samples. The limited sensitivity of conventional XRF hampers its widespread use in biological samples. Here, we describe the use of high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-Ray fluorescence spectroscopy (EDXRF) in tandem with a three-dimensional optics design to determine 0.1-5.1μgg(-1) levels of selenium in biological samples. The effects of various experimental parameters such as applied voltage, acquisition time, secondary target and various filters were thoroughly investigated. The detection limit of selenium in biological samples via high-energy (100kV, 600W) linearly polarized beam energy-dispersive X-ray fluorescence spectroscopy was decreased by one order of magnitude versus conventional XRF (Paltridge et al., 2012) and found to be 0.1μg/g. To the best of our knowledge, this is the first report to describe EDXRF measurements of Se in biological samples with important implications for the nutrition and analytical chemistry communities. PMID:26922394

  14. Chemometric and Statistical Analyses of ToF-SIMS Spectra of Increasingly Complex Biological Samples

    SciTech Connect

    Berman, E S; Wu, L; Fortson, S L; Nelson, D O; Kulp, K S; Wu, K J

    2007-10-24

    Characterizing and classifying molecular variation within biological samples is critical for determining fundamental mechanisms of biological processes that will lead to new insights including improved disease understanding. Towards these ends, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to examine increasingly complex samples of biological relevance, including monosaccharide isomers, pure proteins, complex protein mixtures, and mouse embryo tissues. The complex mass spectral data sets produced were analyzed using five common statistical and chemometric multivariate analysis techniques: principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares discriminant analysis (PLSDA), soft independent modeling of class analogy (SIMCA), and decision tree analysis by recursive partitioning. PCA was found to be a valuable first step in multivariate analysis, providing insight both into the relative groupings of samples and into the molecular basis for those groupings. For the monosaccharides, pure proteins and protein mixture samples, all of LDA, PLSDA, and SIMCA were found to produce excellent classification given a sufficient number of compound variables calculated. For the mouse embryo tissues, however, SIMCA did not produce as accurate a classification. The decision tree analysis was found to be the least successful for all the data sets, providing neither as accurate a classification nor chemical insight for any of the tested samples. Based on these results we conclude that as the complexity of the sample increases, so must the sophistication of the multivariate technique used to classify the samples. PCA is a preferred first step for understanding ToF-SIMS data that can be followed by either LDA or PLSDA for effective classification analysis. This study demonstrates the strength of ToF-SIMS combined with multivariate statistical and chemometric techniques to classify increasingly complex biological samples

  15. Maryland biological stream survey: Ecological assessment of non-tidal streams sampled in 1996

    SciTech Connect

    Roth, N.E.; Southerland, M.T.; Chaillou, J.C.; Wilson, W.T.; Heimbuch, D.G.

    1998-10-01

    The report summarizes results from the second of three years of sampling for the first round of the statewide Maryland Biological Stream Survey (MBSS or the Survey) and provides an update on the program`s progress in assessing the condition of Maryland`s non-tidal streams. Supported and led by the Maryland Department of Natural Resources (MDNR), the MBSS is a comprehensive program to assess the status of biological resources in Maryland`s non-tidal streams; quantify the extent to which acidic deposition has affected or may be affecting critical biological resources in the state; examine which other water chemistry, physical habitat, and land use factors are important in explaining the current status of biological resources in streams; establish a benchmark for long-term monitoring of trends in these resources; and target future local-scale assessments and mitigation measures needed to restore degraded biological resources.

  16. Correlation of mRNA and protein in complex biological samples.

    PubMed

    Maier, Tobias; Güell, Marc; Serrano, Luis

    2009-12-17

    The correlation between mRNA and protein abundances in the cell has been reported to be notoriously poor. Recent technological advances in the quantitative analysis of mRNA and protein species in complex samples allow the detailed analysis of this pathway at the center of biological systems. We give an overview of available methods for the identification and quantification of free and ribosome-bound mRNA, protein abundances and individual protein turnover rates. We review available literature on the correlation of mRNA and protein abundances and discuss biological and technical parameters influencing the correlation of these central biological molecules.

  17. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Kasviki, K.; Stamatelatos, I. E.; Yannakopoulou, E.; Papadopoulou, P.; Kalef-Ezra, J.

    2007-10-01

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv.

  18. Programa De Educacion Interamericana.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station.

    PROGRAMA DE EDUCACION INTERAMERICANA is a project of Texas A&M University in liaison with the Bryan Independent School District. The objectives of the program are to improve the knowledge and understanding of Texas teachers and students about other American cultures. Study teams of educators research and, in midsummer, travel to selected…

  19. Methods for collection and analysis of aquatic biological and microbiological samples

    USGS Publications Warehouse

    Greeson, Phillip E., (Edited By); Ehlke, T.A.; Irwin, G.A.; Lium, B.W.; Slack, K.V.

    1977-01-01

    Chapter A4 contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. Part 1 discusses biological sampling and sampling statistics. The statistical procedures are accompanied by examples. Part 2 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity, and bioassays. Each method is summarized, and the application, interferences, apparatus, reagents, collection, analysis, calculations, reporting of results, precision and references are given. Part 3 consists of a glossary. Part 4 is a list of taxonomic references.

  20. Views of female breast cancer patients who donated biologic samples regarding storage and use of samples for genetic research.

    PubMed

    Kaphingst, K A; Janoff, J M; Harris, L N; Emmons, K M

    2006-05-01

    Although social and ethical issues related to the storage and use of biologic specimens for genetic research have been discussed extensively in the medical literature, few empiric data exist describing patients' views. This qualitative study explored the views of 26 female breast cancer patients who had consented to donate blood or tissue samples for breast cancer research. Participants generally did not expect personal benefits from research and had few unprompted concerns. Few participants had concerns about use of samples for studies not planned at the time of consent. Some participants did express concerns about insurance or employment discrimination, while others believed that current privacy protections might actually slow breast cancer research. Participants were generally more interested in receiving individual genetic test results from research studies than aggregate results. Most participants did not want individual results of uncertain clinical significance, although others believed that they should be able to receive such information. These data examined the range of participants' views regarding the storage and use of biologic samples. Further research with different and diverse patient populations is critical to establishing an appropriate balance between protecting the rights of human subjects in genetic research and allowing research to progress.

  1. Spectroscopic analysis of bosentan in biological samples after a liquid-liquid microextraction

    PubMed Central

    Sajedi-Amin, Sanaz; Assadpour-Zeynali, Karim; Panahi-Azar, Vahid; Kebriaeezadeh, Abbas; Khoubnasabjafari, Maryam; Ansarin, Khalil; Jouyban-Gharamaleki, Vahid; Jouyban, Abolghasem

    2015-01-01

    Introduction:Microextraction processes with UV-Vis measurement have been developed and validated for analysis of bosentan in biological samples. Methods:In this work, liquid–liquid microextraction procedures (DLLME & USAEME) were employed for cleanup, pre-concentration, and determination of bosentan in biological samples by UV-Vis spectroscopy at 270 nm. The method was validated and applied to the determination of bosentan in spiked serum, exhaled breath condensate and urine samples. Results:Various experimental factors including type of extraction and dispersive solvents and their volumes, pH, sonication time and centrifuging time were investigated. Under the optimum conditions, the method was linear in the range of 1.0–5.0 μg.mL-1, with coefficient of determination (R2) of > 0.998. The limit of detection (LOD) was 0.07 mg.L-1. Recovery of the target analyte in biological samples was 106.2%. The method could be easily applied for higher concentration of bosentan and needs more improvement for application in the pharmacokinetic investigations where more sensitive methods are required. Conclusion:A simple, low cost, precise and accurate spectrophotometric analysis of bosentan in biological samples after liquid-liquid microextraction were developed and validated for routine analyses. PMID:26929923

  2. Imaging material properties of biological samples with a force feedback microscope.

    PubMed

    Costa, Luca; Rodrigues, Mario S; Newman, Emily; Zubieta, Chloe; Chevrier, Joёl; Comin, Fabio

    2013-12-01

    Mechanical properties of biological samples have been imaged with a force feedback microscope. Force, force gradient, and dissipation are measured simultaneously and quantitatively, merely knowing the atomic force microscopy cantilever spring constant. Our first results demonstrate that this robust method provides quantitative high resolution force measurements of the interaction. The small oscillation imposed on the cantilever and the small value of its stiffness result in vibrational energies much smaller than the thermal energy, reducing interaction with the sample to a minimum. We show that the observed mechanical properties of the sample depend on the force applied by the tip and consequently on the sample indentation.

  3. American Indian/Alaska Native Willingness to Provide Biological Samples for Research Purposes

    PubMed Central

    Young, Kristin L.; Nazir, Niaman; Williams, Chandler; Brown, Travis; Choi, Won S.; Greiner, K. A.; Daley, Christine M.

    2011-01-01

    This article examines the willingness of American Indian/Alaska Natives (AI/AN) to provide biological samples for research purposes. Prior cases of abuse and misuse of individuals, materials, and data highlight ethical research concerns. Investigators may be hesitant to engage AI/ANs in research projects. We conducted a survey of AI/ANs in the central plains region of the US over 1 year. This convenience sample completed a series of questions on biological samples and research. Survey results (N = 998) indicate that 70.15% of AI/ANs would be willing to provide saliva/spit for a specific study with the proper consent and control of samples. In conclusion, researchers should find ways to work with and for AI/ANs, assuring participant input in the research process. PMID:22057422

  4. Tomographic imaging of transparent biological samples using the pyramid phase microscope.

    PubMed

    Iglesias, Ignacio

    2016-08-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated.

  5. Tomographic imaging of transparent biological samples using the pyramid phase microscope.

    PubMed

    Iglesias, Ignacio

    2016-08-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  6. Photothermal method using a pyroelectric sensor for thermophysical characterization of agricultural and biological samples

    NASA Astrophysics Data System (ADS)

    Frandas, A.; Dadarlat, Dorin; Chirtoc, Mihai; Jalink, Henk; Bicanic, Dane D.; Paris, D.; Antoniow, Jean S.; Egee, Michel; Ungureanu, Costica

    1998-07-01

    The photopyroelectric method in different experimental configurations was used for thermophysical characterization of agricultural and biological samples. The study appears important due to the relation of thermal parameters to the quality of foodstuffs (connected to their preservation, storage and adulteration), migration profiles in biodegradable packages, and the mechanism of desiccation tolerance of seeds. Results are presented on the thermal parameters measurement and their dependence on temperature and water content for samples such as: honey, starch, seeds.

  7. Tomographic imaging of transparent biological samples using the pyramid phase microscope

    PubMed Central

    Iglesias, Ignacio

    2016-01-01

    We show how a pyramid phase microscope can be used to obtain tomographic information of the spatial variation of refractive index in biological samples using the Radon transform. A method that uses the information provided by the phase microscope for axial and lateral repositioning of the sample when it rotates is also described. Its application to the reconstruction of mouse embryos in the blastocyst stage is demonstrated. PMID:27570696

  8. Probes for High Field Solid-state NMR of Lossy Biological Samples

    PubMed Central

    Grant, Christopher V.; Wu, Chin H.; Opella, Stanley J.

    2010-01-01

    In solid-state NMR exphydrated samples biopolymers are susceptible to radio-frequency heating and have a significant impact on probe tuning frequency and performance parameters such as sensitivity. These considerations are increasingly important as magnetic field strengths increase with improved magnet technology. Recent developments in the design, construction, and performance of probes for solid-state NMR experiments on stationary lossy biological samples at high magnetic fields are reviewed. PMID:20435493

  9. Method for the concentration and separation of actinides from biological and environmental samples

    DOEpatents

    Horwitz, E.P.; Dietz, M.L.

    1989-05-30

    A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting. 3 figs.

  10. Method for the concentration and separation of actinides from biological and environmental samples

    DOEpatents

    Horwitz, E. Philip; Dietz, Mark L.

    1989-01-01

    A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting.

  11. Optimization of dielectrophoretic separation and concentration of pathogens in complex biological samples

    NASA Astrophysics Data System (ADS)

    Bisceglia, E.; Cubizolles, M.; Mallard, F.; Pineda, F.; Francais, O.; Le Pioufle, B.

    2013-05-01

    Sample preparation is a key issue of modern analytical methods for in vitro diagnostics of diseases with microbiological origins: methods to separate bacteria from other elements of the complex biological samples are of great importance. In the present study, we investigated the DEP force as a way to perform such a de-complexification of the sample by extracting micro-organisms from a complex biological sample under a highly non-uniform electric field in a micro-system based on an interdigitated electrodes array. Different parameters were investigated to optimize the capture efficiency, such as the size of the gap between the electrodes and the height of the capture channel. These parameters are decisive for the distribution of the electric field inside the separation chamber. To optimize these relevant parameters, we performed numerical simulations using COMSOL Multiphysics and correlated them with experimental results. The optimization of the capture efficiency of the device has first been tested on micro-organisms solution but was also investigated on human blood samples spiked with micro-organisms, thereby mimicking real biological samples.

  12. MCT-based SWIR hyperspectral imaging system for evaluation of biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral imaging has been shown to be a powerful tool for nondestructive evaluation of biological samples. We recently developed a new line-scan-based shortwave infrared (SWIR) hyperspectral imaging system. Critical sensing components of the system include a SWIR spectrograph, an MCT (HgCdTe) a...

  13. Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples Botulinum neurotoxins (BoNTs), the causative agents of botulism, are among the most lethal human bacterial toxins and the causative agent of botulism. BoNTs are also classified as Select Agents ...

  14. Biological sample evaluation using a line-scan based SWIR hyperspectral imaging system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new line-scan hyperspectral imaging system was developed to enable short wavelength infrared (SWIR) imagery for biological sample evaluation. Critical sensing components include a SWIR imaging spectrograph and an HgCdTe (MCT) focal plane array detector. To date, agricultural applications of infra...

  15. Fast quantitative retardance imaging of biological samples using quadri-wave interferometry (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of polarized spatially coherent illumination to perform linear retardance imaging and measurements of semi-transparent biological samples using a quantitative phase imaging technique [1]. Quantitative phase imaging techniques [2-5] are used in microscopy for the imaging of semi-transparent samples and gives information about the optical path difference (OPD). The strength of those techniques is their non-invasive (the sample is not labelled) and fast approach. However, this high contrast is non-specific and cannot be linked to specific properties of the sample. To overcome this limitation, we propose to use polarized light in combination with QPI. Indeed, anisotropy has been used to reveal ordered fibrous structures in biological samples without any staining or labelling with polarized light microscopy [6-8]. Recent studies have shown polarimetry as a potential diagnostic tool for various dermatological diseases on thick tissue samples [9]. Particularly, specific collagen fibers spatial distribution has been demonstrated to be a signature for the optical diagnosis and prognosis of cancer in tissues [10]. In this paper, we describe a technical improvement of our technique based on high-resolution quadri-wave lateral shearing interferometry (QWLSI) and liquid crystal retarder to perform quantitative linear birefringence measurements on biological samples. The system combines a set of quantitative phase images with different excitation polarizations to create birefringence images. These give information about the local retardance and orientation of biological anisotropic components. We propose using a commercial QWLSI [11] (SID4Bio, Phasics SA, Saint Aubin, France) directly plugged onto a lateral video port of an inverted microscope (TE2000-U, Nikon, Japan). We are able to take retardance images in less than 1 second which allows us to record dynamic phenomena (living cells study) and make high speed acquisitions to reconstruct tissues virtual

  16. Optimal sample preparation conditions for the determination of uranium in biological samples by kinetic phosphorescence analysis (KPA).

    PubMed

    Ejnik, J W; Hamilton, M M; Adams, P R; Carmichael, A J

    2000-12-15

    Kinetic phosphorescence analysis (KPA) is a proven technique for rapid, precise, and accurate determination of uranium in aqueous solutions. Uranium analysis of biological samples require dry-ashing in a muffle furnace between 400 and 600 degrees C followed by wet-ashing with concentrated nitric acid and hydrogen peroxide to digest the organic component in the sample that interferes with uranium determination by KPA. The optimal dry-ashing temperature was determined to be 450 degrees C. At dry-ashing temperatures greater than 450 degrees C, uranium loss was attributed to vaporization. High temperatures also caused increased background values that were attributed to uranium leaching from the glass vials. Dry-ashing temperatures less than 450 degrees C result in the samples needing additional wet-ashing steps. The recovery of uranium in urine samples was 99.2+/-4.02% between spiked concentrations of 1.98-1980 ng (0.198-198 microg l(-1)) uranium, whereas the recovery in whole blood was 89.9+/-7.33% between the same spiked concentrations. The limit of quantification in which uranium in urine and blood could be accurately measured above the background was determined to be 0.05 and 0.6 microg l(-1), respectively. PMID:11130202

  17. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration. PMID:21793731

  18. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

  19. Effects of different temperature treatments on biological ice nuclei in snow samples

    NASA Astrophysics Data System (ADS)

    Hara, Kazutaka; Maki, Teruya; Kakikawa, Makiko; Kobayashi, Fumihisa; Matsuki, Atsushi

    2016-09-01

    The heat tolerance of biological ice nucleation activity (INA) depends on their types. Different temperature treatments may cause varying degrees of inactivation on biological ice nuclei (IN) in precipitation samples. In this study, we measured IN concentration and bacterial INA in snow samples using a drop freezing assay, and compared the results for unheated snow and snow treated at 40 °C and 90 °C. At a measured temperature of -7 °C, the concentration of IN in untreated snow was 100-570 L-1, whereas the concentration in snow treated at 40 °C and 90 °C was 31-270 L-1 and 2.5-14 L-1, respectively. In the present study, heat sensitive IN inactivated by heating at 40 °C were predominant, and ranged 23-78% of IN at -7 °C compared with untreated samples. Ice nucleation active Pseudomonas strains were also isolated from the snow samples, and heating at 40 °C and 90 °C inactivated these microorganisms. Consequently, different temperature treatments induced varying degrees of inactivation on IN in snow samples. Differences in the concentration of IN across a range of treatment temperatures might reflect the abundance of different heat sensitive biological IN components.

  20. Rapid methods to detect organic mercury and total selenium in biological samples

    PubMed Central

    2011-01-01

    Background Organic mercury (Hg) is a global pollutant of concern and selenium is believed to afford protection against mercury risk though few approaches exist to rapidly assess both chemicals in biological samples. Here, micro-scale and rapid methods to detect organic mercury (< 1.5 ml total sample volume, < 1.5 hour) and total selenium (Se; < 3.0 ml total volume, < 3 hour) from a range of biological samples (10-50 mg) are described. Results For organic Hg, samples are digested using Tris-HCl buffer (with sequential additions of protease, NaOH, cysteine, CuSO4, acidic NaBr) followed by extraction with toluene and Na2S2O3. The final product is analyzed via commercially available direct/total mercury analyzers. For Se, a fluorometric assay has been developed for microplate readers that involves digestion (HNO3-HClO4 and HCl), conjugation (2,3-diaminonaphthalene), and cyclohexane extraction. Recovery of organic Hg (86-107%) and Se (85-121%) were determined through use of Standard Reference Materials and lemon shark kidney tissues. Conclusions The approaches outlined provide an easy, rapid, reproducible, and cost-effective platform for monitoring organic Hg and total Se in biological samples. Owing to the importance of organic Hg and Se in the pathophysiology of Hg, integration of such methods into established research monitoring efforts (that largely focus on screening total Hg only) will help increase understanding of Hg's true risks. PMID:21232132

  1. Microfluidic solutions enabling continuous processing and monitoring of biological samples: A review.

    PubMed

    Karle, Marc; Vashist, Sandeep Kumar; Zengerle, Roland; von Stetten, Felix

    2016-07-27

    The last decade has witnessed tremendous advances in employing microfluidic solutions enabling Continuous Processing and Monitoring of Biological Samples (CPMBS), which is an essential requirement for the control of bio-processes. The microfluidic systems are superior to the traditional inline sensors due to their ability to implement complex analytical procedures, such as multi-step sample preparation, and enabling the online measurement of parameters. This manuscript provides a backgound review of microfluidic approaches employing laminar flow, hydrodynamic separation, acoustophoresis, electrophoresis, dielectrophoresis, magnetophoresis and segmented flow for the continuous processing and monitoring of biological samples. The principles, advantages and limitations of each microfluidic approach are described along with its potential applications. The challenges in the field and the future directions are also provided. PMID:27251944

  2. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    PubMed

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. PMID:25864956

  3. Nanocharacterization of Soft Biological Samples in Shear Mode with Quartz Tuning Fork Probes

    PubMed Central

    Otero, Jorge; Gonzalez, Laura; Puig-Vidal, Manel

    2012-01-01

    Quartz tuning forks are extremely good resonators and their use is growing in scanning probe microscopy. Nevertheless, only a few studies on soft biological samples have been reported using these probes. In this work, we present the methodology to develop and use these nanosensors to properly work with biological samples. The working principles, fabrication and experimental setup are presented. The results in the nanocharacterization of different samples in different ambients are presented by using different working modes: amplitude modulation with and without the use of a Phase-Locked Loop (PLL) and frequency modulation. Pseudomonas aeruginosa bacteria are imaged in nitrogen using amplitude modulation. Microcontact printed antibodies are imaged in buffer using amplitude modulation with a PLL. Finally, metastatic cells are imaged in air using frequency modulation. PMID:22666059

  4. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    PubMed

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples.

  5. Swabs as DNA collection devices for sampling different biological materials from different substrates.

    PubMed

    Verdon, Timothy J; Mitchell, Robert J; van Oorschot, Roland A H

    2014-07-01

    Currently, there is a variety of swabs for collection of biological evidence from crime scenes, but their comparative efficiency is unknown. Here, we report the results of an investigation into the efficiency of different swab types to collect blood, saliva and touch DNA from a range of substrates. The efficiency of extracting blood and saliva from each swab type was also tested. Some swabs were significantly more effective than others for sampling biological materials from different substrates. Swabs with the highest sampling efficiency, however, often did not have the highest extraction efficiency. Observations were recorded regarding practicality of each swab in a variety of situations. Our study demonstrates that selection of sampling device impacts greatly upon successful collection and extraction of DNA. We present guidelines to assist in evaluation of swab choice. PMID:24502761

  6. Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy.

    PubMed

    Ogura, Toshihiko

    2010-01-01

    Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si(3)N(4)) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si(3)N(4) film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes.

  7. Biological sample collections from minors for genetic research: a systematic review of guidelines and position papers

    PubMed Central

    Hens, Kristien; Nys, Herman; Cassiman, Jean-Jacques; Dierickx, Kris

    2009-01-01

    Stored tissue samples are an important resource for epidemiological genetic research. Genetic research on biological material from minors can yield valuable information on the development and genesis of early-onset genetic disorders and the early interaction of environmental and genetic factors. The use of such tissue raises some specific ethical and governance questions, which are not completely covered by the discussion on biological materials from adults. We have retrieved 29 guidelines and position papers pertaining to the storage and use of biological tissue samples for genetic research, originating from 27 different organizations. Five documents have an international scope, three have an European scope and 21 have a national scope. We discovered that 11 of these documents did not contain a section on biological materials from minors. The content of the remaining 18 documents was categorized according to four themes: consent, principles of non-therapeutic research on vulnerable populations, ethics committee approval and difference between anonymous and identifiable samples. We found out that these themes are not consistently mentioned by each document, but that documents discussing the same themes were mostly in agreement with their recommendations. However, a systematic reflection on the ethical and policy issues arising from the participation of minors in biobank research is missing. PMID:19223929

  8. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    NASA Astrophysics Data System (ADS)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  9. Specific absorption rate in electrically coupled biological samples between metal plates.

    PubMed

    Joines, W T; Blackman, C F; Spiegel, R J

    1986-01-01

    The specific absorption rate (SAR) in a biological sample irradiated by electromagnetic fields between the metal plates of a transmission line can be altered significantly by the spacing of the metal plates and the distance between neighboring samples. The SAR in spherical biological samples is calculated for a number of neighboring sample arrangements and metal-plate spacings by using the method of images and induced dipole coupling. For a decrease in metal-plate spacing, the derived equations predict an increase in SAR within a sample and a decrease in SAR with a decrease in neighboring-sample spacing. The calculations are compared with measurements made with the aid of an array of 1-in radius metal hemispheres on the lower plate of two parallel plates (thus forming an image system). The hemisphere on which measurements are taken is insulated from the metal plate and is connected via a coaxial center conductor to an HP 3582A spectrum analyzer that measures the voltage and hence the electric field intensity at the hemisphere. Measurements made at a frequency where wavelength is large compared with sample size (48 Hz) are in good agreement with calculations. PMID:3741491

  10. Solid Phase Microextraction and Related Techniques for Drugs in Biological Samples

    PubMed Central

    Moein, Mohammad Mahdi; Said, Rana; Bassyouni, Fatma

    2014-01-01

    In drug discovery and development, the quantification of drugs in biological samples is an important task for the determination of the physiological performance of the investigated drugs. After sampling, the next step in the analytical process is sample preparation. Because of the low concentration levels of drug in plasma and the variety of the metabolites, the selected extraction technique should be virtually exhaustive. Recent developments of sample handling techniques are directed, from one side, toward automatization and online coupling of sample preparation units. The primary objective of this review is to present the recent developments in microextraction sample preparation methods for analysis of drugs in biological fluids. Microextraction techniques allow for less consumption of solvent, reagents, and packing materials, and small sample volumes can be used. In this review the use of solid phase microextraction (SPME), microextraction in packed sorbent (MEPS), and stir-bar sorbtive extraction (SBSE) in drug analysis will be discussed. In addition, the use of new sorbents such as monoliths and molecularly imprinted polymers will be presented. PMID:24688797

  11. A supplement to "Methods for collection and analysis of aquatic biological and microbiological samples"

    USGS Publications Warehouse

    1979-01-01

    The report contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. It supplements, "Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples" (TWRI, Book 5, Chapter A4, 1977, edited by P. E. Greeson, T. A. Ehlke, G. A. Irwin, B. W. Lium, and K. V. Slack). Included in the supplement are 5 new methods, a new section of selected taxonomic references for Ostracoda, and 6 revised methods.

  12. Creating internal conductivity in dry biological SEM samples by a simple vapour treatment.

    PubMed

    Ensikat, H-J; Weigend, M

    2014-12-01

    Internal sample conductivity in scanning electron microscopy can be a valuable alternative to metal coating. Proton conductivity may be used for this purpose. Many solid materials with active hydrogen atoms, such as hydrogen- and ammonium-salts, organic acids, and even ice, are protonic conductors or semiconductors. Here we present a method to generate proton conductivity in dry biological materials. A simple treatment with hydrogen chloride gas or hydrochloric acid vapour for a few minutes provides sufficient conductivity for many samples. After a removal of excess hydrogen chloride vapour with a vacuum desiccator, the objects may be examined in the SEM without metal coating. The use of internally conductive samples extends the range of easy-to-perform SEM preparation techniques. It is advantageous for material contrast imaging of uncoated samples, and it can be used in combination with metal coating to enhance conductivity on difficult samples with complex overlapping surfaces, where simple metal coating does not reliably eliminate charging problems. PMID:25204567

  13. Biological sampling methods and effects of exposure to municipal and chemical landfill leachate on aquatic organisms

    SciTech Connect

    Janisz, A.J.; Butterfield, W.S.

    1983-03-01

    Extensive biological sampling on five abandoned hazardous waste sites in New York, New Jersey, and Puerto Rico was undertaken during 1981 and 1982 to determine the impact of priority pollutants on aquatic fauna and, potentially, on human health. The selection criteria for sites, sampling equipment, problems in personnel protection, and sample handling procedures are presented. The effects of the hazardous waste sites were assessed using a wide range of fish and invertebrate species. Tissue specimens from eleven vertebrate and eight invertebrate species were analyzed. Forty samples of these tissue specimens were analyzed for all inorganic priority pollutant parameters; an additional 35 samples were analyzed for organic priority pollutants or an appropriate subset of them. High concentrations of polychlorinated biphenyls (PCBs) were found in aquatic organisms exposed to chemical landfill leachate; the results of the tissue analyses at other sites were negative.

  14. Hyperspectral imaging of nanoparticles in biological samples: Simultaneous visualization and elemental identification.

    PubMed

    Peña, María Del Pilar Sosa; Gottipati, Abhishek; Tahiliani, Sahil; Neu-Baker, Nicole M; Frame, Mary D; Friedman, Adam J; Brenner, Sara A

    2016-05-01

    While engineered nanomaterials (ENMs) are increasingly incorporated into industrial processes and consumer products, the potential biological effects and health outcomes of exposure remain unknown. Novel advanced direct visualization techniques that require less time, cost, and resource investment than electron microscopy (EM) are needed for identifying and locating ENMs in biological samples. Hyperspectral imaging (HSI) combines spectrophotometry and imaging, using advanced optics and algorithms to capture a spectrum from 400 to 1000 nm at each pixel in an enhanced dark-field microscopic (EDFM) image. HSI-EDFM can be used to confirm the identity of the materials of interest in a sample and generate an image "mapping" their presence and location in a sample. Hyperspectral mapping is particularly important for biological samples, where ENM morphology is visually indistinct from surrounding tissue structures. While use of HSI (without mapping) is increasing, no studies to date have compared results from hyperspectral mapping with conventional methods. Thus, the objective of this study was to utilize EDFM-HSI to locate, identify, and map metal oxide ENMs in ex vivo histological porcine skin tissues, a toxicological model of cutaneous exposure, and compare findings with those of Raman spectroscopy (RS), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Results demonstrate that EDFM-HSI mapping is capable of locating and identifying ENMs in tissue, as confirmed by conventional methods. This study serves as initial confirmation of EDFM-HSI mapping as a novel and higher throughput technique for ENM identification in biological samples, and serves as the basis for further protocol development utilizing EDFM-HSI for semiquantitation of ENMs. PMID:26864497

  15. Presence of Atrazine in the Biological Samples of Cattle and Its Consequence Adversity in Human Health

    PubMed Central

    Peighambarzadeh, SZ; Safi, S; Shahtaheri, SJ; Javanbakht, M; Rahimi Forushani, A

    2011-01-01

    Background Cattle can be considered as an important source for herbicides through nutrition. Therefore, herbicide residue in animal products is a potential human exposure to herbicides causing public health problems in human life. Triazines are a group of herbicides primarily used to control broadleaf weeds in corn and other feed ingredients and are considered as possible human carcinogens. To evaluate trace residue of these pollutants molecular imprinted solid phase extraction (MISPE) method has been developed, using biological samples. Methods: Blood samples were taken from the jugular vein of 45 Holstein cows in 3 commercial dairy farms in Khuzestan Province, Iran. Urine samples were also taken from the cows. Results: The mean ± SD concentrations of atrazine in serum and urine samples of the study group (0.739 ± 0.567 ppm and 1.389 ± 0.633 ppm, respectively) were higher (P < 0.05) than the concentrations in serum and urine samples of the control group (0.002 ± 0.005 ppm and 0.012 ± 0.026 ppm, respectively). Conclusion: Atrazine in the feed ingredients ingested by cattle could be transferred into the biological samples and consequently can be considered as a potential hazard for the public health. PMID:23113110

  16. Elemental and isotopic imaging of biological samples using NanoSIMS.

    PubMed

    Kilburn, Matt R; Clode, Peta L

    2014-01-01

    With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research.

  17. Elemental and isotopic imaging of biological samples using NanoSIMS.

    PubMed

    Kilburn, Matt R; Clode, Peta L

    2014-01-01

    With its low detection limits and the ability to analyze most of the elements in the periodic table, secondary ion mass spectrometry (SIMS) represents one of the most versatile in situ analytical techniques available, and recent developments have resulted in significant advantages for the use of imaging mass spectrometry in biological and biomedical research. Increases in spatial resolution and sensitivity allow detailed interrogation of samples at relevant scales and chemical concentrations. Advances in dynamic SIMS, specifically with the advent of NanoSIMS, now allow the tracking of stable isotopes within biological systems at subcellular length scales, while static SIMS combines subcellular imaging with molecular identification. In this chapter, we present an introduction to the SIMS technique, with particular reference to NanoSIMS, and discuss its application in biological and biomedical research. PMID:24357388

  18. Derivatization of steroids in biological samples for GC-MS and LC-MS analyses.

    PubMed

    Marcos, Josep; Pozo, Oscar J

    2015-10-01

    The determination of steroids in biological samples is essential in different areas of knowledge. MS combined with either GC or LC is considered the best analytical technique for specific and sensitive determinations. However, due to the physicochemical properties of some steroids, and the low concentrations found in biological samples, the formation of a derivative prior to their analysis is required. In GC-MS determinations, derivatization is needed for generating volatile and thermally stable compounds. The improvement in terms of stability and chromatographic retention are the main reasons for selecting the derivatization agent. On the other hand, derivatization is not compulsory in LC-MS analyses and the derivatization is typically used for improving the ionization and therefore the overall sensitivity achieved.

  19. Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

    PubMed

    Rao, R R; Chatt, A

    1991-07-01

    A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples. PMID:1897721

  20. Electrochemical cells for voltammetry, coulometry, and protein activity assays of small-volume biological samples.

    PubMed

    Feldman, B J; Gheller, S F; Bailey, G F; Newton, W E; Schultz, F A

    1990-02-15

    Cell designs, experimental protocols, and results for electrochemical investigation of small quantitites of biological materials under anaerobic conditions are reported. Three types of electrochemical experiments are considered: (i) cyclic voltammetry of 20- to 100-microliters samples; (ii) direct coulometry of 0.5- to 1.5-ml samples; and (iii) an electrochemically initiated protein activity assay which includes provision for analysis of gaseous reaction products and correlation with electron flux. The first two procedures are illustrated by measurement of the formal electrode potential (E0') and number of electrons transferred (n) in redox reactions of small quantities of biological and inorganic materials. The third procedure is illustrated by assaying the activity of the MoFe protein plus Fe protein complex from Azotobacter vinelandii nitrogenase for reduction of C2H2 to C2H4.

  1. Recent advances in salt-assisted LLE for analyzing biological samples.

    PubMed

    Valente, Inês Maria; Rodrigues, José António

    2015-01-01

    Salt-assisted LLE (SALLE) has been attracting growing interest in bioanalysis. The technique is particularly advantageous due to its simple and fast experimental execution using conventional laboratory equipment. Besides, SALLE uses water-miscible organic solvents making the extracts readily compatible with various analytical separation and detection techniques. This article presents a brief overview of the extraction technique and its role in bioanalysis. Some of the most relevant achievements on SALLE application to biological samples are discussed - namely the study of the main extraction parameters, the combination with other extraction techniques and the instrumental analysis of the extracts. Developments on automation, miniaturization and microextraction for SALLE procedures are also discussed as a perspective for future applications even more attractive for the analysis of biological samples.

  2. Axial-scanning low-coherence interferometer method for noncontact thickness measurement of biological samples

    SciTech Connect

    Kim, Do-Hyun; Song, Chul-Gyu; Ilev, Ilko K.; Kang, Jin U.

    2011-02-20

    We investigated a high-precision optical method for measuring the thickness of biological samples regardless of their transparency. The method is based on the precise measurement of optical path length difference of the end surfaces of objects, using a dual-arm axial-scanning low-coherence interferometer. This removes any consideration of the shape, thickness, or transparency of testing objects when performing the measurement. Scanning the reference simplifies the measurement setup, resulting in unambiguous measurement. Using a 1310 nm wavelength superluminescent diode, with a 65 nm bandwidth, the measurement accuracy was as high as 11.6 {mu}m. We tested the method by measuring the thickness of both transparent samples and nontransparent soft biological tissues.

  3. Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

    PubMed

    Rao, R R; Chatt, A

    1991-07-01

    A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples.

  4. Applications of PIXE to biological and biomedical samples at the university of gent

    NASA Astrophysics Data System (ADS)

    Maenhaut, W.; Vandenhaute, J.; Duflou, H.; De Reuck, J.

    1987-03-01

    The research on biological and biomedical samples, conducted at the University of Gent during the last 4-5 years and using PIXE as analytical technique, is presented. Our optimized sample/target preparation methods are described, and the accuracy and precision obtainable with them are discussed. Two comprehensive biological/biomedical research projects, initiated at Gent, are presented. The first aims at investigating possible trace element changes in tissues of experimental animals (rats) as a result of liver necrosis or cirrhosis, induced by intraperitoneal injection with CCl 4. The second project involves the determination of the regional distribution of trace elements in the human brain. Eight elements, i.e. K, Ca, Mn, Fe, Cu, Zn, Se and Rb, are being measured in up to 50 different regions of 12 normal brains, and in selected brain regions from patients with neurological disorders. Some of the results of the two projects are discussed.

  5. A Rapid and Specific Method for the Detection of Indole in Complex Biological Samples

    PubMed Central

    Chappell, Cynthia; Gonzales, Christopher; Okhuysen, Pablo

    2015-01-01

    Indole, a bacterial product of tryptophan degradation, has a variety of important applications in the pharmaceutical industry and is a biomarker in biological and clinical specimens. Yet, specific assays to quantitate indole are complex and require expensive equipment and a high level of training. Thus, indole in biological samples is often estimated using the simple and rapid Kovács assay, which nonspecifically detects a variety of commonly occurring indole analogs. We demonstrate here a sensitive, specific, and rapid method for measuring indole in complex biological samples using a specific reaction between unsubstituted indole and hydroxylamine. We compared the hydroxylamine-based indole assay (HIA) to the Kovács assay and confirmed that the two assays are capable of detecting microgram amounts of indole. However, the HIA is specific to indole and does not detect other naturally occurring indole analogs. We further demonstrated the utility of the HIA in measuring indole levels in clinically relevant biological materials, such as fecal samples and bacterial cultures. Mean and median fecal indole concentrations from 53 healthy adults were 2.59 mM and 2.73 mM, respectively, but varied widely (0.30 mM to 6.64 mM) among individuals. We also determined that enterotoxigenic Escherichia coli strain H10407 produces 3.3 ± 0.22 mM indole during a 24-h period in the presence of 5 mM tryptophan. The sensitive and specific HIA should be of value in a variety of settings, such as the evaluation of various clinical samples and the study of indole-producing bacterial species in the gut microbiota. PMID:26386049

  6. Comparison of various dissolution techniques for determination of Po-210 in biological samples.

    PubMed

    Planinšek, P; Benedik, L; Smodiš, B

    2013-11-01

    The aim of the present study was to compare three wet digestion procedures for dissolution of biological samples in the determination of Po-210. Classical wet ashing over a gas flame with acids in a long-necked Kjeldahl flask, digestion with acids in an Erlenmeyer flask and microwave digestion in a Teflon vessel at temperatures at up to 200°C were investigated. The results obtained showed that the activity concentrations of Po-210 found in the samples analysed were comparable for all the procedures used.

  7. Assessment of the differential linear coherent scattering coefficient of biological samples

    NASA Astrophysics Data System (ADS)

    Conceição, A. L. C.; Antoniassi, M.; Poletti, M. E.

    2010-07-01

    New differential linear coherent scattering coefficient, μ CS, data for four biological tissue types (fat pork, tendon chicken, adipose and fibroglandular human breast tissues) covering a large momentum transfer interval (0.07≤ q≤70.5 nm -1), resulted from combining WAXS and SAXS data, are presented in order to emphasize the need to update the default data-base by including the molecular interference and the large-scale arrangements effect. The results showed that the differential linear coherent scattering coefficient demonstrates influence of the large-scale arrangement, mainly due to collagen fibrils for tendon chicken and fibroglandular breast samples, and triacylglycerides for fat pork and adipose breast samples at low momentum transfer region. While, at high momentum transfer, the μ CS reflects effects of molecular interference related to water for tendon chicken and fibroglandular samples and, fatty acids for fat pork and adipose samples.

  8. Sampling designs matching species biology produce accurate and affordable abundance indices

    PubMed Central

    Farley, Sean; Russell, Gareth J.; Butler, Matthew J.; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions, which

  9. Sampling designs matching species biology produce accurate and affordable abundance indices.

    PubMed

    Harris, Grant; Farley, Sean; Russell, Gareth J; Butler, Matthew J; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km(2) cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions

  10. Correction of radiation absorption on biological samples using Rayleigh to Compton scattering ratio

    NASA Astrophysics Data System (ADS)

    Pereira, Marcelo O.; Conti, Claudio de Carvalho; dos Anjos, Marcelino J.; Lopes, Ricardo T.

    2012-06-01

    The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E < 30 keV) applied to a biological matrix based on the Rayleigh to Compton scattering ratio and the effective atomic number. For calibration, scattering measurements were performed on standard samples of radiation produced by a gamma-ray source of 241Am (59.54 keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples.

  11. Synthesis of surface nano-molecularly imprinted polymers for sensitive baicalin detection from biological samples

    PubMed Central

    Gu, Xiaoli; He, Hongliang; Wang, Chong-Zhi; Gao, Yankun; Zhang, Hongjuan; Hong, Junli; Du, Shuhu; Chen, Lina; Yuan, Chun-Su

    2015-01-01

    Surface molecularly imprinted polymers (MIP@SBA-15) imprinted on the surface of hybrid nanostructured organic/inorganic materials (SBA-15) were prepared for the selective extraction and detection of baicalin (BA) from biological samples. The surface morphologies and characteristics of the imprinted and non-imprinted polymers were characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo–gravimetric analysis (TGA) and nitrogen adsorption–desorption isotherms. The results indicated that the polymers were successfully grafted on the surface of SBA-15 and possessed a highly ordered mesoporous structure. In binding tests, MIP@SBA-15 reached saturated adsorption within 80 min and exhibited significant specific recognition toward BA with large adsorption capacity. Meanwhile, the prepared MIP@SBA-15 was used as a selective sorbent for solid-phase extraction of BA from biological samples. Recoveries of BA from the liver and spleen ranged from 90.6% to 90.9% with RSD < 3.7%. All these results reveal that this method is simple, rapid and sensitive for effectively extracting and detecting trace BA in biological samples. PMID:26257892

  12. Development of an on-line preconcentration system for zinc determination in biological samples.

    PubMed

    Dutra, Rosilene L; Maltez, Heloisa F; Carasek, Eduardo

    2006-04-15

    An on-line preconcentration system for zinc determination in 24-h urine, blood plasma and erythrocyte matrices by flame atomic absorption spectrometry (FAAS) was used. This procedure was based on adsorption of Zn(II) ions onto a minicolumn filled with silica gel, chemically modified with niobium(V) oxide (Nb(2)O(5)-SiO(2)). The determination of the optimum conditions for Zn(II) preconcentration was done using two-level full factorial and Doehlert designs. In the optimization procedure, four variables (sample pH, eluent concentration, sample flow rate and eluent flow rate) were investigated. The results obtained from the full factorial design demonstrated that the sample pH and sample flow rate variables, and their interactions, were statistically significant. A Doehlert matrix was used in order to determine the optimum conditions for the sample pH and sample flow rate. The optimized conditions for sample pH and flow rate sampling were 6.6 and 7.1 ml min(-1), respectively, to obtain the maximum Zn(II) preconcentration and determination in the biological samples studied. Parameters of analytical curve, precision, effect of other ions in the proposed system and accuracy were achieved to assess the proposed method. The accuracy was confirmed by analysis of certified reference materials (urine Seronorm Trace Elements) and recovery tests in blood plasma and erythrocyte samples. Detection limit (3sigma/S) of 0.77 microg l(-1), precision (calculated as relative standard deviation) of 1.5% for Zn(II) concentration of 10 microg l(-1) (n=7) and a sampling frequency of 27 samples/h were obtained from the proposed system. PMID:18970593

  13. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1 3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  14. Attempts to develop a new nuclear measurement technique of β-glucuronidase levels in biological samples

    NASA Astrophysics Data System (ADS)

    Ünak, T.; Avcibasi, U.; Yildirim, Y.; Çetinkaya, B.

    2003-01-01

    β-Glucuronidase is one of the most important hydrolytic enzymes in living systems and plays an essential role in the detoxification pathway of toxic materials incorporated into the metabolism. Some organs, especially liver and some tumour tissues, have high level of β-glucuronidase activity. As a result the enzymatic activity of some kind of tumour cells, the radiolabelled glucuronide conjugates of cytotoxic, as well as radiotoxic compounds have potentially very valuable diagnostic and therapeutic applications in cancer research. For this reason, a sensitive measurement of β-glucuronidase levels in normal and tumour tissues is a very important step for these kinds of applications. According to the classical measurement method of β-glucuronidase activity, in general, the quantity of phenolphthalein liberated from its glucuronide conjugate, i.e. phenolphthalein-glucuronide, by β-glucuronidase has been measured by use of the spectrophotometric technique. The lower detection limit of phenolphthalein by the spectrophotometric technique is about 1-3 μg. This means that the β-glucuronidase levels could not be detected in biological samples having lower levels of β-glucuronidase activity and therefore the applications of the spectrophotometric technique in cancer research are very seriously limited. Starting from this consideration, we recently attempted to develop a new nuclear technique to measure much lower concentrations of β-glucuronidase in biological samples. To improve the detection limit, phenolphthalein-glucuronide and also phenyl-N-glucuronide were radioiodinated with 131I and their radioactivity was measured by use of the counting technique. Therefore, the quantity of phenolphthalein or aniline radioiodinated with 131I and liberated by the deglucuronidation reactivity of β-glucuronidase was used in an attempt to measure levels lower than the spectrophotometric measurement technique. The results obtained clearly verified that 0.01 pg level of

  15. Trace iodine quantitation in biological samples by mass spectrometric methods: the optimum internal standard.

    PubMed

    Dyke, Jason V; Dasgupta, Purnendu K; Kirk, Andrea B

    2009-07-15

    Accurate quantitation of iodine in biological samples is essential for studies of nutrition and medicine, as well as for epidemiological studies for monitoring intake of this essential nutrient. Despite the importance of accurate measurement, a standardized method for iodine analysis of biological samples is yet to be established. We have evaluated the effectiveness of (72)Ge, (115)In, and (129)I as internal standards for measurement of iodine in milk and urine samples by induction coupled plasma mass spectrometry (ICP-MS) and of (35)Cl(18)O(4)(-), (129)I(-), and 2-chlorobenzenesulfonate (2-CBS) as internal standards for ion chromatography-tandem mass spectrometry (IC-MS/MS). We found recovery of iodine to be markedly low when IC-MS/MS was used without an internal standard. Percent recovery was similarly low using (35)Cl(18)O(4) as an internal standard for milk and unpredictable when used for urine. 2-Chlorobenzebenzenesulfonate provided accurate recovery of iodine from milk, but overestimated iodine in urine samples by as much as a factor of 2. Percent recovery of iodine from milk and urine using ICP-MS without an internal standard was approximately 120%. Use of (115)In predicted approximately 60% of known values for both milk and urine samples. (72)Ge provided reasonable and consistent percent recovery for iodine in milk samples (approximately 108%) but resulted in approximately 80% recovery of iodine from urine. Use of (129)I as an internal standard resulted in excellent recovery of iodine from both milk and urine samples using either IC-MS/MS and ICP-MS.

  16. The Tip-Sample Interaction in Atomic Force Microscopy and its Implications for Biological Applications.

    NASA Astrophysics Data System (ADS)

    Baselt, David Randall

    This thesis describes the construction of an atomic force microscope and its application to the study of tip -sample interactions, primarily through the use of friction and hardness (elasticity) imaging. Part one describes the atomic force microscope, which consists of a scanned-cantilever stage (chapter 2); a versatile digital signal processor-based control system with self-optimizing feedback, lock-in amplifier emulation (for hardness imaging), and macro programmability (chapter 3); and image processing software (chapter 4). Part two describes a number of results that have helped to characterize the tip-sample interaction and the contact imaging modes used for its study. Meniscus forces act laterally as well as normally, and that they vary with position (chapter 5). Friction measurements couple with scanner position and feedback, and the meniscus effects friction images (chapter 6). Sliding of the tip over the sample surface introduces slope-dependence into hardness measurements (chapter 7). Dull tips can create prominent topography artifacts even on very flat surfaces (chapter 8). In an investigation of collagen fibrils, AFM has revealed the characteristic 65 nm banding pattern, a second, minor banding pattern, and microfibrils that run along the fibril axis. The distribution of proteoglycans along the fibrils creates a characteristic pattern in friction images. Although imaging in water reduces interaction forces, water can also make biological samples more sensitive to force. However, for robust biological samples imaged in air, tip shape presents a greater obstacle than tip -sample interaction forces to obtaining high-resolution images. Tip contamination increases tip-sample friction and can occasionally improve resolution (chapter 9). For a separate project I have designed a general -purpose nearfield scanning optical microscope (chapter 10).

  17. Toxicological importance of human biomonitoring of metallic and metalloid elements in different biological samples.

    PubMed

    Gil, F; Hernández, A F

    2015-06-01

    Human biomonitoring has become an important tool for the assessment of internal doses of metallic and metalloid elements. These elements are of great significance because of their toxic properties and wide distribution in environmental compartments. Although blood and urine are the most used and accepted matrices for human biomonitoring, other non-conventional samples (saliva, placenta, meconium, hair, nails, teeth, breast milk) may have practical advantages and would provide additional information on health risk. Nevertheless, the analysis of these compounds in biological matrices other than blood and urine has not yet been accepted as a useful tool for biomonitoring. The validation of analytical procedures is absolutely necessary for a proper implementation of non-conventional samples in biomonitoring programs. However, the lack of reliable and useful analytical methodologies to assess exposure to metallic elements, and the potential interference of external contamination and variation in biological features of non-conventional samples are important limitations for setting health-based reference values. The influence of potential confounding factors on metallic concentration should always be considered. More research is needed to ascertain whether or not non-conventional matrices offer definitive advantages over the traditional samples and to broaden the available database for establishing worldwide accepted reference values in non-exposed populations.

  18. Potentiometric detection in UPLC as an easy alternative to determine cocaine in biological samples.

    PubMed

    Daems, Devin; van Nuijs, Alexander L N; Covaci, Adrian; Hamidi-Asl, Ezat; Van Camp, Guy; Nagels, Luc J

    2015-07-01

    The analytical methods which are often used for the determination of cocaine in complex biological matrices are a prescreening immunoassay and confirmation by chromatography combined with mass spectrometry. We suggest an ultra-high-pressure liquid chromatography combined with a potentiometric detector, as a fast and practical method to detect and quantify cocaine in biological samples. An adsorption/desorption model was used to investigate the usefulness of the potentiometric detector to determine cocaine in complex matrices. Detection limits of 6.3 ng mL(-1) were obtained in plasma and urine, which is below the maximum residue limit (MRL) of 25 ng mL(-1). A set of seven plasma samples and 10 urine samples were classified identically by both methods as exceeding the MRL or being inferior to it. The results obtained with the UPLC/potentiometric detection method were compared with the results obtained with the UPLC/MS method for samples spiked with varying cocaine concentrations. The intraclass correlation coefficient was 0.997 for serum (n =7) and 0.977 for urine (n =8). As liquid chromatography is an established technique, and as potentiometry is very simple and cost-effective in terms of equipment, we believe that this method is potentially easy, inexpensive, fast and reliable.

  19. Tailored magnetic nanoparticles for direct and sensitive detection of biomolecules in biological samples.

    PubMed

    Fornara, Andrea; Johansson, Petter; Petersson, Karolina; Gustafsson, Stefan; Qin, Jian; Olsson, Eva; Ilver, Dag; Krozer, Anatol; Muhammed, Mamoun; Johansson, Christer

    2008-10-01

    We developed nanoparticles with tailored magnetic properties for direct and sensitive detection of biomolecules in biological samples in a single step. Thermally blocked nanoparticles obtained by thermal hydrolysis, functionalized with specific ligands, are mixed with sample solutions, and the variation of the magnetic relaxation due to surface binding is used to detect the presence of biomolecules. The binding significantly increases the hydrodynamic volume of nanoparticles, thus changing their Brownian relaxation frequency which is measured by a specifically developed AC susceptometer. The system was tested for the presence of Brucella antibodies, a dangerous pathogen causing brucellosis with severe effects both on humans and animals, in serum samples from infected cows and the surface of the nanoparticles was functionalized with lipopolysaccharides (LPS) from Brucella abortus. The hydrodynamic volume of LPS-functionalized particles increased by 25-35% as a result of the binding of the antibodies, measured by changes in the susceptibility in an alternating magnetic field. The method has shown high sensitivity, with detection limit of 0.05 microg x mL(-1) of antibody in the biological samples without any pretreatment. This magnetic-based assay is very sensitive, cost-efficient, and versatile, giving a direct indication whether the animal is infected or not, making it suitable for point-of-care applications. The functionalization of tailored magnetic nanoparticles can be modified to suit numerous homogeneous assays for a wide range of applications. PMID:18754596

  20. Offer of rapid testing and alternative biological samples as practical tools to implement HIV screening programs.

    PubMed

    Parisi, Maria Rita; Soldini, Laura; Di Perri, Giovanni; Tiberi, Simon; Lazzarin, Adriano; Lillo, Flavia B

    2009-10-01

    Implementation of HIV testing has the objective to increase screening, identify and counsel persons with infection, link them to clinical services and reduce transmission. Rapid tests and/or alternative biological samples (like oral fluid) give the option for a better general consent in approaching screening, immediate referral of HIV positives to medical treatment and partner notification. We tested the performance characteristics of an oral fluid-based rapid HIV test (Rapidtest HIV lateral flow-Healthchem diag. LLC) in comparison with routinely utilized methods in a selected population of known positive (N = 121) or negative (N = 754) subjects. The sensitivity of the rapid test was 99.1% (one false negative sample) and the specificity 98.8%. Five negatives showed a faint reactivity, 3 of these were reactive also in the reference test, one with a p24 only reaction in Western blot. If these 3 samples were excluded from the analysis the specificity increases to 99.2%. Results from our study confirm that, although a continuous improvement of the test performance is still needed to minimize false negative and positive results, rapid test and alternative biological samples may contribute to HIV prevention strategies by reaching a larger population particularly when and where regular screening procedures are difficult to obtain. PMID:20128446

  1. A review on determination of steroids in biological samples exploiting nanobio-electroanalytical methods.

    PubMed

    Yadav, Saurabh K; Chandra, Pranjal; Goyal, Rajendra N; Shim, Yoon-Bo

    2013-01-31

    The applications of nanomaterial modified sensors, molecularly imprinting polymer based, aptamer based, and immunosensors have been described in the determination of steroids using electroanalytical techniques. After a brief description of the steroids and assays in biological fluids, the principles of electrochemical detection with the advantages and the limitations of the various sensors are presented. The nanomaterial modified sensors catalyze the oxidation/reduction of steroids and are suitable for sensing them in environmental samples and biological fluids. The determination of steroids based on their reduction has been found more useful in comparison to oxidation as the common metabolites present in the biological fluids do not undergo reduction in the usual potential window and hence, do not interfere in the determination. The sensors based on immunosensors and aptamers were found more sensitive and selective for steroid determination. Conducting polymer modified bio-sensors and microchip devices are suggested as possible future prospects for the ultra sensitive and simultaneous determination of steroids and their metabolites in various samples.

  2. Application of probe electrospray to direct ambient analysis of biological samples.

    PubMed

    Chen, Lee Chuin; Nishidate, Kentaro; Saito, Yuta; Mori, Kunihiko; Asakawa, Daiki; Takeda, Sen; Kubota, Takeo; Terada, Nobuo; Hashimoto, Yutaka; Hori, Hirokazu; Hiraoka, Kenzo

    2008-08-01

    Recently, we have developed probe electrospray ionization (PESI) that uses a solid needle. In this system, the probe needle moves up and down along the vertical axis by a motor-driven system. At the highest position of the probe needle, electrospray is generated by applying a high voltage. In this study, we applied PESI directly to biological samples such as urine, mouse brain, mouse liver, salmon egg, and fruits (orange, banana, etc.). Strong ion signals for almost all the samples were obtained. The amount of liquid sample picked up by the needle is as small as pL or less, making PESI a promising non-invasive technique for detecting biomolecules in living systems such as cells. Therefore, PESI may be useful as a versatile and ready-to-use semi-online analytical tool in the fields of medicine, pharmaceuticals, agriculture, food science, etc. PMID:18623622

  3. MALDI-MS drug analysis in biological samples: opportunities and challenges.

    PubMed

    Steuer, Andrea E; Poetzsch, Michael; Kraemer, Thomas

    2016-09-01

    Drug analysis represents a large field in different disciplines. Plasma is commonly considered to be the biosample of choice for that purpose. However, concentrations often do not represent the levels present within deeper compartments and therefore cannot sufficiently explain efficacy or toxicology of drugs. MALDI-MS in drug analysis is of great interest for high-throughput quantification and particularly spatially resolved tissue imaging. The current perspective article will deal with challenges and opportunities of MALDI-MS drug analysis in different biological samples. A particular focus will be on hair samples. Recent applications were included, reviewed for their instrumental setup and sample preparation and pros and cons as well as future perspectives are critically discussed. PMID:27524467

  4. Mapping molecular orientational distributions for biological sample in 3D (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    HE, Wei; Ferrand, Patrick; Richter, Benjamin; Bastmeyer, Martin; Brasselet, Sophie

    2016-04-01

    Measuring molecular orientation properties is very appealing for scientists in molecular and cell biology, as well as biomedical research. Orientational organization at the molecular scale is indeed an important brick to cells and tissues morphology, mechanics, functions and pathologies. Recent work has shown that polarized fluorescence imaging, based on excitation polarization tuning in the sample plane, is able to probe molecular orientational order in biological samples; however this applies only to information in 2D, projected in the sample plane. To surpass this limitation, we extended this approach to excitation polarization tuning in 3D. The principle is based on the decomposition of any arbitrary 3D linear excitation in a polarization along the longitudinal z-axis, and a polarization in the transverse xy-sample plane. We designed an interferometer with one arm generating radial polarization light (thus producing longitudinal polarization under high numerical aperture focusing), the other arm controlling a linear polarization in the transverse plane. The amplitude ratio between the two arms can vary so as to get any linear polarized excitation in 3D at the focus of a high NA objective. This technique has been characterized by polarimetry imaging at the back focal plane of the focusing objective, and modeled theoretically. 3D polarized fluorescence microscopy is demonstrated on actin stress fibers in non-flat cells suspended on synthetic polymer structures forming supporting pillars, for which heterogeneous actin orientational order could be identified. This technique shows a great potential in structural investigations in 3D biological systems, such as cell spheroids and tissues.

  5. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    SciTech Connect

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  6. A direct solid sampling analysis method for the detection of silver nanoparticles in biological matrices.

    PubMed

    Feichtmeier, Nadine S; Ruchter, Nadine; Zimmermann, Sonja; Sures, Bernd; Leopold, Kerstin

    2016-01-01

    Engineered silver nanoparticles (AgNPs) are implemented in food contact materials due to their powerful antimicrobial properties and so may enter the human food chain. Hence, it is desirable to develop easy, sensitive and fast analytical screening methods for the determination of AgNPs in complex biological matrices. This study describes such a method using solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS). A recently reported novel evaluation strategy uses the atomization delay of the respective GFAAS signal as significant indicator for AgNPs and thereby allows discrimination of AgNPs from ionic silver (Ag(+)) in the samples without elaborate sample pre-treatment. This approach was further developed and applied to a variety of biological samples. Its suitability was approved by investigation of eight different food samples (parsley, apple, pepper, cheese, onion, pasta, maize meal and wheat flour) spiked with ionic silver or AgNPs. Furthermore, the migration of AgNPs from silver-impregnated polypropylene food storage boxes to fresh pepper was observed and a mussel sample obtained from a laboratory exposure study with silver was investigated. The differences in the atomization delays (Δt(ad)) between silver ions and 20-nm AgNPs vary in a range from -2.01 ± 1.38 s for maize meal to +2.06 ± 1.08 s for mussel tissue. However, the differences were significant in all investigated matrices and so indicative of the presence/absence of AgNPs. Moreover, investigation of model matrices (cellulose, gelatine and water) gives the first indication of matrix-dependent trends. Reproducibility and homogeneity tests confirm the applicability of the method.

  7. A direct solid sampling analysis method for the detection of silver nanoparticles in biological matrices.

    PubMed

    Feichtmeier, Nadine S; Ruchter, Nadine; Zimmermann, Sonja; Sures, Bernd; Leopold, Kerstin

    2016-01-01

    Engineered silver nanoparticles (AgNPs) are implemented in food contact materials due to their powerful antimicrobial properties and so may enter the human food chain. Hence, it is desirable to develop easy, sensitive and fast analytical screening methods for the determination of AgNPs in complex biological matrices. This study describes such a method using solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS). A recently reported novel evaluation strategy uses the atomization delay of the respective GFAAS signal as significant indicator for AgNPs and thereby allows discrimination of AgNPs from ionic silver (Ag(+)) in the samples without elaborate sample pre-treatment. This approach was further developed and applied to a variety of biological samples. Its suitability was approved by investigation of eight different food samples (parsley, apple, pepper, cheese, onion, pasta, maize meal and wheat flour) spiked with ionic silver or AgNPs. Furthermore, the migration of AgNPs from silver-impregnated polypropylene food storage boxes to fresh pepper was observed and a mussel sample obtained from a laboratory exposure study with silver was investigated. The differences in the atomization delays (Δt(ad)) between silver ions and 20-nm AgNPs vary in a range from -2.01 ± 1.38 s for maize meal to +2.06 ± 1.08 s for mussel tissue. However, the differences were significant in all investigated matrices and so indicative of the presence/absence of AgNPs. Moreover, investigation of model matrices (cellulose, gelatine and water) gives the first indication of matrix-dependent trends. Reproducibility and homogeneity tests confirm the applicability of the method. PMID:26483187

  8. Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

    NASA Astrophysics Data System (ADS)

    Manno, D.; Filippo, E.; Fiore, R.; Serra, A.; Urso, E.; Rizzello, A.; Maffia, M.

    2010-04-01

    Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrPC. In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrPC at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

  9. H2S Analysis in Biological Samples Using Gas Chromatography with Sulfur Chemiluminescence Detection

    PubMed Central

    Vitvitsky, Victor; Banerjee, Ruma

    2015-01-01

    Hydrogen sulfide (H2S) is a metabolite and signaling molecule in biological tissues that regulates many physiological processes. Reliable and sensitive methods for H2S analysis are necessary for a better understanding of H2S biology and for the pharmacological modulation of H2S levels in vivo. In this chapter, we describe the use of gas chromatography coupled to sulfur chemiluminescence detection to measure the rates of H2S production and degradation by tissue homogenates at physiologically relevant concentrations of substrates. This method allows separation of H2S from other sulfur compounds and provides sensitivity of detection to ~15 pg (or 0.5 pmol) of H2S per injected sample. PMID:25725519

  10. Temperature-responsive Solid-phase Extraction Column for Biological Sample Pretreatment.

    PubMed

    Akimaru, Michiko; Okubo, Kohei; Hiruta, Yuki; Kanazawa, Hideko

    2015-01-01

    We have developed a novel solid-phase extraction (SPE) system utilizing a temperature-responsive polymer hydrogel-modified stationary phase. Aminopropyl silica beads (average diameter, 40 - 64 μm) were coated with poly(N-isopropylacrylamide) (PNIPAAm)-based thermo-responsive hydrogels. Butyl methacrylate (BMA) and N,N-dimethylaminopropyl acrylamide (DMAPAAm) were used as the hydrophobic and cationic monomers, respectively, and copolymerized with NIPAAm. To evaluate the use of this SPE cartridge for the analysis of drugs and proteins in biological fluids, we studied the separation of phenytoin and theophylline from human serum albumin (HSA) as a model system. The retention of the analytes in an exclusively aqueous eluent could be modulated by changing the temperature and salt content. These results indicated that this temperature-responsive SPE system can be applied to the pretreatment of biological samples for the measurement of serum drug levels.

  11. Measurement of copper in biological samples by flame or electrothermal atomic absorption spectrometry.

    PubMed

    Evenson, M A

    1988-01-01

    Guidelines presented here allow for copper analysis of biological materials by methods that are very sensitive, that require little sample preparation, that have few chemical or spectral interferences, that are inexpensive, and that require only usual care in contamination control. The commercial instruments for FAAS and ETAAS from Perkin-Elmer, from Varian, and from Instrumentation Laboratories Inc. (Allied Analytical Systems) all work well in either the flame or the flameless mode. Background correction techniques are not essential for copper analysis if care is taken with the sample preparation to minimize the background signals. Different types of burners will work adequately if one makes certain that the viscosity of the sample and the control products are similar to the calibration standards. Further, dilution of samples is preferred over increasing the viscosity of the calibration standards by the addition of a protein containing solution or a substance such as glycerol. A 1:10 dilution of blood plasma or serum with dilute nitric acid or water is all that is necessary for copper analysis by the FFAS methods. Cation and anion effects should be tested by bracketing the concentrations of the ions found in the sample with known amounts of ions in the sample solutions. Increasing the concentrations of the ions thought to interfere while keeping the copper concentration constant is another way to test for ion interferences.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3374386

  12. Surface-enhanced Raman scattering detection of silver nanoparticles in environmental and biological samples.

    PubMed

    Guo, Huiyuan; Xing, Baoshan; Hamlet, Leigh C; Chica, Andrea; He, Lili

    2016-06-01

    Growing concerns over the potential release and threat of silver nanoparticles (AgNPs) to environmental and biological systems urge researchers to investigate their fate and behavior. However, current analytical techniques cannot meet the requirements for rapidly, sensitively and reliably probing AgNPs in complex matrices. Surface-enhanced Raman spectroscopy (SERS) has shown great capability for rapid detection of AgNPs based on an indicator molecule that can bind on the AgNP surface. The objective of this study was to exploit SERS to detect AgNPs in environmental and biological samples through optimizing the Raman indicator for SERS. Seven indicator molecules were selected and determined to obtain their SERS signals at optimal concentrations. Among them, 1,2-di(4-pyridyl)ethylene (BPE), crystal violet and ferric dimethyl-dithiocarbamate (ferbam) produced the highest SERS intensities. Further experiments on binding competition between each two of the three candidates showed that ferbam had the highest AgNPs-binding ability. The underlying mechanism lies in the strong binding affinity of ferbam with AgNPs via multiple sulfur atoms. We further validated ferbam to be an effective indicator for SERS detection of as low as 0.1mg/L AgNPs in genuine surface water and 0.57 mg/L in spinach juice. Moreover, limited interference on SERS detection of AgNPs was found from environmentally relevant inorganic ions, organic matter, inorganic particles, as well as biologically relevant components, demonstrating the ferbam-assisted SERS is an effective and sensitive method to detect AgNPs in complex environmental and biological samples.

  13. [Identification of two interference peaks during dioxin analysis for biological samples].

    PubMed

    Ren, Daiwei; Liang, Tao; Li, Gang; Zhang, Haidong; Wang, Pu; Xiao, Ke; Li, Yingming; Zhang, Qinghua

    2014-09-01

    Two interference peaks which generally appeared in company with 13C labeled 2,3,7,8-tetrachlorodibenzofuran (13C12-2,3,7,8-TCDF) in the same ion channel during dioxin analysis for biological samples were identified using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) and high resolution gas chromatography/low resolution mass spectrometry (HRGC/LRMS). It was firstly inferred that the interference peaks should be the two isomers of dichlorodiphenyldichloroethylene (DDE), which was a breakdown product of dichlorodiphenyltrichloroethane (DDT), one of the typical organic chlorine pesticides (OCPs). Thereafter, the standard solution of DDE including o,p'-DDE and p,p'-DDE was analyzed for confirmation. By evaluation of the peak separation in HRGC/HRMS, comparison of the GC retention times and ion abundance ratios of the two interference peaks in real samples with the two DDE isomers in standard solution, the interference peaks were finally confirmed as o,p'-DDE and p,p'-DDE in sequence on a DB-5MS column. This study provided valuable information for accurate identification of dioxin compounds during the biological sample analysis.

  14. Bayesian Model Comparison and Parameter Inference in Systems Biology Using Nested Sampling

    PubMed Central

    Pullen, Nick; Morris, Richard J.

    2014-01-01

    Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focusses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891

  15. Bayesian model comparison and parameter inference in systems biology using nested sampling.

    PubMed

    Pullen, Nick; Morris, Richard J

    2014-01-01

    Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focuses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891

  16. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    NASA Astrophysics Data System (ADS)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  17. Quantitative LC-MS/MS Glycomic Analysis of Biological Samples Using AminoxyTMT.

    PubMed

    Zhou, Shiyue; Hu, Yunli; Veillon, Lucas; Snovida, Sergei I; Rogers, John C; Saba, Julian; Mechref, Yehia

    2016-08-01

    Protein glycosylation plays an important role in various biological processes, such as modification of protein function, regulation of protein-protein interactions, and control of turnover rates of proteins. Moreover, glycans have been considered as potential biomarkers for many mammalian diseases and development of aberrant glycosylation profiles is an important indicator of the pathology of a disease or cancer. Hence, quantitation is an important aspect of a comprehensive glycomics study. Although numerous MS-based quantitation strategies have been developed in the past several decades, some issues affecting sensitivity and accuracy of quantitation still exist, and the development of more effective quantitation strategies is still required. Aminoxy tandem mass tag (aminoxyTMT) reagents are recently commercialized isobaric tags which enable relative quantitation of up to six different glycan samples simultaneously. In this study, liquid chromatography and mass spectrometry conditions have been optimized to achieve reliable LC-MS/MS quantitative glycomic analysis using aminoxyTMT reagents. Samples were resuspended in 0.2 M sodium chloride solution to promote the formation of sodium adduct precursor ions, which leads to higher MS/MS reporter ion yields. This method was first evaluated with glycans from model glycoproteins and pooled human blood serum samples. The observed variation of reporter ion ratios was generally less than 10% relative to the theoretical ratio. Even for the highly complex minor N-glycans, the variation was still below 15%. This strategy was further applied to the glycomic profiling of N-glycans released from blood serum samples of patients with different esophageal diseases. Our results demonstrate the benefits of utilizing aminoxyTMT reagents for reliable quantitation of biological glycomic samples. PMID:27377957

  18. The correlation of arsenic levels in drinking water with the biological samples of skin disorders.

    PubMed

    Kazi, Tasneem Gul; Arain, Muhammad Balal; Baig, Jameel Ahmed; Jamali, Muhammad Khan; Afridi, Hassan Imran; Jalbani, Nusrat; Sarfraz, Raja Adil; Shah, Abdul Qadir; Niaz, Abdul

    2009-01-15

    Arsenic (As) poisoning has become a worldwide public health concern. The skin is quite sensitive to As and skin lesions are the most common and earliest nonmalignant effects associated to chronic As exposure. In 2005-2007, a survey was carried out on surface and groundwater arsenic contamination and relationships between As exposure via the drinking water and related adverse health effects (melanosis and keratosis) on villagers resides on the banks of Manchar lake, southern part of Sindh, Pakistan. We screened the population from arsenic-affected villages, 61 to 73% population were identified patients suffering from chronic arsenic toxicity. The effects of As toxicity via drinking water were estimated by biological samples (scalp hair and blood) of adults (males and females), have or have not skin problem (n=187). The referent samples of both genders were also collected from the areas having low level of As (<10 microg/L) in drinking water (n=121). Arsenic concentration in drinking water and biological samples were analyzed using electrothermal atomic absorption spectrometry. The range of arsenic concentrations in lake surface water was 35.2-158 microg/L, which is 3-15 folds higher than World Health Organization [WHO, 2004. Guidelines for drinking-water quality third ed., WHO Geneva Switzerland.]. It was observed that As concentration in the scalp hair and blood samples were above the range of permissible values 0.034-0.319 microg As/g for hair and <0.5-4.2 microg/L for blood. The linear regressions showed good correlations between arsenic concentrations in water versus hair and blood samples of exposed skin diseased subjects (R2=0.852 and 0.718) as compared to non-diseased subjects (R2=0.573 and 0.351), respectively.

  19. Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Barai, A.; Watson, S.; Griffiths, H.; Patz, R.

    2012-08-01

    Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode-sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50-400 g l-1) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m-1 at 200 kHz, improving to 0.01 S m-1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality.

  20. High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

    SciTech Connect

    Loo, B.W. Jr. ||; Rothman, S.S. |

    1997-02-01

    High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

  1. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    NASA Astrophysics Data System (ADS)

    Lavers, C.; Franklin, P.; Franklin, P.; Plowman, A.; Sayers, G.; Bol, J.; Shepard, D.; Fields, D.

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  2. Separation Technique for the Determination of Highly Polar Metabolites in Biological Samples

    PubMed Central

    Iwasaki, Yusuke; Sawada, Takahiro; Hatayama, Kentaro; Ohyagi, Akihito; Tsukuda, Yuri; Namekawa, Kyohei; Ito, Rie; Saito, Koichi; Nakazawa, Hiroyuki

    2012-01-01

    Metabolomics is a new approach that is based on the systematic study of the full complement of metabolites in a biological sample. Metabolomics has the potential to fundamentally change clinical chemistry and, by extension, the fields of nutrition, toxicology, and medicine. However, it can be difficult to separate highly polar compounds. Mass spectrometry (MS), in combination with capillary electrophoresis (CE), gas chromatography (GC), or high performance liquid chromatography (HPLC) is the key analytical technique on which emerging "omics" technologies, namely, proteomics, metabolomics, and lipidomics, are based. In this review, we introduce various methods for the separation of highly polar metabolites. PMID:24957644

  3. Analysis of zinc in biological samples by flame atomic absorption spectrometry: use of addition calibration technique.

    PubMed

    Dutra, Rosilene L; Cantos, Geny A; Carasek, Eduardo

    2006-01-01

    The quantification of target analytes in complex matrices requires special calibration approaches to compensate for additional capacity or activity in the matrix samples. The standard addition is one of the most important calibration procedures for quantification of analytes in such matrices. However, this technique requires a great number of reagents and material, and it consumes a considerable amount of time throughout the analysis. In this work, a new calibration procedure to analyze biological samples is proposed. The proposed calibration, called the addition calibration technique, was used for the determination of zinc (Zn) in blood serum and erythrocyte samples. The results obtained were compared with those obtained using conventional calibration techniques (standard addition and standard calibration). The proposed addition calibration was validated by recovery tests using blood samples spiked with Zn. The range of recovery for blood serum and erythrocyte samples were 90-132% and 76-112%, respectively. Statistical studies among results obtained by the addition technique and conventional techniques, using a paired two-tailed Student's t-test and linear regression, demonstrated good agreement among them. PMID:16943611

  4. Evaluation of chemical and biological methods for the identification of mutagenic and cytotoxic hazardous waste samples

    SciTech Connect

    Andon, B.; Jackson, M.; Houk, V.; Claxton, L.

    1984-06-01

    To assist in the development of methods for identifying potentially hazardous wastes, the authors have conducted studies on the extraction of toxicants from several solid waste samples. The extracts were tested for toxicity in the Chinese Hamster Ovary (CHO) Cytotoxicity Test and for mutagenic potential in the Salmonella Histidine Reversion Assay. A new technique was also employed which measured the mutagenicity of neat waste samples by coupling Thin Layer Chromatography (TLC) with the Salmonella Histidine Reversion Assay. The wastes selected for study were coke plant waste, herbicide manufacturing acetone-water effluent, and oil refining waste. Three extraction solvents, ethanol (ETOH), dichloromethane (DCM), and dimethylsulfoxide (DMSO), were chosen based on their solubility and compatibility with bioassay procedures. Each sample was divided into three parts and extracted with each of the three solvents separately. All extracts were tested in the Salmonella assay at five dose levels with five Ames tester strains in the presence and in the absence of an exogenous metabolizing system. DMSO and DCM extracts were utilized for CHO cytotoxicity evaluations. The three neat waste samples and two extracts were assayed with the TLC technique. In addition to the biological assessments, the gross chemical parameters for each sample were determined. Results showed that coke plant waste and herbicide mfg. acetone-water were mutagenic to S. typhimurium with the standard plate test. With the TLC technique, the neat coke plant waste was mutagenic and oil refining waste was toxic. Oil refining waste was also toxic to CHO cells.

  5. Micro-organism extraction from biological samples using DEP forces enhanced by osmotic shock.

    PubMed

    Bisceglia, Emilie; Cubizolles, Myriam; Mallard, Frédéric; Vinet, Françoise; Français, Olivier; Le Pioufle, Bruno

    2013-03-01

    On the road towards efficient diagnostics of infectious diseases, sample preparation is considered as the key step and remains a real technical challenge. Finding new methods for extraction of micro-organisms from a complex biological sample remains a major challenge prior to pathogen detection and analysis. This paper reports a new technique for capturing and isolating micro-organisms from a complex sample. To achieve the segregation of pathogens and blood cells, dielectrophoretic forces applied to bioparticles previously subjected to an osmotic shock are successfully implemented within a dedicated microfluidic device. Our device involves an electrode array of interdigitated electrodes, coated with an insulating layer, to minimize electrochemical reactions with the electrolyte and to enable long-time use. The electric field intensity inside the device is optimized, considering the insulating layer, for a given frequency bandwidth, enabling the separation of bioparticles by dielectrophoretic forces. Our predictions are based on analytical models, consistent with numerical simulations (using COMSOL Multiphysics) and correlated to experimental results. The method and device have been shown to extract different types of micro-organisms spiked in a blood cell sample. We strongly believe that this new separation approach may open the way towards a simple device for pathogen extraction from blood and more generally complex samples, with potential advantages of genericness and simplicity.

  6. Combined LIBS-Raman for remote detection and characterization of biological samples

    SciTech Connect

    Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; Clegg, Samuel M.

    2015-02-07

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interest were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. Lastly, these results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.

  7. Combined LIBS-Raman for remote detection and characterization of biological samples

    DOE PAGES

    Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; Clegg, Samuel M.

    2015-02-07

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interestmore » were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. Lastly, these results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.« less

  8. Combined LIBS-Raman for remote detection and characterization of biological samples

    NASA Astrophysics Data System (ADS)

    Anderson, Aaron S.; Mukundan, Harshini; McInroy, Rhonda E.; Clegg, Samuel M.

    2015-03-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interest were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. These results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.

  9. Fiber laser-microscope system for femtosecond photodisruption of biological samples

    PubMed Central

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F. Ömer; Eldeniz, Y. Burak; Tazebay, Uygar H.

    2012-01-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells. PMID:22435105

  10. Analytical Methodologies for the Determination of Endocrine Disrupting Compounds in Biological and Environmental Samples

    PubMed Central

    Sosa-Ferrera, Zoraida; Mahugo-Santana, Cristina; Santana-Rodríguez, José Juan

    2013-01-01

    Endocrine-disruptor compounds (EDCs) can mimic natural hormones and produce adverse effects in the endocrine functions by interacting with estrogen receptors. EDCs include both natural and synthetic chemicals, such as hormones, personal care products, surfactants, and flame retardants, among others. EDCs are characterised by their ubiquitous presence at trace-level concentrations and their wide diversity. Since the discovery of the adverse effects of these pollutants on wildlife and human health, analytical methods have been developed for their qualitative and quantitative determination. In particular, mass-based analytical methods show excellent sensitivity and precision for their quantification. This paper reviews recently published analytical methodologies for the sample preparation and for the determination of these compounds in different environmental and biological matrices by liquid chromatography coupled with mass spectrometry. The various sample preparation techniques are compared and discussed. In addition, recent developments and advances in this field are presented. PMID:23738329

  11. Enzymatic determination of carbon-14 labeled L-alanine in biological samples

    SciTech Connect

    Serra, F.; Palou, A.; Pons, A.

    1987-07-15

    A method for determination of L-alanine-specific radioactivity in biological samples is presented. This method is based on the specific enzymatic transformation of L-alanine to pyruvic acid hydrazone catalyzed by the enzyme L-alanine dehydrogenase, formation of the pyruvic acid 2,4-dinitrophenylhydrazone derivative, and quantitative trapping in Amberlite XAD-7 columns, followed by radioactivity counting of the lipophilic eluate. No interferences from other UC-labeled materials such as D-glucose, glycerol, L-lactate, L-serine, L-glutamate, L-phenylalanine, glycine, L-leucine, and L-arginine were observed. This inexpensive and high-speed method is applicable to the simultaneous determination of L-alanine-specific radioactivity for a large number of samples.

  12. An introduction to sample preparation and imaging by cryo-electron microscopy for structural biology

    PubMed Central

    Thompson, Rebecca F.; Walker, Matt; Siebert, C. Alistair; Muench, Stephen P.; Ranson, Neil A.

    2016-01-01

    Transmission electron microscopy (EM) is a versatile technique that can be used to image biological specimens ranging from intact eukaryotic cells to individual proteins >150 kDa. There are several strategies for preparing samples for imaging by EM, including negative staining and cryogenic freezing. In the last few years, cryo-EM has undergone a ‘resolution revolution’, owing to both advances in imaging hardware, image processing software, and improvements in sample preparation, leading to growing number of researchers using cryo-EM as a research tool. However, cryo-EM is still a rapidly growing field, with unique challenges. Here, we summarise considerations for imaging of a range of specimens from macromolecular complexes to cells using EM. PMID:26931652

  13. Phytochemical analysis and biological evaluation of selected African propolis samples from Cameroon and Congo.

    PubMed

    Papachroni, Danai; Graikou, Konstantia; Kosalec, Ivan; Damianakos, Harilaos; Ingram, Verina; Chinou, Ioanna

    2015-01-01

    The objective of this study was the chemical analysis of four selected samples of African propolis (Congo and Cameroon) and their biological evaluation. Twenty-one secondary metabolites belonging to four different chemical groups were isolated from the 70% ethanolic extracts of propolis and their structures were elucidated on the basis of spectral evidence. Three triterpenes and two diprenyl-flavonoids were identified from Congo propolis, which has been investigated for the first time, while thirteen triterpenes, three diprenyl-flavonoids, two monoterpenic alcohols and one fatty acid ester have been identified from Cameroon propolis samples. To our knowledge, the identified diprenyl-flavonoids, as well as five of the isolated and determined triterpenes, are reported for the first time in propolis. Moreover, the total polyphenol content was estimated in all extracts and the antimicrobial activities of all four extracts were studied against six Gram-positive and -negative bacteria and three pathogenic fungi, showing an interesting antibacterial profile.

  14. 4D x-ray phase contrast tomography for repeatable motion of biological samples

    NASA Astrophysics Data System (ADS)

    Hoshino, Masato; Uesugi, Kentaro; Yagi, Naoto

    2016-09-01

    X-ray phase contrast tomography based on a grating interferometer was applied to fast and dynamic measurements of biological samples. To achieve this, the scanning procedure in the tomographic scan was improved. A triangle-shaped voltage signal from a waveform generator to a Piezo stage was used for the fast phase stepping in the grating interferometer. In addition, an optical fiber coupled x-ray scientific CMOS camera was used to achieve fast and highly efficient image acquisitions. These optimizations made it possible to perform an x-ray phase contrast tomographic measurement within an 8 min scan with density resolution of 2.4 mg/cm3. A maximum volume size of 13 × 13 × 6 mm3 was obtained with a single tomographic measurement with a voxel size of 6.5 μm. The scanning procedure using the triangle wave was applied to four-dimensional measurements in which highly sensitive three-dimensional x-ray imaging and a time-resolved dynamic measurement of biological samples were combined. A fresh tendon in the tail of a rat was measured under a uniaxial stretching and releasing condition. To maintain the freshness of the sample during four-dimensional phase contrast tomography, the temperature of the bathing liquid of the sample was kept below 10° using a simple cooling system. The time-resolved deformation of the tendon and each fascicle was measured with a temporal resolution of 5.7 Hz. Evaluations of cross-sectional area size, length of the axis, and mass density in the fascicle during a stretching process provided a basis for quantitative analysis of the deformation of tendon fascicle.

  15. Wavelet data processing of micro-Raman spectra of biological samples

    NASA Astrophysics Data System (ADS)

    Camerlingo, C.; Zenone, F.; Gaeta, G. M.; Riccio, R.; Lepore, M.

    2006-02-01

    A wavelet multi-component decomposition algorithm is proposed for processing data from micro-Raman spectroscopy (μ-RS) of biological tissue. The μ-RS has been recently recognized as a promising tool for the biopsy test and in vivo diagnosis of degenerative human tissue pathologies, due to the high chemical and structural information contents of this spectroscopic technique. However, measurements of biological tissues are usually hampered by typically low-level signals and by the presence of noise and background components caused by light diffusion or fluorescence processes. In order to overcome these problems, a numerical method based on discrete wavelet transform is used for the analysis of data from μ-RS measurements performed in vitro on animal (pig and chicken) tissue samples and, in a preliminary form, on human skin and oral tissue biopsy from normal subjects. Visible light μ-RS was performed using a He-Ne laser and a monochromator with a liquid nitrogen cooled charge coupled device equipped with a grating of 1800 grooves mm-1. The validity of the proposed data procedure has been tested on the well-characterized Raman spectra of reference acetylsalicylic acid samples.

  16. Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

    PubMed

    Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

    2016-10-20

    The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively.

  17. Methods to Detect Nitric Oxide and its Metabolites in Biological Samples

    PubMed Central

    Bryan, Nathan S.; Grisham, Matthew B.

    2007-01-01

    Nitric oxide (NO) methodology is a complex and often confusing science and the focus of many debates and discussion concerning NO biochemistry. NO is involved in many physiological processes including regulation of blood pressure, immune response and neural communication. Therefore its accurate detection and quantification is critical to understanding health and disease. Due to the extremely short physiological half life of this gaseous free radical, alternative strategies for the detection of reaction products of NO biochemistry have been developed. The quantification of NO metabolites in biological samples provides valuable information with regards to in vivo NO production, bioavailability and metabolism. Simply sampling a single compartment such as blood or plasma may not always provide an accurate assessment of whole body NO status, particularly in tissues. Therefore, extrapolation of plasma or blood NO status to specific tissues of interest is no longer a valid approach. As a result, methods continue to be developed and validated which allow the detection and quantification of NO and NO-related products/metabolites in multiple compartments of experimental animals in vivo. The methods described in this review is not an exhaustive or comprehensive discussion of all methods available for the detection of NO but rather a description of the most commonly used and practical methods which allow accurate and sensitive quantification of NO products/metabolites in multiple biological matrices under normal physiological conditions. PMID:17664129

  18. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    NASA Astrophysics Data System (ADS)

    Beasley, D. G.; Alves, L. C.; Barberet, Ph.; Bourret, S.; Devès, G.; Gordillo, N.; Michelet, C.; Le Trequesser, Q.; Marques, A. C.; Seznec, H.; da Silva, R. C.

    2014-07-01

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans - a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

  19. Respondent driven sampling for HIV biological and behavioral surveillance in Latin America and the Caribbean.

    PubMed

    Montealegre, Jane R; Johnston, Lisa G; Murrill, Christopher; Monterroso, Edgar

    2013-09-01

    Since 2005, respondent driven sampling (RDS) has been widely used for HIV biological and behavioral surveillance surveys (BBSS) in Latin America and the Caribbean (LAC). In this manuscript, we provide a focused review of RDS among hard-to-reach high-risk populations in LAC and describe their principal operational, design, and analytical considerations. We reviewed published and unpublished reports, protocols, and manuscripts for RDS studies conducted in LAC between January 1, 2005 and December 31, 2011. We abstracted key operational information and generated summary statistics across all studies. Between 2005 and 2011, 87 RDS studies were conducted in 15 countries in LAC (68 % in South America, 18 % in Mexico and Central America, and 14 % in the Caribbean). The target populations were primarily men who have sex with men (43 %), sex workers (29 %), and drug users (26 %). Study considerations included establishing clear eligibility criteria, measuring social network sizes, collecting specimens for biological testing, among others. Most of the reviewed studies are the first in their respective countries to collect data on hard-to-reach populations and the first attempt to use a probability-based sampling method. These RDS studies allowed researchers and public health practitioners in LAC to access hard-to-reach HIV high-risk populations and collect valuable data on the prevalence of HIV and other infections, as well as related risk behaviors. PMID:23568227

  20. Respondent driven sampling for HIV biological and behavioral surveillance in Latin America and the Caribbean.

    PubMed

    Montealegre, Jane R; Johnston, Lisa G; Murrill, Christopher; Monterroso, Edgar

    2013-09-01

    Since 2005, respondent driven sampling (RDS) has been widely used for HIV biological and behavioral surveillance surveys (BBSS) in Latin America and the Caribbean (LAC). In this manuscript, we provide a focused review of RDS among hard-to-reach high-risk populations in LAC and describe their principal operational, design, and analytical considerations. We reviewed published and unpublished reports, protocols, and manuscripts for RDS studies conducted in LAC between January 1, 2005 and December 31, 2011. We abstracted key operational information and generated summary statistics across all studies. Between 2005 and 2011, 87 RDS studies were conducted in 15 countries in LAC (68 % in South America, 18 % in Mexico and Central America, and 14 % in the Caribbean). The target populations were primarily men who have sex with men (43 %), sex workers (29 %), and drug users (26 %). Study considerations included establishing clear eligibility criteria, measuring social network sizes, collecting specimens for biological testing, among others. Most of the reviewed studies are the first in their respective countries to collect data on hard-to-reach populations and the first attempt to use a probability-based sampling method. These RDS studies allowed researchers and public health practitioners in LAC to access hard-to-reach HIV high-risk populations and collect valuable data on the prevalence of HIV and other infections, as well as related risk behaviors.

  1. Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

    PubMed

    Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

    2016-10-20

    The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively. PMID:27474582

  2. Label-free three-dimensional reconstruction of biological samples (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

  3. Label-free three dimensional reconstruction of biological samples (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

  4. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction.

    PubMed

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz

    2006-11-01

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 mug g(-1) and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. PMID:16896613

  5. Preparative divergent flow IEF without carrier ampholytes for separation of complex biological samples.

    PubMed

    Stastna, Miroslava; Slais, Karel

    2010-01-01

    Efficient separation method is a crucial part of the process in which components of highly complex biological sample are identified and characterized. Based on the principles of recently newly established electrophoretic method called divergent flow IEF (DF IEF), we have tested the DF IEF instrument which is able to operate without the use of background carrier ampholytes. We have verified that during separation and focusing of sample consisting of high numbers of proteins (yeast lysate and wheat flour extract), the pH gradient of preparative DF IEF can be created by autofocusing of the sample components themselves without any addition of carrier ampholytes. In DF IEF, the proteins are separated, desalted and concentrated in one step. The fractions of yeast lysate sample, collected at the DF IEF output and subjected to gel IEF, contained the zones of proteins gradually covering the pI values from 3.7 to 8.5. In our experimental arrangement, the highest number of proteins has been found in fractions with pI values around 5.3 as detected by polyacrylamide gel IEF with CBB staining. During DF IEF, the selected protein bands have been concentrated up to 16.8-fold.

  6. An inexpensive and portable microvolumeter for rapid evaluation of biological samples.

    PubMed

    Douglass, John K; Wcislo, William T

    2010-08-01

    We describe an improved microvolumeter (MVM) for rapidly measuring volumes of small biological samples, including live zooplankton, embryos, and small animals and organs. Portability and low cost make this instrument suitable for widespread use, including at remote field sites. Beginning with Archimedes' principle, which states that immersing an arbitrarily shaped sample in a fluid-filled container displaces an equivalent volume, we identified procedures that maximize measurement accuracy and repeatability across a broad range of absolute volumes. Crucial steps include matching the overall configuration to the size of the sample, using reflected light to monitor fluid levels precisely, and accounting for evaporation during measurements. The resulting precision is at least 100 times higher than in previous displacement-based methods. Volumes are obtained much faster than by traditional histological or confocal methods and without shrinkage artifacts due to fixation or dehydration. Calibrations using volume standards confirmed accurate measurements of volumes as small as 0.06 microL. We validated the feasibility of evaluating soft-tissue samples by comparing volumes of freshly dissected ant brains measured with the MVM and by confocal reconstruction.

  7. Validation of the orthogonal tilt reconstruction method with a biological test sample.

    PubMed

    Chandramouli, Preethi; Hernandez-Lopez, Rogelio; Wang, Hong-Wei; Leschziner, Andres E

    2011-07-01

    Electron microscopy of frozen-hydrated samples (cryo-EM) can yield high resolution structures of macromolecular complexes by accurately determining the orientation of large numbers of experimental views of the sample relative to an existing 3D model. The "initial model problem", the challenge of obtaining these orientations ab initio, remains a major bottleneck in determining the structure of novel macromolecules, chiefly those lacking internal symmetry. We previously proposed a method for the generation of initial models--orthogonal tilt reconstruction (OTR)--that bypasses limitations inherent to the other two existing methods, random conical tilt (RCT) and angular reconstitution (AR). Here we present a validation of OTR with a biological test sample whose structure was previously solved by RCT: the complex between the yeast exosome and the subunit Rrp44. We show that, as originally demonstrated with synthetic data, OTR generates initial models that do not exhibit the "missing cone" artifacts associated with RCT and show an isotropic distribution of information when compared with the known structure. This eliminates the need for further user intervention to solve these artifacts and makes OTR ideal for automation and the analysis of heterogeneous samples. With the former in mind, we propose a set of simple quantitative criteria that can be used, in combination, to select from a large set of initial reconstructions a subset that can be used as reliable references for refinement to higher resolution.

  8. An inexpensive and portable microvolumeter for rapid evaluation of biological samples.

    PubMed

    Douglass, John K; Wcislo, William T

    2010-08-01

    We describe an improved microvolumeter (MVM) for rapidly measuring volumes of small biological samples, including live zooplankton, embryos, and small animals and organs. Portability and low cost make this instrument suitable for widespread use, including at remote field sites. Beginning with Archimedes' principle, which states that immersing an arbitrarily shaped sample in a fluid-filled container displaces an equivalent volume, we identified procedures that maximize measurement accuracy and repeatability across a broad range of absolute volumes. Crucial steps include matching the overall configuration to the size of the sample, using reflected light to monitor fluid levels precisely, and accounting for evaporation during measurements. The resulting precision is at least 100 times higher than in previous displacement-based methods. Volumes are obtained much faster than by traditional histological or confocal methods and without shrinkage artifacts due to fixation or dehydration. Calibrations using volume standards confirmed accurate measurements of volumes as small as 0.06 microL. We validated the feasibility of evaluating soft-tissue samples by comparing volumes of freshly dissected ant brains measured with the MVM and by confocal reconstruction. PMID:20701591

  9. An enzyme-based DNA preparation method for application to forensic biological samples and degraded stains.

    PubMed

    Lounsbury, Jenny A; Coult, Natalie; Miranian, Daniel C; Cronk, Stephen M; Haverstick, Doris M; Kinnon, Paul; Saul, David J; Landers, James P

    2012-09-01

    Extraction of DNA from forensic samples typically uses either an organic extraction protocol or solid phase extraction (SPE) and these methods generally involve numerous sample transfer, wash and centrifugation steps. Although SPE has been successfully adapted to the microdevice, it can be problematic because of lengthy load times and uneven packing of the solid phase. A closed-tube enzyme-based DNA preparation method has recently been developed which uses a neutral proteinase to lyse cells and degrade proteins and nucleases [14]. Following a 20 min incubation of the buccal or whole blood sample with this proteinase, DNA is polymerase chain reaction (PCR)-ready. This paper describes the optimization and quantitation of DNA yield using this method, and application to forensic biological samples, including UV- and heat-degraded whole blood samples on cotton or blue denim substrates. Results demonstrate that DNA yield can be increased from 1.42 (±0.21)ng/μL to 7.78 (±1.40)ng/μL by increasing the quantity of enzyme per reaction by 3-fold. Additionally, there is a linear relationship between the amount of starting cellular material added and the concentration of DNA in the solution, thereby allowing DNA yield estimations to be made. In addition, short tandem repeat (STR) profile results obtained using DNA prepared with the enzyme method were comparable to those obtained with a conventional SPE method, resulting in full STR profiles (16 of 16 loci) from liquid samples (buccal swab eluate and whole blood), dried buccal swabs and bloodstains and partial profiles from UV or heat-degraded bloodstains on cotton or blue denim substrates. Finally, the DNA preparation method is shown to be adaptable to glass or poly(methyl methacrylate) (PMMA) microdevices with little impact on STR peak height but providing a 20-fold reduction in incubation time (as little as 60 s), leading to a ≥1 h reduction in DNA preparation time.

  10. Investigation of resins suitable for the preparation of biological sample for 3-D electron microscopy.

    PubMed

    Kizilyaprak, Caroline; Longo, Giovanni; Daraspe, Jean; Humbel, Bruno M

    2015-02-01

    In the last two decades, the third-dimension has become a focus of attention in electron microscopy to better understand the interactions within subcellular compartments. Initially, transmission electron tomography (TEM tomography) was introduced to image the cell volume in semi-thin sections (∼ 500 nm). With the introduction of the focused ion beam scanning electron microscope, a new tool, FIB-SEM tomography, became available to image much larger volumes. During TEM tomography and FIB-SEM tomography, the resin section is exposed to a high electron/ion dose such that the stability of the resin embedded biological sample becomes an important issue. The shrinkage of a resin section in each dimension, especially in depth, is a well-known phenomenon. To ensure the dimensional integrity of the final volume of the cell, it is important to assess the properties of the different resins and determine the formulation which has the best stability in the electron/ion beam. Here, eight different resin formulations were examined. The effects of radiation damage were evaluated after different times of TEM irradiation. To get additional information on mass-loss and the physical properties of the resins (stiffness and adhesion), the topography of the irradiated areas was analysed with atomic force microscopy (AFM). Further, the behaviour of the resins was analysed after ion milling of the surface of the sample with different ion currents. In conclusion, two resin formulations, Hard Plus and the mixture of Durcupan/Epon, emerged that were considerably less affected and reasonably stable in the electron/ion beam and thus suitable for the 3-D investigation of biological samples. PMID:25433274

  11. Troubleshooting digital macro photography for image acquisition and the analysis of biological samples.

    PubMed

    Liepinsh, Edgars; Kuka, Janis; Dambrova, Maija

    2013-01-01

    For years, image acquisition and analysis have been an important part of life science experiments to ensure the adequate and reliable presentation of research results. Since the development of digital photography and digital planimetric methods for image analysis approximately 20 years ago, new equipment and technologies have emerged, which have increased the quality of image acquisition and analysis. Different techniques are available to measure the size of stained tissue samples in experimental animal models of disease; however, the most accurate method is digital macro photography with software that is based on planimetric analysis. In this study, we described the methodology for the preparation of infarcted rat heart and brain tissue samples before image acquisition, digital macro photography techniques and planimetric image analysis. These methods are useful in the macro photography of biological samples and subsequent image analysis. In addition, the techniques that are described in this study include the automated analysis of digital photographs to minimize user input and exclude the risk of researcher-generated errors or bias during image analysis.

  12. New photoacoustic cell with diamond window for mid-infrared investigations on biological samples

    NASA Astrophysics Data System (ADS)

    Kottmann, Jonas; Rey, Julien M.; Sigrist, Markus W.

    2012-02-01

    We present a new photoacoustic (PA) cell, which is sealed on the sample side with a 163 μm thick chemical vapor deposition (CVD) diamond window. The investigation of samples containing volatile compounds with an openended PA cell leads to varying conditions in the PA chamber (changing light absorption or relative humidity) and thus causes unstable signals. In contrast the diamond cover ensures stable conditions in the PA chamber and thereby enables sensitive measurements. This is particularly important for the investigation of biological samples with a high water content. Due to the high thermal conductivity of CVD diamond (1800 W/mK) strong PA signals are generated and the broad optical transmission range (250 nm to THz) renders the cell useful for various applications. The performance of the cell is demonstrated by tracking glucose in aqueous keratinocyte solutions with an external-cavity quantum cascade laser (1010-1095 cm-1). These measurements yield a detection limit of 100 mg/dl (SNR=3). Although glucose measurements within the human physiological range (30-500 mg/dl) are feasible, further improvements are needed for non-invasive glucose monitoring of diabetes patients. First in vivo measurements at the human forearm show an additional PA signal induced by blood pulsation at a frequency around 1 Hz and a steadily increasing relative humidity in the PA chamber due to transepidermal water loss if the cell is neither closed with a diamond window nor ventilated with N2.

  13. Molecular dynamics simulations of biological membranes and membrane proteins using enhanced conformational sampling algorithms.

    PubMed

    Mori, Takaharu; Miyashita, Naoyuki; Im, Wonpil; Feig, Michael; Sugita, Yuji

    2016-07-01

    This paper reviews various enhanced conformational sampling methods and explicit/implicit solvent/membrane models, as well as their recent applications to the exploration of the structure and dynamics of membranes and membrane proteins. Molecular dynamics simulations have become an essential tool to investigate biological problems, and their success relies on proper molecular models together with efficient conformational sampling methods. The implicit representation of solvent/membrane environments is reasonable approximation to the explicit all-atom models, considering the balance between computational cost and simulation accuracy. Implicit models can be easily combined with replica-exchange molecular dynamics methods to explore a wider conformational space of a protein. Other molecular models and enhanced conformational sampling methods are also briefly discussed. As application examples, we introduce recent simulation studies of glycophorin A, phospholamban, amyloid precursor protein, and mixed lipid bilayers and discuss the accuracy and efficiency of each simulation model and method. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov.

  14. Mercury speciation and total trace element determination of low-biomass biological samples.

    PubMed

    Taylor, Vivien F; Jackson, Brian P; Chen, Celia Y

    2008-12-01

    Current approaches to mercury speciation and total trace element analysis require separate extraction/digestions of the sample. Ecologically important aquatic organisms--notably primary consumers such as zooplankton, polychaetes and amphipods--usually yield very low biomass for analysis, even with significant compositing of multiple organisms. Individual organisms in the lower aquatic food chains (mussels, snails, oysters, silversides, killifish) can also have very low sample mass, and analysis of whole single organisms is important to metal uptake studies. A method for the determination of both methyl Hg and total heavy metal concentrations (Zn, As, Se, Cd, Hg, Pb) in a single, low-mass sample of aquatic organisms was developed. Samples (2 to 50 mg) were spiked with enriched with (201)MeHg and (199)Hg, then leached in 4 M HNO(3) at 55 degrees C for extraction of MeHg. After 16 h, an aliquot (0.05 mL) was removed to determine mercury species (methyl and inorganic Hg) by isotope dilution gas chromatography inductively coupled plasma mass spectrometry (ICP-MS). The leachate was then acidified to 9 M HNO(3) and digested in a microwave at 150 degrees C for 10 min, and total metal concentrations were determined by collision cell ICP-MS. The method was validated by analyzing five biological certified reference materials. Average percent recoveries for Zn, As, Se, Cd, MeHg, Hg(total) and Pb were 99.9%, 103.5%, 100.4%, 103.3%, 101%, 97.7%, and 97.1%, respectively. The correlation between the sum of MeHg and inorganic Hg from the speciation analysis and total Hg by conventional digestion of the sample was determined for a large sample set of aquatic invertebrates (n = 285). Excellent agreement between the two measured values was achieved. This method is advantageous in situations where sample size is limited, and where correlations between Hg species and other metals are required in the same sample. The method also provides further validation of speciation data, by

  15. Characterisation of radiation field for irradiation of biological samples at nuclear reactor-comparison of twin detector and recombination methods.

    PubMed

    Golnik, N; Gryziński, M A; Kowalska, M; Meronka, K; Tulik, P

    2014-10-01

    Central Laboratory for Radiological Protection is involved in achieving scientific project on biological dosimetry. The project includes irradiation of blood samples in radiation fields of nuclear reactor. A simple facility for irradiation of biological samples has been prepared at horizontal channel of the nuclear reactor MARIA in NCBJ in Poland. The radiation field, composed mainly of gamma radiation and thermal neutrons, has been characterised in terms of tissue kerma using twin-detector technique and recombination chambers.

  16. A data-independent acquisition workflow for qualitative screening of new psychoactive substances in biological samples.

    PubMed

    Kinyua, Juliet; Negreira, Noelia; Ibáñez, María; Bijlsma, Lubertus; Hernández, Félix; Covaci, Adrian; van Nuijs, Alexander L N

    2015-11-01

    Identification of new psychoactive substances (NPS) is challenging. Developing targeted methods for their analysis can be difficult and costly due to their impermanence on the drug scene. Accurate-mass mass spectrometry (AMMS) using a quadrupole time-of-flight (QTOF) analyzer can be useful for wide-scope screening since it provides sensitive, full-spectrum MS data. Our article presents a qualitative screening workflow based on data-independent acquisition mode (all-ions MS/MS) on liquid chromatography (LC) coupled to QTOFMS for the detection and identification of NPS in biological matrices. The workflow combines and structures fundamentals of target and suspect screening data processing techniques in a structured algorithm. This allows the detection and tentative identification of NPS and their metabolites. We have applied the workflow to two actual case studies involving drug intoxications where we detected and confirmed the parent compounds ketamine, 25B-NBOMe, 25C-NBOMe, and several predicted phase I and II metabolites not previously reported in urine and serum samples. The screening workflow demonstrates the added value for the detection and identification of NPS in biological matrices.

  17. A data-independent acquisition workflow for qualitative screening of new psychoactive substances in biological samples.

    PubMed

    Kinyua, Juliet; Negreira, Noelia; Ibáñez, María; Bijlsma, Lubertus; Hernández, Félix; Covaci, Adrian; van Nuijs, Alexander L N

    2015-11-01

    Identification of new psychoactive substances (NPS) is challenging. Developing targeted methods for their analysis can be difficult and costly due to their impermanence on the drug scene. Accurate-mass mass spectrometry (AMMS) using a quadrupole time-of-flight (QTOF) analyzer can be useful for wide-scope screening since it provides sensitive, full-spectrum MS data. Our article presents a qualitative screening workflow based on data-independent acquisition mode (all-ions MS/MS) on liquid chromatography (LC) coupled to QTOFMS for the detection and identification of NPS in biological matrices. The workflow combines and structures fundamentals of target and suspect screening data processing techniques in a structured algorithm. This allows the detection and tentative identification of NPS and their metabolites. We have applied the workflow to two actual case studies involving drug intoxications where we detected and confirmed the parent compounds ketamine, 25B-NBOMe, 25C-NBOMe, and several predicted phase I and II metabolites not previously reported in urine and serum samples. The screening workflow demonstrates the added value for the detection and identification of NPS in biological matrices. PMID:26396082

  18. METHODS FOR USING 3-D ULTRASOUND SPECKLE TRACKING IN BIAXIAL MECHANICAL TESTING OF BIOLOGICAL TISSUE SAMPLES

    PubMed Central

    Yap, Choon Hwai; Park, Dae Woo; Dutta, Debaditya; Simon, Marc; Kim, Kang

    2014-01-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making full assessment and understanding of their mechanical behavior challenging. Current standard mechanical testing uses surface markers to track tissue deformations and does not provide deformation data below the surface. In the study described here, we found that combining mechanical testing with 3-D ultrasound speckle tracking could overcome this limitation. Rat myocardium was tested with a biaxial tester and was concurrently scanned with high-frequency ultrasound in three dimensions. The strain energy function was computed from stresses and strains using an iterative non-linear curve-fitting algorithm. Because the strain energy function consists of terms for the base matrix and for embedded fibers, spatially varying fiber orientation was also computed by curve fitting. Using finite-element simulations, we first validated the accuracy of the non-linear curve-fitting algorithm. Next, we compared experimentally measured rat myocardium strain energy function values with those in the literature and found a matching order of magnitude. Finally, we retained samples after the experiments for fiber orientation quantification using histology and found that the results satisfactorily matched those computed in the experiments. We conclude that 3-D ultrasound speckle tracking can be a useful addition to traditional mechanical testing of biological tissues and may provide the benefit of enabling fiber orientation computation. PMID:25616585

  19. Determination of steroid hormones in biological and environmental samples using green microextraction techniques: an overview.

    PubMed

    Aufartová, Jana; Mahugo-Santana, Cristina; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Nováková, Lucie; Solich, Petr

    2011-10-17

    Residues of steroid hormones have become a cause for concern because they can affect the biological activity of non-target organisms. Steroid hormones are a potential risk for wildlife and humans through the consumption of contaminated food or water. Their determination requires extraction and clean-up steps, prior to detection, to reach low concentration levels. In recent years, a great effort has been made to develop new analytical methodologies, such as microextraction techniques, that reduce environmental pollution. Researchers have modified old methods to incorporate procedures that use less-hazardous chemicals or that use smaller amounts of them. They are able to do direct analysis using miniaturised equipment and reduced amounts of solvents and wastes. These accomplishments are the main objectives of green analytical chemistry. In this overview, we focus on microextraction techniques for the determination of steroid hormones in biological (e.g., human urine, human serum, fish, shrimp and prawn tissue and milk) and environmental (e.g., wastewaters, surface waters, tap waters, river waters, sewage sludges, marine sediments and river sediments) samples. We comment on the most recent applications in sorptive-microextraction modes, such as solid phase microextraction (SPME) with molecularly imprinted polymers (MIPs), in-tube solid-phase microextraction (IT-SPME), stir-bar sorptive extraction (SBSE) and microextraction in packed sorbent (MEPS). We also describe liquid-phase microextraction (LPME) approaches reported in the literature that are applied to the determination of steroid hormones.

  20. Chelation ion chromatography as a method for trace elemental analysis in complex environmental and biological samples

    SciTech Connect

    Siriraks, A.; Kingston, H.M. ); Riviello, J.M. )

    1990-06-01

    The development and evaluation of a new method for the determination of trace transition and rare-earth elements based on the combination of chelation and ion chromatography are described. The new method, chelation ion chromatography (Chelation IC), uses a chelating column to concentrate and separate transition and rare-earth elements from the common alkali and alkaline-earth metals, as well as other matrix components, prior to analysis by ion chromatography. The sample fraction from the chelating column contains only the concentrated analyte ions, thus eliminating interfering matrix components from complex matrices such as seawater and digested biological, botanical, and geological materials. This combination of chelation and ion chromatography provides a technique that makes possible the determination of trace elements in complex matrices that have proven to be difficult or impossible to analyze by ion chromatography or conventional atomic spectroscopy techniques.

  1. Biological sample preparation and {sup 41}Ca AMS measurement at LLNL

    SciTech Connect

    Freeman, S.P.H.T.; Southon, J.R.; Bench, G.S.; McAninch, J.E.; Serfass, R.E.; Fang, Y.; King, J.C.; Woodhouse, L.R.

    1994-10-10

    Calcium metabolism in biology may be better understood by the use of {sup 41}Ca labels, although detection by accelerator mass spectrometry (AMS) is required. Methodologies for preparation of urine samples and subsequent AMS measurement were investigated. Novel attempts at preparing CaH{sub 2} were unsuccessful, but CaF{sub 2} of sufficient purity could be produced by precipitation of calcium from urine as oxalate, followed by separation of calcium by cation exchange chromatography and washing the CaF{sub 2} precipitate. The presence of some remaining impurities could be compensated for by selecting the appropriate accelerated ion charge state for AMS. The use of projectile x rays for isobar discrimination was explored as an alternative to the conventional dE/dx device.

  2. Magnetically responsive polycaprolactone nanoparticles for progesterone screening in biological and environmental samples using gas chromatography.

    PubMed

    Es'haghi, Zarrin; Nezhadali, Azizollah; Khatibi, Aram-Dokht

    2016-08-01

    A new Fe3O4/poly(є-caprolactone) (PCL) magnetite nanocomposite was fabricated and used as a sorbent for magnetically mediated PCL microspheres solid-phase extraction (MM-PCL-SPE) followed by gas chromatography-flame ionization detection (GC-FID) for monitoring of progesterone (PGN) hormone in biological and environmental matrices, namely blood serum, tap water, urine, and hospital wastewater. The nanomagnetite core of the sorbent was synthesized by a co-precipitation method. Magnetic nanoparticles (MNPs) were then microencapsulated with PCL microspheres using emulsion polymerization. The nanocomposite was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The magnetite sorbent can be effectively dispersed in aqueous solution and attracted to an external magnetic field. The MM-PCL-SPE process for PGN assay involved (a) dispersion of the sorbent in the donor phase aqueous solution with sonication, (b) exposure to a magnetic field to collect sorbent that had adsorbed the analyte, and (c) solvent desorption of extracted PGN for GC-FID analysis. The work demonstrates the usefulness of MM-PCL-SPE in the rapid and sensitive monitoring of trace amounts of PGN in real samples. The limit of detection (LOD) and limit of quantification (LOQ) were 1.00 and 3.30 ng/mL, respectively. The relative recoveries in real samples were adequate. Linearity was observed over a wide range of 2.2-10,000.0 ng/mL in aqueous media and urine and 0.01-70.0 μg/mL in blood serum. Graphical Abstract In this research new Fe3O4/poly(є-caprolactone) (PCL) magnetite microspheres were developed as an efficient sorbent for solid-phase extraction of progesterone hormone in biological and environmental matrices. PMID:27299775

  3. Nested sampling for parameter inference in systems biology: application to an exemplar circadian model

    PubMed Central

    2013-01-01

    Background Model selection and parameter inference are complex problems that have yet to be fully addressed in systems biology. In contrast with parameter optimisation, parameter inference computes both the parameter means and their standard deviations (or full posterior distributions), thus yielding important information on the extent to which the data and the model topology constrain the inferred parameter values. Results We report on the application of nested sampling, a statistical approach to computing the Bayesian evidence Z, to the inference of parameters, and the estimation of log Z in an established model of circadian rhythms. A ten-fold difference in the coefficient of variation between degradation and transcription parameters is demonstrated. We further show that the uncertainty remaining in the parameter values is reduced by the analysis of increasing numbers of circadian cycles of data, up to 4 cycles, but is unaffected by sampling the data more frequently. Novel algorithms for calculating the likelihood of a model, and a characterisation of the performance of the nested sampling algorithm are also reported. The methods we develop considerably improve the computational efficiency of the likelihood calculation, and of the exploratory step within nested sampling. Conclusions We have demonstrated in an exemplar circadian model that the estimates of posterior parameter densities (as summarised by parameter means and standard deviations) are influenced predominately by the length of the time series, becoming more narrowly constrained as the number of circadian cycles considered increases. We have also shown the utility of the coefficient of variation for discriminating between highly-constrained and less-well constrained parameters. PMID:23899119

  4. Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers

    SciTech Connect

    Doak, R. B.; DePonte, D. P.; Nelson, G.; Camacho-Alanis, F.; Ros, A.; Spence, J. C. H.; Weierstall, U.

    2012-11-27

    Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

  5. Characterization of α-Synuclein Multimer Stoichiometry in Complex Biological Samples by Electrophoresis

    PubMed Central

    2016-01-01

    The aberrant aggregation of α-synuclein in the brain is a hallmark of Parkinson’s disease (PD). In vivo soluble α-synuclein occurs as a monomer and several multimers, the latter of which may be important for the biological function of α-synuclein. Currently, there is a lack of reproducible methods to compare α-synuclein multimer abundance between complex biological samples. Here we developed a method, termed “multimer-PAGE,” that combines in-gel chemical cross-linking with several common electrophoretic techniques to measure the stoichiometry of soluble α-synuclein multimers in brain tissue lysates. Results show that soluble α-synuclein from the rat brain exists as several high molecular weight species of approximately 56 kDa (αS56), 80 kDa (αS80), and 100 kDa (αS100) that comigrate with endogenous lipids, detergents, and/or micelles during blue native gel electrophoresis (BN-PAGE). Co-extraction of endogenous lipids with α-synuclein was essential for the detection of soluble α-synuclein multimers. Homogenization of brain tissue in small buffer volumes (>50 mg tissue per 1 mL buffer) increased relative lipid extraction and subsequently resulted in abundant soluble multimer detection via multimer-PAGE. α-Synuclein multimers captured by directly cross-linking soluble lysates resembled those observed following multimer-PAGE. The ratio of multimer (αS80) to monomer (αS17) increased linearly with protein input into multimer-PAGE, suggesting to some extent, multimers were also formed during electrophoresis. Overall, soluble α-synuclein maintains lipid interactions following tissue disruption and readily forms multimers when this lipid–protein complex is preserved. Once the multimer-PAGE technique was validated, relative stoichiometric comparisons could be conducted simultaneously between 14 biological samples. Multimer-PAGE provides a simple inexpensive biochemical technique to study the molecular factors influencing α-synuclein multimerization

  6. 3D surface scan of biological samples with a Push-broom Imaging Spectrometer

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Kincaid, Russell; Hruska, Zuzana; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

    2013-08-01

    The food industry is always on the lookout for sensing technologies for rapid and nondestructive inspection of food products. Hyperspectral imaging technology integrates both imaging and spectroscopy into unique imaging sensors. Its application for food safety and quality inspection has made significant progress in recent years. Specifically, hyperspectral imaging has shown its potential for surface contamination detection in many food related applications. Most existing hyperspectral imaging systems use pushbroom scanning which is generally used for flat surface inspection. In some applications it is desirable to be able to acquire hyperspectral images on circular objects such as corn ears, apples, and cucumbers. Past research describes inspection systems that examine all surfaces of individual objects. Most of these systems did not employ hyperspectral imaging. These systems typically utilized a roller to rotate an object, such as an apple. During apple rotation, the camera took multiple images in order to cover the complete surface of the apple. The acquired image data lacked the spectral component present in a hyperspectral image. This paper discusses the development of a hyperspectral imaging system for a 3-D surface scan of biological samples. The new instrument is based on a pushbroom hyperspectral line scanner using a rotational stage to turn the sample. The system is suitable for whole surface hyperspectral imaging of circular objects. In addition to its value to the food industry, the system could be useful for other applications involving 3-D surface inspection.

  7. Biological Monitoring of Human Exposure to Neonicotinoids Using Urine Samples, and Neonicotinoid Excretion Kinetics

    PubMed Central

    Harada, Kouji H.; Tanaka, Keiko; Sakamoto, Hiroko; Imanaka, Mie; Niisoe, Tamon; Hitomi, Toshiaki; Kobayashi, Hatasu; Okuda, Hiroko; Inoue, Sumiko; Kusakawa, Koichi; Oshima, Masayo; Watanabe, Kiyohiko; Yasojima, Makoto; Takasuga, Takumi; Koizumi, Akio

    2016-01-01

    Background Neonicotinoids, which are novel pesticides, have entered into usage around the world because they are selectively toxic to arthropods and relatively non-toxic to vertebrates. It has been suggested that several neonicotinoids cause neurodevelopmental toxicity in mammals. The aim was to establish the relationship between oral intake and urinary excretion of neonicotinoids by humans to facilitate biological monitoring, and to estimate dietary neonicotinoid intakes by Japanese adults. Methodology/Principal Findings Deuterium-labeled neonicotinoid (acetamiprid, clothianidin, dinotefuran, and imidacloprid) microdoses were orally ingested by nine healthy adults, and 24 h pooled urine samples were collected for 4 consecutive days after dosing. The excretion kinetics were modeled using one- and two-compartment models, then validated in a non-deuterium-labeled neonicotinoid microdose study involving 12 healthy adults. Increased urinary concentrations of labeled neonicotinoids were observed after dosing. Clothianidin was recovered unchanged within 3 days, and most dinotefuran was recovered unchanged within 1 day. Around 10% of the imidacloprid dose was excreted unchanged. Most of the acetamiprid was metabolized to desmethyl-acetamiprid. Spot urine samples from 373 Japanese adults were analyzed for neonicotinoids, and daily intakes were estimated. The estimated average daily intake of these neonicotinoids was 0.53–3.66 μg/day. The highest intake of any of the neonicotinoids in the study population was 64.5 μg/day for dinotefuran, and this was <1% of the acceptable daily intake. PMID:26731104

  8. Methods of biological fluids sample preparation - biogenic amines, methylxanthines, water-soluble vitamins.

    PubMed

    Płonka, Joanna

    2015-01-01

    In recent years demands on the amount of information that can be obtained from the analysis of a single sample have increased. For time and economic reasons it is necessary to examine at the same time larger number of compounds, and compounds from different groups. This can best be seen in such areas as clinical analysis. In many diseases, the best results for patients are obtained when treatment fits the individual characteristics of the patient. Dosage monitoring is important at the beginning of therapy and in the full process of treatment. In the treatment of many diseases biogenic amines (dopamine, serotonin) and methylxanthines (theophylline, theobromine, caffeine) play an important role. They are used as drugs separately or in combination with others to support and strengthen the action of other drugs - for example, the combination of caffeine and paracetamol. Vitamin supplementation may be also an integral part of the treatment process. Specification of complete sample preparation parameters for extraction of the above compounds from biological matrices has been reviewed. Particular attention was given to the preparation stage and extraction methods. This review provides universal guidance on establishing a common procedures across laboratories to facilitate the preparation and analysis of all discussed compounds. PMID:25381720

  9. Multispectral diode laser based shifted excitation Raman difference spectroscopy for biological sample identification

    NASA Astrophysics Data System (ADS)

    Sowoidnich, Kay; Kronfeldt, Heinz-Detlef

    2012-06-01

    Raman spectroscopy is a well established analytical method with applications in many areas, e.g. analysis of biological samples. To overcome the problem of an undesired fluorescence background masking the Raman signals we present a multi-spectral approach using shifted excitation Raman difference spectroscopy (SERDS). For our investigations we applied microsystem diode lasers which realize two slightly shifted excitation wavelengths required to perform SERDS at 488 nm, 671 nm, and 785 nm. The emission at 488 nm with an optical power of up to 30 mW and a spectral shift of 0.3 nm (12 cm-1) is realized by frequency doubling of a 976 nm distributed feedback (DFB) diode laser. The 671 nm laser diode contains two separate laser cavities (spectral shift: 0.7 nm (13 cm-1)) each incorporating a volume Bragg grating as frequency selective element. In that case, optical powers up to 50 mW can be obtained. For investigations at 785 nm we used a DFB laser with a maximum optical power of 110 mW and a spectral shift of 0.5 nm (7 cm-1). Meat, fat tissue, connective tissue and bones from pork and beef were used as test samples to demonstrate the effective background removal using SERDS. For all three wavelengths integration times of only 5 - 10 seconds were necessary showing the possibility of SERDS for rapid sample identification. A comparison with conventional Raman spectra is given pointing out the improvement of spectral quality. The applicability of SERDS for other analytical applications, e.g. medical diagnosis will be discussed.

  10. Stable-isotope GC-MS/MS determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples

    PubMed Central

    Tsikas, Dimitrios; Evans, Christopher E.; Denton, Travis T.; Mitschke, Anja; Gutzki, Frank-Mathias; Pinto, John T.; Khomenko, Tetyana; Szabo, Sandor; Cooper, Arthur J.L.

    2012-01-01

    Aminoethylcysteine ketimine decarboxylated dimer [AECK-DD; systematic name: 1,2–3,4–5,6–7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one] is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, cells in culture and vegetables, and to possess potent anti-oxidative properties. Here, we describe a stable-isotope GC-MS/MS method for specific and sensitive determination of AECK-DD in biological samples. 13C2-AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected-reaction monitoring of the mass transitions m/z 328 to m/z 268 for AECK-DD and m/z 330 to m/z 270 for 13C2-AECK-DD in the electron-capture negative-ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above ~ 4 nM, but was present in urine samples of healthy humans at a maximal concentration of 46 nM. AECK-DD was detectable in rat brain at very low levels of about 8 pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (~1 nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (~ 6.8 pmol/g fresh tissue). PMID:22858756

  11. Parameters Affecting Spore Recovery from Wipes Used in Biological Surface Sampling ▿ †

    PubMed Central

    Da Silva, Sandra M.; Filliben, James J.; Morrow, Jayne B.

    2011-01-01

    The need for the precise and reliable collection of potential biothreat contaminants has motivated research in developing a better understanding of the variability in biological surface sampling methods. In this context, the objective of this work was to determine parameters affecting the efficiency of extracting Bacillus anthracis Sterne spores from commonly used wipe sampling materials and to describe performance using the interfacial energy concept. In addition, surface thermodynamics was applied to understand and predict surface sampling performance. Wipe materials were directly inoculated with known concentrations of B. anthracis spores and placed into extraction solutions, followed by sonication or vortexing. Experimental factors investigated included wipe material (polyester, cotton, and polyester-rayon), extraction solution (sterile deionized water [H2O], deionized water with 0.04% Tween 80 [H2O-T], phosphate-buffered saline [PBS], and PBS with 0.04% Tween 80 [PBST]), and physical dissociation method (vortexing or sonication). The most efficient extraction from wipes was observed for solutions containing the nonionic surfactant Tween 80. The increase in extraction efficiency due to surfactant addition was attributed to an attractive interfacial energy between Tween 80 and the centrifuge tube wall, which prevented spore adhesion. Extraction solution significantly impacted the extraction efficiency, as determined by statistical analysis (P < 0.05). Moreover, the extraction solution was the most important factor in extraction performance, followed by the wipe material. Polyester-rayon was the most efficient wipe material for releasing spores into solution by rank; however, no statistically significant difference between polyester-rayon and cotton was observed (P > 0.05). Vortexing provided higher spore recovery in H2O and H2O-T than sonication, when all three wipe materials and the reference control were considered (P < 0.05). PMID:21296945

  12. A high-resolution 2D J-resolved NMR detection technique for metabolite analyses of biological samples

    NASA Astrophysics Data System (ADS)

    Huang, Yuqing; Zhang, Zhiyong; Chen, Hao; Feng, Jianghua; Cai, Shuhui; Chen, Zhong

    2015-02-01

    NMR spectroscopy is a commonly used technique for metabolite analyses. Due to the observed macroscopic magnetic susceptibility in biological tissues, current NMR acquisitions in measurements of biological tissues are generally performed on tissue extracts using liquid NMR or on tissues using magic-angle spinning techniques. In this study, we propose an NMR method to achieve high-resolution J-resolved information for metabolite analyses directly from intact biological samples. A dramatic improvement in spectral resolution is evident in our contrastive demonstrations on a sample of pig brain tissue. Metabolite analyses for a postmortem fish from fresh to decayed statuses are presented to further reveal the capability of the proposed method. This method is a previously-unreported high-resolution 2D J-resolved spectroscopy for biological applications without specialised hardware requirements or complicated sample pretreatments. It provides a significant contribution to metabolite analyses of biological samples, and may be potentially applicable to in vivo samples. Furthermore, this method also can be applied to measurements of semisolid and viscous samples.

  13. Visualizing preparation using asymmetrical choline-like ionic liquids for scanning electron microscope observation of non-conductive biological samples.

    PubMed

    Abe, Shigeaki; Hyono, Atsushi; Kawai, Koji; Yonezawa, Tetsu

    2014-03-01

    In this study, we investigated conductivity preparation for scanning electron microscope (SEM) observation that used novel asymmetrical choline-type room temperature ionic liquids (RTIL). By immersion in only an RTIL solution, clear SEM images of several types of biological samples were successfully observed. In addition, we could visualize protozoans using RTILs without any dilution. These results suggested that the asymmetrical choline-type RTILs used in this study are suitable for visualizing of biological samples by SEM. Treatment without the need for dilution can obviate the need for adjusting the RTIL concentration and provide for a rapid and easy conductivity treatment for insulating samples.

  14. Decommissioning samples from the Ft. Lewis, WA, solvent refined coal pilot plant: chemical analysis and biological testing

    SciTech Connect

    Weimer, W.C.; Wright, C.W.

    1985-10-01

    This report presents the results from chemical analyses and limited biological assays of three sets of samples from the Ft. Lewis, WA solvent refined coal (SRC) pilot plant. The samples were collected during the process of decommissioning this facility. Chemical composition was determined for chemical class fractions of the samples by using high-resolution gas chromatography (GC), high-resolution GC/mass spectrometry (MS) and high-resolution MS. Biological activity was measuring using both the histidine reversion microbial mutagenicity assay with Salmonella typhimurium, TA98 and an initiation/promotion mouse-skin tumorigenicity assay. 19 refs., 7 figs., 27 tabs.

  15. A validated HPTLC method for determination of terbutaline sulfate in biological samples: Application to pharmacokinetic study

    PubMed Central

    Faiyazuddin, Md.; Rauf, Abdul; Ahmad, Niyaz; Ahmad, Sayeed; Iqbal, Zeenat; Talegaonkar, Sushma; Bhatnagar, Aseem; Khar, Roop K.; Ahmad, Farhan J.

    2011-01-01

    Terbutaline sulfate (TBS) was assayed in biological samples by validated HPTLC method. Densitometric analysis of TBS was carried out at 366 nm on precoated TLC aluminum plates with silica gel 60F254 as a stationary phase and chloroform–methanol (9.0:1.0, v/v) as a mobile phase. TBS was well resolved at RF 0.34 ± 0.02. In all matrices, the calibration curve appeared linear (r2 ⩾ 0.9943) in the tested range of 100–1000 ng spot−1 with a limit of quantification of 18.35 ng spot−1. Drug recovery from biological fluids averaged ⩾95.92%. In both matrices, rapid degradation of drug favored and the T0.5 of drug ranged from 9.92 to 12.41 h at 4 °C and from 6.31 to 9.13 h at 20 °C. Frozen at −20 °C, this drug was stable for at least 2 months (without losses >10%). The maximum plasma concentration (Cpmax) was found to be 5875.03 ± 114 ng mL−1, which is significantly higher than the maximum saliva concentration (Csmax, 1501.69 ± 96 ng mL−1). Therefore, the validated method could be used to carry out pharmacokinetic studies of the TBS from novel drug delivery systems. PMID:23960758

  16. Recent advances in SPE-chiral-HPLC methods for enantiomeric separation of chiral drugs in biological samples.

    PubMed

    Ali, Imran; Alam, Syed Dilshad; Al-Othman, Zeid A; Farooqi, Javed A

    2013-08-01

    In medical practices, the determination of enantiomeric ratio of the chiral drugs is very important for their activities, bioavailabilities and biodegradation. Only homochiral medication is safe for humans. The chiral analysis in biological samples is the first and most important step. The present article describes the technical strategies of the enantiomeric resolution of racemic drugs in biological samples. Attempts have been made to describe sample preparation by solid-phase extraction and enantiomeric resolution by chiral high-performance liquid chromatography. Various chiral stationary phases used in chiral separations of racemic drugs have been described. Efforts are also made to discuss the chiral recognition mechanism and future perspectives of chiral analyses in biological samples.

  17. Levels of arsenic, cadmium, lead, manganese and zinc in biological samples of paralysed steel mill workers with related to controls.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Atif G; Shah, Faheem; Wadhwa, Sham Kumar; Kolachi, Nida Fatima; Shah, Abdul Qadir; Baig, Jameel Ahmed; Kazi, Naveed

    2011-12-01

    The determination of essential trace and toxic elements in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible effects of environmental exposure on paralysed male workers (n = 75) belonging to the production and quality control departments of a steel mill. In this investigation, the concentrations of arsenic, cadmium, lead, manganese and zinc were determined in biological samples (blood, urine and scalp hair samples) of exposed paralysis and non-paralysed steel mill workers. For comparative purposes, unexposed healthy subjects of same age group were selected as referents. The elements in the biological samples were measured by atomic absorption spectrophotometry prior to microwave-assisted acid digestion. The validity of the methodology was checked by the biological certified reference materials. The results indicate that the level understudy elements in all three biological samples were significantly higher in paralysed workers of both groups (quality control and production) as compared to referents (p < 0.01). The possible connection of these elements with the aetiology of disease is discussed. The results also show the need for immediate improvements of workplace ventilation and industrial hygiene practices.

  18. Toward proteome-scale identification and quantification of isoaspartyl residues in biological samples

    PubMed Central

    Yang, Hongqian; Fung, Eva Y. M.; Zubarev, Alexander R.; Zubarev, Roman A.

    2009-01-01

    Deamidation of asparaginyl and isomerization of aspartyl residues in proteins produce a mixture of aspartyl and isoaspartyl residues, the latter being involved in protein aging and inactivation. Electron capture dissociation (ECD) combined with Fourier transform mass spectrometry (FT MS) are known to be able to distinguish the isoaspartyl peptides by unique fragments of cn• + 58.0054 (C2H2O2) and zl−n − 56.9976 (C2HO2), where n is the position of the aspartyl residue and l is the peptide length. In the present study, we tested the specificity of isoAsp detection using the accurate masses of the specific fragments. For this purpose we analyzed 32 whole and partial proteomes obtained from human cells as well as tissue samples and identified by ECD 466 isoaspartyl peptide candidates. Detailed inspection revealed that many of these candidates were unreliable. In order to increase the isoAsp detection specificity, additional criteria had to be used, e.g. adjacent c/z fragments, specific losses from the reduced species, and the shape of the chromatographic peak. Most stringent filtering of candidates yielded several cases where the presence of isoAsp was beyond doubt. Among the identified proteins with isoAsp, actin, heat shock cognate 71 kDa protein and pyruvate kinase have previously been identified as substrates for L-isoaspartyl methyltransferase, an important repair enzyme converting isoaspartyl to aspartyl. Quantification of relative isomerization degree was performed by the label-free approach. This is the first attempt to analyze the human isoaspartome in a high-throughput manner. The developed workflow allows for further enhancement of the detection rate of isoaspartyl residues in biological samples. PMID:19663459

  19. Nanoparticle sensor for label free detection of swine DNA in mixed biological samples

    NASA Astrophysics Data System (ADS)

    Ali, M. E.; Hashim, U.; Mustafa, S.; Che Man, Y. B.; Yusop, M. H. M.; Bari, M. F.; Islam, Kh N.; Hasan, M. F.

    2011-05-01

    We used 40 ± 5 nm gold nanoparticles (GNPs) as colorimetric sensor to visually detect swine-specific conserved sequence and nucleotide mismatch in PCR-amplified and non-amplified mitochondrial DNA mixtures to authenticate species. Colloidal GNPs changed color from pinkish-red to gray-purple in 2 mM PBS. Visually observed results were clearly reflected by the dramatic reduction of surface plasmon resonance peak at 530 nm and the appearance of new features in the 620-800 nm regions in their absorption spectra. The particles were stabilized against salt-induced aggregation upon the adsorption of single-stranded DNA. The PCR products, without any additional processing, were hybridized with a 17-base probe prior to exposure to GNPs. At a critical annealing temperature (55 °C) that differentiated matched and mismatched base pairing, the probe was hybridized to pig PCR product and dehybridized from the deer product. The dehybridized probe stuck to GNPs to prevent them from salt-induced aggregation and retained their characteristic red color. Hybridization of a 27-nucleotide probe to swine mitochondrial DNA identified them in pork-venison, pork-shad and venison-shad binary admixtures, eliminating the need of PCR amplification. Thus the assay was applied to authenticate species both in PCR-amplified and non-amplified heterogeneous biological samples. The results were determined visually and validated by absorption spectroscopy. The entire assay (hybridization plus visual detection) was performed in less than 10 min. The LOD (for genomic DNA) of the assay was 6 µg ml - 1 swine DNA in mixed meat samples. We believe the assay can be applied for species assignment in food analysis, mismatch detection in genetic screening and homology studies between closely related species.

  20. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed.

  1. Unbiased Rare Event Sampling in Spatial Stochastic Systems Biology Models Using a Weighted Ensemble of Trajectories.

    PubMed

    Donovan, Rory M; Tapia, Jose-Juan; Sullivan, Devin P; Faeder, James R; Murphy, Robert F; Dittrich, Markus; Zuckerman, Daniel M

    2016-02-01

    The long-term goal of connecting scales in biological simulation can be facilitated by scale-agnostic methods. We demonstrate that the weighted ensemble (WE) strategy, initially developed for molecular simulations, applies effectively to spatially resolved cell-scale simulations. The WE approach runs an ensemble of parallel trajectories with assigned weights and uses a statistical resampling strategy of replicating and pruning trajectories to focus computational effort on difficult-to-sample regions. The method can also generate unbiased estimates of non-equilibrium and equilibrium observables, sometimes with significantly less aggregate computing time than would be possible using standard parallelization. Here, we use WE to orchestrate particle-based kinetic Monte Carlo simulations, which include spatial geometry (e.g., of organelles, plasma membrane) and biochemical interactions among mobile molecular species. We study a series of models exhibiting spatial, temporal and biochemical complexity and show that although WE has important limitations, it can achieve performance significantly exceeding standard parallel simulation--by orders of magnitude for some observables.

  2. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor

    NASA Astrophysics Data System (ADS)

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-01

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based ‘cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  3. Development of a new catalase activity assay for biological samples using optical CUPRAC sensor.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Alkan, Fulya Üstün; Apak, Reşat

    2014-11-11

    A novel catalase activity assay was developed for biological samples (liver and kidney tissue homogenates) using a rapid and low-cost optical sensor-based 'cupric reducing antioxidant capacity' (CUPRAC) method. The reagent, copper(II)-neocuproine (Cu(II)-Nc) complex, was immobilized onto a cation-exchanger film of Nafion, and the absorbance changes associated with the formation of the highly-colored Cu(I)-Nc chelate as a result of reaction with hydrogen peroxide (H2O2) was measured at 450 nm. When catalase was absent, H2O2 produced the CUPRAC chromophore, whereas catalase, being an effective H2O2 scavenger, completely annihilated the CUPRAC signal due to H2O2. Thus, the CUPRAC absorbance due to H2O2 oxidation concomitant with Cu(I)-Nc formation decreased proportionally with catalase. The developed sensor gave a linear response over a wide concentration range of H2O2 (0.68-78.6 μM). This optical sensor-based method applicable to tissue homogenates proved to be efficient for low hydrogen peroxide concentrations (physiological and nontoxic levels) to which the widely used UV method is not accurately responsive. Thus, conventional problems of the UV method arising from relatively low sensitivity and selectivity, and absorbance disturbance due to gaseous oxygen evolution were overcome. The catalase findings of the proposed method for tissue homogenates were statistically alike with those of HPLC.

  4. The method of radioactive tracer for measuring the amount of inorganic nanoparticles in biological samples

    NASA Astrophysics Data System (ADS)

    Buzulukov, Yu; Antsiferova, A.; Demin, V. A.; Demin, V. F.; Kashkarov, P.

    2015-11-01

    The method to measure the mass of inorganic nanoparticles in biological (or any other samples) using nanoparticles labeled with radioactive tracers is developed and applied to practice. The tracers are produced in original nanoparticles by radioactive activation of some of their atomic nuclei. The method of radioactive tracers demonstrates a sensitivity, specificity and accuracy equal or better than popular methods of optical and mass spectrometry, or electron microscopy and has some specific advantages. The method can be used for study of absorption, distribution, metabolism and excretion in living organism, as well as in ecological and fundamental research. It was used in practice to study absorption, distribution, metabolism and excretion of nanoparticles of Ag, Au, Se, ZnO, TiO2 as well as to study transportation of silver nanoparticles through the barriers of blood-brain, placenta and milk gland of rats. Brief descriptions of data obtained in experiments with application of this method included in the article. The method was certified in Russian Federation standard system GOST-R and recommended by the Russian Federation regulation authority ROSPOTREBNADZOR for measuring of toxicokinetic and organotropy parameters of nanoparticles.

  5. Development of novel separation techniques for biological samples in capillary electrophoresis

    SciTech Connect

    Chang, H.T.

    1994-07-27

    This dissertation includes three different topics: general introduction of capillary electrophoresis (CE); gradient in CE and CE in biological separations; and capillary gel electrophoresis (CGE) for DNA separation. Factors such as temperature, viscosity, pH, and the surface of capillary walls affecting the separation performance are demonstrated. A pH gradient between 3.0 and 5.2 is useful to improve the resolution among eight different organic acids. A flow gradient due to the change in the concentration of surfactant, which is able to coat to the capillary wall to change the flow rate and its direction, is also shown as a good way to improve the resolution for organic compounds. A temperature gradient caused by joule heat is shown by voltage programming to enhance the resolution and shorten the separation time for several phenolic compounds. The author also shows that self-regulating dynamic control of electroosmotic flow in CE by simply running separation in different concentrations of surfactant has less matrix effect on the separation performance. One of the most important demonstrations in this dissertation is that the author proposes on-column reaction which gives several advantages including the use of a small amount of sample, low risk of contamination, and time saving and kinetic features. The author uses this idea with laser induced fluorescence (LIF) as a detection mode to detect an on-column digestion of sub-ng of protein. This technique also is applied to single cell analysis in the group.

  6. Smart oxygen cuvette for optical monitoring of dissolved oxygen in biological blood samples

    NASA Astrophysics Data System (ADS)

    Dabhi, Harish; Alla, Suresh Kumar; Shahriari, Mahmoud R.

    2010-02-01

    A smart Oxygen Cuvette is developed by coating the inner surface of a cuvette with oxygen sensitive thin film material. The coating is glass like sol-gel based sensor that has an embedded ruthenium compound in the glass film. The fluorescence of the ruthenium is quenched depending on the oxygen level. Ocean Optics phase fluorometer, NeoFox is used to measure this rate of fluorescence quenching and computes it for the amount of oxygen present. Multimode optical fibers are used for transportation of light from an LED source to cuvette and from cuvette to phase fluorometer. This new oxygen sensing system yields an inexpensive solution for monitoring the dissolved oxygen in samples for biological and medical applications. In addition to desktop fluorometers, smart oxygen cuvettes can be used with the Ocean Optics handheld Fluorometers, NeoFox Sport. The Smart Oxygen Cuvettes provide a resolution of 4PPB units, an accuracy of less than 5% of the reading, and 90% response in less than 10 seconds.

  7. Quantification of transition metals in biological samples and its possible impact on ferro-alloy workers.

    PubMed

    Mishra, Sandhya; Ramteke, Dilip S; Wate, Satish R

    2007-10-01

    Increased risk of ill-health and diseases has been associated with employment in the ferro-alloy factory. Since measurement of transition metals in human blood and hair along with respective exposure rates, provides a means of assessing individual risk, it has been the most important part of the study. In the study majority of the elements in the transition series, such as, vanadium (V), chromium (Cr), iron (Fe), manganese (Mn), cobalt, (Co) nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo) and cadmium (Cd) were considered which are randomly emitted from the source, that is, manganese ore (used during ferro-alloy manufacturing process). The commonly available transition, metals, observed in biological samples of ferro-alloy workers, were found to be Fe, Zn, Co, Ni, Cu, Cr, Cd, V Mn and Mo in blood, while in hair, Mn, Fe, Zn, Co, Ni, Cu, Cr, Cd, V and Mo were present in decreasing order Surveillance of bio-concentration of these metals in workers, exposed to close proximity of the coke-ovens and smelting furnaces, revealed that the workers were prone to several physical disorders. PMID:18405124

  8. Quantitation of retinaldehyde in small biological samples using ultrahigh-performance liquid chromatography MS/MS

    PubMed Central

    Wang, Jinshan; Yoo, Hong Sik; Obrochta, Kristin M.; Huang, Priscilla; Napoli, Joseph L.

    2015-01-01

    We report an UHPLC-MS/MS to quantify all-trans-retinal in biological samples of limited size (15-35 mg), which is especially advantageous for use with adipose. To facilitate recovery, retinal and the internal standard 3,4-didehydroretinal were derivatized in situ into their O-ethyloximes. UHPLC resolution combined with high sensitivity and specificity of MS/MS allowed quantification of retinal-O-ethyloximes with a 5 fmol lower limit of detection and a linear range from 5 fmol to 1 pmol. This assay revealed that extra-ocular concentrations of retinal range from ~2 to 40 pmol/g in multiple tissues: the same range as all-trans-retinoic acid. All-trans-retinoic acid has high affinity (kd ≤ 0.4 nM) for its nuclear receptors (RARα, β, γ), whereas retinal has low, if any affinity for these receptors, making it unlikely that these retinal concentrations would activate RAR. We also show that the copious amount of vitamin A used in chow diets increases retinal in adipose depots 2 to 5-fold relative to levels in adipose of mice fed a vitamin A-sufficient diet, as recommended for laboratory rodents. This assay also is proficient for quantifying conversion of retinol into retinal in vitro, and therefore provides an efficient method to study metabolism of retinol in vivo and in vitro. PMID:26045160

  9. An integrative strategy for quantitative analysis of the N-glycoproteome in complex biological samples

    PubMed Central

    2014-01-01

    Background The complexity of protein glycosylation makes it difficult to characterize glycosylation patterns on a proteomic scale. In this study, we developed an integrated strategy for comparatively analyzing N-glycosylation/glycoproteins quantitatively from complex biological samples in a high-throughput manner. This strategy entailed separating and enriching glycopeptides/glycoproteins using lectin affinity chromatography, and then tandem labeling them with 18O/16O to generate a mass shift of 6 Da between the paired glycopeptides, and finally analyzing them with liquid chromatography-mass spectrometry (LC-MS) and the automatic quantitative method we developed based on Mascot Distiller. Results The accuracy and repeatability of this strategy were first verified using standard glycoproteins; linearity was maintained within a range of 1:10–10:1. The peptide concentration ratios obtained by the self-build quantitative method were similar to both the manually calculated and theoretical values, with a standard deviation (SD) of 0.023–0.186 for glycopeptides. The feasibility of the strategy was further confirmed with serum from hepatocellular carcinoma (HCC) patients and healthy individuals; the expression of 44 glycopeptides and 30 glycoproteins were significantly different between HCC patient and control serum. Conclusions This strategy is accurate, repeatable, and efficient, and may be a useful tool for identification of disease-related N-glycosylation/glycoprotein changes. PMID:24428921

  10. Quantification of transition metals in biological samples and its possible impact on ferro-alloy workers.

    PubMed

    Mishra, Sandhya; Ramteke, Dilip S; Wate, Satish R

    2007-10-01

    Increased risk of ill-health and diseases has been associated with employment in the ferro-alloy factory. Since measurement of transition metals in human blood and hair along with respective exposure rates, provides a means of assessing individual risk, it has been the most important part of the study. In the study majority of the elements in the transition series, such as, vanadium (V), chromium (Cr), iron (Fe), manganese (Mn), cobalt, (Co) nickel (Ni), copper (Cu), zinc (Zn), molybdenum (Mo) and cadmium (Cd) were considered which are randomly emitted from the source, that is, manganese ore (used during ferro-alloy manufacturing process). The commonly available transition, metals, observed in biological samples of ferro-alloy workers, were found to be Fe, Zn, Co, Ni, Cu, Cr, Cd, V Mn and Mo in blood, while in hair, Mn, Fe, Zn, Co, Ni, Cu, Cr, Cd, V and Mo were present in decreasing order Surveillance of bio-concentration of these metals in workers, exposed to close proximity of the coke-ovens and smelting furnaces, revealed that the workers were prone to several physical disorders.

  11. A novel visible spectrophotometric method for the determination of ethamsylate in pharmaceutical preparations and biological samples.

    PubMed

    Zhang, Meiyun; Zhang, Yan; Li, Quanmin

    2010-03-01

    A highly sensitive visible spectrophotometric method has been developed to determine ethamsylate in this paper, which is based on using Cu(II) as spectroscopic probe reagent. The study indicates that in the presence of SCN(-) and KNO(3), Cu(II) is reduced to Cu(I) by ethamsylate at pH 5.0, and the in situ formed Cu(I) reacts with SCN(-) to form into the white emulsion CuSCN that could be stayed upon the surface of water. According to the amount of residual Cu(II), the amount of ethamsylate can be indirectly determined. Under the optimal conditions, Beer's law is applicable in the range of 0.2-9.0 microg/mL (7.60x10(-7)-3.42x10(-5)mol/L) for aqueous standard solution of ethamsylate with linear correlation coefficient of 0.9998. The detection limit and relative standard deviation are 0.12 microg/mL and 1.5%, respectively. And the molar absorption coefficient of the indirect determination of ethamsylate is 1.0x10(5)L/mol cm. The method is successfully applied to determine ethamsylate in pharmaceutical preparations and biological samples.

  12. Unbiased Rare Event Sampling in Spatial Stochastic Systems Biology Models Using a Weighted Ensemble of Trajectories

    PubMed Central

    Donovan, Rory M.; Tapia, Jose-Juan; Sullivan, Devin P.; Faeder, James R.; Murphy, Robert F.; Dittrich, Markus; Zuckerman, Daniel M.

    2016-01-01

    The long-term goal of connecting scales in biological simulation can be facilitated by scale-agnostic methods. We demonstrate that the weighted ensemble (WE) strategy, initially developed for molecular simulations, applies effectively to spatially resolved cell-scale simulations. The WE approach runs an ensemble of parallel trajectories with assigned weights and uses a statistical resampling strategy of replicating and pruning trajectories to focus computational effort on difficult-to-sample regions. The method can also generate unbiased estimates of non-equilibrium and equilibrium observables, sometimes with significantly less aggregate computing time than would be possible using standard parallelization. Here, we use WE to orchestrate particle-based kinetic Monte Carlo simulations, which include spatial geometry (e.g., of organelles, plasma membrane) and biochemical interactions among mobile molecular species. We study a series of models exhibiting spatial, temporal and biochemical complexity and show that although WE has important limitations, it can achieve performance significantly exceeding standard parallel simulation—by orders of magnitude for some observables. PMID:26845334

  13. Square wave voltammetry in the determination of Ni2+ and Al3+ in biological sample.

    PubMed

    Paulino, Alexandre T; Vargas, Alexandro M M; Santos, Lídia B; Nozaki, Jorge; Muniz, Edvani C; Tambourgi, Elias B

    2008-01-01

    In this contribution, the amounts of Ni (nickel) and Al (aluminum) in tilapias (Oreochromis niloticus) were determined using square wave voltammetry (SWV) with glassy carbon working microelectrode with a mercury thin film, platinum counter electrode, and Ag/AgCl reference electrode. Ni was studied through the formation of the dimethylglyoxime-Ni (Ni-DMG) complex, while Al was studied through the formation of the Alizarin R-Al complex. The detection limit found for Ni-DMG and Alizarin R-Al complexes were 1.70 x 10(-7) and 1.0 x 10(-8) mol L(-1), respectively. The voltammetric anodic curves for the Alizarin R-Al complex were recorded over the potential range from -0.8 to -0.05 V while the voltammetric cathodic curve for the Ni-DMG complex was recorded over the potential range from -0.7 to -1.2 V. These methods detected low concentrations of Ni and Al in biological samples efficiently.

  14. Method development for mass spectrometry based molecular characterization of fossil fuels and biological samples

    NASA Astrophysics Data System (ADS)

    Mahat, Rajendra K.

    In an analytical (chemical) method development process, the sample preparation step usually determines the throughput and overall success of the analysis. Both targeted and non-targeted methods were developed for the mass spectrometry (MS) based analyses of fossil fuels (coal) and lipidomic analyses of a unique micro-organism, Gemmata obscuriglobus. In the non-targeted coal analysis using GC-MS, a microwave-assisted pressurized sample extraction method was compared with the traditional extraction method, such as Soxhlet. On the other hand, methods were developed to establish a comprehensive lipidomic profile and to confirm the presence of endotoxins (a.k.a. lipopolysaccharides, LPS) in Gemmata.. The performance of pressurized heating techniques employing hot-air oven and microwave irradiation were compared with that of Soxhlet method in terms of percentage extraction efficiency and extracted analyte profiles (via GC-MS). Sub-bituminous (Powder River Range, Wyoming, USA) and bituminous (Fruitland formation, Colorado, USA) coal samples were tested. Overall 30-40% higher extraction efficiencies (by weight) were obtained with a 4 hour hot-air oven and a 20 min microwave-heating extraction in a pressurized container when compared to a 72 hour Soxhlet extraction. The pressurized methods are 25 times more economic in terms of solvent/sample amount used and are 216 times faster in term of time invested for the extraction process. Additionally, same sets of compounds were identified by GC-MS for all the extraction methods used: n-alkanes and diterpanes in the sub-bituminous sample, and n-alkanes and alkyl aromatic compounds in the bituminous coal sample. G. obscuriglobus, a nucleated bacterium, is a micro-organism of high significances from evolutionary, cell and environmental biology standpoints. Although lipidomics is an essential tool in microbiological systematics and chemotaxonomy, complete lipid profile of this bacterium is still lacking. In addition, the presence of

  15. Dimensional comparison between amplitude-modulation atomic force microscopy and scanning ion conductance microscopy of biological samples

    NASA Astrophysics Data System (ADS)

    Kim, Joonhui; Choi, MyungHoon; Jung, Goo-Eun; Rahim Ferhan, Abdul; Cho, Nam-Joon; Cho, Sang-Joon

    2016-08-01

    The range of scanning probe microscopy (SPM) applications for atomic force microscopy (AFM) is expanding in the biological sciences field, reflecting an increasing demand for tools that can improve our fundamental understanding of the physics behind biological systems. However, the complexity associated with applying SPM techniques in biomedical research hampers the full exploitation of its capabilities. Recently, the development of scanning ion conductance microscopy (SICM) has overcome these limitations and enabled contact-free, high resolution imaging of live biological specimens. In this work, we demonstrate the limitation of AFM for imaging biological samples in liquid due to artifacts arising from AFM tip-sample interaction, and how SICM imaging is able to overcome those limitations with contact-free scanning. We also demonstrate that SICM measurements, when compared to AFM, show better fit to the actual dimensions of the biological samples. Our results highlight the superiority of SICM imaging, enabling it to be widely adopted as a general and versatile research tool for biological studies in the nanoscale.

  16. Dimensional comparison between amplitude-modulation atomic force microscopy and scanning ion conductance microscopy of biological samples

    NASA Astrophysics Data System (ADS)

    Kim, Joonhui; Choi, MyungHoon; Jung, Goo-Eun; Rahim Ferhan, Abdul; Cho, Nam-Joon; Cho, Sang-Joon

    2016-08-01

    The range of scanning probe microscopy (SPM) applications for atomic force microscopy (AFM) is expanding in the biological sciences field, reflecting an increasing demand for tools that can improve our fundamental understanding of the physics behind biological systems. However, the complexity associated with applying SPM techniques in biomedical research hampers the full exploitation of its capabilities. Recently, the development of scanning ion conductance microscopy (SICM) has overcome these limitations and enabled contact-free, high resolution imaging of live biological specimens. In this work, we demonstrate the limitation of AFM for imaging biological samples in liquid due to artifacts arising from AFM tip–sample interaction, and how SICM imaging is able to overcome those limitations with contact-free scanning. We also demonstrate that SICM measurements, when compared to AFM, show better fit to the actual dimensions of the biological samples. Our results highlight the superiority of SICM imaging, enabling it to be widely adopted as a general and versatile research tool for biological studies in the nanoscale.

  17. Insights on Antioxidant Assays for Biological Samples Based on the Reduction of Copper Complexes—The Importance of Analytical Conditions

    PubMed Central

    Marques, Sara S.; Magalhães, Luís M.; Tóth, Ildikó V.; Segundo, Marcela A.

    2014-01-01

    Total antioxidant capacity assays are recognized as instrumental to establish antioxidant status of biological samples, however the varying experimental conditions result in conclusions that may not be transposable to other settings. After selection of the complexing agent, reagent addition order, buffer type and concentration, copper reducing assays were adapted to a high-throughput scheme and validated using model biological antioxidant compounds of ascorbic acid, Trolox (a soluble analogue of vitamin E), uric acid and glutathione. A critical comparison was made based on real samples including NIST-909c human serum certified sample, and five study samples. The validated method provided linear range up to 100 µM Trolox, (limit of detection 2.3 µM; limit of quantification 7.7 µM) with recovery results above 85% and precision <5%. The validated developed method with an increased sensitivity is a sound choice for assessment of TAC in serum samples. PMID:24968275

  18. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy.

    PubMed

    Takayama, Yuki; Nakasako, Masayoshi

    2012-05-01

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  19. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy

    SciTech Connect

    Takayama, Yuki; Nakasako, Masayoshi

    2012-05-15

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  20. Novel spectroscopic sensor for the hydroxyl radical scavenging activity measurement of biological samples.

    PubMed

    Bekdeşer, Burcu; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2012-09-15

    A novel spectroscopic sensor was developed and validated for hydroxyl radical scavenging (HRS) activity estimation using terephthalate (TP) as probe. This sensor was designed by electrostatic immobilization of the chromogenic oxidizing agent of the CUPric Reducing Antioxidant Capacity (CUPRAC) method, Cu(II)-Neocuproine (Cu(II)-Nc) complex, on a Nafion cation-exchange membrane, and the spectrophotometric assay developed in aqueous-alcoholic solutions was integrated to the CUPRAC sensor. Hydroxyl radicals ((•)OH) generated from an equivalent mixture of Fe(II)+EDTA with hydrogen peroxide attacked both the probe and the (•)OH scavengers in 37 °C-incubated solutions for 1/2h. The HRS activity was measured using the decrease in CUPRAC absorbance at 450 nm - arising from the reduction of Cu(II)-Nc reagent to the Cu(I)-neocuproine chelate - of the hydroxylated probe (TP) undergoing radical attack in the presence of (•)OH scavengers. The HRS activity was evaluated as the second-order rate constants of biologically active compounds for (•)OH scavenging and also as the percentage scavenging of a measured compound or sample relative to a reference compound. Using this reaction, a kinetic approach was adopted to assess the HRS activity of amino acids, plasma- and thiol-antioxidants. This assay, applicable to small molecule antioxidants and tissue homogenates, proved to be efficient for serine and albumin for which the widely used TBARS (thiobarbituric acid-reactive substances) test is nonresponsive. Under optimal conditions, about half of the probe (TP) was converted into 2-hydroxyterephthalate (hTP), and this monohydroxylated derivative, being the only product of hydroxylation, was a more specific marker of (•)OH than the non-specific malondialdehyde end-product of the TBARS test. The sensor gave a linear response to scavenger concentration in the competition kinetic equation.

  1. Latest developments and opportunities for 3D analysis of biological samples by confocal μ-XRF

    NASA Astrophysics Data System (ADS)

    Perez, Roberto D.; Sánchez, Héctor J.; Perez, Carlos A.; Rubio, Marcelo

    2010-02-01

    X-ray fluorescence analysis performed with a primary radiation focused in the micrometer range is known as micro-X-ray fluorescence (μ-XRF). It is characterized by a penetration depth higher than other micro-analytical methods, reaching hundreds of micrometers in biological samples. This characteristic of the X-ray beam can be employed in 3D analysis. An innovative method to perform 3D analysis by μ-XRF is the so-called confocal setup. The confocal setup consists of X-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro-volume defined by the overlap of the foci of both X-ray lenses is analyzed. Scanning this micro-volume through the sample can be used to perform a study in three dimensions. At present, X-ray lenses used in confocal μ-XRF experiments are mainly glass capillaries and polycapillaries. Glass capillaries are used in the excitation channel with sources of high photon flux like synchrotron radiation. Half polycapillaries or conical polycapillary concentrators are used almost exclusively in the detection channel. Spatial resolution of the confocal μ-XRF depends on the dimensions of the foci of both X-ray lenses. The overlap of these foci forms an ellipsoid which is the probing volume of the confocal setup. The axis length of the probing volume reported in confocal μ-XRF experiments are of order of few tens of micrometer. In our confocal setup, we used a commercial glass monocapillary in the excitation channel and a monolithic half polycapillary in the detection channel. The polycapillary was home-made by means of drawing of multibundles of glass capillaries in a heating furnace. The experiment was carried out at the beamline D09B-XRF of the Synchrotron Light National Laboratory (Laboratório Nacional de Luz Síncrotron, LNLS) using white beam. A model for the theoretical description of X-ray fluorescence intensity registered by confocal μ-XRF was introduced by Malzer and Kanngieβer [2005. A model for the

  2. Correlations among Five Variables and the Biology Performance of a Sample of Jamaican High School Students

    ERIC Educational Resources Information Center

    Blair-Walters, Shonette; Soyibo, Kola

    2004-01-01

    This study investigates whether or not (a) 252 Jamaican high school students (168 boys, 84 girls, 171 grade 10 and 81 grade 11 students) had favourable attitudes to biology, (b) their level of biology performance was satisfactory, (c) there were significant differences in their performance based on their gender, grade level, school-type,…

  3. Accelerator mass spectrometry analysis of 14C-oxaliplatin concentrations in biological samples and 14C contents in biological samples and antineoplastic agents

    NASA Astrophysics Data System (ADS)

    Toyoguchi, Teiko; Kobayashi, Takeshi; Konno, Noboru; Shiraishi, Tadashi; Kato, Kazuhiro; Tokanai, Fuyuki

    2015-10-01

    Accelerator mass spectrometry (AMS) is expected to play an important role in microdose trials. In this study, we measured the 14C concentration in 14C-oxaliplatin-spiked serum, urine and supernatant of fecal homogenate samples in our Yamagata University (YU) - AMS system. The calibration curves of 14C concentration in serum, urine and supernatant of fecal homogenate were linear (the correlation coefficients were ⩾0.9893), and the precision and accuracy was within the acceptance criteria. To examine a 14C content of water in three vacuum blood collection tubes and a syringe were measured. 14C was not detected from water in these devices. The mean 14C content in urine samples of 6 healthy Japanese volunteers was 0.144 dpm/mL, and the intra-day fluctuation of 14C content in urine from a volunteer was little. The antineoplastic agents are administered to the patients in combination. Then, 14C contents of the antineoplastic agents were quantitated. 14C contents were different among 10 antineoplastic agents; 14C contents of paclitaxel injection and docetaxel hydrate injection were higher than those of the other injections. These results indicate that our quantitation method using YU-AMS system is suited for microdosing studies and that measurement of baseline and co-administered drugs might be necessary for the studies in low concentrations.

  4. Optimization of microwave digestion for mercury determination in marine biological samples by cold vapour atomic absorption spectrometry.

    PubMed

    Cardellicchio, Nicola; Di Leo, Antonella; Giandomenico, Santina; Santoro, Stefania

    2006-01-01

    Optimization of acid digestion method for mercury determination in marine biological samples (dolphin liver, fish and mussel tissues) using a closed vessel microwave sample preparation is presented. Five digestion procedures with different acid mixtures were investigated: the best results were obtained when the microwave-assisted digestion was based on sample dissolution with HNO3-H2SO4-K2Cr2O7 mixture. A comparison between microwave digestion and conventional reflux digestion shows there are considerable losses of mercury in the open digestion system. The microwave digestion method has been tested satisfactorily using two certified reference materials. Analytical results show a good agreement with certified values. The microwave digestion proved to be a reliable and rapid method for decomposition of biological samples in mercury determination.

  5. A Promising Raman Spectroscopy Technique for the Investigation of trans and cis Cholesteryl Ester Isomers in Biological Samples.

    PubMed

    Melchiorre, Michele; Ferreri, Carla; Tinti, Anna; Chatgilialoglu, Chryssostomos; Torreggiani, Armida

    2015-05-01

    Lipid geometry is an important issue in biology and medicine. The cis-trans geometry conversion of double bonds in lipids is an endogenous process that can be mediated by sulfur-centered free radicals. Trans isomers of polyunsaturated fatty acids can be used as biological markers of free radical stress, and their presence in biological samples can be determined by synthesis and characterization of appropriate reference compounds. Fractions of plasma lipids, such as cholesteryl linoleate and arachidonate esters, are interesting targets because of their connection with membrane phospholipid turnover and their roles in cardiovascular health. In this context, Raman spectroscopy can provide a useful contribution, since Raman analysis can be performed directly on the lipid extracts without any derivatization reaction, is nondestructive, and can rapidly supply biochemical information. This study focused on the build up of Raman spectral libraries of different cis and trans isomers of cholesteryl esters to be used as references for the examination of complex biological samples and to facilitate isomer recognition. Unsaturated cholesteryl esters obtained by chemical synthesis and with different alkyl chain lengths, double bond numbers, or both, were analyzed. The potential of Raman analysis for trans isomer detection in biological samples was successfully tested on some cholesteryl ester lipid fractions from human serum. The data suggest promising applications of Raman spectroscopy in metabolomics and lipidomics.

  6. Development of a biaxial compression device for biological samples: preliminary experimental results for a closed cell foam.

    PubMed

    Little, J P; Tevelen, G; Adam, C J; Evans, J H; Pearcy, M J

    2009-07-01

    Biological tissues are subjected to complex loading states in vivo and in order to define constitutive equations that effectively simulate their mechanical behaviour under these loads, it is necessary to obtain data on the tissue's response to multiaxial loading. Single axis and shear testing of biological tissues is often carried out, but biaxial testing is less common. We sought to design and commission a biaxial compression testing device, capable of obtaining repeatable data for biological samples. The apparatus comprised a sealed stainless steel pressure vessel specifically designed such that a state of hydrostatic compression could be created on the test specimen while simultaneously unloading the sample along one axis with an equilibrating tensile pressure. Thus a state of equibiaxial compression was created perpendicular to the long axis of a rectangular sample. For the purpose of calibration and commissioning of the vessel, rectangular samples of closed cell ethylene vinyl acetate (EVA) foam were tested. Each sample was subjected to repeated loading, and nine separate biaxial experiments were carried out to a maximum pressure of 204 kPa (30 psi), with a relaxation time of two hours between them. Calibration testing demonstrated the force applied to the samples had a maximum error of 0.026 N (0.423% of maximum applied force). Under repeated loading, the foam sample demonstrated lower stiffness during the first load cycle. Following this cycle, an increased stiffness, repeatable response was observed with successive loading. While the experimental protocol was developed for EVA foam, preliminary results on this material suggest that this device may be capable of providing test data for biological tissue samples. The load response of the foam was characteristic of closed cell foams, with consolidation during the early loading cycles, then a repeatable load-displacement response upon repeated loading. The repeatability of the test results demonstrated the

  7. Critical tests for determination of microbiological quality and biological activity in commercial vermicompost samples of different origins.

    PubMed

    Grantina-Ievina, Lelde; Andersone, Una; Berkolde-Pīre, Dace; Nikolajeva, Vizma; Ievinsh, Gederts

    2013-12-01

    The aim of the present paper was to show that differences in biological activity among commercially produced vermicompost samples can be found by using a relatively simple test system consisting of microorganism tests on six microbiological media and soilless seedling growth tests with four vegetable crop species. Significant differences in biological properties among analyzed samples were evident both at the level of microbial load as well as plant growth-affecting activity. These differences were mostly manufacturer- and feedstock-associated, but also resulted from storage conditions of vermicompost samples. A mature vermicompost sample that was produced from sewage sludge still contained considerable number of Escherichia coli. Samples from all producers contained several potentially pathogenic fungal species such as Aspergillus fumigatus, Pseudallescheria boidii, Pseudallescheria fimeti, Pseudallescheria minutispora, Scedosporium apiospermum, Scedosporium prolificans, Scopulariopsis brevicaulis, Stachybotrys chartarum, Geotrichum spp., Aphanoascus terreus, and Doratomyces columnaris. In addition, samples from all producers contained plant growth-promoting fungi from the genera Trichoderma and Mortierella. The described system can be useful both for functional studies aiming at understanding of factors affecting quality characteristics of vermicompost preparations and for routine testing of microbiological quality and biological activity of organic waste-derived composts and vermicomposts.

  8. Hybrid random walk-linear discriminant analysis method for unwrapping quantitative phase microscopy images of biological samples

    PubMed Central

    Kim, Diane N. H.; Teitell, Michael A.; Reed, Jason; Zangle, Thomas A.

    2015-01-01

    Abstract. Standard algorithms for phase unwrapping often fail for interferometric quantitative phase imaging (QPI) of biological samples due to the variable morphology of these samples and the requirement to image at low light intensities to avoid phototoxicity. We describe a new algorithm combining random walk-based image segmentation with linear discriminant analysis (LDA)-based feature detection, using assumptions about the morphology of biological samples to account for phase ambiguities when standard methods have failed. We present three versions of our method: first, a method for LDA image segmentation based on a manually compiled training dataset; second, a method using a random walker (RW) algorithm informed by the assumed properties of a biological phase image; and third, an algorithm which combines LDA-based edge detection with an efficient RW algorithm. We show that the combination of LDA plus the RW algorithm gives the best overall performance with little speed penalty compared to LDA alone, and that this algorithm can be further optimized using a genetic algorithm to yield superior performance for phase unwrapping of QPI data from biological samples. PMID:26305212

  9. Interaction between selenium and mercury in biological samples of Pakistani myocardial infarction patients at different stages as related to controls.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Talpur, Farah Naz; Kazi, Atif; Arain, Sadaf Sadia; Arain, Salma Aslam; Brahman, Kapil Dev; Panhwar, Abdul Haleem; Naeemullah

    2014-05-01

    It has been speculated that trace elements may a play role in the pathogenesis of heart diseases. In the present study, we aimed to assess the levels of selenium (Se) and mercury (Hg) in biological samples (whole blood, urine, and scalp hair) of myocardial infarction (MI) patients of both genders (age range 45-60 years) at the first, second, and third heart attack (n = 130), hospitalized in a cardiac ward of a civil hospital of Hyderabad City (Pakistan). For comparison, healthy age-matched referent subjects (n = 61) of both genders were also selected. Se and Hg in biological samples were measured by electrothermal atomic absorption spectrometry and cold vapor atomic absorption spectrometry, prior to microwave acid digestion, respectively. The validity of the methodology was checked by biological certified reference materials. During this study, 78 % of the 32 registered patients of third MI attack (aged >50 years) died. The concentration of Se was decreased in scalp hair and blood samples of MI patients, while Hg was higher in all biological samples as compared to referent subjects. Se concentration was inversely associated with the risk of MI attacks in both genders. These results add to an increasing body of evidence that Se is a protective element for cardiovascular health. PMID:24643467

  10. Label-free visual detection of nucleic acids in biological samples with single-base mismatch detection capability.

    PubMed

    Song, Yanling; Zhang, Weiting; An, Yuan; Cui, Liang; Yu, Chundong; Zhu, Zhi; Yang, Chaoyong James

    2012-01-14

    We have combined an allosteric molecular beacon for target recognition and guanine-rich DNAzyme for signal amplification to develop a new platform for visual detection of nucleic acids with single-base mismatch detection capability. The fully DNA-structured platform can undergo color change in response to target DNA/RNA, which enables sensitive and selective visual detection in biological samples.

  11. Socioeconomic Status and School Grades: Placing Their Association in Broader Context in a Sample of Biological and Adoptive Families

    ERIC Educational Resources Information Center

    Johnson, Wendy; McGue, Matt; Iacono, William G.

    2007-01-01

    SES has long interested researchers investigating school achievement. Its effects are often addressed by studying predictors of achievement in economically disadvantaged samples living primarily in biological families, confounding genetic and environmental influences. Little is known about SES's purely environmental effects. We measured them in…

  12. State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

    PubMed

    Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. PMID:26755134

  13. Microwave digestion using dual PTFE containers for analysis of trace elements in small amounts of biological samples.

    PubMed

    Mizushima, R; Yonezawa, M; Ejima, A; Koyama, H; Satoh, H

    1996-01-01

    The analysis of trace elements in biological samples is essential to extend our knowledge on human health and disease. Inductively coupled plasma mass spectrometry (ICP-MS) makes it possible to simultaneously determine these elements in trace amounts. Before analysis, however, biological samples such as organs and tissues must be liquefied and extra organic materials must be decomposed by acid digestion. We established a method of microwave digestion using dual PTFE containers to minimize the amount of samples. Samples (35-45 mg) of standard reference materials, bovine liver (1577a, NIST) and fish flesh (MA-A-2, IAEA), were weighed in PTFE-PFA vials and a small amount of nitric acid (0.5 ml) was added. The vials were sealed and two PTFE-PFA vials were placed in a PTFE-TFM vessel containing 6 ml of pure water. Then the vessels were placed in a rotor and the samples were digested for 38 min in a microwave oven according to a pre-set program. After the program was completed, the samples were analyzed by ICP-MS. The determined values of elements of the microwave-digested samples matched the certified values of the standard reference materials. Therefore, the digestion using dual containers was successfully applied to small samples.

  14. Standard Reporting Requirements for Biological Samples in Metabolomics Experiments: Environmental Context

    EPA Science Inventory

    Metabolomic technologies are increasingly being applied to study biological questions in a range of different settings from clinical through to environmental. As with other high-throughput technologies, such as those used in transcriptomics and proteomics, metabolomics continues...

  15. Estimation of calcium, magnesium, cadmium, and lead in biological samples from paralyzed quality control and production steel mill workers.

    PubMed

    Afridi, Hassan Imran; Talpur, Farah Naz; Kazi, Tasneem Gul; Kazi, Naveed; Arain, Sadaf Sadia; Shah, Faheem

    2015-06-01

    The determination of trace and toxic metals in the biological samples of human beings is an important clinical screening procedure. The aim of the present study was to compare the level of essential trace and toxic elements cadmium (Cd), calcium (Ca), lead (Pb), and magnesium (Mg) in biological samples (whole blood, urine, and scalp hair) of male paralyzed production (PPW) and quality control workers (PQW) of a steel mill, age ranged (35-55 years). For comparison purposes, healthy age-matched exposed referent subjects (EC), working in steel mill and control subjects (NEC), who were not working in industries and lived far away from the industrial areas, were selected as control subjects. The concentrations of electrolytes and toxic elements in biological samples were measured by atomic absorption spectrometry after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair, blood, and urine samples of PPW and PQW as compared to NEC and EC (p < 0.001), whereas the concentrations of Ca and Mg were found to be lower in the scalp hair and blood but higher in the urine samples of PPW and PQW. The results show the need for immediate improvements in workplace, ventilation, and industrial hygiene practices.

  16. The bank of biological samples representing individuals exposed to long-term ionizing radiation at various doses.

    PubMed

    Takhauov, Ravil M; Karpov, Andrey B; Albach, Elena N; Khalyuzova, Maria V; Freidin, Maxim B; Litviakov, Nicolai V; Sazonov, Aleksey E; Isubakova, Daria S; Bolshakov, Mikhail A; Mezheritskiy, Stanislav A; Mironova, Elena B; Semenova, Julia V; Nekrasov, Gennadiy B; Izosimov, Andrey S; Gagarin, Aleksey A; Brendakov, Roman V; Maksimov, Dmitriy E; Ermolaev, Yuriy D

    2015-04-01

    Collection and storage of biological specimens in biobanks aims to obtain and preserve samples of different kinds for biological and medical studies. Here we present a description of the Bank of Biological Materials (BBM) housed by the Seversk Biophysical Research Centre (SBRC; Seversk, Russia). The main goal of maintaining the BBM is to collect and store biological samples suitable for genetic studies of people exposed to long-term ionizing radiation. Currently, the collection includes 19,194 biological specimens obtained from 8105 donors, of whom 42.3% are diagnosed with malignant neoplasms, 28.7% are healthy residents of the city of Seversk, 18.8% are healthy employees of the Siberian Group of Chemical Enterprises (SGCE), and 10.2% are patients diagnosed with acute myocardial infarction. The donors were enrolled using the Regional Medical and Dosimetric Register database created by the SBRC. For each donor, DNA specimens were extracted from peripheral blood and tissues and cell suspensions for cytogenetic analysis were prepared routinely. The BBM's unique collection is suitable primarily for studies of individual radiosensitivity of humans (IRH), and genetic aspects of the pathophysiology of common human diseases, especially in populations exposed to long-term low-dose ionizing radiation.

  17. An Integrated Microfabricated Device for Dual Microdialysis and On-line ESI Ion Trap Mass Spectrometry for the Analysis of Complex Biological Samples

    SciTech Connect

    Xiang, Fan; Lin, Yuehe ); Wen, Jian Y.; Matson, Dean W. ); Smith, Richard D. )

    1999-05-01

    A microfabricated dual-microdialysis device in a single integrated microfabricated platform was constructed using laser micromachining techniques for the rapid fractionation and cleanup of complex biological samples. Results suggest the potential for integration of such microfabricated devices with other sample manipulations for the rapid ESI-MS analysis of complex biological samples.

  18. Automatic instrument for chemical processing to detect microorganism in biological samples by measuring light reactions

    NASA Technical Reports Server (NTRS)

    Kelbaugh, B. N.; Picciolo, G. L.; Chappelle, E. W.; Colburn, M. E. (Inventor)

    1973-01-01

    An automated apparatus is reported for sequentially assaying urine samples for the presence of bacterial adenosine triphosphate (ATP) that comprises a rotary table which carries a plurality of sample containing vials and automatically dispenses fluid reagents into the vials preparatory to injecting a light producing luciferase-luciferin mixture into the samples. The device automatically measures the light produced in each urine sample by a bioluminescence reaction of the free bacterial adenosine triphosphate with the luciferase-luciferin mixture. The light measured is proportional to the concentration of bacterial adenosine triphosphate which, in turn, is proportional to the number of bacteria present in the respective urine sample.

  19. Biological variation in a large sample of mouse lemurs from Amboasary, Madagascar: implications for interpreting variation in primate biology and paleobiology.

    PubMed

    Cuozzo, Frank P; Rasoazanabary, Emilienne; Godfrey, Laurie R; Sauther, Michelle L; Youssouf, Ibrahim Antho; LaFleur, Marni M

    2013-01-01

    A thorough knowledge of biological variation in extant primates is imperative for interpreting variation, and for delineating species in primate biology and paleobiology. This is especially the case given the recent, rapid taxonomic expansion in many primate groups, notably among small-bodied nocturnal forms. Here we present data on dental, cranial, and pelage variation in a single-locality museum sample of mouse lemurs from Amboasary, Madagascar. To interpret these data, we include comparative information from other museum samples, and from a newly collected mouse lemur skeletal sample from the Beza Mahafaly Special Reserve (BMSR), Madagascar. We scored forty dental traits (n = 126) and three pelage variants (n = 19), and collected 21 cranial/dental measures. Most dental traits exhibit variable frequencies, with some only rarely present. Individual dental variants include misshapen and supernumerary teeth. All Amboasary pelage specimens display a "reversed V" on the cap, and a distinct dorsal median stripe on the back. All but two displayed the dominant gray-brown pelage coloration typical of Microcebus griseorufus. Cranial and dental metric variability are each quite low, and craniometric variation does not illustrate heteroscedasticity. To assess whether this sample represents a single species, we compared dental and pelage variation to a documented, single-species M. griseorufus sample from BMSR. As at Amboasary, BMSR mouse lemurs display limited odontometric variation and wide variation in non-metric dental traits. In contrast, BMSR mouse lemurs display diverse pelage, despite reported genetic homogeneity. Ranges of dental and pelage variation at BMSR and Amboasary overlap. Thus, we conclude that the Amboasary mouse lemurs represent a single species - most likely (in the absence of genetic data to the contrary) M. griseorufus, and we reject their previous allocation to Microcebus murinus. Patterns of variation in the Amboasary sample provide a comparative

  20. Correlation of Arsenic Levels in Smokeless Tobacco Products and Biological Samples of Oral Cancer Patients and Control Consumers.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Afridi, Hassan I; Talpur, Farah N; Kazi, Atif G; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Kamboh, Muhammad A

    2015-12-01

    It has been extensively reported that chewing of smokeless tobacco (SLT) can lead to cancers of oral cavity. In present study, the relationship between arsenic (As) exposure via chewing/inhaling different SLT products in oral cancer patients have or/not consumed SLT products was studied. The As in different types of SLT products (gutkha, mainpuri, and snuff) and biological (scalp hair and blood) samples of different types of oral cancer patients and controls were analyzed. Both controls and oral cancer patients have same age group (ranged 30-60 years), socio-economic status, localities, and dietary habits. The concentrations of As in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data of present study indicates that the concentration of As was significantly higher in scalp hair and blood samples of oral cancer patients than those of controls (p<0.001). It was also observed that the values of As were two- to threefolds higher in biological samples of controls subjects, consuming SLT products as compared to those have none of these habits (p>0.01). The intake of As via consuming different SLT may have synergistic effects, in addition to other risk factors associated with oral cancer.

  1. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples.

    PubMed

    Furuta, T; Maeyama, T; Ishikawa, K L; Fukunishi, N; Fukasaku, K; Takagi, S; Noda, S; Himeno, R; Hayashi, S

    2015-08-21

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning. PMID:26266894

  2. Correlation of Arsenic Levels in Smokeless Tobacco Products and Biological Samples of Oral Cancer Patients and Control Consumers.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Afridi, Hassan I; Talpur, Farah N; Kazi, Atif G; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Kamboh, Muhammad A

    2015-12-01

    It has been extensively reported that chewing of smokeless tobacco (SLT) can lead to cancers of oral cavity. In present study, the relationship between arsenic (As) exposure via chewing/inhaling different SLT products in oral cancer patients have or/not consumed SLT products was studied. The As in different types of SLT products (gutkha, mainpuri, and snuff) and biological (scalp hair and blood) samples of different types of oral cancer patients and controls were analyzed. Both controls and oral cancer patients have same age group (ranged 30-60 years), socio-economic status, localities, and dietary habits. The concentrations of As in SLT products and biological samples were measured by electrothermal atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials. The resulted data of present study indicates that the concentration of As was significantly higher in scalp hair and blood samples of oral cancer patients than those of controls (p<0.001). It was also observed that the values of As were two- to threefolds higher in biological samples of controls subjects, consuming SLT products as compared to those have none of these habits (p>0.01). The intake of As via consuming different SLT may have synergistic effects, in addition to other risk factors associated with oral cancer. PMID:25975948

  3. A direct solid sampling electrothermal atomic absorption spectrometry method for the determination of silicon in biological materials

    NASA Astrophysics Data System (ADS)

    Huang, M. D.; Krivan, V.

    2007-03-01

    A solid sampling electrothermal atomic absorption spectrometry method for direct determination of trace silicon in biological materials was developed and applied to analysis of pork liver, bovine liver SRM 1577b and pure cellulose. The organic matrix was destroyed and expelled from the furnace in the pyrolysis stage involving a step-wise increasing the temperature from 160 °C to 1200 °C. The mixed Pd/Mg(NO 3) 2 modifier has proved to be the optimum one with respect to the achievement of maximum sensitivity, elimination of the effect of the remaining inorganic substances and the possibility of using calibration curves measured with aqueous standard solutions for quantification. For the maximum applicable sample amount of 6 mg, the limit of detection was found to be 30 ng g - 1 . The results were compared with those obtained by different spectrometric methods involving sample digestion, by electrothermal atomic absorption spectrometry using slurry sampling, by wavelength dispersive X-ray fluorescence spectrometry and by radiochemical neutron activation analysis. The method seems to be a promising one for analysis of biological materials containing no significant fraction of silicon in form of not naturally occurring volatile organosilicon compounds. The still incessant serious limitations and uncertainties in the determination of trace silicon in solid biological materials are discussed.

  4. Comparison between Monte Carlo simulation and measurement with a 3D polymer gel dosimeter for dose distributions in biological samples

    NASA Astrophysics Data System (ADS)

    Furuta, T.; Maeyama, T.; Ishikawa, K. L.; Fukunishi, N.; Fukasaku, K.; Takagi, S.; Noda, S.; Himeno, R.; Hayashi, S.

    2015-08-01

    In this research, we used a 135 MeV/nucleon carbon-ion beam to irradiate a biological sample composed of fresh chicken meat and bones, which was placed in front of a PAGAT gel dosimeter, and compared the measured and simulated transverse-relaxation-rate (R2) distributions in the gel dosimeter. We experimentally measured the three-dimensional R2 distribution, which records the dose induced by particles penetrating the sample, by using magnetic resonance imaging. The obtained R2 distribution reflected the heterogeneity of the biological sample. We also conducted Monte Carlo simulations using the PHITS code by reconstructing the elemental composition of the biological sample from its computed tomography images while taking into account the dependence of the gel response on the linear energy transfer. The simulation reproduced the experimental distal edge structure of the R2 distribution with an accuracy under about 2 mm, which is approximately the same as the voxel size currently used in treatment planning.

  5. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    NASA Astrophysics Data System (ADS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; da Silva, Alessandra Furtado; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson José

    2005-06-01

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 °C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 °C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1.

  6. Direct determination and speciation of mercury compounds in environmental and biological samples by carbon bed atomic absorption spectroscopy

    SciTech Connect

    Skelly, E.M.

    1982-01-01

    A method was developed for the direct determination of mercury in water and biological samples using a unique carbon bed atomizer for atomic absorption spectroscopy. The method avoided sources of error such as loss of volatile mercury during sample digestion and contamination of samples through added reagents by eliminating sample pretreatment steps. The design of the atomizer allowed use of the 184.9 nm mercury resonance line in the vacuum ultraviolet region, which increased sensitivity over the commonly used spin-forbidden 253.7 nm line. The carbon bed atomizer method was applied to a study of mercury concentrations in water, hair, sweat, urine, blood, breath and saliva samples from a non-occupationally exposed population. Data were collected on the average concentration, the range and distribution of mercury in the samples. Data were also collected illustrating individual variations in mercury concentrations with time. Concentrations of mercury found were significantly higher than values reported in the literature for a ''normal'' population. This is attributed to the increased accuracy gained by eliminating pretreatment steps and increasing atomization efficiency. Absorption traces were obtained for various solutions of pure and complexed mercury compounds. Absorption traces of biological fluids were also obtained. Differences were observed in the absorption-temperatures traces of various compounds. The utility of this technique for studying complexation was demonstrated.

  7. Stable isotope imaging of biological samples with high resolution secondary ion mass spectrometry and complementary techniques

    PubMed Central

    Jiang, H.; Favaro, E.; Goulbourne, C. N.; Rakowska, P. D.; Hughes, G. M.; Ryadnov, M. G.; Fong, L.G.; Young, S. G.; Ferguson, D. J. P.; Harris, A. L.; Grovenor, C. R. M.

    2014-01-01

    Stable isotopes are ideal labels for studying biological processes because they have little or no effect on the biochemical properties of target molecules. The NanoSIMS is a tool that can image the distribution of stable isotope labels with up to 50 nm spatial resolution and with good quantitation. This combination of features has enabled several groups to undertake significant experiments on biological problems in the last decade. Combining the NanoSIMS with other imaging techniques also enables us to obtain not only chemical information but also the structural information needed to understand biological processes. This article describes the methodologies that we have developed to correlate atomic force microscopy and backscattered electron imaging with NanoSIMS experiments to illustrate the imaging of stable isotopes at molecular, cellular, and tissue scales. Our studies make it possible to address 3 biological problems: (1) the interaction of antimicrobial peptides with membranes; (2) glutamine metabolism in cancer cells; and (3) lipoprotein interactions in different tissues. PMID:24556558

  8. neutron activation analysis using thermochromatography. III. analysis of samples of biological origin

    SciTech Connect

    Sattarov, G.; Davydov, A.V.; Khamatov, S.; Kist, A.A.

    1986-07-01

    The use of gas thermochromatography (GTC) in the radioactivation analysis of biological materials is discussed. A group separation of a number of highly volatile elements from sodium and bromine radionuclides has been achieved. The limit of detection of the elements by INAA and neutron activation analysis was estimated using GTC. The advantages of the procedure and the analytical parameters are discussed.

  9. Perceived Use of Inquiry Teaching by a Sample of Malaysian Biology Teachers.

    ERIC Educational Resources Information Center

    Ismail, Nor Asma; Rubba, Peter A.

    1981-01-01

    Determined degree to which Malaysian biology teachers (N=26) perceived they understood and used inquiry teaching. Data indicated that these teachers perceived they had a moderate amount of knowledge about inquiry and occasionally used the 21 inquiry-related behaviors assessed by "A Generic Problem Solving (Inquiry) Model" (Hungerford, 1975).…

  10. Application of a complex constraint for biological samples in coherent diffractive imaging.

    PubMed

    Jones, M W M; Peele, A G; van Riessen, G A

    2013-12-16

    We demonstrate the application of a complex constraint in the reconstruction of images from phase-diverse Fresnel coherent diffraction data for heterogeneous biological objects. The application of this constraint is shown to improve the quality of the reconstruction of both the phase and the magnitude of the complex object transmission function. PMID:24514606

  11. Determination of the Biologically Relevant Sampling Depth for Terrestrial and Aquatic Ecological Risk Assessments (Final Report)

    EPA Science Inventory

    This technical paper provides defensible approximations for what the depth of the biologically active zone, or “biotic zone” is within certain environments. The methods used in this study differ somewhat between Part 1 (Terrestrial Biotic Zone) and Part 2 (Aquatic Biotic Zone). ...

  12. Preparation of Plant Samples for Phytochemical Research and the Study of Their Biological Activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior to investigating plant natural products for biologically active constituents, it is necessary to establish guidelines and procedures for carefully collecting, cataloging, and storing specimens. All field collections should begin with detailed records on location, which should include a list o...

  13. How Parents Influence School Grades: Hints from a Sample of Adoptive and Biological Families

    ERIC Educational Resources Information Center

    Johnson, Wendy; McGue, Matt; Iacono, William G.

    2007-01-01

    Using the biological and adoptive families in the Minnesota-based Sibling Interaction and Behavior Study, we investigated the associations among genetic and environmental influences on IQ, parenting, parental expectations for offspring educational attainment, engagement in school, and school grades. All variables showed substantial genetic…

  14. Automated sample mounting and technical advance alignment system for biological crystallography at a synchrotron source

    SciTech Connect

    Snell, Gyorgy; Cork, Carl; Nordmeyer, Robert; Cornell, Earl; Meigs, George; Yegian, Derek; Jaklevic, Joseph; Jin, Jian; Stevens, Raymond C.; Earnest, Thomas

    2004-01-07

    High-throughput data collection for macromolecular crystallography requires an automated sample mounting system for cryo-protected crystals that functions reliably when integrated into protein-crystallography beamlines at synchrotrons. Rapid mounting and dismounting of the samples increases the efficiency of the crystal screening and data collection processes, where many crystals can be tested for the quality of diffraction. The sample-mounting subsystem has random access to 112 samples, stored under liquid nitrogen. Results of extensive tests regarding the performance and reliability of the system are presented. To further increase throughput, we have also developed a sample transport/storage system based on ''puck-shaped'' cassettes, which can hold sixteen samples each. Seven cassettes fit into a standard dry shipping Dewar. The capabilities of a robotic crystal mounting and alignment system with instrumentation control software and a relational database allows for automated screening and data collection to be developed.

  15. Simple method to measure power density entering a plane biological sample at millimeter wavelengths.

    PubMed

    Shen, Z Y; Birenbaum, L; Chu, A; Motzkin, S; Rosenthal, S; Sheng, K M

    1987-01-01

    A simple method for measuring microwave power density is described. It is applicable to situations where exposure of samples in the near field of a horn is necessary. A transmitted power method is used to calibrate the power density entering the surface of the sample. Once the calibration is available, the power density is known in terms of the incident and reflected powers within the waveguide. The calibration has been carried out for liquid samples in a quartz cell. Formulas for calculating specific absorption rate (SAR) are derived in terms of the power density and the complex dielectric constant of the sample. An error analysis is also given.

  16. Determination of total iodine in nutritional and biological samples by ICP-MS following their combustion within an oxygen stream.

    PubMed

    Gélinas, Y; Krushevska, A; Barnes, R M

    1998-03-01

    A mineralization and determination method for total iodine in nutritional and biological samples is described. Combustion of the sample in an oxygen stream is followed by collection of the combustion products in a 5% water-soluble tertiary amine solution. Iodine is determined by inductively coupled plasma mass spectrometry. The accuracy and precision of the quantitative iodine analysis using standard addition is better than +/- 10%. A semi-quantitative analysis of four standard reference materials is evaluated. Owing to the presence of low-level iodine contaminant in the blank solution, the determination limit of the method is +/- 10 micrograms kg-1. Good agreement with certified iodine values is obtained for six reference materials. The use of the tertiary amine matrix solution permits the simultaneous determination of iodine and other trace metals of biological and toxicological importance, including Mn, Co, Ni, Cu, Zn, Rb, Cd, and Pb.

  17. Sample Preparation Techniques for the Untargeted LC-MS-Based Discovery of Peptides in Complex Biological Matrices

    PubMed Central

    Finoulst, Inez; Pinkse, Martijn; Van Dongen, William; Verhaert, Peter

    2011-01-01

    Although big progress has been made in sample pretreatment over the last years, there are still considerable limitations when it comes to overcoming complexity and dynamic range problems associated with peptide analyses from biological matrices. Being the little brother of proteomics, peptidomics is a relatively new field of research aiming at the direct analysis of the small proteins, called peptides, many of which are not amenable for typical trypsin-based analytics. In this paper, we present an overview of different techniques and methods currently used for reducing a sample's complexity and for concentrating low abundant compounds to enable successful peptidome analysis. We focus on techniques which can be employed prior to liquid chromatography coupled to mass spectrometry for peptide detection and identification and indicate their advantages as well as their shortcomings when it comes to the untargeted analysis of native peptides from complex biological matrices. PMID:22203783

  18. A 96-well screen filter plate for high-throughput biological sample preparation and LC-MS/MS analysis.

    PubMed

    Peng, Sean X; Cousineau, Martin; Juzwin, Stephen J; Ritchie, David M

    2006-01-01

    A novel 96-well screen filter plate (patent pending) has been invented to eliminate a time-consuming and labor-intensive step in preparation of in vivo study samples--to remove blood or plasma clots. These clots plug the pipet tips during a manual or automated sample-transfer step causing inaccurate pipetting or total pipetting failure. Traditionally, these blood and plasma clots are removed by picking them out manually one by one from each sample tube before any sample transfer can be made. This has significantly slowed the sample preparation process and has become a bottleneck for automated high-throughput sample preparation using robotic liquid handlers. Our novel screen filter plate was developed to solve this problem. The 96-well screen filter plate consists of 96 stainless steel wire-mesh screen tubes connected to the 96 openings of a top plate so that the screen filter plate can be readily inserted into a 96-well sample storage plate. Upon insertion, the blood and plasma clots are excluded from entering the screen tube while clear sample solutions flow freely into it. In this way, sample transfer can be easily completed by either manual or automated pipetting methods. In this report, three structurally diverse compounds were selected to evaluate and validate the use of the screen filter plate. The plasma samples of these compounds were transferred and processed in the presence and absence of the screen filter plate and then analyzed by LC-MS/MS methods. Our results showed a good agreement between the samples prepared with and without the screen filter plate, demonstrating the utility and efficiency of this novel device for preparation of blood and plasma samples. The device is simple, easy to use, and reusable. It can be employed for sample preparation of other biological fluids that contain floating particulates or aggregates. PMID:16383347

  19. Gelatin embedding: a novel way to preserve biological samples for terahertz imaging and spectroscopy

    NASA Astrophysics Data System (ADS)

    Fan, Shuting; Ung, Benjamin; Parrott, Edward P. J.; Pickwell-MacPherson, Emma

    2015-04-01

    Sample dehydration has traditionally been a challenging problem in ex vivo terahertz biomedical experiments as water content changes significantly affect the terahertz properties and can diminish important contrast features. In this paper, we propose a novel method to prevent sample dehydration using gelatin embedding. By looking at terahertz image data and calculating the optical properties of the gelatin-embedded sample, we find that our method successfully preserves the sample for at least 35 h, both for imaging and spectroscopy. Our novel preservation method demonstrates for the first time the capability to simultaneously maintain sample structural integrity and prevent dehydration at room temperature. This is particularly relevant for terahertz studies of freshly excised tissues but could be beneficial for other imaging and spectroscopy techniques.

  20. A sensitive method for the determination of uranium in biological samples utilizing kinetic phosphorescence analysis (KPA).

    PubMed

    Hedaya, M A; Birkenfeld, H P; Kathren, R L

    1997-05-01

    Kinetic phosphorescence analysis is a technique that provides rapid, precise and accurate determination of uranium concentration in aqueous solutions. This technique utilizes a laser source to excite an aqueous solution of uranium, and measures the emission luminescence intensity over time to determine the luminescence decay profile. The lifetime of the luminescence decay profile and the linearity of the log luminescence intensity versus time profile are indications of the specificity of the technique for uranium determination. The luminescence intensity at the onset of decay (the initial luminescence intensity), which is the luminescence intensity at time zero after termination of the laser pulse used for excitation, is proportional to the uranium concentration in the sample. Calibration standards of known uranium concentrations are used to construct the calibration curve between the initial luminescence intensity and uranium concentration. This calibration curve is used to determine the uranium concentration of unknown samples from their initial luminescence intensity. We developed the sample preparation method that allows the determination of uranium concentrations in urine, plasma, kidney, liver, bone spleen and soft tissue samples. Tissue samples are subjected to dry-ashing in a muffle furnace at 600 degrees C and wet-ashing with concentrated nitric acid and hydrogen peroxide twice to destroy the organic component in the sample that may interfere with uranium determination by KPA. Samples are then solubilized in 0.82 M nitric acid prior to analysis by KPA. The assay calibration curves are linear and cover the range of uranium concentrations between 0.05 micrograms l-1 and 1000 micrograms l-1 (0.05-1000 ppb). The developed sample preparation procedures coupled with the KPA technique provide a specific, sensitive, precise and accurate method for the determination of uranium concentration in tissue samples. This method was used to quantify uranium in different

  1. Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

    PubMed Central

    Afridi, H I; Kazi, T G; Kazi, N G; Jamali, M K; Arain, M B; Sirajuddin; Baig, J A; Kandhro, G A; Wadhwa, S K; Shah, A Q

    2010-01-01

    The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension. PMID:20010608

  2. A high-performance direct transmethylation method for total fatty acids assessment in biological and foodstuff samples.

    PubMed

    Castro-Gómez, Pilar; Fontecha, Javier; Rodríguez-Alcalá, Luis M

    2014-10-01

    Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods.

  3. Data mining and biological sample exportation from South Africa: A new wave of bioexploitation under the guise of clinical care?

    PubMed

    Staunton, Ciara; Moodley, Keymanthri

    2016-02-01

    Discovery Health, one of the leading healthcare funders in South Africa (SA), will offer genetic testing to its members for USD250 (approximately ZAR3 400) per test from 2016. On the surface, this appears to be innovative and futuristic. However, a deeper look at this announcement reveals considerable problems in the exportation of biological samples and data out of SA, and brings into sharp focus the lack of protection in place for potential donors. In return for a reduced-cost genetic test, which will nevertheless be billed to a member's savings plan, data from the patient's results, and probably the sample itself, will be sent to the USA for storage, research purposes and possible commercial use, with no further benefit for the patient. This development has demonstrated the need for more stringent protection of the movement of biological samples and data out of SA, particularly with reference to consenting procedures, material transfer agreements, and the export of biological data themselves. PMID:26821890

  4. Recent on-line processing procedures for biological samples for determination of trace elements by atomic spectrometric methods

    NASA Astrophysics Data System (ADS)

    Burguera, José L.; Burguera, Marcela

    2009-06-01

    Few of the elements present in nature play a metabolic role in living organisms. According to their abundance, these elements are classified as macro-, micro- or trace elements, representing 93%, 5% and around 1% respectively, of the total body weight. The remaining percentage could be attributed to those elements with unknown biological functions, to others which are present only because of the exposure to polluted environment or to those intentionally introduced into the body for a special treatment. This review summarizes and discusses the most recent publications related to the on-line processing of biological samples for trace element determination using atomic spectrometry-based detectors. Preconcentration/separation procedures based on solid phase or cloud point extractions, electrochemical deposition, microdialysis, as well as chemical vapor generation are the common practice for improving the sensitivity and selectivity of the available atomic spectrometric techniques. The advantages of using isotope dilution mass spectrometry in speciation studies are also emphasized. Digestion or leaching in oxidizing acidic mixtures aided by heat or by ultrasound or microwave radiation, performed off- or on-line, is necessary to previous steps when processing solid biological samples. The most relevant analytical figures of merit such as detection limits, enrichment factors and sample throughput as well as some aspects related to the on-line system configurations and accuracy assessments are critically presented.

  5. Capillary zone electrophoresis for analysis of phytochelatins and other thiol peptides in complex biological samples derivatized with monobromobimane.

    PubMed

    Perez-Rama, Mónica; Torres Vaamonde, Enrique; Abalde Alonso, Julio

    2005-02-01

    A new method to improve the analysis of phytochelatins and their precursors (cysteine, gamma-Glu-Cys, and glutathione) derivatized with monobromobimane (mBrB) in complex biological samples by capillary zone electrophoresis is described. The effects of the background electrolyte pH, concentration, and different organic additives (acetonitrile, methanol, and trifluoroethanol) on the separation were studied to achieve optimum resolution and number of theoretical plates of the analyzed compounds in the electropherograms. Optimum separation of the thiol peptides was obtained with 150 mM phosphate buffer at pH 1.60. Separation efficiency was improved when 2.5% v/v methanol was added to the background electrolyte. The electrophoretic conditions were 13 kV and capillary dimensions with 30 cm length from the inlet to the detector (38 cm total length) and 50 microm inner diameter. The injection was by pressure at 50 mbar for 17 s. Under these conditions, the separation between desglycyl-peptides and phytochelatins was also achieved. We also describe the optimum conditions for the derivatization of biological samples with mBrB to increase electrophoretic sensitivity and number of theoretical plates. The improved method was shown to be simple, reproducible, selective, and accurate in measuring thiol peptides in complex biological samples, the detection limit being 2.5 microM glutathione at a wavelength of 390 nm.

  6. A high-performance direct transmethylation method for total fatty acids assessment in biological and foodstuff samples.

    PubMed

    Castro-Gómez, Pilar; Fontecha, Javier; Rodríguez-Alcalá, Luis M

    2014-10-01

    Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods. PMID:25059195

  7. Metabolomics identifies a biological response to chronic low-dose natural uranium contamination in urine samples.

    PubMed

    Grison, Stéphane; Favé, Gaëlle; Maillot, Matthieu; Manens, Line; Delissen, Olivia; Blanchardon, Eric; Banzet, Nathalie; Defoort, Catherine; Bott, Romain; Dublineau, Isabelle; Aigueperse, Jocelyne; Gourmelon, Patrick; Martin, Jean-Charles; Souidi, Maâmar

    2013-01-01

    Because uranium is a natural element present in the earth's crust, the population may be chronically exposed to low doses of it through drinking water. Additionally, the military and civil uses of uranium can also lead to environmental dispersion that can result in high or low doses of acute or chronic exposure. Recent experimental data suggest this might lead to relatively innocuous biological reactions. The aim of this study was to assess the biological changes in rats caused by ingestion of natural uranium in drinking water with a mean daily intake of 2.7 mg/kg for 9 months and to identify potential biomarkers related to such a contamination. Subsequently, we observed no pathology and standard clinical tests were unable to distinguish between treated and untreated animals. Conversely, LC-MS metabolomics identified urine as an appropriate biofluid for discriminating the experimental groups. Of the 1,376 features detected in urine, the most discriminant were metabolites involved in tryptophan, nicotinate, and nicotinamide metabolic pathways. In particular, N-methylnicotinamide, which was found at a level seven times higher in untreated than in contaminated rats, had the greatest discriminating power. These novel results establish a proof of principle for using metabolomics to address chronic low-dose uranium contamination. They open interesting perspectives for understanding the underlying biological mechanisms and designing a diagnostic test of exposure.

  8. Active Learning Not Associated with Student Learning in a Random Sample of College Biology Courses

    PubMed Central

    Andrews, T. M.; Leonard, M. J.; Colgrove, C. A.; Kalinowski, S. T.

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning. PMID:22135373

  9. Active learning not associated with student learning in a random sample of college biology courses.

    PubMed

    Andrews, T M; Leonard, M J; Colgrove, C A; Kalinowski, S T

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning.

  10. Impact of processing method on recovery of bacteria from wipes used in biological surface sampling.

    PubMed

    Downey, Autumn S; Da Silva, Sandra M; Olson, Nathan D; Filliben, James J; Morrow, Jayne B

    2012-08-01

    Environmental sampling for microbiological contaminants is a key component of hygiene monitoring and risk characterization practices utilized across diverse fields of application. However, confidence in surface sampling results, both in the field and in controlled laboratory studies, has been undermined by large variation in sampling performance results. Sources of variation include controlled parameters, such as sampling materials and processing methods, which often differ among studies, as well as random and systematic errors; however, the relative contributions of these factors remain unclear. The objective of this study was to determine the relative impacts of sample processing methods, including extraction solution and physical dissociation method (vortexing and sonication), on recovery of Gram-positive (Bacillus cereus) and Gram-negative (Burkholderia thailandensis and Escherichia coli) bacteria from directly inoculated wipes. This work showed that target organism had the largest impact on extraction efficiency and recovery precision, as measured by traditional colony counts. The physical dissociation method (PDM) had negligible impact, while the effect of the extraction solution was organism dependent. Overall, however, extraction of organisms from wipes using phosphate-buffered saline with 0.04% Tween 80 (PBST) resulted in the highest mean recovery across all three organisms. The results from this study contribute to a better understanding of the factors that influence sampling performance, which is critical to the development of efficient and reliable sampling methodologies relevant to public health and biodefense.

  11. Effect of poppy seed consummation on the positive results of opiates screening in biological samples.

    PubMed

    Jankovicová, Katarína; Ulbrich, Pavol; Fuknová, Mária

    2009-04-01

    Poppy seed is a popular substance of many traditional Slovak cakes. We can eat quite great amount of it, sometimes more than 50 g. Existing problem in interpreting the results of opiate urine analysis in case of drug abuse arises from the natural occurrence of opiate alkaloids in poppy seed. Interpretation of morphine presence in urine sample is in some cases a problem because morphine present in the urine sample may come from different "sources". The presence of additional, respectively, other opiate in urine sample is significant help when interpreting the presence of morphine. We used poppy seed bought in supermarket for our experiment. Presence of morphine and codeine was determined in poppy seed extracts, whereas the concentration of majority opiate-morphine was 0.9 mg/100 g (9 ppm). This poppy seed was used for two series of experiment-poppy seed consummation, where four persons consumed 100g of poppy seed in the first series and 50 g in the second series. Urine samples were taken in regular 1h intervals where first urine sample was given for testing 3 h after consummation. Concentrations of total opiates were determined in each urine sample by screening examination. Morphine concentrations were determined in selected urine samples using GC/MS with internal standard.

  12. Computed tomography and X-ray fluorescence CT of biological samples

    NASA Astrophysics Data System (ADS)

    Pereira, G. R.; Anjos, M. J.; Rocha, H. S.; Faria, P.; Pérez, C. A.; Lopes, R. T.

    2007-10-01

    Transmission microtomography ( μCT) and X-ray fluorescence microtomography (XRF μCT) are complementary and noninvasive techniques used for sample characterization. μCT provide information on the attenuation coefficients, while XRF μCT can provide the distribution of all elements in a sample. XRF μCT is a noninvasive technique, based on the detection of X-ray fluorescence emitted by the elements in the sample, and it is used to complement other techniques for sample characterization. The experiments were performed at the X-Ray Fluorescence (XRF) beamline of the Brazilian Synchrotron Light Laboratory (LNLS), Campinas, Brazil. A monochromatic beam of 9.8 keV was used for excitation of the elements within samples and the fluorescence photons were detected by an HPGe detector. The incident beam was monitored by an ionization chamber and a fast scintillator detector was used to detect the transmitted radiation. In this work, several intestine and breast tissue samples were investigated in order to verify the concentration of some elements correlated with the characteristics and pathology of each tissue observed by transmission μCT. All XRF μCT were reconstructed using a filtered back-projection algorithm. In those samples the elements Zn, Cu, and Fe were observed.

  13. Automated Sample Exchange Robots for the Structural Biology Beam Lines at the Photon Factory

    SciTech Connect

    Hiraki, Masahiko; Watanabe, Shokei; Yamada, Yusuke; Matsugaki, Naohiro; Igarashi, Noriyuki; Gaponov, Yurii; Wakatsuki, Soichi

    2007-01-19

    We are now developing automated sample exchange robots for high-throughput protein crystallographic experiments for onsite use at synchrotron beam lines. It is part of the fully automated robotics systems being developed at the Photon Factory, for the purposes of protein crystallization, monitoring crystal growth, harvesting and freezing crystals, mounting the crystals inside a hutch and for data collection. We have already installed the sample exchange robots based on the SSRL automated mounting system at our insertion device beam lines BL-5A and AR-NW12A at the Photon Factory. In order to reduce the time required for sample exchange further, a prototype of a double-tonged system was developed. As a result of preliminary experiments with double-tonged robots, the sample exchange time was successfully reduced from 70 seconds to 10 seconds with the exception of the time required for pre-cooling and warming up the tongs.

  14. Accelerating analysis for metabolomics, drugs and their metabolites in biological samples using multidimensional gas chromatography.

    PubMed

    Mitrevski, Blagoj S; Kouremenos, Konstantinos A; Marriott, Philip J

    2009-05-01

    Gas chromatography (GC) with mass spectrometry (MS) is one of the great enabling analytical tools available to the chemical and biochemical analyst for the measurement of volatile and semi-volatile compounds. From the analysis result, it is possible to assess progress in chemical reactions, to monitor environmental pollutants in a wide range of soil, water or air samples, to determine if an athlete or horse trainer has contravened doping laws, or if crude oil has migrated through subsurface rock to a reservoir. Each of these scenarios and samples has an associated implementation method for GC-MS. However, few samples and the associated interpretation of data is as complex or important as biochemical sample analysis for trace drugs or metabolites. Improving the analysis in both the GC and MS domains is a continual search for better separation, selectivity and sensitivity. Multidimensional methods are playing important roles in providing quality data to address the needs of analysts.

  15. Sample Preparation Approaches for iTRAQ Labeling and Quantitative Proteomic Analyses in Systems Biology.

    PubMed

    Spanos, Christos; Moore, J Bernadette

    2016-01-01

    Among a variety of global quantification strategies utilized in mass spectrometry (MS)-based proteomics, isobaric tags for relative and absolute quantitation (iTRAQ) are an attractive option for examining the relative amounts of proteins in different samples. The inherent complexity of mammalian proteomes and the diversity of protein physicochemical properties mean that complete proteome coverage is still unlikely from a single analytical method. Numerous options exist for reducing protein sample complexity and resolving digested peptides prior to MS analysis. Indeed, the reliability and efficiency of protein identification and quantitation from an iTRAQ workflow strongly depend on sample preparation upstream of MS. Here we describe our methods for: (1) total protein extraction from immortalized cells; (2) subcellular fractionation of murine tissue; (3) protein sample desalting, digestion, and iTRAQ labeling; (4) peptide separation by strong cation-exchange high-performance liquid chromatography; and (5) peptide separation by isoelectric focusing.

  16. Oxygen bomb combustion of biological samples for inductively coupled plasma optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    Souza, Gilberto B.; Carrilho, Elma Neide V. M.; Oliveira, Camila V.; Nogueira, Ana Rita A.; Nóbrega, Joaquim A.

    2002-12-01

    A rapid sample preparation method is proposed for decomposition of milk powder, corn bran, bovine and fish tissues, containing certified contents of the analytes. The procedure involves sample combustion in a commercial stainless steel oxygen bomb operating at 25 bar. Most of the samples were decomposed within 5 min. Diluted nitric acid or water-soluble tertiary amines 10% v/v were used as absorption solutions. Calcium, Cu, K, Mg, Na, P, S and Zn were recovered with the bomb washings and determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Ethanol mixed with paraffin was used as a combustion aid to allow complete combustion. A cooling step prior releasing of the bomb valve was employed to increase the efficiency of sample combustion. Iodine was also determined in milk samples spiked with potassium iodide to evaluate the volatilization and collection of iodine in amine CFA-C medium and the feasibility of its determination by ICP-OES with axial view configuration. Most of the element recoveries in the samples were between 91 and 105% and the certified and found contents exhibited a fair agreement at a 95% confidence level.

  17. Methods for collection and analysis of aquatic biological and microbiological samples

    USGS Publications Warehouse

    Britton, Linda J., (Edited By); Greeson, Phillip E.

    1989-01-01

    Chapter A4 contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water to determine its biological and microbiological properties. Part 1 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity, and bioassays. Each method is summarized, and the applications, interferences, apparatus, reagents, analyses, calculations, reporting of results, precisions, and references are given. Part 2 consists of a glossary. Part 3 is a list of taxonomic references.

  18. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM.

    PubMed

    Ogura, Toshihiko

    2009-08-01

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si3N4) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si3N4 film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  19. Supercritical fluid extraction and ultra performance liquid chromatography of respiratory quinones for microbial community analysis in environmental and biological samples.

    PubMed

    Hanif, Muhammad; Atsuta, Yoichi; Fujie, Koichi; Daimon, Hiroyuki

    2012-03-05

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA) detector was successfully applied to the simultaneous determination of ubiquinones (UQ) and menaquinones (MK) without tedious pretreatment. Supercritical carbon dioxide (scCO(2)) extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost) and biological samples (swine and Japanese quail feces).

  20. Detection of motile micro-organisms in biological samples by means of a fully automated image processing system

    NASA Astrophysics Data System (ADS)

    Alanis, Elvio; Romero, Graciela; Alvarez, Liliana; Martinez, Carlos C.; Hoyos, Daniel; Basombrio, Miguel A.

    2001-08-01

    A fully automated image processing system for detection of motile microorganism is biological samples is presented. The system is specifically calibrated for determining the concentration of Trypanosoma Cruzi parasites in blood samples of mice infected with Chagas disease. The method can be adapted for use in other biological samples. A thin layer of blood infected by T. cruzi parasites is examined in a common microscope in which the images of the vision field are taken by a CCD camera and temporarily stored in the computer memory. In a typical field, a few motile parasites are observable surrounded by blood red cells. The parasites have low contrast. Thus, they are difficult to detect visually but their great motility betrays their presence by the movement of the nearest neighbor red cells. Several consecutive images of the same field are taken, decorrelated with each other where parasites are present, and digitally processed in order to measure the number of parasites present in the field. Several fields are sequentially processed in the same fashion, displacing the sample by means of step motors driven by the computer. A direct advantage of this system is that its results are more reliable and the process is less time consuming than the current subjective evaluations made visually by technicians.

  1. Systematic ratio normalization of gas chromatography signals for biological sample discrimination and biomarker discovery.

    PubMed

    Lehallier, Benoist; Ratel, Jérémy; Hanafi, Mohamed; Engel, Erwan

    2012-07-01

    The present paper introduces a new gas chromatography data processing procedure dubbed systematic ratio normalization (SRN) enabling to improve both sample set discrimination and biomarker identification. SRN consists in (1) calculating, for each sample, all the log-ratios between abundances of chromatography-analyzed compounds, then (2) selecting the log-ratio(s) that best maximize the discrimination between sample-sets. The relevance of SRN was evaluated on two data sets acquired through gas chromatography-mass spectrometry as part of separate studies designed (i) to discriminate source-origins between vegetable oils analyzed via an analytical system exposed to instrument drift (data set 1) and (ii) to discriminate animal feed between meat samples aged for different durations (data set 2). Applying SRN to raw data made it possible to obtain robust discrimination models for the two data sets by enhancing the contribution to the data variance of the factor-of-interest while stabilizing the contribution of the disturbance factor. The most discriminant log-ratios were shown to employ the most relevant biomarkers presenting relative independence of the factor-of-interest as well as co-behavior of the disturbance effects potentially biasing the discrimination, such as instrument drift or sample biochemical changes. SRN can be run a posteriori on any data set, and might be generalizable to most of separating methods. PMID:22704370

  2. Validity of extracellular water assessment with saliva samples using plasma as the reference biological fluid.

    PubMed

    Matias, Catarina N; Silva, Analiza M; Santos, Diana A; Gobbo, Luis A; Schoeller, Dale A; Sardinha, Luís B

    2012-11-01

    Extracellular water (ECW) assessment is based on dilution techniques, commonly using blood sampling. However, plasma collection is an invasive procedure. We aimed to validate the use of saliva for ECW estimation by the bromide dilution technique using plasma as the reference method, in a sample of elite athletes. A total of 89 elite athletes with a mean age of 20.4 ± 4.4 years were evaluated. Baseline samples were collected before sodium bromide oral dose administration, and enriched samples were collected 3 h post-dose administration. The bromide concentration was assessed by high-performance liquid chromatography. Comparison of means, concordance coefficient correlation (CCC), multiple regression and Bland-Altman analysis were performed. The ECW from saliva explained 91% of the variance in ECW by plasma with a standard error of estimation of 0.91 kg. The CCC between alternative and reference methods was 0.952. No significant trend was observed between the mean and difference of the methods, with limits of agreement ranging between -1.5 and 2.1 kg. These findings reveal that bromide dilution volume calculated from saliva samples is a valid noninvasive method for ECW assessment in elite athletes. PMID:22275182

  3. Ultra-weak photon emission from biological samples: definition, mechanisms, properties, detection and applications.

    PubMed

    Cifra, Michal; Pospíšil, Pavel

    2014-10-01

    This review attempts to summarize molecular mechanisms, spectral and intensity properties, detection techniques and applications of ultra-weak photon emission. Ultra-weak photon emission is the chemiluminescence from biological systems where electronically excited species are formed during oxidative metabolic or oxidative stress processes. It is generally accepted that photons are emitted (1) at near UVA, visible, and near IR spectral ranges from 350 to 1300nm and (2) at the intensity of photon emission in the range of several units to several hundreds (oxidative metabolic process) and several hundreds to several thousands (oxidative stress process) photons s(-1)cm(-2). Current development in detection using low-noise photomultiplier tubes and imaging using highly sensitive charge coupled device cameras allows temporal and spatial visualization of oxidative metabolic or oxidative stress processes, respectively. As the phenomenon of ultra-weak photon emission reflects oxidative metabolic or oxidative stress processes, it can be widely used as a non-invasive tool for monitoring of the physiological state of biological systems.

  4. A combined method for correlative 3D imaging of biological samples from macro to nano scale

    PubMed Central

    Kellner, Manuela; Heidrich, Marko; Lorbeer, Raoul-Amadeus; Antonopoulos, Georgios C.; Knudsen, Lars; Wrede, Christoph; Izykowski, Nicole; Grothausmann, Roman; Jonigk, Danny; Ochs, Matthias; Ripken, Tammo; Kühnel, Mark P.; Meyer, Heiko

    2016-01-01

    Correlative analysis requires examination of a specimen from macro to nano scale as well as applicability of analytical methods ranging from morphological to molecular. Accomplishing this with one and the same sample is laborious at best, due to deformation and biodegradation during measurements or intermediary preparation steps. Furthermore, data alignment using differing imaging techniques turns out to be a complex task, which considerably complicates the interconnection of results. We present correlative imaging of the accessory rat lung lobe by combining a modified Scanning Laser Optical Tomography (SLOT) setup with a specially developed sample preparation method (CRISTAL). CRISTAL is a resin-based embedding method that optically clears the specimen while allowing sectioning and preventing degradation. We applied and correlated SLOT with Multi Photon Microscopy, histological and immunofluorescence analysis as well as Transmission Electron Microscopy, all in the same sample. Thus, combining CRISTAL with SLOT enables the correlative utilization of a vast variety of imaging techniques. PMID:27759114

  5. Selenium levels in related biological samples: human placenta, maternal and umbilical cord blood, hair and nails.

    PubMed

    Lorenzo Alonso, Maria José; Bermejo Barrera, Adela; Cocho de Juan, José Angel; Fraga Bermúdez, José María; Bermejo Barrera, Pilar

    2005-01-01

    A study on selenium levels has been carried out in human placenta, maternal and umbilical cord blood, hair and nails of a group of 50 mothers and in the hair of the newborns. The determinations were perfomed by electrothermal atomic absorption spectrometry. The selenium concentration obtained for each sample type was as follows: For the human placenta the values obtained were between 0.56 and 1.06 microg/g (mean +/- standard deviation: 0.81 +/- 0.02 microg/g). The levels for the umbilical cord blood were 51.1-104.2 microg/l (76.3 +/- 6.5 microg/l). For the maternal blood the values measured were between 57.3 and 117.9 microg/l (90.0 +/- 15.2 microg/l), and for hair and nails were 0.22-1.5 microg/g (0.60 +/- 0.37 microg/g) and 0.46-1.57 microg/g (0.90 +/- 0.27 microg/g), respectively. For the hair of the newborns the values obtained were between 0.40 and 2.53 microg/g (1.04 +/- 0.48 microg/g). The effect of different variables as age, habitat, nutritional index or gestation age of the mothers on the selenium concentration in the samples was studied. The influence of the habitat is significant with a confidence level of 95% for the selenium concentration in maternal blood and umbilical cord blood samples. The influence of the mothers' age is significant with a confidence level of 95% for the selenium concentration in the umbilical cord blood samples. For the placenta samples, the effect of the nutritional index is significant with a confidence level of 95%. There is a positive correlation between samples of umbilical cord blood and the newborns' hair, between placenta and umbilical cord, and between cord blood and maternal blood.

  6. Simultaneous determination of trace cadmium and arsenic in biological samples by hydride generation-double channel atomic fluorescence spectrometry.

    PubMed

    Lu, Yun-kai; Sun, Han-Wen; Yuan, Chun-Gang; Yan, Xiu-Ping

    2002-04-01

    Hydride generation atomic fluorescence spectrometry (HG-AFS) has been used for determination of hydride-forming elements because of its high sensitivity, simplicity, and low costs, but most of such work has been concentrated on single element analysis, and reports dealing with multielement determination by HG-nondispersive (ND)AFS are rare. In this work, a sensitive HG-NDAFS method was developed for simultaneous determination of trace cadmium and arsenic in biological materials. The conditions for the generation of volatile cadmium and arsenic species from the reaction with KBH4 in aqueous solution were investigated using a double-channel AFS integrated with an intermittent flow reactor. Like thiourea and Co(II), ascorbic acid was found to significantly enhance the generation efficiency of volatile Cd and As species. The interferences of coexisting ions were evaluated. Under optimal conditions, the detection limits for Cd and As were determined to be 10 and 150 ng L(-1), respectively. The precision for 11 replicate determinations at the 1 microg L(-1) Cd level and the 10 microg L(-1) As level were 3.5 and 2.7% (RSD), respectively. The recoveries of spike analytes in the biological samples studied ranged from 94 to 109%. The proposed method was successfully applied to the simultaneous determination of Cd and As in a variety of biological samples.

  7. Detection of triglycerides using immobilized enzymes in food and biological samples

    NASA Astrophysics Data System (ADS)

    Raichur, Ashish; Lesi, Abiodun; Pedersen, Henrik

    1996-04-01

    A scheme for the determination of total triglyceride (fat) content in biomedical and food samples is being developed. The primary emphasis is to minimize the reagents used, simplify sample preparation and develop a robust system that would facilitate on-line monitoring. The new detection scheme developed thus far involves extracting triglycerides into an organic solvent (cyclohexane) and performing partial least squares (PLS) analysis on the NIR (1100 - 2500 nm) absorbance spectra of the solution. A training set using 132 spectra of known triglyceride mixtures was complied. Eight PLS calibrations were generated and were used to predict the total fat extracted from commercial samples such as mayonnaise, butter, corn oil and coconut oil. The results typically gave a correlation coefficient (r) of 0.99 or better. Predictions were typically within 90% and better at higher concentrations. Experiments were also performed using an immobilized lipase reactor to hydrolyze the fat extracted into the organic solvent. Performing PLS analysis on the difference spectra of the substrate and product could enhance specificity. This is being verified experimentally. Further work with biomedical samples is to be performed. This scheme may be developed into a feasible detection method for triglycerides in the biomedical and food industries.

  8. Determination of methenamine in biological samples by gas-liquid chromatography.

    PubMed

    Nieminen, A L; Kangas, L; Anttila, M; Hautoniemi, L

    1980-01-11

    Methenamine (hexamethylenetetramine), a urinary disinfectant, was determined in human plasma and urine by gas-liquid chromatography with a short (10 m) open-bore glass capillary column (split ratio 1:20) and nitrogen-selective detector. An almost quantitative recovery (92.1%) was achieved by simple dilution of water-containing samples (0.5 ml) with acetone (4.5 ml). After centrifugation an aliquot (2 microliter) of the supernatant was injected into the gas chromatograph. Selectivity and sensitivity of the nitrogen detector allowed the quantitation of unchanged methenamine in plasma and urine up to 24 h after a single therapeutic dose of 1 g. Reproducibility of the method was 7.6 and 2.1% (C.V.) in serum and urine, respectively. The time required for the analysis of one sample was approx. 2 min. Due to the simple extraction and short analysis time it was possible to analyze the samples concurrently with sample taking. Absorption of standard tablets and an enterosoluble preparation of methenamine hippurate was compared.

  9. Determination of alkylresorcinols and their metabolites in biological samples by gas chromatography-mass spectrometry.

    PubMed

    Wierzbicka, Roksana; Wu, Huaxing; Franek, Milan; Kamal-Eldin, Afaf; Landberg, Rikard

    2015-09-01

    High throughput GC-MS methods for quantification of alkylresorcinols (AR), biomarkers of whole grain wheat and rye intake, in plasma and adipose tissue and their metabolites in urine were developed and optimised. Alkylresorcinols in plasma (200μL) and adipose tissues (10-50mg) were extracted with diethyl ether, whereas main AR metabolites such as DHBA and DHPPA and newly identified metabolites in urine (50μL) were extracted with ethyl acetate after enzymatic deconjugation. All extracts were purified on OASIS-MAX solid phase extraction cartridges. Plasma and adipose tissue sample extracts were then derivatised with trifluoroacetic anhydride and reconstituted in undecane, whereas AR metabolites in urine samples were derivatised with BSTFA+TMCS (99:1, v/v, 100μL). Prepared samples were quantified by GC-MS (EI-SIM). Analysis of all compounds in the different matrices showed good selectivity, sensitivity, linearity, precision (<15% within and between batches), adequate recovery (75-108%), and short total run time (10-12min). The methods developed are applicable to large-scale sample sets such as epidemiological studies. PMID:26218771

  10. Quantitation of Bacillus clausii in biological samples by real-time polymerase chain reaction.

    PubMed

    Perotti, Mario; Mancini, Nicasio; Cavallero, Annalisa; Carletti, Silvia; Canducci, Filippo; Burioni, Roberto; Clementi, Massimo

    2006-06-01

    A real-time PCR assay targeting the highly specific erm34 sequence of Bacillus clausii DNA was developed and optimized. The quantitative assay showed a sensitivity level of 10(2) CFU/microl of sample. The method may represent a useful tool for monitoring the role of B. clausii as probiotic in vivo. PMID:16318892

  11. Rapid, fluorimetric-liquid chromatographic determination of malondialdehyde in biological samples.

    PubMed

    Agarwal, Rajiv; Chase, Shawn D

    2002-07-25

    Current chromatographic methods of estimation of malondialdehyde, a marker of oxidative lipid injury, often require extensive extraction procedures, column cleaning or specialized equipment. A rapid and sensitive HPLC method is described for the determination of MDA in plasma and urine. The mobile phase consisted of 40:60 ratio (v/v) of methanol to 50 mM potassium monobasic phosphate at pH 6.8, pumped at a rate of 1.0 ml/min on a Hewlett-Packard Hypersil 5 micro ODS 100 x 4.6 mm placed in a column warmer set to 37 degrees C. Samples of plasma and urine were treated with the antioxidant, butylated hydroxytoluene and heat derivatized at 100 degrees C for 1 h with thiobarbituric acid at an acid pH. Samples were extracted with n-butanol and 10 microl of the extract was injected at 1 min intervals using an autosampler. The Hewlett-Packard model 1046A programmable fluorescence detector was set at excitation of 515 nm and emission of 553 nm. Retention time was 1.87 min, however absence of interfering peaks, allowed analysis to be carried out in increments of 1 min per sample. Within day variability in estimation was between 8.6% and 10.3%. Between days variability was 3.6-7.9%. Recovery was between 88 and 101%. Samples of urine and plasma from ten normotensive volunteers were 1.94 +/- 0.79 micromol/g creatinine and 0.69 +/- 0.13 micromol/l respectively and were similar to those reported in the literature. MDA degrades at room temperature at a rate of 10% per hour. It is therefore, suggested that the total assay time be limited to 1 h beginning with sample preparation.

  12. Solid-phase extraction and liquid chromatographic quantitation of quinfamide in biological samples.

    PubMed

    Morales, J M; Jung, C H; Alarcón, A; Barreda, A

    2000-09-15

    This paper describes a high-performance liquid chromatographic method for the assay of quinfamide and its main metabolite, 1-(dichloroacetyl)-1,2,3,4,-tetrahydro-6-quinolinol, in plasma, urine and feces. It requires 1 ml of biological fluid, an extraction using Sep-Pack cartridges and acetonitrile for drug elution. Analysis was performed on a CN column (5 microm) using water-acetonitrile-methanol (40:50:10) as a mobile phase at 269 nm. Results showed that the assay was linear in the range between 0.08 and 2.0 microg/ml. The limit of quantitation was 0.08 microg/ml. Maximum assay coefficient of variation was 14%. Recovery obtained in plasma, urine and feces ranged from 82% to 98%.

  13. Electrophoresis tests on STS-3 and ground control experiments - A basis for future biological sample selections

    NASA Technical Reports Server (NTRS)

    Morrison, D. R.; Lewis, M. L.

    1982-01-01

    Static zone electrophoresis is an electrokinetic method of separating macromolecules and small particles. However, its application for the isolation of biological cells and concentrated protein solutions is limited by sedimentation and convection. Microgravity eliminates or reduces sedimentation, floatation, and density-driven convection arising from either Joule heating or concentration differences. The advantages of such an environment were first demonstrated in space during the Apollo 14 and 16 missions. In 1975 the Electrophoresis Technology Experiment (MA-011) was conducted during the Apollo-Soyuz Test Project flight. In 1979 a project was initiated to repeat the separations of human kidney cells. One of the major objectives of the Electrophoresis Equipment Verification Tests (EEVT) on STS-3 was to repeat and thereby validate the first successful electrophoretic separation of human kidney cells. Attention is given to the EEVT apparatus, the preflight electrophoresis, and inflight operational results.

  14. Contrastive analysis of hedges in a sample of Chinese and English molecular biology papers.

    PubMed

    Gao, Xiaofang

    2004-10-01

    Hedge is defined as the expression of provisionalness and possibility that makes scientific messages tentative, vague, and imprecise, thereby reducing the force of claims scientists make. Linguistic study of hedges began in the early 1970s in generative semantics. Since then, the focus has shifted from seeking linguistic properties in spoken discourse to analyzing its pragmatic functions in written contextual communication. The purpose of this paper was to analyze hedges in Chinese and English scientific articles from the perspective of contrastive pragmatics. Based on a contextual analysis of 5 Chinese and 5 English scientific articles, selected randomly, from two journals in molecular biology--Science in China and Proceedings of the National Academy of Sciences of the United States of America, there were significant differences between Chinese and English scientific articles in use of hedges.

  15. A flexible microfluidic processor for molecular biology: application to microarray sample preparation.

    PubMed

    Li, Yuan; Jones, Wendell; Rasti, Farzaneh; Blaga, Iuliu; Bogdan, Greg; Eberhart, David; Kobrin, Boris; Lee, Dongho; Nielsen, Bill; van Gelder, Ezra; Jovanovich, Stevan; Stern, Seth

    2011-08-01

    We describe a programmable microfluidic system with onboard pumps and valves that has the ability to process reaction volumes in the sub-microlitre to hundred microlitre range. The flexibility of the architecture is demonstrated with a commercial molecular biology protocol for mRNA amplification, implemented without significant modification. The performance of the microchip system is compared to conventional bench processing at each stage of the multistep protocol, and DNA microarrays are used to assess the quality and performance of bench- and microchip-amplified RNA. The results show that the microchip system reactions are similar to bench control reactions at each step, and that the microchip- and bench-derived amplified RNAs are virtually indistinguishable in differential microarray analyses.

  16. Analysis of Biological Samples Using Paper Spray Mass Spectrometry: An Investigation of Impacts by the Substrates, Solvents and Elution Methods

    PubMed Central

    Ren, Yue; Wang, He; Liu, Jiangjiang; Zhang, Zhiping; McLuckey, Morgan N.; Ouyang, Zheng

    2013-01-01

    Paper spray has been developed as a fast sampling ionization method for direct analysis of raw biological and chemical samples using mass spectrometry (MS). Quantitation of therapeutic drugs in blood samples at high accuracy has also been achieved using paper spray MS without traditional sample preparation or chromatographic separation. The paper spray ionization is a process integrated with a fast extraction of the analyte from the raw sample by a solvent, the transport of the extracted analytes on the paper, and a spray ionization at the tip of the paper substrate with a high voltage applied. In this study, the influence on the analytical performance by the solvent-substrate systems and the selection of the elution methods was investigated. The protein hemoglobin could be observed from fresh blood samples on silanized paper or from dried blood spots on silica-coated paper. The on-paper separation of the chemicals during the paper spray was characterized through the analysis of a mixture of the methyl violet 2B and methylene blue. The mode of applying the spray solvent was found to have a significant impact on the separation. The results in this study led to a better understanding of the analyte elution, on-paper separation, as well as the ionization processes of the paper spray. This study also help to establish a guideline for optimizing the analytical performance of paper spray for direct analysis of target analytes using mass spectrometry. PMID:24072932

  17. Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays

    NASA Astrophysics Data System (ADS)

    Ploykrachang, K.; Hasegawa, J.; Kondo, K.; Fukuda, H.; Oguri, Y.

    2014-07-01

    We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface.

  18. The influence of target preparation and mode of irradiation on PIXE analysis of biological samples

    NASA Astrophysics Data System (ADS)

    Galuszka, Janusz; Jarczyk, Lucjan; Rokita, Eugeniusz; Strzalkowski, Adam; Sych, Marek

    1984-04-01

    The following methods of target preparation were examined and compared: dry ashing at high temperature, low temperature ashing in plasma asher, wet ashing, lyophilization at a temperature of 35°C, cryofixation with drying in vacuum and dehydration in alcohol with drying in vacuum. All these techniques were applied to prepare targets from five different rat organs: liver, kidney, brain, lung and muscle tissue. The dried and powdered sample material was pressed into pellets or was distributed on formvar film. The evaporation of the thin carbon layer on the investigated target and placing of the thin carbon film in front of a target were also tested. The targets were irradiated in vacuum using an external beam in the air chamber. The influence of the method of target preparation on the detection limits, time requirements and escape of elements from the sample material is discussed.

  19. Implementing Self-collection of Biological Specimens With a Diverse Sample

    PubMed Central

    Fernandes, April; Skinner, Martie L.; Woelfel, Tiffany; Carpenter, Thomas; Haggerty, Kevin P.

    2013-01-01

    Collecting saliva is the most noninvasive way to detect changing levels of cortisol (Adam & Kumari, 2009; Soo-Quee Koh & Choon-Huat Koh, 2007), a stress hormone of interest to behavioral and health scientists, where there are benefits from multiple samples taken over a period of days. Various self-collection strategies have been employed, ranging from treated cards to cotton swabs and passive drool methods. The current study investigates the effectiveness of a variety of reminder techniques in encouraging adherence with procedures requiring 4 samples per day on 3 separate days of passive drool collection among African American and European American young adults. The findings suggest that direct texts were associated with the greatest level of adherence, while phone reminders were most effective when controlling for total number of contacts. Results indicate that both traditional and novel reminder methods can positively influence adherence, even with challenging populations. PMID:24376374

  20. Estimation of toxic elements in the samples of different cigarettes and their effect on the essential elemental status in the biological samples of Irish smoker rheumatoid arthritis consumers.

    PubMed

    Afridi, Hassan Imran; Talpur, Farah Naz; Kazi, Tasneem Gul; Brabazon, Dermot

    2015-04-01

    Cigarette smoking interferes with the metal homeostasis of the human body, which plays a crucial role for maintaining the health. A significant flux of heavy metals, among other toxins, reaches the lungs through smoking. In the present study, the relationship between toxic element (TE) exposure via cigarette smoking and rheumatoid arthritis incidence in population living in Dublin, Ireland, is investigated. The trace {zinc (Zn), copper (Cu), manganese (Mn), and selenium (Se)} and toxic elements arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were determined in biological (scalp hair and blood) samples of patients diagnosed with rheumatoid arthritis, who are smokers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmoker controls. The different brands of cigarette (filler tobacco, filter, and ash) consumed by the studied population were also analyzed for As, Cd, Hg, and Pb. The concentrations of trace and TEs in biological samples and different components of cigarette were measured by inductively coupled plasma mass spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The recovery of all the studied elements was found to be in the range of 96.4-99.8% in certified reference materials. The filler tobacco of different branded cigarettes contains Hg, As, Cd, and Pb concentrations in the ranges of 9.55-12.4 ng, 0.432-0.727 μg, 1.70-2.12 μg, and 0.378-1.16 μg/cigarette, respectively. The results of this study showed that the mean values of As, Cd, Hg, and Pb were significantly higher in scalp hair and blood samples of rheumatoid arthritis patients as compare to healthy controls, while Zn, Cu, Mn, and Se concentrations were found to be lower in rheumatoid arthritis patients, the difference was significant in the case of smoker patients (p<0.001). The levels of four toxic elements were 2-3-folds higher in scalp hair and

  1. Sensing performance of protein C immuno-biosensor for biological samples and sensor minimization.

    PubMed

    Kwon, Hyun J; Balcer, Heath I; Kang, Kyung A

    2002-05-01

    Protein C (PC) is an important anticoagulant and antithrombotic agent in human blood plasma. PC deficiency can result in clotting complications that interfere with oxygen and nutrient transport. A fiber-optic biosensor is being developed to provide real time diagnosis of PC deficiency. The PC sensor was tested to quantify PC level in human plasma. The signal intensity obtained from the plasma sample was 30% of the buffered sample, possibly due to the increased viscosity. The feasibility of monitoring PC level in animal cell culture broth and animal milk was tested. For the cell culture broth, 80% of signal was observed. However, the decrease was consistent over the sensing range. For whole and 1:100 diluted bovine milk, the signals were 60 and 78% of buffered sample, respectively. The biosensor length was reduced from 12.5 to 6 cm with sufficient sensitivity. To increase the sensor reusability, various elution buffers were applied after each sensing. Triethylamine elution buffer provided the best sensor regeneration capability and increased the number of assays from 2.5 to 7 times for 6 cm fibers.

  2. Electrochemical Analysis of Antichemotherapeutic Drug Zanosar in Pharmaceutical and Biological Samples by Differential Pulse Polarography

    PubMed Central

    Reddy, Chennupalle Nageswara; ReddyPrasad, Puthalapattu; Sreedhar, NeelamYughandhar

    2013-01-01

    The electrochemical reduction of zanosar was investigated systematically by direct current polarography, cyclic voltammetry, and differential pulse polarography (DPP). A simple DPP technique was proposed for the direct quantitative determination of anticancer drug zanosar in pharmaceutical formulation and spiked human urine samples for the first time. The reduction potential was −0.28 V versus Ag/AgCl with a hanging mercury drop electrode in Britton-Robinson buffer as supporting electrolyte. The dependence of the intensities of currents and potentials on pH, concentration, scan rate, deposition time, and nature of the supporting electrolyte was investigated. The calibration curve was found to be linear with the following equation: y = 0.4041x + 0.012, with a correlation coefficient of 0.992 (R2) over a concentration range from 1.0 × 10−7 M to 1.0 × 10−3 M. In the present investigation, the achieved limit of detection (LOD) and limit of quantization (LQD) were 7.42 × 10−8 M and 2.47 × 10−8 M; respectively. Excipients did not interfere with the determination of zanosar in pharmaceutical formulation and spiked urine samples. Precision and accuracy of the developed method were checked by recovery studies in pharmaceutical formulation and spiked human urine samples. PMID:24455423

  3. Determination of lead in biological samples of children with different physiological consequences using cloud point extraction method.

    PubMed

    Shah, Faheem; Kazi, Tasneem Gul; Ullah, Naeem; Afridi, Hassan Imran

    2013-06-01

    In present study, lead (Pb) level in biological samples of children with physiological disorders (liver, bone, and gastrointestinal; age ranged 1-10 years) have been assessed. For comparison purpose, age-matched healthy children were also selected. Cloud point extraction (CPE) was employed for preconcentration of Pb in acid-digested biological samples prior to its determination by flame atomic absorption spectrometry (FAAS). Dithizone (diphenylthiocarbazone) and nonionic surfactant Triton X-114 (TX-114) were used as complexing reagent and extractant, respectively. The effects of several experimental variables on proposed CPE were evaluated. Under the optimum experimental conditions, the observed detection limit (LOD) and the enhancement factor (EF) were 0.08 μg L(-1) and 53, respectively. Relative standard deviation (RSD) of 10 μg L(-1) Pb was 3.4 %. It was observed that children with liver-, bone-, and gastrointestinal-related disorders had three- to fourfold higher Pb level in blood and scalp hair samples. PMID:23625698

  4. Evaluation of an ultrasonic acid digestion procedure for total heavy metals determination in environmental and biological samples.

    PubMed

    Kazi, Tasneem G; Jamali, Mohammad K; Arain, Mohammad B; Afridi, Hassan I; Jalbani, Nusrat; Sarfraz, Raja A; Ansari, Rehana

    2009-01-30

    In this study, a sample preparation method based on ultrasonic assisted acid digestion (UAD) has been evaluated for total heavy metals (Cd, Cr, Ni and Pb) determination in different environmental (soil, sediment and sewage sludge), and biological (fish muscles, vegetables and grains) samples, using electrothermal atomic absorption spectrometry (ETAAS). The investigated parameters influencing UAD such as presonication time, sonication time, temperature of ultrasonic bath, and different acid mixtures were fully optimized, whereas power was maintained constant at 100% of nominal power of ultrasonic bath. Six different sets of above parameters were applied on six certified reference materials (CRMs) having different matrices. The accuracy of the method was also tested by comparing the results with those obtained from conventional hot plate assisted acid digestion method on same CRMs. Analytical results for HMs by both methods showed no significant difference at 95% confidence limit (p<0.05). Recoveries of HMs ranging from 96.2% to 102% and 96.3% to 98.6% were obtained from biological and environmental samples, respectively. The average relative standard deviation of UAD method varied between 3.5% and 8.2%, depending on the analyte.

  5. Sensor structure concepts for the analysis or local radiation exposure of biological samples at terahertz and millimeter wave frequencies

    NASA Astrophysics Data System (ADS)

    Dornuf, Fabian; Dörr, Roland; Lämmle, David; Schlaak, Helmut F.; Krozer, Viktor

    2016-03-01

    We have studied several sensor concepts for biomedical applications operating in the millimeter wave and terahertz range. On one hand, rectangular waveguide structure were designed and extended with microfluidic channels. In this way a simple analysis of aqueous solutions at various waveguide bands is possible. In our case, we focused on the frequency range between 75 GHz and 110 GHz. On the other hand, planar sensor structures for aqueous solutions have been developed based on coplanar waveguides. With these planar sensors it is possible to concentrate the interaction volume on small sensor areas, which achieve a local exposure of the radiation to the sample. When equipping the sensor with microfluidic structures the sample volume could be reduced significantly and enabled a localized interaction with the sensor areas. The sensors are designed to exhibit a broadband behavior up to 300 GHz. Narrow-band operation can also be achieved for potentially increased sensitivity by using resonant structures. Several tests with Glucose dissolved in water show promising results for the distinction of different glucose levels at millimeter wave frequencies. The planar structures can also be used for the exposure of biological cells or cell model systems like liposomes with electromagnetic radiation. Several studies are planned to distinguish on one hand the influence of millimeter wave exposure on biological systems and also to have a spectroscopic method which enables the analysis of cell processes, like membrane transport processes, with millimeter wave and terahertz frequencies by focusing the electric field directly on the analyzing sample.

  6. Determination of lead in biological samples of children with different physiological consequences using cloud point extraction method.

    PubMed

    Shah, Faheem; Kazi, Tasneem Gul; Ullah, Naeem; Afridi, Hassan Imran

    2013-06-01

    In present study, lead (Pb) level in biological samples of children with physiological disorders (liver, bone, and gastrointestinal; age ranged 1-10 years) have been assessed. For comparison purpose, age-matched healthy children were also selected. Cloud point extraction (CPE) was employed for preconcentration of Pb in acid-digested biological samples prior to its determination by flame atomic absorption spectrometry (FAAS). Dithizone (diphenylthiocarbazone) and nonionic surfactant Triton X-114 (TX-114) were used as complexing reagent and extractant, respectively. The effects of several experimental variables on proposed CPE were evaluated. Under the optimum experimental conditions, the observed detection limit (LOD) and the enhancement factor (EF) were 0.08 μg L(-1) and 53, respectively. Relative standard deviation (RSD) of 10 μg L(-1) Pb was 3.4 %. It was observed that children with liver-, bone-, and gastrointestinal-related disorders had three- to fourfold higher Pb level in blood and scalp hair samples.

  7. A sensitive phage-based capture ELISA for sub-femtomolar detection of protein variants directly from biological samples.

    PubMed

    Williams, Stephanie; Schulz, Philip; Sierks, Michael R

    2015-01-01

    To determine the role of proteins, and in particular protein variants, in human health, it may often be necessary to quantitatively determine the concentration of a specific protein variant present in complex biological samples such as blood, cerebral spinal fluid (CSF), or tissue. Many protein variants are present only at trace levels and therefore a simple assay with very high sensitivity and reliability would greatly facilitate correlation of the presence of particular protein variants with the progression of specific diseases. We have developed a simple phage based capture ELISA system that enables femtomolar or better detection of individual protein variants directly from complex biological samples. The protocol utilizes a capture reagent that selectively recognizes a unique epitope of the protein variant and a phage based detection reagent that binds to a second epitope present in all forms of the target protein. The phage based detection reagent is essentially a self-assembling nanoparticle consisting of several thousand coat proteins that can each be labeled to amplify the detection signal by several orders of magnitude. Here we demonstrate that we can achieve subfemtomolar detection of individual protein variants that have been implicated in neurodegenerative disease directly from complex tissue homogenates and sera. The ELISA system should facilitate identification of disease specific protein variants or other compounds even when present at trace amounts in samples including blood, CSF, saliva and urine. PMID:25203940

  8. Sample handling in surface sensitive chemical and biological sensing: a practical review of basic fluidics and analyte transport.

    PubMed

    Orgovan, Norbert; Patko, Daniel; Hos, Csaba; Kurunczi, Sándor; Szabó, Bálint; Ramsden, Jeremy J; Horvath, Robert

    2014-09-01

    This paper gives an overview of the advantages and associated caveats of the most common sample handling methods in surface-sensitive chemical and biological sensing. We summarize the basic theoretical and practical considerations one faces when designing and assembling the fluidic part of the sensor devices. The influence of analyte size, the use of closed and flow-through cuvettes, the importance of flow rate, tubing length and diameter, bubble traps, pressure-driven pumping, cuvette dead volumes, and sample injection systems are all discussed. Typical application areas of particular arrangements are also highlighted, such as the monitoring of cellular adhesion, biomolecule adsorption-desorption and ligand-receptor affinity binding. Our work is a practical review in the sense that for every sample handling arrangement considered we present our own experimental data and critically review our experience with the given arrangement. In the experimental part we focus on sample handling in optical waveguide lightmode spectroscopy (OWLS) measurements, but the present study is equally applicable for other biosensing technologies in which an analyte in solution is captured at a surface and its presence is monitored. Explicit attention is given to features that are expected to play an increasingly decisive role in determining the reliability of (bio)chemical sensing measurements, such as analyte transport to the sensor surface; the distorting influence of dead volumes in the fluidic system; and the appropriate sample handling of cell suspensions (e.g. their quasi-simultaneous deposition). At the appropriate places, biological aspects closely related to fluidics (e.g. cellular mechanotransduction, competitive adsorption, blood flow in veins) are also discussed, particularly with regard to their models used in biosensing. PMID:24846752

  9. Non-target time trend screening: a data reduction strategy for detecting emerging contaminants in biological samples.

    PubMed

    Plassmann, Merle M; Tengstrand, Erik; Åberg, K Magnus; Benskin, Jonathan P

    2016-06-01

    Non-targeted mass spectrometry-based approaches for detecting novel xenobiotics in biological samples are hampered by the occurrence of naturally fluctuating endogenous substances, which are difficult to distinguish from environmental contaminants. Here, we investigate a data reduction strategy for datasets derived from a biological time series. The objective is to flag reoccurring peaks in the time series based on increasing peak intensities, thereby reducing peak lists to only those which may be associated with emerging bioaccumulative contaminants. As a result, compounds with increasing concentrations are flagged while compounds displaying random, decreasing, or steady-state time trends are removed. As an initial proof of concept, we created artificial time trends by fortifying human whole blood samples with isotopically labelled standards. Different scenarios were investigated: eight model compounds had a continuously increasing trend in the last two to nine time points, and four model compounds had a trend that reached steady state after an initial increase. Each time series was investigated at three fortification levels and one unfortified series. Following extraction, analysis by ultra performance liquid chromatography high-resolution mass spectrometry, and data processing, a total of 21,700 aligned peaks were obtained. Peaks displaying an increasing trend were filtered from randomly fluctuating peaks using time trend ratios and Spearman's rank correlation coefficients. The first approach was successful in flagging model compounds spiked at only two to three time points, while the latter approach resulted in all model compounds ranking in the top 11 % of the peak lists. Compared to initial peak lists, a combination of both approaches reduced the size of datasets by 80-85 %. Overall, non-target time trend screening represents a promising data reduction strategy for identifying emerging bioaccumulative contaminants in biological samples. Graphical abstract

  10. Non-target time trend screening: a data reduction strategy for detecting emerging contaminants in biological samples.

    PubMed

    Plassmann, Merle M; Tengstrand, Erik; Åberg, K Magnus; Benskin, Jonathan P

    2016-06-01

    Non-targeted mass spectrometry-based approaches for detecting novel xenobiotics in biological samples are hampered by the occurrence of naturally fluctuating endogenous substances, which are difficult to distinguish from environmental contaminants. Here, we investigate a data reduction strategy for datasets derived from a biological time series. The objective is to flag reoccurring peaks in the time series based on increasing peak intensities, thereby reducing peak lists to only those which may be associated with emerging bioaccumulative contaminants. As a result, compounds with increasing concentrations are flagged while compounds displaying random, decreasing, or steady-state time trends are removed. As an initial proof of concept, we created artificial time trends by fortifying human whole blood samples with isotopically labelled standards. Different scenarios were investigated: eight model compounds had a continuously increasing trend in the last two to nine time points, and four model compounds had a trend that reached steady state after an initial increase. Each time series was investigated at three fortification levels and one unfortified series. Following extraction, analysis by ultra performance liquid chromatography high-resolution mass spectrometry, and data processing, a total of 21,700 aligned peaks were obtained. Peaks displaying an increasing trend were filtered from randomly fluctuating peaks using time trend ratios and Spearman's rank correlation coefficients. The first approach was successful in flagging model compounds spiked at only two to three time points, while the latter approach resulted in all model compounds ranking in the top 11 % of the peak lists. Compared to initial peak lists, a combination of both approaches reduced the size of datasets by 80-85 %. Overall, non-target time trend screening represents a promising data reduction strategy for identifying emerging bioaccumulative contaminants in biological samples. Graphical abstract

  11. Applications of High Resolution Laser: Induced Breakdown Spectroscopy for Environmental and Biological Samples

    NASA Astrophysics Data System (ADS)

    Martin, Madhavi Z.; Labbe, Nicole; Wagner, Rebekah J.

    This chapter details the application of LIBS in a number of environmental areas of research such as carbon sequestration and climate change. LIBS has also been shown to be useful in other high resolution environmental applications for example, elemental mapping and detection of metals in plant materials. LIBS has also been used in phytoremediation applications. Other biological research involves a detailed understanding of wood chemistry response to precipitation variations and also to forest fires. A cross-section of Mountain pine (pinceae Pinus pungen Lamb.) was scanned using a translational stage to determine the differences in the chemical features both before and after a fire event. Consequently, by monitoring the elemental composition pattern of a tree and by looking for abrupt changes, one can reconstruct the disturbance history of a tree and a forest. Lastly we have shown that multivariate analysis of the LIBS data is necessary to standardize the analysis and correlate to other standard laboratory techniques. LIBS along with multivariate statistical analysis makes it a very powerful technology that can be transferred from laboratory to field applications with ease.

  12. Applications of High Resolution Laser Induced Breakdown Spectroscopy for Environmental and Biological Samples

    SciTech Connect

    Martin, Madhavi Z; Labbe, Nicole; Wagner, Rebekah J.

    2013-01-01

    This chapter details the application of LIBS in a number of environmental areas of research such as carbon sequestration and climate change. LIBS has also been shown to be useful in other high resolution environmental applications for example, elemental mapping and detection of metals in plant materials. LIBS has also been used in phytoremediation applications. Other biological research involves a detailed understanding of wood chemistry response to precipitation variations and also to forest fires. A cross-section of Mountain pine (pinceae Pinus pungen Lamb.) was scanned using a translational stage to determine the differences in the chemical features both before and after a fire event. Consequently, by monitoring the elemental composition pattern of a tree and by looking for abrupt changes, one can reconstruct the disturbance history of a tree and a forest. Lastly we have shown that multivariate analysis of the LIBS data is necessary to standardize the analysis and correlate to other standard laboratory techniques. LIBS along with multivariate statistical analysis makes it a very powerful technology that can be transferred from laboratory to field applications with ease.

  13. Spectrophotometric determination of copper(II) in pharmaceutical, biological and water samples by 4-(2'-benzothiazolylazo)-salicylic acid

    NASA Astrophysics Data System (ADS)

    Hashem, E. Y.; Seleim, M. M.; El-Zohry, A. M.

    2011-09-01

    A highly sensitive method is proposed to determine copper(II) ions by forming a stable complex through their interaction with 4-(2'-benzothiazolylazo)-salicylic acid (BTAS) at room temperature and pH of about 5.0. The complex gave a maximum absorption at λ = 485 nm with a molar absorptivity coefficient of 2.35·104 l/(mol·cm). The linear range for the copper determination is 0.63-5.04 mg/l. The method can be applied to determine copper ions in different biological specimens like some drugs and water samples.

  14. Quantification of creatinine in biological samples based on the pseudoenzyme activity of copper-creatinine complex

    NASA Astrophysics Data System (ADS)

    Nagaraja, Padmarajaiah; Avinash, Krishnegowda; Shivakumar, Anantharaman; Krishna, Honnur

    Glomerular filtration rate (GFR), the marker of chronic kidney disease can be analyzed by the concentration of cystatin C or creatinine and its clearance in human urine and serum samples. The determination of cystatin C alone as an indicator of GFR does not provide high accuracy, and is more expensive, thus measurement of creatinine has an important role in estimating GFR. We have made an attempt to quantify creatinine based on its pseudoenzyme activity of creatinine in the presence of copper. Creatinine in the presence of copper oxidizes paraphenylenediamine dihydrochloride (PPDD) which couples with dimethylamino benzoicacid (DMAB) giving green colored chromogenic product with maximum absorbance at 710 nm. Kinetic parameters relating this reaction were evaluated. Analytical curves of creatinine by fixed time and rate methods were linear at 8.8-530 μmol L-1 and 0.221-2.65 mmol L-1, respectively. Recovery of creatinine varied from 97.8 to 107.8%. Limit of detection and limit of quantification were 2.55 and 8.52 μmol L-1 respectively whereas Sandell's sensitivity and molar absorption coefficient values were 0.0407 μg cm-2 and 0.1427 × 104 L mol-1 cm-1 respectively. Precision studies showed that within day imprecision was 0.745-1.26% and day-to-day imprecision was 1.55-3.65%. The proposed method was applied to human urine and serum samples and results were validated in accordance with modified Jaffe's procedure. Wide linearity ranges with good recovery, less tolerance from excipients and application of the method to serum and urine samples are the claims which ascertain much advantage to this method.

  15. [Mercury determination in prehispanic Colombian biological samples: first experiences and investigation perspectives].

    PubMed

    Idrovo, Alvaro J; Romero, William M; Silva, Elizabeth; Villamil de García, Gladys; Ortiz, Jaime E

    2002-03-01

    Mercury is useful as a tracer of environmental pollution levels. We measured mercury levels in hair from two human mummies (XII and XIV centuries, respectively) and from a stag (Odocoileus virginianus). The total and inorganic mercury levels found in the samples were very low. This findings indicated a minimal exposure to mercury in food and its absence in the atmosphere. Mercury levels can be used to explore the relationship between humans and environment, especially after metallurgy appeared, and to assess environmental contamination in different periods.

  16. The Upgrade Programme for the Structural Biology beamlines at the European Synchrotron Radiation Facility - High throughput sample evaluation and automation

    NASA Astrophysics Data System (ADS)

    Theveneau, P.; Baker, R.; Barrett, R.; Beteva, A.; Bowler, M. W.; Carpentier, P.; Caserotto, H.; de Sanctis, D.; Dobias, F.; Flot, D.; Guijarro, M.; Giraud, T.; Lentini, M.; Leonard, G. A.; Mattenet, M.; McCarthy, A. A.; McSweeney, S. M.; Morawe, C.; Nanao, M.; Nurizzo, D.; Ohlsson, S.; Pernot, P.; Popov, A. N.; Round, A.; Royant, A.; Schmid, W.; Snigirev, A.; Surr, J.; Mueller-Dieckmann, C.

    2013-03-01

    Automation and advances in technology are the key elements in addressing the steadily increasing complexity of Macromolecular Crystallography (MX) experiments. Much of this complexity is due to the inter-and intra-crystal heterogeneity in diffraction quality often observed for crystals of multi-component macromolecular assemblies or membrane proteins. Such heterogeneity makes high-throughput sample evaluation an important and necessary tool for increasing the chances of a successful structure determination. The introduction at the ESRF of automatic sample changers in 2005 dramatically increased the number of samples that were tested for diffraction quality. This "first generation" of automation, coupled with advances in software aimed at optimising data collection strategies in MX, resulted in a three-fold increase in the number of crystal structures elucidated per year using data collected at the ESRF. In addition, sample evaluation can be further complemented using small angle scattering experiments on the newly constructed bioSAXS facility on BM29 and the micro-spectroscopy facility (ID29S). The construction of a second generation of automated facilities on the MASSIF (Massively Automated Sample Screening Integrated Facility) beam lines will build on these advances and should provide a paradigm shift in how MX experiments are carried out which will benefit the entire Structural Biology community.

  17. Closer to the native state. Critical evaluation of cryo-techniques for Transmission Electron Microscopy: preparation of biological samples.

    PubMed

    Mielanczyk, Lukasz; Matysiak, Natalia; Michalski, Marek; Buldak, Rafal; Wojnicz, Romuald

    2014-01-01

    Over the years Transmission Electron Microscopy (TEM) has evolved into a powerful technique for the structural analysis of cells and tissues at various levels of resolution. However, optimal sample preservation is required to achieve results consistent with reality. During the last few decades, conventional preparation methods have provided most of the knowledge about the ultrastructure of organelles, cells and tissues. Nevertheless, some artefacts can be introduced at all stagesofstandard electron microscopy preparation technique. Instead, rapid freezing techniques preserve biological specimens as close as possible to the native state. Our review focuses on different cryo-preparation approaches, starting from vitrification methods dependent on sample size. Afterwards, we discuss Cryo-Electron Microscopy Of VItreous Sections (CEMOVIS) and the main difficulties associated with this technique. Cryo-Focused Ion Beam (cryo-FIB) is described as a potential alternative for CEMOVIS. Another post-processing route for vitrified samples is freeze substitution and embedding in resin for structural analysis or immunolocalization analysis. Cryo-sectioning according to Tokuyasu is a technique dedicated to high efficiency immunogold labelling. Finally, we introduce hybrid techniques, which combine advantages of primary techniques originally dedicated to different approaches. Hybrid approaches permit to perform the study of difficult-to-fix samples and antigens or help optimize the sample preparation protocol for the integrated Laser and Electron Microscopy (iLEM) technique.

  18. An experimental system for controlled exposure of biological samples to electrostatic discharges.

    PubMed

    Marjanovič, Igor; Kotnik, Tadej

    2013-12-01

    Electrostatic discharges occur naturally as lightning strokes, and artificially in light sources and in materials processing. When an electrostatic discharge interacts with living matter, the basic physical effects can be accompanied by biophysical and biochemical phenomena, including cell excitation, electroporation, and electrofusion. To study these phenomena, we developed an experimental system that provides easy sample insertion and removal, protection from airborne particles, observability during the experiment, accurate discharge origin positioning, discharge delivery into the sample either through an electric arc with adjustable air gap width or through direct contact, and reliable electrical insulation where required. We tested the system by assessing irreversible electroporation of Escherichia coli bacteria (15 mm discharge arc, 100 A peak current, 0.1 μs zero-to-peak time, 0.2 μs peak-to-halving time), and gene electrotransfer into CHO cells (7 mm discharge arc, 14 A peak current, 0.5 μs zero-to-peak time, 1.0 μs peak-to-halving time). Exposures to natural lightning stroke can also be studied with this system, as due to radial current dissipation, the conditions achieved by a stroke at a particular distance from its entry are also achieved by an artificial discharge with electric current downscaled in magnitude, but similar in time course, correspondingly closer to its entry.

  19. An experimental system for controlled exposure of biological samples to electrostatic discharges.

    PubMed

    Marjanovič, Igor; Kotnik, Tadej

    2013-12-01

    Electrostatic discharges occur naturally as lightning strokes, and artificially in light sources and in materials processing. When an electrostatic discharge interacts with living matter, the basic physical effects can be accompanied by biophysical and biochemical phenomena, including cell excitation, electroporation, and electrofusion. To study these phenomena, we developed an experimental system that provides easy sample insertion and removal, protection from airborne particles, observability during the experiment, accurate discharge origin positioning, discharge delivery into the sample either through an electric arc with adjustable air gap width or through direct contact, and reliable electrical insulation where required. We tested the system by assessing irreversible electroporation of Escherichia coli bacteria (15 mm discharge arc, 100 A peak current, 0.1 μs zero-to-peak time, 0.2 μs peak-to-halving time), and gene electrotransfer into CHO cells (7 mm discharge arc, 14 A peak current, 0.5 μs zero-to-peak time, 1.0 μs peak-to-halving time). Exposures to natural lightning stroke can also be studied with this system, as due to radial current dissipation, the conditions achieved by a stroke at a particular distance from its entry are also achieved by an artificial discharge with electric current downscaled in magnitude, but similar in time course, correspondingly closer to its entry. PMID:24076535

  20. Determination of amphetamines in biological samples using electro enhanced solid-phase microextraction-gas chromatography.

    PubMed

    Zeng, Jingbin; Chen, Jingjing; Li, Min; Subhan, Fazle; Chong, Fayun; Wen, Chongying; Yu, Jianfeng; Cui, Bingwen; Chen, Xi

    2015-09-01

    In this work, an ordered mesoporous carbon (OMC)/Nafion coated fiber for solid-phase microextraction (SPME) was prepared and used as the working electrode for electro-enhanced SPME (EE-SPME) of amphetamines. The EE-SPME strategy is primarily based on the electro-migration and complementary charge interaction between fiber coating and ionic compounds. Compared with traditional SPME, EE-SPME exhibited excellent extraction efficiency for amphetamine (AP) and methamphetamine (MA) with an enhancement factor of 7.8 and 12.1, respectively. The present strategy exhibited good linearity for the determination of AP and MA in urine samples in the range of 10-1000ngmL(-1) and 20-1000ngmL(-1), respectively. The detection limits were found to be 1.2ngmL(-1) for AP and 4.8ngmL(-1) for MA. The relative standard deviations were calculated to be 6.2% and 8.5% for AP and MA, respectively. Moreover, the practical application of the proposed method was demonstrated by analyzing the amphetamines in urine and serum samples with satisfactory results.

  1. Graphene modified glassy carbon sensor for the determination of aspirin metabolites in human biological samples.

    PubMed

    Purushotham, Meruva; Gupta, Pankaj; Goyal, Rajendra N

    2015-10-01

    A graphene modified glassy carbon (GR/GCE) sensor has been developed for the determination of aspirin metabolites 2,3- and 2,5-dihydroxybenzoic acids (2,3- and 2,5-DHB). The modified sensor was characterized by Field Emission Scanning Electron Microscopy and Electrochemical Impedance Spectroscopy. The electrochemical behavior of 2,3- and 2,5-DHB was investigated by cyclic and square wave voltammetry. The modified sensor exhibited excellent electrocatalytic activity for the oxidation of 2,3- and 2,5-DHB, leading to a remarkable enhancement in the peak current as compared to the bare sensor. The results were attributed to the enhanced surface area and high conductivity of GR. The anodic peak currents of 2,3- and 2,5-DHB were found to be linear in the concentration range of 1-150 µM and 1-200 µM with the detection limits of 47 nM and 51 nM, respectively. The sensor was capable to determine 2,5-DHB effectively without any interference from the uric acid and other metabolites present in the urine samples. The practical utility of GR/GCE has been successfully demonstrated for the determination of 2,5-DHB in the urine samples of persons undergoing treatment with aspirin. PMID:26078167

  2. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

    NASA Astrophysics Data System (ADS)

    Fuchs, O.; Weinhardt, L.; Blum, M.; Weigand, M.; Umbach, E.; Bär, M.; Heske, C.; Denlinger, J.; Chuang, Y.-D.; McKinney, W.; Hussain, Z.; Gullikson, E.; Jones, M.; Batson, P.; Nelles, B.; Follath, R.

    2009-06-01

    We present a variable line-space grating spectrometer for soft x-rays that covers the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite its slitless design, such a resolving power can be achieved for a source spot as large as (30×3000) μm2, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scattering (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken within 10 min.

  3. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

    SciTech Connect

    Fuchs, Oliver; Weinhardt, L.; Blum, M.; Weigand, M.; Umbach, E.; Bar, M.; Heske, Clemens; Denlinger, Jonathan; Chuang, Y.-D.; McKinney, Wayne; Hussain, Zahid; Gullikson, Eric; Jones, M.; Batson, Phil; Nelles, B.; Follath, R.

    2009-03-09

    We present a variable line-space grating spectrometer for soft x-rays that covers the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite its slitless design, such a resolving power can be achieved for a source spot as large as 30x3000 mu m2, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scattering (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken within 10 min.

  4. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples

    SciTech Connect

    Fuchs, Oliver; Weinhardt, L.; Blum, M.; Welgand, M.; Umbach, E.; Bar, M.; Heske, C.; Denlinger, J.; Chuang, Y.-D.; McKinney, W.; Hussain, Z.; Gullikson, E.; Jones, M.; Batson, P.; Nelles, B.; Follath, R.

    2009-06-11

    We present a variable line-space grating spectrometer for soft s-rays that coverst the photon energy range between 130 and 650 eV. The optical design is based on the Hettrick-Underwood principle and tailored to synchrotron-based studies of radiation-sensitive biological samples. The spectrometer is able to record the entire spectral range in one shot, i.e., without any mechanical motion, at a resolving power of 1200 or better. Despite is slitless design, such a resolving power can be achieved for a source spot as large as (30 x 3000) micrometers squared, which is important for keeping beam damage effects in radiation-sensitive samples low. The high spectrometer efficiency allows recording of comprehensive two-dimensional resonant inelastic soft x-ray scatters (RIXS) maps with good statistics within several minutes. This is exemplarily demonstrated for a RIXS map of highly oriented pyrolytic graphite, which was taken with 10 min.

  5. H-1 Relaxation Times of Metabolites in Biological Samples Obtained with Nondestructive Ex-vivo Slow-MAS NMR

    SciTech Connect

    Hu, Jian Zhi; Wind, Robert A.; Rommereim, Donald N.

    2006-03-01

    Methods suitable for measuring 1H relaxation times such as T1, T2 and T1p, in small sized biological objects including live cells, excised organs and tissues, oil seeds etc., were developed in this work. This was achieved by combining inversion-recovery, spin-echo, or spin lock segment with the phase-adjusted spinning sideband (PASS) technique that was applied at slow sample spinning rate. Here, 2D-PASS was used to produce a high-resolution 1H spectrum free from the magnetic susceptibility broadening so that the relaxation parameters of individual metabolite can be determined. Because of the slow spinning employed, tissue and cell damage due to sample spinning is minimized. The methodologies were demonstrated by measuring 1H T1, T2 and T1p of metabolites in excised rat livers and sesame seeds at spinning rates of as low as 40 Hz.

  6. The BioCAT Microprobe for X-Ray Fluorescence Imaging, MicroXAFS and Microdiffraction Studies on Biological Samples

    SciTech Connect

    Barrea, R.A.; Gore, D.; Kondrashkina, E.; Weng, T.; Heurich, R.; Vukonich, M.; Orgel, J.; Davidson, M.; Collingwood, J.F.; Mikhaylova, A.; Irving, T.C.

    2007-07-31

    Microbeam capabilities have been recently added to the Biophysics Collaborative Access Team (BioCAT) beamline 18-ID at the Advanced Photon Source to allow x-ray elemental mapping, micro x-ray absorption fine structure and microdiffraction studies on biological samples. The microprobe setup comprises a pair of platinum coated silicon KB mirrors; a sample holder mounted in a high precision positioner (100 nm accuracy); fluorescence detectors including a Si drift detector, Fe and Zn Bent Laue analyzers and a Ge detector; and a CCD detector for micro-diffraction experiments. The energy range of the microprobe is from 3.5 keV up to 17 keV. The fast scanning capabilities of the Bio-CAT beamline facilitate rapid acquisition of x-ray elemental images and micro-XAFS spectra. This paper reports the results of commissioning the KB mirror system and its performance in initial x-ray fluorescence mapping and micro-diffraction studies.

  7. Strategies for quantifying C60 fullerenes in environmental and biological samples and implications for studies in environmental health and ecotoxicology

    PubMed Central

    Pycke, Benny F.G.; Benn, Troy M.; Herckes, Pierre; Westerhoff, Paul; Halden, Rolf U.

    2010-01-01

    Fullerenes are sphere-like molecules with unique physico-chemical properties, which render them of particular interest in biomedical research, consumer products and industrial applications. Human and environmental exposure to fullerenes is not a new phenomenon, due to a long history of hydrocarbon-combustion sources, and will only increase in the future, as incorporation of fullerenes into consumer products becomes more widespread for use as anti-aging, anti-bacterial or anti-apoptotic agents. An essential step in the determination of biological effects of fullerenes (and their surface-functionalized derivatives) is establishment of exposure-assessment techniques. However, in ecotoxicological studies, quantification of fullerenes is performed infrequently because robust, uniformly applicable analytical approaches have yet to be identified, due to the wide variety of sample types. Moreover, the unique physico-chemistry of fullerenes in aqueous matrices requires reassessment of conventional analytical approaches, especially in more complex biological matrices (e.g., urine, blood, plasma, milk, and tissue). Here, we present a review of current analytical approaches for the quantification of fullerenes and propose a consensus approach for determination of these nanomaterials in a variety of environmental and biological matrices. PMID:21359100

  8. Rapid extraction of oxygenated metabolites of arachidonic acid from biological samples using octadecylsilyl silica.

    PubMed

    Powell, W S

    1980-11-01

    A rapid procedure for the efficient extraction of prostaglandins, thromboxanes and hydroxy fatty acids from urine, plasma and tissue homogenates has been developed. Fractions containing these substances are acidified and passed through a column of octadecylsilyl silica, which retains oxygenated metabolites of arachidonic acid. Phospholipids, proteins and very polar materials either are not retained or can be eluted with dilute aqueous ethanol. Nonpolar lipids and monohydroxy fatty acids are then eluted with petroleum ether or benzene. Subsequent elution of the column with methyl formate gives a fraction containing prostaglandins and thromboxanes which is much less contaminated with extraneous material than that obtained by conventional extraction of aqueous media with organic solvents. The methyl formate can be removed rapidly under a stream of nitrogen and the components of the sample purified directly by high pressure liquid chromatography (HPLC). An improved method for the purification of prostaglandins and TXB2 by HPLC on silica columns is reported.

  9. Kinetic spectrophotometric method for the determination of morphine in biological samples

    NASA Astrophysics Data System (ADS)

    Sheibani, A.; Shishehbore, M. Reza; Mirparizi, E.

    2010-10-01

    In this paper a simple, selective and inexpensive kinetic method was developed for the determination of morphine based on its inhibitory effect on the Janus green-bromate system in sulfuric acid media. The reaction was monitored spectrophotometrically at 618 nm by a fixed time method. The effect of different parameters such as concentration of reactants and temperature on the rate of reaction was investigated and optimum conditions were obtained. The calibration curve was linear in the concentration range 0.07-7.98 mg L -1 of morphine, and detection limit of the method was 3.0 × 10 -2 mg L -1. The relative standard deviation for five determinations of 3.74 mg L -1 of morphine was 0.57%. Finally, the proposed method was successfully applied to the determination of morphine in human urine and serum as real samples.

  10. Analytical methods for measuring uric acid in biological samples and food products.

    PubMed

    Pachla, L A; Reynolds, D L; Wright, D S; Kissinger, P T

    1987-01-01

    During the last 7 decades, uric acid methodology has kept pace with the introduction of state-of-the-art technology (e.g., spectroscopy, electrochemistry, chromatography) or the discovery of unique chemical processes (e.g., redox, enzymatic). We envision this practice will continue in the future. There never will be a single analytical method applicable for biofluids or foodstuffs. Therefore, it is imperative that the analyst not only understand the advantages and disadvantages of a procedure, but also thoroughly understand its underlying chemical and technological principles. Since many procedures available for analysis of biofluids and foodstuffs rely on identical chemical or technological principles, this report shall review both sample types and the available spectroscopic, electroanalytical, and chromatographic methods.

  11. Simulated radioactive decontamination of biological samples using a portable DNA extraction instrument for rapid DNA profiling.

    PubMed

    Frégeau, Chantal J; Dalpé, Claude

    2016-02-01

    A portable DNA extraction instrument was evaluated for its ability to decontaminate blood and saliva samples deposited on different surfaces (metal, plastic and glass) contaminated with stable isotopes of cobalt (Co), cesium (Cs), and strontium (Sr) as equivalents to their radiogenic (60)Co, (137)Cs, and (90)Sr isotopes, respectively, that could be released during a nuclear weapon accident or a radiological dispersal device (RDD) detonation. Despite the very high contamination levels tested in this study, successful removal of greater than 99.996% of the Co, Cs, Sr contaminants was achieved based on inductively coupled plasma-mass spectrometry (ICP-MS) and neutron activation analyses carried out on all liquids (including DNA eluates) and solid waste produced during automated DNA extraction. The remaining amounts of Co, Cs and Sr in the DNA eluates, when converted to dose rates (corresponding to (60)Co, (137)Cs and (90)Sr), were determined to be below the recommended dose limits for the general public in most of the scenarios tested. The presence of Co, Cs and Sr contaminants in the cell lysates had no adverse impact on the binding of DNA onto the magnetic DNA IQ™ beads. DNA yields were similar to uncontaminated controls. The remaining Co, Cs and Sr in the DNA eluates did not interfere with real-time PCR DNA quantification. In addition, the quality of the AmpFlSTR(®) Identifiler(®) profiles derived in 26min using an accelerated protocol was very good and comparable to controls. This study emphasizes the use of an accelerated process involving a portable DNA extraction instrument to significantly reduce radioactive dose rates to allow contaminated samples to be processed safely in a forensic mobile laboratory to expedite the identification of individuals potentially involved in the dispersal of nuclear or other radioactive materials. PMID:26773226

  12. A bench-top K X-ray fluorescence system for quantitative measurement of gold nanoparticles for biological sample diagnostics

    NASA Astrophysics Data System (ADS)

    Ricketts, K.; Guazzoni, C.; Castoldi, A.; Royle, G.

    2016-04-01

    Gold nanoparticles can be targeted to biomarkers to give functional information on a range of tumour characteristics. X-ray fluorescence (XRF) techniques offer potential quantitative measurement of the distribution of such heavy metal nanoparticles. Biologists are developing 3D tissue engineered cellular models on the centimetre scale to optimise targeting techniques of nanoparticles to a range of tumour characteristics. Here we present a high energy bench-top K-X-ray fluorescence system designed for sensitivity to bulk measurement of gold nanoparticle concentration for intended use in such thick biological samples. Previous work has demonstrated use of a L-XRF system in measuring gold concentrations but being a low energy technique it is restricted to thin samples or superficial tumours. The presented system comprised a high purity germanium detector and filtered tungsten X-ray source, capable of quantitative measurement of gold nanoparticle concentration of thicker samples. The developed system achieved a measured detection limit of between 0.2 and 0.6 mgAu/ml, meeting specifications of biologists and being approximately one order of magnitude better than the detection limit of alternative K-XRF nanoparticle detection techniques. The scatter-corrected K-XRF signal of gold was linear with GNP concentrations down to the detection limit, thus demonstrating potential in GNP concentration quantification. The K-XRF system demonstrated between 5 and 9 times less sensitivity than a previous L-XRF bench-top system, due to a fundamental limitation of lower photoelectric interaction probabilities at higher K-edge energies. Importantly, the K-XRF technique is however less affected by overlying thickness, and so offers future potential in interrogating thick biological samples.

  13. Utility of solid-phase spectrophotometry to determine trace amounts of zinc in environmental and biological samples.

    PubMed

    Amin, Alaa S

    2011-11-15

    A solid-phase spectrophotometric analysis has been proposed for preconcentration and determination of Zn(II) in real samples. The procedure is based on sorption of zinc(II) as 5-(2-benzothiazolylazo)-8-hydroxyquinoline (BTAHQ) complex on dextran-type anion-exchange gel (Sephadex DEAE A-25). The influences of the analytical parameters, including pH of the aqueous solution, amounts of BTAHQ, and sample volume, were investigated. The absorbance of the gel at 675 and 750 nm, packed in a 1.0-mm cell, was measured directly. The molar absorptivities were found to be 2.50×10(7) and 9.55×10(7)L mol(-1) cm(-1) for 500 and 1000 ml, respectively. Calibration was linear over the range of 0.05-1.10 μg L(-1) with a relative standard deviation of less than 1.60% (n=10). The detection and quantification limits of the 500-ml sample method were 12 and 40 ng L(-1) on using 50 mg. For the 1000-ml sample, the detection and quantification limits were 7.5 and 25 ng L(-1) using a 50-mg exchanger. Increasing the sample volume can enhance sensitivity. No considerable interferences were observed from other investigated anions and cations on the Zn(II) determination. The proposed method was applied to determine zinc in environmental samples, including natural water, food, certified reference materials, meat, and biological samples, comparing the results simultaneously with those obtained using a flame atomic absorption spectrophotometer, whereby the validity of the method was tested. PMID:21820999

  14. Use of cloud-point preconcentration for spectrophotometric determination of trace amounts of antimony in biological and environmental samples.

    PubMed

    El-Sharjawy, Abdel-Azeem M; Amin, Alaa S

    2016-01-01

    This work presents a cloud-point extraction process using the micelle-mediated extraction method for simultaneous preconcentration and determination of Sb(III) and Sb(V) species in biological and environmental samples as a prior preconcentration step to their spectrophotometric determination. The analytical system is based on the selective reaction between Sb(III) and 3-dichloro-6-(3-carboxy-2-hydroxy-1-naphthylazo)quinoxaline (DCHNAQ) in the presence of cetyltrimethylammonium bromide (CTAB) and potassium iodide at pH 4.5. Total Sb concentration was determined after reduction of Sb(V) to Sb(III) in the presence of potassium iodide and ascorbic acid. The optimal reaction conditions and extraction were studied, and the analytical characteristics of the method (e.g., limits of detection and quantification, linear range, preconcentration, improvement factors) were obtained. Linearity for Sb(III) was obeyed in the range of 0.2-20 ng ml(-1). The detection and quantification limits for the determination of Sb(III) were 0.055 and 0.185 ng ml(-1), respectively. The method has a lower detection limit and wider linear range, inexpensive instrument, and low cost, and is more sensitive compared with most other methods. The interference effect of some anions and cations was also studied. The method was applied to the determination of Sb(III) in the presence of Sb(V) and total antimony in blood plasma, urine, biological, and water samples.

  15. Sensitive determination of glutathione in biological samples by capillary electrophoresis with green (515 nm) laser-induced fluorescence detection.

    PubMed

    Hodáková, Júlia; Preisler, Jan; Foret, František; Kubáň, Petr

    2015-04-24

    A new sensitive capillary electrophoretic method with laser-induced fluorescence (LIF) was developed for quantitation of glutathione (GSH) in biological samples. Eosin-5-maleimide was used to label the GSH molecule and the formed conjugate was separated in a 15 mM 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid electrolyte at pH 7.0 in less than 3 min. The conjugate was detected with an in-house built LIF system, utilizing an inexpensive 515 nm diode laser module. Studies were performed to optimize the derivatization (the ratio of reagent to analyte, the reaction time, pH, etc.) and separation conditions. Sensitive detection of GSH at concentrations as low as 0.18 nM was obtained. The method was applied in the analysis of biological fluids (exhaled breath condensate, saliva) and was found to be suitable for determination of GSH in these samples at trace levels below 1 nM. To the best of our knowledge, this is the first report on determination of GSH in exhaled breath condensate by capillary electrophoresis (CE).

  16. The detection and discovery of glycan motifs in biological samples using lectins and antibodies: new methods and opportunities

    PubMed Central

    Tang, Huiyuan; Hsueh, Peter; Kletter, Doron; Bern, Marshall; Haab, Brian

    2015-01-01

    Recent research is uncovering unexpected ways that glycans contribute to biology, as well as new strategies for combatting disease using approaches involving glycans. To make full use of glycans for clinical applications, we need more detailed information on the location, nature, and dynamics of glycan expression in vivo. Such studies require the use of specimens acquired directly from patients. Effective studies of clinical specimens require low-volume assays, high precision measurements, and the ability to process many samples. Assays using affinity reagents—lectins and glycan-binding antibodies—can meet these requirements, but further developments are needed to make the methods routine and effective. Recent advances in the use of glycan-binding proteins could meet that need. The advances involve improved determination of specificity using glycan arrays; the availability of databases for mining and analyzing glycan array data; lectin engineering methods; and the ability to quantitatively interpret lectin measurements. Here we describe many of the challenges and opportunities involved in the application of these new approaches to the study of biological samples. The new tools hold promise for developing methods to improve the outcomes of patients afflicted with diseases characterized by aberrant glycan expression. PMID:25727148

  17. Cloud-point extraction, preconcentration and spectrophotometric determination of trace quantities of copper in food, water and biological samples.

    PubMed

    Gouda, Ayman A; Amin, Alaa S

    2014-01-01

    A new, simple and sensitive cloud point extraction procedure was presented for the preconcentration and determination of copper(II) ion in food, water and biological samples. The analyte was complexed with a new synthesized reagent, 2-amino-4-(m-tolylazo)pyridine-3-ol (ATAP) as a new complexing agent and Triton X-114 as the surfactant. After centrifugation, dilution of the surfactant-rich phase with 0.4 mL of ethanol acidified with 1.0M HNO3 was performed after phase separation, and the copper contents were measured by spectrophotometry at λmax 608 nm. The influence of analytical parameters including concentration of complexing agent, Triton X-114, pH, equilibration temperature and time, centrifuge rate and time were optimized. The analytical characteristics of the method (e.g. linear range, molar absorptivity, Sandell sensitivity, optimum Ringbom concentration ranges limits of detection and quantification, preconcentration factor, and improvement factors) were obtained. Linearity was obeyed in the range of 4.0-115 ng mL(-1) of Cu(II) ion. The detection and quantification limits of the method were 1.20 and 3.94 ng mL(-1) of Cu(II) ion, respectively. The interference effect of some anions and cations was also tested. The method was applied for determination of copper in food, water and biological samples.

  18. Development of a mild mercaptoethanol extraction method for determination of mercury species in biological samples by HPLC-ICP-MS.

    PubMed

    Wang, Meng; Feng, Weiyue; Shi, Junwen; Zhang, Fang; Wang, Bing; Zhu, Motao; Li, Bai; Zhao, Yuliang; Chai, Zhifang

    2007-03-30

    A mild, efficient and convenient extraction method of using 2-mercaptoethanol contained extractant solution combined with an incubator shaker for determination of mercury species in biological samples by HPLC-ICP-MS has been developed. The effects of the concentration of 2-mercaptoethanol, the composition of the extractant solution and the shaking time on the efficiency of mercury extraction were evaluated. The optimization experiments indicated that the quantitative extraction of mercury species from biological samples could be achieved by using 0.1% (v/v) HCl, 0.1% (v/v) 2-mercapoethanol and 0.15% (m/v) KCl extractant solution in an incubator shaker for shaking overnight (about 12h) at room temperature. The established method was validated by analysis of various biological certified reference materials, including NRCC DOLT-3 (dogfish liver), IAEA 436 (tuna fish), IAEA MA-B-3/TM (garfish filet), IAEA MA-M-2/TM (mussel tissue), GBW 08193 (bovine liver) and GBW 08572 (prawn). The analytical results of the reference materials were in good agreement with the certified or reference values of both methyl and total mercury, indicating that no distinguishable transformation between mercury species had occurred during the extraction and determination procedures. The limit of detection (LOD) for methyl (CH(3)Hg(+)) and inorganic mercury (Hg(2+)) by the method are both as 0.2microg L(-1). The relative standard deviation (R.S.D.s) for CH(3)Hg(+) and Hg(2+) are 3.0% and 5.8%, respectively. The advantages of the developed extraction method are that (1) it is easy to operate in HPLC-ICP-MS for mercury species determination since the extracted solution can be directly injected into the HPLC column without pH adjustment and (2) the memory effect of mercury in the ICP-MS measurement system can be reduced.

  19. Molecularly imprinted photonic hydrogels for fast screening of atropine in biological samples with high sensitivity.

    PubMed

    Meng, Liang; Meng, Pinjia; Tang, Bugang; Zhang, Qingqing; Wang, Yanji

    2013-09-10

    Based on molecularly imprinted photonic hydrogels (MIPHs) that combined the colloidal-crystal with molecular imprinting technique, a novel label-free colorimetric chemosensor for convenient and fast efficient detection of atropine with high sensitivity and specificity was developed. Due to the special inverse opal arrays with a thin polymer wall in which the imprinted nanocavities of atropine moleculars distributed, the proposed MIPHs designed as water-compatible exhibited high sensitive (as low as 1 pg/mL), rapid responsive (less than 30 s) and specific detection of atropine in complex matrix. The unique three-dimensional, highly-ordered photonic hydrogels would be obviously swelling in response to the specific atropine molecular recognition process and the response would be directly transferred into visually perceptible optical signal (change in color) that could be detected by the naked eye through Bragg diffractive shifts of ordered macroporous arrays. With a broad concentration range varying from 1 pg/mL to 1 μg/mL of atropine, the distinct color changes of MIPHs almost covered the whole visible-light wavelength range from blue to red for semi-quantitative analysis. The smart chemosensor was successfully employed to determine the trace level atropine in human urine samples, providing a fast and effective alternative for semi-quantitative detection of atropine for clinical analysis and forensic investigations.

  20. Biological variability of the minutiae in the fingerprints of a sample of the Spanish population.

    PubMed

    Gutiérrez, Esperanza; Galera, Virginia; Martínez, Jose Manuel; Alonso, Concepción

    2007-10-25

    The minutiae, a term coined by Galton to refer to the small peculiarities present along the length of every isolated ridge, or characteristic points, a term used primarily by the Spanish Police Scientists, have an inter- and intrapopulation variability which has not been extensively studied. However, these peculiarities constitute the bases for the fingerprint identification of individuals in the field of criminology. Using the adhesive paper and graphite method, the fingerprints of 200 students, 100 males and 100 females, with ages ranging between 20 and 35, have been taken at the University of Alcala (Madrid). From this sample, the distal phalanx of the index finger of the right hand has been studied. The total count of the minutiae, as well as that of each different type, was made of the entire print area, and inside and outside of a circle with a radius of 18 ridges. The highest frequencies were of ridge endings, followed by bifurcations and convergences, all others appearing with frequencies of lower than 5%. The distribution of the minutiae was not homogeneous for the area of the fingerprint (inside and outside the circle). In the study of minutiae statistically significant differences were found between the sexes, and between the different types of general pattern (arches, loops, and whorls).

  1. Validated method for the quantification of free and total carnitine, butyrobetaine, and acylcarnitines in biological samples.

    PubMed

    Minkler, Paul E; Stoll, Maria S K; Ingalls, Stephen T; Kerner, Janos; Hoppel, Charles L

    2015-09-01

    A validated quantitative method for the determination of free and total carnitine, butyrobetaine, and acylcarnitines is presented. The versatile method has four components: (1) isolation using strong cation-exchange solid-phase extraction, (2) derivatization with pentafluorophenacyl trifluoromethanesulfonate, (3) sequential ion-exchange/reversed-phase (ultra) high-performance liquid chromatography [(U)HPLC] using a strong cation-exchange trap in series with a fused-core HPLC column, and (4) detection with electrospray ionization multiple reaction monitoring (MRM) mass spectrometry (MS). Standardized carnitine along with 65 synthesized, standardized acylcarnitines (including short-chain, medium-chain, long-chain, dicarboxylic, hydroxylated, and unsaturated acyl moieties) were used to construct multiple-point calibration curves, resulting in accurate and precise quantification. Separation of the 65 acylcarnitines was accomplished in a single chromatogram in as little as 14 min. Validation studies were performed showing a high level of accuracy, precision, and reproducibility. The method provides capabilities unavailable by tandem MS procedures, making it an ideal approach for confirmation of newborn screening results and for clinical and basic research projects, including treatment protocol studies, acylcarnitine biomarker studies, and metabolite studies using plasma, urine, tissue, or other sample matrixes. PMID:26270397

  2. Rapid determination of amino acids in biological samples using a monolithic silica column.

    PubMed

    Song, Yanting; Funatsu, Takashi; Tsunoda, Makoto

    2012-05-01

    A high-performance liquid chromatography method in which fluorescence detection is used for the simultaneous determination of 21 amino acids is proposed. Amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and then separated on a monolithic silica column (MonoClad C18-HS, 150 mm×3 mm i.d.). A mixture of 25 mM citrate buffer containing 25 mM sodium perchlorate (pH 5.5) and acetonitrile was used as the mobile phase. We found that the most significant factor in the separation was temperature, and a linear temperature gradient from 30 to 49°C was used to control the column temperature. The limits of detection and quantification for all amino acids ranged from 3.2 to 57.2 fmol and 10.8 to 191 fmol, respectively. The calibration curves for the NBD-amino acid had good linearity within the range of 40 fmol to 40 pmol when 6-aminocaproic acid was used as an internal standard. Using only conventional instruments, the 21 amino acids could be analyzed within 10 min. This method was found to be suitable for the quantification of the contents of amino acids in mouse plasma and adrenal gland samples.

  3. [Solid phase microextraction (SPME) of sample preparation during of a complex biological matrix in biotransformation studies].

    PubMed

    Kroll, C; Borchert, H H

    1998-03-01

    Within the scope of the investigation of drug metabolism in keratinocytes solid phase microextraction (SPME) was investigated as a suitable method for sample preparation. The application of SPME is based on the fact, that a amount of analyte is absorbed by the polymer fiber at equilibrium, and the fiber is localized on a tip of a GC-syringe. The stable nitroxyl radical TEMPO (2,2,6,6-tetramthylpiperidine-1-oxyl) and its apolar metabolite 2,2,6,6-tetramethylpiperidine were analyzed by SPME and subsequent GC using thymol as internal standard. By means of the headspace-technique and an apolar fiber the recovery rate of TEMPO and the metabolite was nearly 100% and the precision was high. However, the results of the direct SPME were unsatisfactory. In comparison with conventional liquid/liquid extraction and solid phase extraction SPE the SPME proved the best results with regard to recovery rate and precision. Furthermore, the main advantages of SPME are the renunciation of organic solvents, the saving of time, the possibility to reuse the fiber about 100-150 times and the option for a complete automatisation of the extraction procedure. PMID:9547519

  4. Radioreceptor assay for analysis of fentanyl and its analogs in biological samples

    SciTech Connect

    Alburges, M.E.

    1988-01-01

    The assay is based on the competition of these drugs with ({sup 3}H) fentanyl for opioid receptors in membrane preparations of rat forebrain in vitro. The binding in stereospecific, reversible and saturable. Scatchard plots of saturation suggest the presence of high and low affinity binding sites. Morphine and hydromorphone complete with ({sup 3}H)fentanyl for the opioid receptor, but other morphine-like compounds were relatively weak displacers of ({sup 3}H)fentanyl. Many other commonly abused drugs do not compete with ({sup 3}H)fentanyl for the opioid receptors. Urine samples from animals injected with fentanyl, ({plus minus})-cis-3-methylfentanyl, alpha-methylfentanyl, butyrylfentanyl and benzylfentanyl were analyzed by radioreceptor assay, radioimmunoassay, and gas chromatography/mass spectrometry. Urinary analysis of fentanyl showed a good correlation with these three methods; however, discrepancies were observed in the analysis of fentanyl analogs. This radioreceptor assay is well-suited as an initial assay for the detection of active analogs of fentanyl in urine with good correlation with other techniques in the analysis of fentanyl; however, there is substantial disagreement between techniques in the quantitation of fentanyl analogs. The implications of these discrepancies are discussed.

  5. Lab on chip optical imaging of biological sample by quantitative phase microscopy

    NASA Astrophysics Data System (ADS)

    Memmolo, P.; Miccio, L.; Merola, F.; Gennari, O.; Mugnano, M.; Netti, P. A.; Ferraro, P.

    2015-03-01

    Quantitative imaging and three dimensional (3D) morphometric analysis of flowing and not-adherent cells is an important aspect for diagnostic purposes at Lab on Chip scale. Diagnostics tools need to be quantitative, label-free and, as much as possible, accurate. In recent years digital holography (DH) has been improved to be considered as suitable diagnostic method in several research field. In this paper we demonstrate that DH can be used for retrieving 3D morphometric data for sorting and diagnosis aims. Several techniques exist for 3D morphological study as optical coherent tomography and confocal microscopy, but they are not the best choice in case of dynamic events as flowing samples. Recently, a DH approach, based on shape from silhouette algorithm (SFS), has been developed for 3D shape display and calculation of cells biovolume. Such approach, adopted in combination with holographic optical tweezers (HOT) was successfully applied to cells with convex shape. Unfortunately, it's limited to cells with convex surface as sperm cells or diatoms. Here, we demonstrate an improvement of such procedure. By decoupling thickness information from refractive index ones and combining this with SFS analysis, 3D shape of concave cells is obtained. Specifically, the topography contour map is computed and used to adjust the 3D shape retrieved by the SFS algorithm. We prove the new procedure for healthy red blood cells having a concave surface in their central region. Experimental results are compared with theoretical model.

  6. Electropolymerized molecular imprinting on glassy carbon electrode for voltammetric detection of dopamine in biological samples.

    PubMed

    Kiss, Laszlo; David, Vasile; David, Iulia Gabriela; Lazăr, Paul; Mihailciuc, Constantin; Stamatin, Ioan; Ciobanu, Adela; Ştefănescu, Cristian Dragoş; Nagy, Livia; Nagy, Géza; Ciucu, Anton Alexandru

    2016-11-01

    A simple and reliable method for preparing a selective dopamine (DA) sensor based on a molecularly imprinted polymer of ethacridine was proposed. The molecularly imprinted polymer electrode was prepared through electrodepositing polyethacridine-dopamine film on the glassy carbon electrode and then removing DA from the film via chemical induced elution. The molecular imprinted sensor was tested by cyclic voltammetry as well as by differential pulse voltammetry (DPV) to verify the changes in oxidative currents of DA. In optimized DPV conditions the oxidation peak current was well-proportional to the concentration of DA in the range from 2.0×10(-8)M up to 1×10(-6)M. The limit of detection (3σ) of DA was found to be as low as 4.4nM, by the proposed sensor that could be considered a sensitive marker of DA depletion in Parkinson's disease. Good reproducibility with relative standard deviation of 1.4% and long term stability within two weeks were also observed. The modified sensor was validated for the analysis of DA in deproteinized human serum samples using differential pulse voltammetric technique. PMID:27591643

  7. Dielectrophoretic label-free immunoassay for rare-analyte quantification in biological samples

    NASA Astrophysics Data System (ADS)

    Velmanickam, Logeeshan; Laudenbach, Darrin; Nawarathna, Dharmakeerthi

    2016-10-01

    The current gold standard for detecting or quantifying target analytes from blood samples is the ELISA (enzyme-linked immunosorbent assay). The detection limit of ELISA is about 250 pg/ml. However, to quantify analytes that are related to various stages of tumors including early detection requires detecting well below the current limit of the ELISA test. For example, Interleukin 6 (IL-6) levels of early oral cancer patients are <100 pg/ml and the prostate specific antigen level of the early stage of prostate cancer is about 1 ng/ml. Further, it has been reported that there are significantly less than 1 pg /mL of analytes in the early stage of tumors. Therefore, depending on the tumor type and the stage of the tumors, it is required to quantify various levels of analytes ranging from ng/ml to pg/ml. To accommodate these critical needs in the current diagnosis, there is a need for a technique that has a large dynamic range with an ability to detect extremely low levels of target analytes (

  8. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples.

    PubMed

    Feizbakhsh, Alireza; Sarrafi, Amir Hossein Mohsen; Ehteshami, Shokooh

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15-1000 μg L(-1) for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits. PMID:27672478

  9. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples

    PubMed Central

    Sarrafi, Amir Hossein Mohsen

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15–1000 μg L−1 for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits. PMID:27672478

  10. Polythiophene-Chitosan Magnetic Nanocomposite as a Highly Efficient Medium for Isolation of Fluoxetine from Aqueous and Biological Samples

    PubMed Central

    Sarrafi, Amir Hossein Mohsen

    2016-01-01

    Polythiophene/chitosan magnetic nanocomposite as an adsorbent of magnetic solid phase extraction was proposed for the isolation of fluoxetine in aqueous and biological samples prior to fluorescence detection at 246 nm. The synthesized nanoparticles, chitosan and polythiophene magnetic nanocomposite, were characterized by scanning electron microscopy, FT-IR, TGA, and EDAX. The separation of the target analyte from the aqueous solution containing the fluoxetine and polythiophene/chitosan magnetic nanocomposite was simply achieved by applying external magnetic field. The main factors affecting the extraction efficiency including desorption conditions, extraction time, ionic strength, and sample solution pH were optimized. The optimum extraction conditions were obtained as 10 min for extraction time, 25 mg for sorbent amount, 50 mL for initial sample volume, methanol as desorption solvent, 1.5 mL for desorption solvent volume, 3 min for desorption time, and being without salt addition. Under the optimum conditions, good linearity was obtained within the range of 15–1000 μg L−1 for fluoxetine, with correlation coefficients 0.9994. Furthermore, the method was successfully applied to the determination of fluoxetine in urine and human blood plasma samples. Compared with other methods, the current method is characterized with highly easy, fast separation and low detection limits.

  11. Within-subject Pooling of Biological Samples to Reduce Exposure Misclassification in Biomarker-based Studies

    PubMed Central

    Perrier, Flavie; Giorgis-Allemand, Lise; Philippat, Claire

    2016-01-01

    Background: For chemicals with high within-subject temporal variability, assessing exposure biomarkers in a spot biospecimen poorly estimates average levels over long periods. The objective is to characterize the ability of within-subject pooling of biospecimens to reduce bias due to exposure misclassification when within-subject variability in biomarker concentrations is high. Methods: We considered chemicals with intraclass correlation coefficients of 0.6 and 0.2. In a simulation study, we hypothesized that the chemical urinary concentrations averaged over a given time period were associated with a health outcome and estimated the bias of studies assessing exposure that collected 1 to 50 random biospecimens per subject. We assumed a classical type error. We studied associations using a within-subject pooling approach and two measurement error models (simulation extrapolation and regression calibration), the latter requiring the assay of more than one biospecimen per subject. Results: For both continuous and binary outcomes, using one sample led to attenuation bias of 40% and 80% for compounds with intraclass correlation coefficients of 0.6 and 0.2, respectively. For a compound with an intraclass correlation coefficient of 0.6, the numbers of biospecimens required to limit bias to less than 10% were 6, 2, and 2 biospecimens with the pooling, simulation extrapolation, and regression calibration methods (these values were, respectively, 35, 8, and 2 for a compound with an intraclass correlation coefficient of 0.2). Compared with pooling, these methods did not improve power. Conclusion: Within-subject pooling limits attenuation bias without increasing assay costs. Simulation extrapolation and regression calibration further limit bias, compared with the pooling approach, but increase assay costs. PMID:27035688

  12. K1-95-HW, cruise report 1995: preliminary results. Phase III: sediment chemistry and biological sampling survey

    USGS Publications Warehouse

    Torresan, M.E.; Hampton, M.A.; Barber, J.H.; Wong, F.L.

    1995-01-01

    Mamala Bay, off the south shore of the island of Oahu, has been used as a repository of dredged material primarily from Pearl and Honolulu Harbors for over a century. The U.S. Geological Survey, U.S. Army Corps of Engineers, and the U.S. Environmental Protection Agency are conducting an integrated study on the distribution and character of dredged materials as well as the effects of dredged material on the marine environment. A three phase study is providing information to evaluate the effects on seafloor substrate and the benthic fauna. The studies include geophysical profiling and imaging, bottom photography, sampling, chemical and physical analyses of sediment, and evaluations of the benthic population, population density, and adverse impacts to the benthic fauna. Phase 1, conducted in 1993, inventoried the seafloor via remote sensing. Sidescan sonar and subbottom profilers characterized the seafloor in and around the disposal sites, and the resulting products reveal the character and extent of the dredged material. These data were used to plan Phase 2 in 1994, a sampling program that employed subbottom profilers, video and still photography, and seafloor sampling to ground truth the sonar mosaic and identify the seafloor substrates responsible for the various acoustic signatures on the sonar images and subbottom profiles. Box coring provided the samples necessary to distinguish dredged material from native sediment, and for the chemical analyses used to determine contaminant concentrations. Phase 3 studies conducted in June of 1995 consisted of box core sampling for chemical and biological analyses. Specific studies include: infaunal taxonomy and population density, bioassay/bioaccumulation, sediment chemistry, and post-disposal resuspension and transport. The 1995 survey, conducted June 14 through 17, resulted in the collection of 39 box cores from 20 different stations. Multiple box cores were composited at 7 different locations occupied in 1994, to provide

  13. Surfactant-Assisted Nanodrop Spectrophotometer Determination of Iron(III) in a Single Drop of Food, Biological, and Environmental Samples

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Tapadia, K.; Sahin, R.; Shrivas, K.

    2016-01-01

    A surfactant-assisted nanodrop spectrophotometric (NDS) method has been developed for the determination of the iron(III) content in single drops (1 μ L) of food, biological, and or environmental sample using disodium 1-nitroso-2-naphthol-3,6-sulfonate (Nitroso-R salt) as a complexing agent and Tween-80 as non-ionic surfactant at pH 4.0. This method is based on the formation of a complex between the Fe(III) present in a sample and the Nitroso-R-salt in the presence of a surfactant to form a green-colored Fe(III)-Nitroso-R salt complex, which can be measured using a NDS method at a λ max = 710 nm. This system was found to obey Beer's law at concentrations in the range of 50-5000 μ g/L with slope, intercept and correlation coefficient values of 0.683, 0.102, and 0.986, respectively. The molar absorptivity of the complex in terms of the Fe(III) content was determined to be 4.86 × 10 5 L· mol -1 · cm -1 . The detection limit and %RSD values of the method were found to be 17 × 10-3 mg/L and ±1.3706%, respectively. This newly developed method was successfully applied to the determination of the Fe(III) content in single drops of food, biological, and environmental samples, and the results were compared with those obtained by atomic absorption spectrometry.

  14. An intercomparison of gamma-spectrometry on two samples of biological origin by eight laboratories in four countries.

    PubMed

    Twining, J R

    1996-08-01

    This report gives details of the first inter-laboratory comparison of gamma-spectrometry to be run within SPERA, the South Pacific Environmental Radioactivity Association since its inauguration in 1991. Laboratories in Australia, Chile, French Polynesia and New Zealand participated in the exercise. Two 'unknown' samples of biological origin were analysed. The first was a sample of milk powder derived from IAEA reference material. This sample provided an assessment of overall accuracy of 134Cs, 137Cs and 40K determinations. The second sample consisted of dried fish flesh including natural 40K and spiked with a mixed nuclide solution containing 210Pb, 109Cd, 54Mn, 60Co and trace 133Ba. Together the samples gave information on analytical precision over a range of energies and activities. When the results were compared with the recommended values and confidence intervals of the IAEA reference material, the overall accuracy of the gamma-spectrometry analytical procedures was found to be good. The average mean values for combined laboratory data fell within the recommended value ranges for each isotope. Ninety percent of the individual laboratory isotope mean values were within two standard errors of the 95% confidence interval of the standard, 75% were within 1 s.e., and 33% of the analyses fell within the confidence interval. Technical precision was also adequate with the overall errors being of the same magnitude as that of the reference material values for each isotope with relative standard deviations of 5-10%. There was a tendency for standard deviations of the combined results to be larger than those reported or derived from individual laboratory results by a factor between 1.2-5.6. This result suggested an under-estimate of systematic errors within individual laboratories. The largest sources of error were derived from reporting and calculation of results which gave a 16% gross error rate.

  15. Evaluation of lead levels in biological samples of mentally retarded children in different stages using advanced extraction method.

    PubMed

    Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Mughal, Moina Akhtar; Naeemullah; Arain, Sadaf Sadia; Arain, Mohammad Balal

    2013-11-01

    In present study the lead (Pb) levels has been assessed by analyzing the scalp hair and blood samples of mentally retarded/intellectual disabled (MR/ID) children of both genders, age ranged 3-8 years. For comparative purpose, healthy age matched children were also selected. The cloud point extraction of Pb from digested biological samples was carried out by complexed with ammonium pyrrolidinedithiocarbamate. The complexed analyte was subsequently isolated from the aqueous matrix in the micelles of a non-ionic surfactant (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Pb content was measured by flame atomic absorption spectrometer. Factors affecting the cloud point extraction were evaluated and optimized. The proposed procedure allowed the determination of lead in certified standard and real samples with detection limits of 0.834μgL(-) and enhancement factor 55. The results were compared with those of healthy children have same age, socioeconomic status and residential areas.

  16. Effects of selenium and zinc status in biological samples of hepatitis C patient after herbal and pharmaceutical supplements.

    PubMed

    Kolachi, Nida F; Kazi, Tasneem G; Afridi, Hassan I; Kazi, Naveed G; Mughal, Moeena A; Khan, Sumaira

    2013-05-01

    The use of natural remedies and pharmacological mineral supplements for liver disease treatment has a long history. In present study, the levels of selenium (Se) and zinc (Zn) were determined in biological samples (serum and whole blood) of female hepatitis C patients (n = 132), age ranged 30-45 years, before and after 30 days treatment with herbal/pharmaceutical supplements. For comparative study, 128 age-matched female subjects, residing in the same residential areas and have socioeconomic status, were selected as referents. The Se and Zn in supplements, blood, and sera were determined by atomic absorption spectrometry. It was observed that Zn and Se in blood and serum samples of viral hepatitis C (HCV) patients were reduced in the range of 28.6-39 % and 24-36 %, respectively, as compared to those of referents. After herbal/pharmaceutical supplementations, 20.6-25.0 and 9.15-13.2 % of Zn and 10.6-12.1 and 19.6-21.4 % of Se were enhanced in sera and blood samples of HCV patients, respectively. The resulted data indicated that the levels of Se and Zn in addition to some biochemical parameters were improved in HCV patients after herbal/pharmaceutical supplementation. The effects of both supplements were not significantly different (p > 0.05).

  17. Evaluation of lead levels in biological samples of mentally retarded children in different stages using advanced extraction method.

    PubMed

    Kazi, Tasneem Gul; Shah, Faheem; Afridi, Hassan Imran; Mughal, Moina Akhtar; Naeemullah; Arain, Sadaf Sadia; Arain, Mohammad Balal

    2013-11-01

    In present study the lead (Pb) levels has been assessed by analyzing the scalp hair and blood samples of mentally retarded/intellectual disabled (MR/ID) children of both genders, age ranged 3-8 years. For comparative purpose, healthy age matched children were also selected. The cloud point extraction of Pb from digested biological samples was carried out by complexed with ammonium pyrrolidinedithiocarbamate. The complexed analyte was subsequently isolated from the aqueous matrix in the micelles of a non-ionic surfactant (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Pb content was measured by flame atomic absorption spectrometer. Factors affecting the cloud point extraction were evaluated and optimized. The proposed procedure allowed the determination of lead in certified standard and real samples with detection limits of 0.834μgL(-) and enhancement factor 55. The results were compared with those of healthy children have same age, socioeconomic status and residential areas. PMID:23981376

  18. Development and validation of an ELISA kit for the detection of ricin toxins from biological specimens and environmental samples.

    PubMed

    Chen, Hsiao Ying; Tran, Hung; Foo, Ling Yann; Sew, Tracey Wenhui; Loke, Weng Keong

    2014-08-01

    Ricin is a toxin that can be easily extracted from seeds of Ricinus communis plants. Ricin is considered to be a major bio-threat as it can be freely and easily acquired in large quantities. A deliberate release of such toxin in civilian populations would very likely overwhelm existing public health systems, resulting in public fear and social unrest. There is currently no commercially available or FDA-approved prophylaxis such as vaccines, or therapeutic antitoxins or antidotes, available for ricin intoxication. Patient treatment is typically supportive care based on symptoms, often designed to reinforce the body's natural response. This paper describes the development and validation of a robust ELISA test kit, which can be used to screen for ricin in biological specimens such as whole blood and faeces. Faecal specimens are shown in this study to have better diagnostic sensitivity and a wider diagnostic window compared to whole blood. From these results, it is concluded that faeces is the most suitable clinical specimen for diagnosis of ricin poisoning via the oral route. The ELISA test kit can also detect ricin in environmental samples. An advantage of this ELISA kit over other commercial off-the-shelf (COTS) detection kits currently on the market that are developed to screen environmental samples only is its ability to diagnose ricin poisoning from clinical specimens as well as detect ricin from environmental samples.

  19. Botulism: a laboratory investigation on biological and food samples from cases and outbreaks in Brazil (1982-2001).

    PubMed

    Gelli, Dilma Scala; Jakabi, Miyoko; Souza, Aldo de

    2002-01-01

    Laboratory investigation of botulism from 1982 to 2001 confirmed the occurrence of eight positive outbreaks/cases of botulism in Brazil. From those, type A botulism was observed in seven of them. Biological material of one case (serum and feces) was positive in the first step of the bioassay, but the amount of sample was not sufficient for typification. One of the outbreaks that occurred in 2001 was negative for botulinum toxin in samples of serum, gastric washing and feces, collected eight days before the onset of the symptoms in the affected person who was clinically diagnosed as presenting the disease. Other two cases presenting compatible clinical diagnoses presented negative results. However, in those cases, the collection of samples was (1) after antiserum administration or (2) later than eight days of the onset of symptoms. Investigation was performed by mouse bioassay, as described in the Compendium of Methods for the Microbiological Examination of Foods (compiled by American Public Health Association--APHA)11, using specific antiserum from Centers for Disease Control (CDC), USA. PMID:12532215

  20. Rapid Isolation and Determination of Flavones in Biological Samples Using Zinc Complexation Coupled with High-Performance Liquid Chromatography.

    PubMed

    Sun, Chenghe; Wang, Hecheng; Wang, Yingping; Xiao, Shengyuan

    2016-01-01

    Chlorophyll-type contaminants are commonly encountered in the isolation and determination of flavones of plant aerial plant parts. Heme is also a difficult background substance in whole blood analysis. Both chlorophyll and heme are porphyrin type compounds. In this study, a rapid method for isolating flavones with 5-hydroxyl or ortho-hydroxyl groups from biological samples was developed based on the different solubilities of porphyrin-metal and flavone-metal complexes. It is important that other background substances, e.g., proteins and lipids, are also removed from flavones without an additional processing. The recoveries of scutellarin, baicalin, baicalein, wogonoside and wogonin, which are the primary constituents of Scutellaria baicalensis (skullcaps) were 99.65% ± 1.02%, 98.98% ± 0.73%, 99.65% ± 0.03%, 97.59% ± 0.09% and 95.19% ± 0.47%, respectively. As a sample pretreatment procedure, this method was coupled to high-performance liquid chromatography (HPLC) with good separation, sensitivity and linearity and was applied to determine the flavone content in different aerial parts of S. baicalensis and in dried blood spot samples. PMID:27537870

  1. Survey of Bovine Enterovirus in Biological and Environmental Samples by a Highly Sensitive Real-Time Reverse Transcription-PCR

    PubMed Central

    Jiménez-Clavero, Miguel Angel; Escribano-Romero, Estela; Mansilla, Carmen; Gómez, Nuria; Córdoba, Laura; Roblas, Neftal; Ponz, Fernando; Ley, Victoria; Sáiz, Juan-Carlos

    2005-01-01

    Animal enteroviruses shed in the feces of infected animals are likely environmental contaminants and thus can be used as indicators of animal fecal pollution. Previous work has demonstrated that bovine enterovirus (BEV) present in bovine feces contaminates waters adjacent to cattle herds and that BEV-like sequences are also present in shellfish and in deer feces from the same geographical area. However, little information is available about the prevalence, molecular epidemiology, and genomic sequence variation of BEV field isolates. Here we describe an optimized highly sensitive real-time reverse transcription-PCR method to detect BEV RNA in biological and environmental samples. A combination of the amplification procedure with a previously described filtration step with electropositive filters allowed us to detect up to 12 BEV RNA molecules per ml of water. The feasibility of using the method to detect BEV in surface waters at a high risk of fecal pollution was confirmed after analysis of water samples obtained from different sources. The method was also used to study the prevalence of BEV in different cattle herds around Spain, and the results revealed that 78% (78 of 100) of the fecal samples were BEV positive. BEV-like sequences were also detected in feces from sheep, goats, and horses. Nucleotide sequence analyses showed that BEV isolates are quite heterogeneous and suggested the presence of species-specific BEV-like variants. Detection of BEV-like sequences may help in the differentiation and characterization of animal sources of contamination. PMID:16000759

  2. Assessment of selenium and mercury in biological samples of normal and night blindness children of age groups (3-7) and (8-12) years.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Talpur, Farah Naz; Kazi, Atif; Arain, Sadaf Sadia; Arain, Salma Aslam; Brahman, Kapil Dev; Panhwar, Abdul Haleem; Khan, Naeemullah; Arain, Mariam Shazadi; Ali, Jamshed

    2015-03-01

    The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. This study was designed to compare the levels of selenium (Se) and mercury (Hg) in scalp hair, blood, and urine of night blindness children age ranged (3-7) and (8-12) years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment for the determination of Se and Hg in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The Se and Hg in biological samples were measured by electrothermal atomic absorption spectrometry and cold vapor atomic absorption spectrometry, prior to microwave acid digestion, respectively. The concentration of Se was decreased in scalp hair and blood samples of male and female night blindness children while Hg was higher in all biological samples as compared to referent subjects. The Se concentration was inversely associated with the risk of night blindness in both genders. These results add to an increasing body of evidence that Se is a protecting element for night blindness. These data present guidance to clinicians and other professional investigating deficiency of essential micronutrients in biological samples (scalp hair and blood) of night blindness children. PMID:25655123

  3. Recent advances in the determination of tocopherols in biological fluids: from sample pretreatment and liquid chromatography to clinical studies.

    PubMed

    Cervinkova, Barbora; Krcmova, Lenka Kujovska; Solichova, Dagmar; Melichar, Bohuslav; Solich, Petr

    2016-04-01

    Vitamin E comprises eight related compounds: α-, β-, γ-, δ-tocopherols and α-, β-, γ-, δ-tocotrienols. In the past, α-tocopherol has been the isomer that was studied most, and its anti-inflammatory and anti-proliferative effects have been described. Therefore, many prevention trials have investigated the effect of α-tocopherol on human health. Current research studies have also defined the important roles of other tocopherols, such as anti-inflammatory, anti-proliferative and cancer preventative effects. Knowledge of the individual tocopherols could help to understand their roles in various metabolic pathways. This review summarizes the recent trends in sample pretreatment, liquid chromatography and selected applications of the determination of tocopherols in various biological materials. The relationship between tocopherol isomers and serious diseases is also described. Graphical Abstract Article structure.

  4. Determination of total mercury in environmental and biological samples by flow injection cold vapour atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Murphy, James; Jones, Phil; Hill, Steve J.

    1996-12-01

    A simple and accurate method has been developed for the determination of total mercury in environmental and biological samples. The method utilises an off-line microwave digestion stage followed by analysis using a flow injection system with detection by cold vapour atomic absorption spectrometry. The method has been validated using two certified reference materials (DORM-1 dogfish and MESS-2 estuarine sediment) and the results agreed well with the certified values. A detection limit of 0.2 ng g -1 Hg was obtained and no significant interference was observed. The method was finally applied to the determination of mercury in river sediments and canned tuna fish, and gave results in the range 0.1-3.0 mg kg -1.

  5. A New Technique for Quantitative Determination of Dexamethasone in Pharmaceutical and Biological Samples Using Kinetic Spectrophotometric Method

    PubMed Central

    Akhoundi-Khalafi, Ali Mohammad; Shishehbore, Masoud Reza

    2015-01-01

    Dexamethasone is a type of steroidal medications that is prescribed in many cases. In this study, a new reaction system using kinetic spectrophotometric method for quantitative determination of dexamethasone is proposed. The method is based on the catalytic effect of dexamethasone on the oxidation of Orange G by bromate in acidic media. The change in absorbance as a criterion of the oxidation reaction progress was followed spectrophotometrically. To obtain the maximum sensitivity, the effective reaction variables were optimized. Under optimized experimental conditions, calibration graph was linear over the range 0.2–54.0 mg L−1. The calculated detection limit (3sb/m) was 0.14 mg L−1 for six replicate determinations of blank signal. The interfering effect of various species was also investigated. The present method was successfully applied for the determination of dexamethasone in pharmaceutical and biological samples satisfactorily. PMID:25737724

  6. Cloud point extraction for the determination of cadmium and lead in biological samples by graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Maranhão, Tatiane De A.; Borges, Daniel L. G.; da Veiga, Márcia A. M. S.; Curtius, Adilson J.

    2005-06-01

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of Cd and Pb from digested biological samples. After complexation with O,O-diethyldithiophosphate (DDTP) in hydrochloric acid medium, the analytes are quantitatively extracted to the phase rich in the non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 0.1 mol L-1 HNO3 was added to the surfactant-rich phase prior to its analysis by electrothermal atomic absorption spectrometry (ET AAS). The adopted concentrations for DDTP, Triton X-114 and hydrochloric acid were all optimized. Pyrolysis and atomization temperatures were optimized using the extracts and pyrolysis temperatures of 700 °C for both elements and atomization temperatures of 1400 and 1600 °C for cadmium and lead, respectively, were used without adding any modifier, which shows that considerable analyte stabilization is provided by the medium itself. A more detailed investigation was carried out to determine which components of the extract were responsible for the high thermal stability achieved and it revealed that the amount of DDTP added and the phosphorus content of the digested samples contributed significantly to this phenomenon. Detection limits (3σB) of 6 and 40 ng g-1, along with enrichment factors of 129 and 18 for Cd and Pb, respectively, were achieved. The proposed procedure was applied to the analysis of five certified biological reference materials after microwave-assisted acid digestion in a mixture of H2O2 and HNO3. Comparison with certified values was performed for accuracy evaluation, resulting in good agreement according to the t-test for a 95% confidence level. The high efficiency of cloud point extraction to carry out the determination of the studied analytes in complex matrices was, therefore, demonstrated.

  7. Supercritical fluid carbon dioxide extraction and liquid chromatographic separation with electrochemical detection of methylmercury from biological samples

    USGS Publications Warehouse

    Simon, N.S.

    1997-01-01

    Using the coupled methods presented in this paper, methylmercury can be accurately and rapidly extracted from biological samples by modified supercritical fluid carbon dioxide and quantitated using liquid chromatography with reductive electrochemical detection. Supercritical fluid carbon dioxide modified with methanol effectively extracts underivatized methylmercury from certified reference materials Dorm-1 (dogfish muscle) and Dolt-2 (dogfish liver). Calcium chloride and water, with a ratio of 5:2 (by weight), provide the acid environment required for extracting methylmercury from sample matrices. Methylmercury chloride is separated from other organomercury chloride compounds using HPLC. The acidic eluent, containing 0.06 mol L-1 NaCl, insures the presence of methylmercury chloride and facilitates the reduction of mercury on a glassy carbon electrode. If dual glassy carbon electrodes are used, a positive peak is observed at -0.65 to -0.70 V and a negative peak is observed at -0.90V with the organomercury compounds that were tested. The practical detection limit for methylmercury is 5 X 10-8 mol L-1 (1 X 10-12 tool injected) when a 20 ??L injection loop is used.

  8. A high-pressure cryocooling method for protein crystals and biological samples with reduced background X-ray scatter

    PubMed Central

    Kim, Chae Un; Wierman, Jennifer L.; Gillilan, Richard; Lima, Enju; Gruner, Sol M.

    2013-01-01

    High-pressure cryocooling has been developed as an alternative method for cryopreservation of macromolecular crystals and successfully applied for various technical and scientific studies. The method requires the preservation of crystal hydration as the crystal is pressurized with dry helium gas. Previously, crystal hydration was maintained either by coating crystals with a mineral oil or by enclosing crystals in a capillary which was filled with crystallization mother liquor. These methods are not well suited to weakly diffracting crystals because of the relatively high background scattering from the hydrating materials. Here, an alternative method of crystal hydration, called capillary shielding, is described. The specimen is kept hydrated via vapor diffusion in a shielding capillary while it is being pressure cryocooled. After cryocooling, the shielding capillary is removed to reduce background X-ray scattering. It is shown that, compared to previous crystal-hydration methods, the new hydration method produces superior crystal diffraction with little sign of crystal damage. Using the new method, a weakly diffracting protein crystal may be properly pressure cryo­cooled with little or no addition of external cryoprotectants, and significantly reduced background scattering can be observed from the resulting sample. Beyond the applications for macromolecular crystallography, it is shown that the method has great potential for the preparation of noncrystalline hydrated biological samples for coherent diffraction imaging with future X-ray sources. PMID:23396891

  9. A monoclonal antibody-based competitive ELISA for the determination of ruscogenin in Chinese traditional medicines and biological samples.

    PubMed

    Xu, Yu; Liu, Ji-Hua; Wang, Jing; Zhang, Jian; Yu, Bo-Yang

    2014-10-01

    A competitive enzyme-linked immunosorbent assay (ELISA) was developed to determine ruscogenin (RUS) by using the monoclonal antibody (McAb). The monoclonal antibody against RUS, secreted from the established hybridoma cell lines, was identified as being of the IgG1 isotype. The McAb exhibited high specificity to RUS, showing a very slight cross reactivity with diosgenin (15.7%), and no cross-reactivity to sarsasapogenin, diammonium glycyrrhizinate, oleanolic acid and notoginsenoside R1. The established ELISA, at an IC50 value of 157.55 ng·mL(-1) and a detection limit (IC20) of 20.57 ng·mL(-1), was compared with HPLC analyses, and a good correlation between ELISA and HPLC-ELSD analyses of RUS in the extract of Radix Ophiopogonis was obtained. The experimental data indicated that the ELISA method exhibits more advantages over HPLC-ELSD, such as low detection limit, high specificity, low background, and no requirement for sample pre-treatment, and is more suitable for the determination of natural components in Chinese traditional medicines and in biological samples for pharmacokinetic studies.

  10. Estimating risk at a Superfund site using passive sampling devices as biological surrogates in human health risk models.

    PubMed

    Allan, Sarah E; Sower, Gregory J; Anderson, Kim A

    2011-10-01

    Passive sampling devices (PSDs) sequester the freely dissolved fraction of lipophilic contaminants, mimicking passive chemical uptake and accumulation by biomembranes and lipid tissues. Public Health Assessments that inform the public about health risks from exposure to contaminants through consumption of resident fish are generally based on tissue data, which can be difficult to obtain and requires destructive sampling. The purpose of this study is to apply PSD data in a Public Health Assessment to demonstrate that PSDs can be used as a biological surrogate to evaluate potential human health risks and elucidate spatio-temporal variations in risk. PSDs were used to measure polycyclic aromatic hydrocarbons (PAHs) in the Willamette River; upriver, downriver and within the Portland Harbor Superfund megasite for 3 years during wet and dry seasons. Based on an existing Public Health Assessment for this area, concentrations of PAHs in PSDs were substituted for fish tissue concentrations. PSD measured PAH concentrations captured the magnitude, range and variability of PAH concentrations reported for fish/shellfish from Portland Harbor. Using PSD results in place of fish data revealed an unacceptable risk level for cancer in all seasons but no unacceptable risk for non-cancer endpoints. Estimated cancer risk varied by several orders of magnitude based on season and location. Sites near coal tar contamination demonstrated the highest risk, particularly during the dry season and remediation activities. Incorporating PSD data into Public Health Assessments provides specific spatial and temporal contaminant exposure information that can assist public health professionals in evaluating human health risks.

  11. Sample preparation of biological macromolecular assemblies for the determination of high-resolution structures by cryo-electron microscopy.

    PubMed

    Stark, Holger; Chari, Ashwin

    2016-02-01

    Single particle cryo-EM has recently developed into a powerful tool to determine the 3D structure of macromolecular complexes at near-atomic resolution, which allows structural biologists to build atomic models of proteins. All technical aspects of cryo-EM technology have been considerably improved over the last two decades, including electron microscopic hardware, image processing software and the ever growing speed of computers. This leads to a more widespread use of the technique, and it can be anticipated that further automation of electron microscopes and image processing tools will soon fully shift the focus away from the technological aspects, onto biological questions that can be answered. In single particle cryo-EM, no crystals of a macromolecule are required. In contrast to X-ray crystallography, this significantly facilitates structure determination by cryo-EM. Nevertheless, a relatively high level of biochemical control is still essential to obtain high-resolution structures by cryo-EM, and it can be anticipated that the success of the cryo-EM technology goes hand in hand with further developments of sample purification and preparation techniques. This will allow routine high-resolution structure determination of the many macromolecular complexes of the cell that until now represent evasive targets for X-ray crystallographers. Here we discuss the various biochemical tools that are currently available and the existing sample purification and preparation techniques for cryo-EM grid preparation that are needed to obtain high-resolution images for structure determination. PMID:26671943

  12. Sensitive determination of fluoride in biological samples by gas chromatography-mass spectrometry after derivatization with 2-(bromomethyl)naphthalene.

    PubMed

    Kwon, Sun-Myung; Shin, Ho-Sang

    2014-12-10

    A gas chromatography-mass spectrometric method was developed in this study in order to determine fluoride in plasma and urine after derivatization with 2-(bromomethyl)naphthalene. 2-Fluoronaphthalene was chosen as the internal standard. The derivatization of fluoride was performed in the biological sample and the best reaction conditions (10.0 mg mL(-1) of 2-(bromomethyl)naphthalene, 1.0 mg mL(-1) of 15-crown-5-ether as a phase transfer catalyst, pH of 7.0, reaction temperature of 70°C, and heating time of 70 min) were established. The organic derivative was extracted with dichloromethane and then measured by a gas chromatography-mass spectrometry. Under the established condition, the detection limits were 11 μg L(-1) and 7 μg L(-1) by using 0.2 mL of plasma or urine, respectively. The accuracy was in a range of 100.8-107.6%, and the precision of the assay was less than 4.3% in plasma or urine. Fluoride was detected in a concentration range of 0.12-0.53 mg L(-1) in six urine samples after intake of natural mineral water containing 0.7 mg L(-1) of fluoride.

  13. Sample preparation of biological macromolecular assemblies for the determination of high-resolution structures by cryo-electron microscopy.

    PubMed

    Stark, Holger; Chari, Ashwin

    2016-02-01

    Single particle cryo-EM has recently developed into a powerful tool to determine the 3D structure of macromolecular complexes at near-atomic resolution, which allows structural biologists to build atomic models of proteins. All technical aspects of cryo-EM technology have been considerably improved over the last two decades, including electron microscopic hardware, image processing software and the ever growing speed of computers. This leads to a more widespread use of the technique, and it can be anticipated that further automation of electron microscopes and image processing tools will soon fully shift the focus away from the technological aspects, onto biological questions that can be answered. In single particle cryo-EM, no crystals of a macromolecule are required. In contrast to X-ray crystallography, this significantly facilitates structure determination by cryo-EM. Nevertheless, a relatively high level of biochemical control is still essential to obtain high-resolution structures by cryo-EM, and it can be anticipated that the success of the cryo-EM technology goes hand in hand with further developments of sample purification and preparation techniques. This will allow routine high-resolution structure determination of the many macromolecular complexes of the cell that until now represent evasive targets for X-ray crystallographers. Here we discuss the various biochemical tools that are currently available and the existing sample purification and preparation techniques for cryo-EM grid preparation that are needed to obtain high-resolution images for structure determination.

  14. Neutron capture autoradiographic determination of 10B distributions and concentrations in biological samples for boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Yanagie, Hironobu; Ogura, Koichi; Matsumoto, Toshio; Eriguchi, Masazumi; Kobayashi, Hisao

    1999-11-01

    It is necessary for effective boron neutron capture therapy (BNCT) to accumulate 10B atoms in the tumor cells. We prepared a cationic liposome entrapped 10B compound for the delivery system and examined the delivery capacity of 10B atoms to pancreatic cancer cell, AsPC-1, in vivo. It is required to achieve an accurate measurement of 10B distributions and concentrations in biological samples with a sensitivity in the ppm range for BNCT. We applied CR-39 (polyallyldiglycol carbonate) plastic track detectors to α-autoradiographic measurements of the 10B biodistribution in sliced whole-body samples of mice. To selectively desensitize undesirable proton tracks, we applied PEW (KOH+C 2H 5OH+H 2O) solution to the etching of CR-39 detector. The subsequent use of an alpha-track radiographic image analysis system enabled a discrimination between alpha tracks and recoiled proton tracks by the track size selection method. This enabled us to estimate quantitatively the distributions of 10B concentrations within the tissue sections by comparing with suitable standards.

  15. Towards a System Level Understanding of Non-Model Organisms Sampled from the Environment: A Network Biology Approach

    PubMed Central

    Williams, Tim D.; Turan, Nil; Diab, Amer M.; Wu, Huifeng; Mackenzie, Carolynn; Bartie, Katie L.; Hrydziuszko, Olga; Lyons, Brett P.; Stentiford, Grant D.; Herbert, John M.; Abraham, Joseph K.; Katsiadaki, Ioanna; Leaver, Michael J.; Taggart, John B.; George, Stephen G.; Viant, Mark R.; Chipman, Kevin J.; Falciani, Francesco

    2011-01-01

    The acquisition and analysis of datasets including multi-level omics and physiology from non-model species, sampled from field populations, is a formidable challenge, which so far has prevented the application of systems biology approaches. If successful, these could contribute enormously to improving our understanding of how populations of living organisms adapt to environmental stressors relating to, for example, pollution and climate. Here we describe the first application of a network inference approach integrating transcriptional, metabolic and phenotypic information representative of wild populations of the European flounder fish, sampled at seven estuarine locations in northern Europe with different degrees and profiles of chemical contaminants. We identified network modules, whose activity was predictive of environmental exposure and represented a link between molecular and morphometric indices. These sub-networks represented both known and candidate novel adverse outcome pathways representative of several aspects of human liver pathophysiology such as liver hyperplasia, fibrosis, and hepatocellular carcinoma. At the molecular level these pathways were linked to TNF alpha, TGF beta, PDGF, AGT and VEGF signalling. More generally, this pioneering study has important implications as it can be applied to model molecular mechanisms of compensatory adaptation to a wide range of scenarios in wild populations. PMID:21901081

  16. Preparation of 17β-estradiol surface molecularly imprinted polymers and their application to the analysis of biological samples.

    PubMed

    Zhang, Jing; Wang, Lingling; Han, Yanting

    2013-11-01

    17β-Estradiol (E2) surface molecularly imprinted polymers have been prepared using functionalized monodispersed poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads as a support. The resulting polymers were found to be uniform in size (5 μm), and the surfaces of the microspheres possessed large pore-like structures. A chromatographic experiment demonstrated that the resulting microspheres exhibited high levels of recognition and selectivity toward the target molecule. The particles were employed as a novel sorbent in a molecularly imprinted SPE protocol. A method was then developed involving the combination of the pretreatment with HPLC to determine the levels of estrogen secreted from Michigan Cancer Foundation-7 cells. The obtained results revealed that the extraction recoveries of E2 from real samples were in the range of 73.0-97.5% with RSDs of < 7.5% (n = 3). Calibration curves were established with R values > 0.9996 for concentrations in the range of 0.50-100.00 ng/mL. The LOD of this new method was 0.14 ng/mL. Compared with traditional C18 SPE agents, the particles showed high selectivity and extraction efficiency for E2 in the pretreatment process. The particles could therefore be used to determine trace estrogen in biological samples with a UV detector only.

  17. Towards a system level understanding of non-model organisms sampled from the environment: a network biology approach.

    PubMed

    Williams, Tim D; Turan, Nil; Diab, Amer M; Wu, Huifeng; Mackenzie, Carolynn; Bartie, Katie L; Hrydziuszko, Olga; Lyons, Brett P; Stentiford, Grant D; Herbert, John M; Abraham, Joseph K; Katsiadaki, Ioanna; Leaver, Michael J; Taggart, John B; George, Stephen G; Viant, Mark R; Chipman, Kevin J; Falciani, Francesco

    2011-08-01

    The acquisition and analysis of datasets including multi-level omics and physiology from non-model species, sampled from field populations, is a formidable challenge, which so far has prevented the application of systems biology approaches. If successful, these could contribute enormously to improving our understanding of how populations of living organisms adapt to environmental stressors relating to, for example, pollution and climate. Here we describe the first application of a network inference approach integrating transcriptional, metabolic and phenotypic information representative of wild populations of the European flounder fish, sampled at seven estuarine locations in northern Europe with different degrees and profiles of chemical contaminants. We identified network modules, whose activity was predictive of environmental exposure and represented a link between molecular and morphometric indices. These sub-networks represented both known and candidate novel adverse outcome pathways representative of several aspects of human liver pathophysiology such as liver hyperplasia, fibrosis, and hepatocellular carcinoma. At the molecular level these pathways were linked to TNF alpha, TGF beta, PDGF, AGT and VEGF signalling. More generally, this pioneering study has important implications as it can be applied to model molecular mechanisms of compensatory adaptation to a wide range of scenarios in wild populations.

  18. Estimating risk at a Superfund site using passive sampling devices as biological surrogates in human health risk models

    PubMed Central

    Allan, Sarah E.; Sower, Gregory J.; Anderson, Kim A.

    2013-01-01

    Passive sampling devices (PSDs) sequester the freely dissolved fraction of lipophilic contaminants, mimicking passive chemical uptake and accumulation by biomembranes and lipid tissues. Public Health Assessments that inform the public about health risks from exposure to contaminants through consumption of resident fish are generally based on tissue data, which can be difficulties to obtain and requires destructive sampling. The purpose of this study is to apply PSD data in a Public Health Assessment to demonstrate that PSDs can be used as a biological surrogate to evaluate potential human health risks and elucidate spatio-temporal variations in risk. PSDs were used to measure polycyclic aromatic hydrocarbons (PAHs) in the Willamette River; upriver, downriver and within the Portland Harbor Superfund megasite for three years during wet and dry seasons. Based on an existing Public Health Assessment for this area, concentrations of PAHs in PSDs were substituted for fish tissue concentrations. PSD measured PAH concentrations captured the magnitude, range and variability of PAH concentrations reported for fish/shellfish from Portland Harbor. Using PSD results in place of fish data revealed an unacceptable risk level for cancer in all seasons but no unacceptable risk for non-cancer endpoints. Estimated cancer risk varied by several orders of magnitude based on season and location. Sites near coal tar contamination demonstrated the highest risk, particularly during the dry season and remediation activities. Incorporating PSD data into Public Health Assessments provides specific spatial and temporal contaminant exposure information that can assist public health professionals in evaluating human health risks. PMID:21741671

  19. Personal air sampling and biological monitoring of occupational exposure to the soil fumigant cis-1,3-dichloropropene

    PubMed Central

    Brouwer, E; Verplanke, A; Boogaard, P; Bloemen, L; Van Sittert, N J; Christian, F; Stokkentreeff, M; Dijksterhuis, A; Mulder, A; De Wolff, F A

    2000-01-01

    OBJECTIVES—To assess exposure of commercial application workers to the nematocide cis-1,3-dichloropropene (cis-DCP).
METHODS—The study was conducted during the annual application season, August to 15 November, in the starch potato growing region in The Netherlands. 14 Application workers collected end of shift urine samples on each fumigation day (n=119). The mercapturic acid metabolite N-acetyl-S-(cis-3-chloro-2-propenyl)-L-cysteine (cis-DCP-MA) in urine was used for biological monitoring of the cis-DCP uptake. Inhalatory exposure was assessed by personal air sampling during a representative sample (n=37) of the fumigation days. Extensive information was collected on factors of possible relevance to the exposure and the application workers were observed for compliance with the statutory directions for use. The inhalatory exposure during all fumigation days was estimated from the relation between the personal air sampling data and the biological monitoring data. Exposure levels were correlated with the general work practice. The fumigation equipment and procedures were in accordance with the statutory directions of use, with the exception of the antidrip systems. Two antidrip systems were used: antidrip nozzles or a compressed air system.
RESULTS—The geometric mean exposure of the application workers was 2.7 mg/m3 (8 hour time weighted average); range 0.1-9.5 mg/m3. On 25 days (21%) the exposure exceeded the Dutch occupational exposure limit (OEL) of 5 mg/m3. This could mainly be explained by prolonged working days of more than 8 hours. The general work practice of the application workers was rated by the observers as good or poor. No difference in exposure to cis-DCP was found in the use of none, one, or two antidrip systems. Malfunctioning of the antidrip systems and lack of experience with the compressed air system were identified as possible causes for the lack of effectiveness of these antidrip systems. The use of personal protection was not

  20. Chemical Data for Rock, Sediment, Biological, Precipitate, and Water Samples from Abandoned Copper Mines in Prince William Sound, Alaska

    USGS Publications Warehouse

    Koski, Randolph A.; Munk, LeeAnn

    2007-01-01

    Introduction In the early 20th century, approximately 6 million metric tons of copper ore were mined from numerous deposits located along the shorelines of fjords and islands in Prince William Sound, Alaska. At the Beatson, Ellamar, and Threeman mine sites (fig. 1), rocks containing Fe, Cu, Zn, and Pb sulfide minerals are exposed to chemical weathering in abandoned mine workings and remnant waste piles that extend into the littoral zone. Field investigations in 2003 and 2005 as well as analytical data for rock, sediment, precipitate, water, and biological samples reveal that the oxidation of sulfides at these sites is resulting in the generation of acid mine drainage and the transport of metals into the marine environment (Koski and others, 2008; Stillings and others, 2008). At the Ellamar and Threeman sites, plumes of acidic and metal-enriched water are flowing through beach gravels into the shallow offshore environment. Interstitial water samples collected from beach sediment at Ellamar have low pH levels (to ~3) and high concentrations of metals including iron, copper, zinc, cobalt, lead, and mercury. The abundant precipitation of the iron sulfate mineral jarosite in the Ellamar gravels also signifies a low-pH environment. At the Beatson mine site (the largest copper mine in the region) seeps containing iron-rich microbial precipitates drain into the intertidal zone below mine dumps (Foster and others, 2008). A stream flowing down to the shoreline from underground mine workings at Beatson has near-neutral pH, but elevated levels of zinc, copper, and lead (Stillings and others, 2008). Offshore sediment samples at Beatson are enriched in these metals. Preliminary chemical data for tissue from marine mussels collected near the Ellamar, Threeman, and Beatson sites reveal elevated levels of copper, zinc, and lead compared to tissue in mussels from other locations in Prince William Sound (Koski and others, 2008). Three papers presenting results of this ongoing

  1. Chemical Data for Rock, Sediment, Biological, Precipitate, and Water Samples from Abandoned Copper Mines in Prince William Sound, Alaska

    USGS Publications Warehouse

    Koski, Randolph A.; Munk, LeeAnn

    2007-01-01

    In the early 20th century, approximately 6 million metric tons of copper ore were mined from numerous deposits located along the shorelines of fjords and islands in Prince William Sound, Alaska. At the Beatson, Ellamar, and Threeman mine sites (fig. 1), rocks containing Fe, Cu, Zn, and Pb sulfide minerals are exposed to chemical weathering in abandoned mine workings and remnant waste piles that extend into the littoral zone. Field investigations in 2003 and 2005 as well as analytical data for rock, sediment, precipitate, water, and biological samples reveal that the oxidation of sulfides at these sites is resulting in the generation of acid mine drainage and the transport of metals into the marine environment (Koski and others, 2008; Stillings and others, 2008). At the Ellamar and Threeman sites, plumes of acidic and metal-enriched water are flowing through beach gravels into the shallow offshore environment. Interstitial water samples collected from beach sediment at Ellamar have low pH levels (to ~3) and high concentrations of metals including iron, copper, zinc, cobalt, lead, and mercury. The abundant precipitation of the iron sulfate mineral jarosite in the Ellamar gravels also signifies a low-pH environment. At the Beatson mine site (the largest copper mine in the region) seeps containing iron-rich microbial precipitates drain into the intertidal zone below mine dumps (Foster and others, 2008). A stream flowing down to the shoreline from underground mine workings at Beatson has near-neutral pH, but elevated levels of zinc, copper, and lead (Stillings and others, 2008). Offshore sediment samples at Beatson are enriched in these metals. Preliminary chemical data for tissue from marine mussels collected near the Ellamar, Threeman, and Beatson sites reveal elevated levels of copper, zinc, and lead compared to tissue in mussels from other locations in Prince William Sound (Koski and others, 2008). Three papers presenting results of this ongoing investigation of

  2. Stable isotope gas chromatography-tandem mass spectrometry determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples.

    PubMed

    Tsikas, Dimitrios; Evans, Christopher E; Denton, Travis T; Mitschke, Anja; Gutzki, Frank-Mathias; Pinto, John T; Khomenko, Tetyana; Szabo, Sandor; Cooper, Arthur J L

    2012-11-01

    Aminoethylcysteine ketimine decarboxylated dimer (AECK-DD; systematic name: 1,2-3,4-5,6-7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one) is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, and cells in culture and vegetables and to possess potent antioxidative properties. Here, we describe a stable isotope gas chromatography-tandem mass spectrometry (GC-MS/MS) method for specific and sensitive determination of AECK-DD in biological samples. (13)C(2)-labeled AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected reaction monitoring of the mass transitions m/z 328 to 268 for AECK-DD and m/z 330 to 270 for [(13)C(2)]AECK-DD in the electron capture negative ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above approximately 4nM but was present in urine samples of healthy humans at a maximal concentration of 46nM. AECK-DD was detectable in rat brain at very low levels of approximately 8pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (∼1nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (∼6.8pmol/g fresh tissue).

  3. Stable isotope gas chromatography-tandem mass spectrometry determination of aminoethylcysteine ketimine decarboxylated dimer in biological samples.

    PubMed

    Tsikas, Dimitrios; Evans, Christopher E; Denton, Travis T; Mitschke, Anja; Gutzki, Frank-Mathias; Pinto, John T; Khomenko, Tetyana; Szabo, Sandor; Cooper, Arthur J L

    2012-11-01

    Aminoethylcysteine ketimine decarboxylated dimer (AECK-DD; systematic name: 1,2-3,4-5,6-7,8-octahydro-1,8a-diaza-4,6-dithiafluoren-9(8aH)-one) is a previously described metabolite of cysteamine that has been reported to be present in mammalian brain, urine, plasma, and cells in culture and vegetables and to possess potent antioxidative properties. Here, we describe a stable isotope gas chromatography-tandem mass spectrometry (GC-MS/MS) method for specific and sensitive determination of AECK-DD in biological samples. (13)C(2)-labeled AECK-DD was synthesized and used as the internal standard. Derivatization was carried out by N-pentafluorobenzylation with pentafluorobenzyl bromide in acetonitrile. Quantification was performed by selected reaction monitoring of the mass transitions m/z 328 to 268 for AECK-DD and m/z 330 to 270 for [(13)C(2)]AECK-DD in the electron capture negative ion chemical ionization mode. The procedure was systematically validated for human plasma and urine samples. AECK-DD was not detectable in human plasma above approximately 4nM but was present in urine samples of healthy humans at a maximal concentration of 46nM. AECK-DD was detectable in rat brain at very low levels of approximately 8pmol/g wet weight. Higher levels of AECK-DD were detected in mouse brain (∼1nmol/g wet weight). Among nine dietary vegetables evaluated, only shallots were found to contain trace amounts of AECK-DD (∼6.8pmol/g fresh tissue). PMID:22858756

  4. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    ERIC Educational Resources Information Center

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  5. Visualization of 30 nm structures in frozen-hydrated biological samples by cryo transmission X-ray microscopy

    NASA Astrophysics Data System (ADS)

    Schneider, G.; Niemann, B.; Guttmann, P.; Weiß, D.; Scharf, J.-G.; Rudolph, D.; Schmahl, G.

    2000-05-01

    A new object stage with extremely low thermal drift at -170 °C was developed for the cryo transmission X-ray microscope (cryo-TXM) at the electron storage ring BESSYI (Berlin). The new set-up enables high resolution studies of frozen-hydrated cells and was applied in investigations of cryogenic Kupffer cells from a rat liver. The ultrastructure and numerous X-ray dense vacuoles are resolved allowing a more comprehensive interpretation of data obtained by TEM studies. Furthermore, the cryo-TXM has been recently used for non-destructive computed tomography of intact frozen-hydrated objects. The resolution obtainable in TXM micrographs is limited significantly by the photon density applied to illuminate an object. The contrast transfer of the TXM was evaluated including the real X-ray optical elements with the help of a so-called multiple plane-wave model which is based on Fourier optics. It allowed to optimize the X-ray optical set-up for best contrast transfer and to minimize the photon density required to detect ice-embedded protein structures. However, the results show that details in biological objects smaller than 30 nm in size, e.g. single chromatin fibers in cell nuclei, can only be visualized if a drastically increased photon flux of the X-ray source is available from undulator insertion devices of electron storage rings. Furthermore, for this purpose new condenser concepts like a rotating condenser and highly efficient X-ray objectives with smallest zone structures of 20 nm have to be employed. This progress in the instrumentation will enable new applications ultimately resulting in artifact-free high-resolution images of radiation sensitive biological samples.

  6. A chemiluminescent assay for hydroperoxide level of phosphatidylcholine hydroperoxide fraction purified by two Sep-Pak cartridges in biological samples.

    PubMed

    Seya, K; Ohkohchi, N; Shibuya, H; Satoh, M; Oikawa, K; Fukumori, T; Satomi, S; Motomura, S

    2000-08-15

    A chemiluminescent assay for hydroperoxide level of phosphatidylcholine hydroperoxide (PCOOH) fraction purified from biological samples was presented. This method utilized of two Sep-Pak cartridges. A lipid soluble fraction was isolated from each homogenized tissue or blood by Folch's method. The mixture of phosphatidylcholine (PC) and PCOOH was separated from the lipid soluble fraction by a Sep-Pak silica cartridge. A Sep-Pak tC18 cartridge made complete separation of both PCOOH and PC possible. The hydroperoxide level of PCOOH fraction was quantified by the reaction with ferrous ion using 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one as a chemiluminescent dye. The mixture of positional isomers, 1-hexadecanoyl-2-[9, or 10-hydroperoxyl octadecanoyl]-sn-glycero-3-phosphocholine was used as an authentic standard. The good recovery rate for authentic PCOOH of 87.1 +/- 11.6% (mean +/- S.E., n = 4) was obtained by using two Sep-Pak cartridges. Linear calibration curve was obtained in the range from 2.5 to 20 nmol, and the detection limit of the standard was 10 pmol (signal-to-noise ratio > 3). This method was applied to the investigation of the lipid peroxidation induced by reperfusion of the liver with cold preservation, mimicking liver transplantation in rats. The effect of liposome-encapsulated dichloromethylene diphosphonate (LEDD), which eliminate of Kupffer cells to prevent the generation of oxygen radicals on the lipid peroxidation, was compared with the untreated group as a control. After 1 h reperfusion at 37 degrees C the hydroperoxide level obtained the liver without preservation in the untreated group was 12.4 +/- 2.4 nmol/100 mg lipid (n = 4) and levels increased significantly by prolongation of the preservation time. On the other hand, the hydroperoxide level in the LEDD treated group did not change up to 24 h preservation. These results suggest that this improved assay for hydroperoxide level of PCOOH fraction in biological

  7. Systematic Analysis of Main Constituents in Rat Biological Samples after Oral Administration of the Methanol Extract of Fructus Aurantii by HPLC-ESI-MS/MS

    PubMed Central

    Zhang, Jingze; Gao, Wenyuan; Liu, Zhen; Zhang, Zhidan; Liu, Changxiao

    2014-01-01

    High performance liquid chromatography (HPLC) with diode array detection (DAD) and electrospray ionization tandem mass spectrometry (ESI/MS/MS) was used to analyze the main components in the methanol extract of Fructus Aurantii (FA) and the metabolites in rat biological samples after oral administration of the methanol extract of FA. There were 31 constituents identified in the extract of FA including 2 alkaloids, 1 coumarin, 10 flavonoid glycosides and 18 ploymethoxylated flavones. According to the UV spectrum and MS fragment character of main components in the methanol extract of FA, 18 parent constituents and 11 metabolites were tentatively identified in rat biological samples. Three groups of components in biological samples detected included flavonoid glycosides, their glucuronides and ploymethoxylated flavones. It was interested that flavonoid glycosides, their glucuronides and ploymethoxylated flavones can be investigated in rat plasma and urine, while in rat feces samples only flavonoid glycosides were detected. Triglycosyl, naringenin, neoeriocitrin, neoeriocitrin narirutin and hesperidin were the main components in rat feces which were found either in the plasma or in urine samples. However, naringin and neohesperidin were the main flavonoid glycosides which absorbed after oral administration. Except flavonoid glycosides and their glucuronides, ploymethoxylated flavones also the constituents absorbed because it was investigated mainly in rat plasma and urine but not in feces samples. The identification and elucidation of parent and metabolism components analyzed in biological samples provided the data for further pharmacological and clinical research on FA. PMID:25237344

  8. Double-salting out assisted liquid-liquid extraction (SALLE) HPLC method for estimation of temozolomide from biological samples.

    PubMed

    Jain, Darshana; Athawale, Rajani; Bajaj, Amrita; Shrikhande, Shruti

    2014-11-01

    The role of temozolomide (TMZ) in treatment of high grade gliomas, melanomas and other malignancies is being defined by the current clinical developmental trials. Temozolomide belongs to the group of alkylating agents and is prescribed to patients suffering from most aggressive forms of brain tumors. The estimation techniques for temozolomide from the extracted plasma or biological samples includes high-performance liquid chromatography with UV detection (HPLC-UV), micellar electrokinetic capillary chromatography (MKEC) and liquid chromatography coupled to mass spectroscopy (LC-MS). These methods suffer from disadvantages like low resolution, low sensitivity, low recovery or cost involvement. An analytical method possessing capacity to estimate low quantities of TMZ in plasma samples with high extraction efficiency (%) and high resolution with cost effectiveness needs to be developed. Cost effective, robust and low plasma component interfering HPLC method using salting out liquid-liquid extraction (SALLE) technique was developed and validated for estimation of drug from plasma samples. The extraction efficiency (%) with conventional LLE technique with methanol, ethyl acetate, dichloromethane and acetonitrile was found to be 5.99±2.45, 45.39±4.56, 46.04±1.14 and 46.23±3.67 respectively. Extraction efficiency (%) improved with SALLE where sodium chloride was used as an electrolyte and was found to be 6.80±5.56, 52.01±3.13, 62.69±2.11 and 69.20±1.18 with methanol, ethyl acetate, dichloromethane and acetonitrile as organic solvent. Upon utilization of two salts for extraction (double salting liquid-liquid extraction) the extraction efficiency (%) was further improved and was twice of LLE. It was found that double salting liquid-liquid extraction technique yielded extraction efficiency (%) of 11.71±5.66, 55.62±3.44, 77.28±2.89 and 87.75±0.89. Hence a method based on double SALLE was developed for quantification of TMZ demonstrating linearity in the range of

  9. The analytical calibration in (bio)imaging/mapping of the metallic elements in biological samples--definitions, nomenclature and strategies: state of the art.

    PubMed

    Jurowski, Kamil; Buszewski, Bogusław; Piekoszewski, Wojciech

    2015-01-01

    Nowadays, studies related to the distribution of metallic elements in biological samples are one of the most important issues. There are many articles dedicated to specific analytical atomic spectrometry techniques used for mapping/(bio)imaging the metallic elements in various kinds of biological samples. However, in such literature, there is a lack of articles dedicated to reviewing calibration strategies, and their problems, nomenclature, definitions, ways and methods used to obtain quantitative distribution maps. The aim of this article was to characterize the analytical calibration in the (bio)imaging/mapping of the metallic elements in biological samples including (1) nomenclature; (2) definitions, and (3) selected and sophisticated, examples of calibration strategies with analytical calibration procedures applied in the different analytical methods currently used to study an element's distribution in biological samples/materials such as LA ICP-MS, SIMS, EDS, XRF and others. The main emphasis was placed on the procedures and methodology of the analytical calibration strategy. Additionally, the aim of this work is to systematize the nomenclature for the calibration terms: analytical calibration, analytical calibration method, analytical calibration procedure and analytical calibration strategy. The authors also want to popularize the division of calibration methods that are different than those hitherto used. This article is the first work in literature that refers to and emphasizes many different and complex aspects of analytical calibration problems in studies related to (bio)imaging/mapping metallic elements in different kinds of biological samples.

  10. An improved lectin-based method for the detection of mucin-type O-glycans in biological samples.

    PubMed

    Lee, Cheng-Siang; Muthusamy, Arivalagan; Abdul-Rahman, Puteri Shafinaz; Bhavanandan, Veer P; Hashim, Onn Haji

    2013-06-21

    Mucins and mucin-type glycoproteins, collectively referred to as mucin-type O-glycans, are implicated in many important biological functions and pathological conditions, including malignancy. Presently, there is no reliable method to measure the total mucin-type O-glycans of a sample, which may contain one or more of these macromolecules of unknown structures. We report the development of an improved microassay that is based on the binding of lectins to the unique and constant GalNAc-Ser/Thr structural feature of mucin-type O-glycans. Since the sugar-amino acid linkage in the mucin-type O-glycans is invariably cryptic, we first chemically removed the heterogeneous peripheral and core saccharides of model glycoconjugates before examining for their interactions using an enzyme-linked lectin assay (ELLA). Desialylation of the model glycoconjugates led to maximal binding of the lectins but additional treatments such as Smith degradation did not result in increased binding. Of the lectins tested for their ability to probe the desialylated O-glycans, jacalin showed the highest sensitivity followed by champedak galactose binding (CGB) lectin and Vicia villosa agglutinin. Further improvement in the sensitivity of ELLA was achieved by using microtiter plates that were pre-coated with the CGB lectin, which increased the specificity of the assay to mucin-type O-glycans. Finally, the applicability of the developed sandwich ELLA to crude samples was demonstrated by estimating trace quantities of the mucin-type O-glycans in the human serum.

  11. High temperature liquid chromatography-inductively coupled plasma mass spectrometry for the determination of arsenosugars in biological samples.

    PubMed

    Terol, Amanda; Ardini, Francisco; Grotti, Marco; Todolí, José Luis

    2012-11-01

    The potential of high temperature liquid chromatography (HTLC) with detection by inductively coupled plasma mass spectrometry (ICP-MS) for the determination of arsenosugars in marine organisms was examined for the first time. The retention behavior of four naturally occurring dimethylarsinoylribosides was studied on a graphite column using plain water as mobile phase. An aqueous solution of pH 8, ionic strength 13.8mM and containing 2% (v/v) of methanol, along with a column temperature of 120°C and a liquid flow rate of 1.0 mL/min, were selected as the optimal conditions, as they allowed the separation of the four arsenosugars in less than 18 min, without any interferences due to other common arsenic species (arsenite, arsenate, dimethylarsinate, methylarsonate and arsenobetaine). The run time could be further decreased to 12 min by working at 1.5 mL/min, although with a 3-4 times loss of sensitivity. The procedural limits of detection were 0.03-0.04 μg As/g dry mass, and the precision of the procedure ranged from 4% for arsenosugar glycerol to 18% for arsenosugar sulfate (RSD%, n=5). The developed method was applied to a number of representative biological samples, such as algae and crustaceans, providing results consistent with previous studies. In the red algae samples, the most of extracted arsenic was as arsenosugars (81-97%), mainly arsenosugar phosphate (56-94%). On the other hand, lower concentrations of these compounds were found in the crustacean, accounting for about 15% of the extracted arsenic.

  12. Enhanced prion detection in biological samples by magnetic particle extraction and real-time quaking-induced conversion.

    PubMed

    Denkers, Nathaniel D; Henderson, Davin M; Mathiason, Candace K; Hoover, Edward A

    2016-08-01

    Prions have been demonstrated in body fluids and excreta using bioassay, but at levels too low for detection by conventional direct-detection assays. More rapid and sensitive detection of prions in these clinically accessible specimens would be valuable for diagnosis and investigations of transmission, environmental impact, and interventions. In addition to very low concentrations of prions, in vitro amplification assays are challenged by the presence of inhibitors in these complex sources. Here, we leverage the prion attribute of avid metal binding with the versatile power of real-time quaking-induced conversion (RT-QuIC) to enhance and simplify detection of chronic wasting-disease prions in biological samples. Iron oxide particle binding and magnetic extraction combined with RT-QuIC permitted rapid analysis of the low concentrations of prions in saliva, urine, faeces, and cerebrospinal fluid. These methods are pertinent to ante-mortem detection, monitoring, and surveillance, and could conceivably be applicable to other protein-misfolding disorders. PMID:27233771

  13. Novel optical fiber reflectometric CUPRAC sensor for total antioxidant capacity measurement of food extracts and biological samples.

    PubMed

    Bener, Mustafa; Özyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

    2013-09-01

    A novel fiber optic sensor was developed for screening the total antioxidant capacity (TAC) based on the use of cupric-neocuproine (Cu(II)-Nc) immobilized onto a Nafion cation-exchange membrane with reflectance spectrometric measurement. The reflectance change associated with the formation of the highly colored Cu(I)-Nc chelate on the membrane as a result of reaction with antioxidants was measured at 530 nm by using a miniature reflectance spectrometer. The calibration graph of trolox (TR) was linear with a slope of 3.40 × 10(3) L mol(-1) mm(-1). The limit of detection (LOD) and limit of quantification (LOQ) for TR in the reflectometric cupric reducing antioxidant capacity (CUPRAC) method were found as 0.53 and 1.76 μM, respectively. The trolox equivalent antioxidant capacities (TEAC) of various antioxidant compounds using the proposed method were comparable to those of the main CUPRAC assay. This assay was validated through linearity, additivity, precision, and recovery. The developed reflectance sensor was used to screen the TAC of some commercial fruit juices and mice tissue homogenates without preliminary treatment. The method is rapid, inexpensive, versatile, and nonlaborious, uses stable reagents on the sensor, and enables the in situ estimation of antioxidant capacity of food extracts and biological samples.

  14. 33S nuclear magnetic resonance spectroscopy of biological samples obtained with a laboratory model 33S cryogenic probe

    NASA Astrophysics Data System (ADS)

    Hobo, Fumio; Takahashi, Masato; Saito, Yuta; Sato, Naoki; Takao, Tomoaki; Koshiba, Seizo; Maeda, Hideaki

    2010-05-01

    S33 nuclear magnetic resonance (NMR) spectroscopy is limited by inherently low NMR sensitivity because of the quadrupolar moment and low gyromagnetic ratio of the S33 nucleus. We have developed a 10 mm S33 cryogenic NMR probe, which is operated at 9-26 K with a cold preamplifier and a cold rf switch operated at 60 K. The S33 NMR sensitivity of the cryogenic probe is as large as 9.8 times that of a conventional 5 mm broadband NMR probe. The S33 cryogenic probe was applied to biological samples such as human urine, bile, chondroitin sulfate, and scallop tissue. We demonstrated that the system can detect and determine sulfur compounds having SO42- anions and -SO3- groups using the S33 cryogenic probe, as the S33 nuclei in these groups are in highly symmetric environments. The NMR signals for other common sulfur compounds such as cysteine are still undetectable by the S33 cryogenic probe, as the S33 nuclei in these compounds are in asymmetric environments. If we shorten the rf pulse width or decrease the rf coil diameter, we should be able to detect the NMR signals for these compounds.

  15. Analytical methods for the quantification of bisphenol A, alkylphenols, phthalate esters, and perfluoronated chemicals in biological samples.

    PubMed

    Nakazawa, Hiroyuki; Iwasaki, Yusuke; Ito, Rie

    2014-01-01

    Our modern society has created a large number of chemicals that are used for the production of everyday commodities including toys, food packaging, cosmetic products, and building materials. We enjoy a comfortable and convenient lifestyle with access to these items. In addition, in specialized areas, such as experimental science and various medical fields, laboratory equipment and devices that are manufactured using a wide range of chemical substances are also extensively employed. The association between human exposure to trace hazardous chemicals and an increased incidence of endocrine disease has been recognized. However, the evaluation of human exposure to such endocrine disrupting chemicals is therefore imperative, and the determination of exposure levels requires the analysis of human biological materials, such as blood and urine. To obtain as much information as possible from limited sample sizes, highly sensitive and reliable analytical methods are also required for exposure assessments. The present review focuses on effective analytical methods for the quantification of bisphenol A (BPA), alkylphenols (APs), phthalate esters (PEs), and perfluoronated chemicals (PFCs), which are chemicals used in the production of everyday commodities. Using data obtained from liquid chromatography/mass spectrometry (LC/MS) and LC/MS/MS analyses, assessments of the risks to humans were also presented based on the estimated levels of exposure to PFCs.

  16. Chemical derivatization for enhancing sensitivity during LC/ESI-MS/MS quantification of steroids in biological samples: a review.

    PubMed

    Higashi, Tatsuya; Ogawa, Shoujiro

    2016-09-01

    Sensitive and specific methods for the detection, characterization and quantification of endogenous steroids in body fluids or tissues are necessary for the diagnosis, pathological analysis and treatment of many diseases. Recently, liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) has been widely used for these purposes due to its specificity and versatility. However, the ESI efficiency and fragmentation behavior of some steroids are poor, which lead to a low sensitivity. Chemical derivatization is one of the most effective methods to improve the detection characteristics of steroids in ESI-MS/MS. Based on this background, this article reviews the recent advances in chemical derivatization for the trace quantification of steroids in biological samples by LC/ESI-MS/MS. The derivatization in ESI-MS/MS is based on tagging a proton-affinitive or permanently charged moiety on the target steroid. Introduction/formation of a fragmentable moiety suitable for the selected reaction monitoring by the derivatization also enhances the sensitivity. The stable isotope-coded derivatization procedures for the steroid analysis are also described.

  17. Kinetic spectrophotometric method as a new strategy for the determination of vitamin B 9 in pharmaceutical and biological samples

    NASA Astrophysics Data System (ADS)

    Shishehbore, M. Reza; Sheibani, A.; Haghdost, A.

    2011-10-01

    In this study, a new method is proposed for the determination of trace amounts of folic acid (vitamin B 9). This method is based on the inhibitory effect of folic acid on the reaction of Thionine and bromate in sulfuric acid media. The reaction can be monitored spectrophotometrically by measuring the decrease in absorbance at 601 nm ( λmax). The effective variables on the reaction rate were investigated. Under optimum experimental conditions, the method allows to determine of the folic acid in a wide linear range with two linear segments. The limit of detection was 0.36 μg mL -1 of folic acid. Relative standard deviations of six replicate determinations of 5.0 and 50.0 μg mL -1 of folic acid were 1.18 and 1.02%, respectively. The interfering effect of the different species was also investigated. The method was evaluated by quantifying of folic acid in biological and pharmaceutical samples with satisfactory assay results.

  18. A New Sample Substrate for Imaging and Correlating Organic and Trace Metal Composition in Biological Cells and Tissues

    SciTech Connect

    Miller,L.; Wang, Q.; Smith, R.; Zhong, H.; Elliott, D.; Warren, J.

    2007-01-01

    Many disease processes involve alterations in the chemical makeup of tissue. Synchrotron-based infrared (IR) and X-ray fluorescence (XRF) microscopes are becoming increasingly popular tools for imaging the organic and trace metal compositions of biological materials, respectively, without the need for extrinsic labels or stains. Fourier transform infrared microspectroscopy (FTIRM) provides chemical information on the organic components of a material at a diffraction-limited spatial resolution of 2-10 {mu}m in the mid-infrared region. The synchrotron X-ray fluorescence (SXRF) microprobe is a complementary technique used to probe trace element content in the same systems with a similar spatial resolution. However to be most beneficial, it is important to combine the results from both imaging techniques on a single sample, which requires precise overlap of the IR and X-ray images. In this work, we have developed a sample substrate containing a gold grid pattern on its surface, which can be imaged with both the IR and X-ray microscopes. The substrate consists of a low trace element glass slide that has a gold grid patterned on its surface, where the major and minor parts of the grid contain 25 and 12 nm gold, respectively. This grid pattern can be imaged with the IR microscope because the reflectivity of gold differs as a function of thickness. The pattern can also be imaged with the SXRF microprobe because the Au fluorescence intensity changes with gold thickness. The tissue sample is placed on top of the patterned substrate. The grid pattern's IR reflectivity image and the gold SXRF image are used as fiducial markers for spatially overlapping the IR and SXRF images from the tissue. Results show that IR and X-ray images can be correlated precisely, with a spatial resolution of less than one pixel (i.e., 2-3 microns). The development of this new tool will be presented along with applications to paraffin-embedded metalloprotein crystals, Alzheimer's disease, and hair

  19. An assessment of the potential of laser-induced breakdown spectroscopy (LIBS) for the analysis of cesium in liquid samples of biological origin.

    PubMed

    Metzinger, Anikó; Kovács-Széles, Eva; Almási, István; Galbács, Gábor

    2014-01-01

    The present study describes the development of an analytical method for the determination of cesium in biological fluid samples (human urine and blood samples) by laser-induced breakdown spectroscopy (LIBS). The developed method is based on sample presentation by liquid-to-solid conversion, enhancing the emission signal by drying the liquid into small "pockets" created in a metal support (zinc plate), and allows the analysis to be carried out on as little as 1 μL of sample volume, in a closed sample cell. Absolute detection limits on the Cs I 852.1 nm spectral line were calculated by the IUPAC 3σ method to be 6 ng in the urine sample and 27 ng in the blood serum sample. It is estimated that LIBS may be used to detect highly elevated concentration levels of Cs in fluid samples taken from people potentially exposed to surges of Cs from non-natural sources.

  20. Evaluation of selenium in biological sample of arsenic exposed female skin lesions and skin cancer patients with related to non-exposed skin cancer patients.

    PubMed

    Kolachi, Nida F; Kazi, Tasneem G; Wadhwa, Sham K; Afridi, Hassan I; Baig, Jameel A; Khan, Sumaira; Shah, Faheem

    2011-08-01

    The antagonistic effects between selenium (Se) and arsenic (As) suggest that low Se status plays an important role in arsenism development. The objective of present study was to assess Se contents in biological samples of As exposed females have skin lesions and cancer with related to non-exposed skin cancer patients. The biological samples (blood and scalp hair) of As exposed group comprises, female skin cancer (ESC) patients admitted in cancer hospitals have skin lesions (ESL) and exposed referents have not both diseases (ER), belongs to As exposed area of Pakistan. For comparative purposes, age matched female skin cancerous patient (RP) and non-cancerous females (NER) belong to non-exposed areas were also selected. The As and Se in acid digests of biological samples were pre-concentrated by complexing with chelating agent (ammonium pyrrolidinedithiocarbamate), and resulted complexes were extracted into non-ionic extractant (Triton X-114), prior to analysis by electrothermal atomic absorption spectrometry. The enhancement factor of about 25 was obtained by pre-concentrating 10 mL of sample solutions. The accuracy of the optimized procedure was evaluated by using certified reference material (BCR 397) with certified values for Se and As and standard addition method at three concentration levels in real samples. No significant differences was observed (p>0.05) when comparing the values obtained by the proposed method, added and certified values of both elements. The biological samples of ESC patients had 2-3 folds higher As and lower Se levels as compared to RP (p<0.001). Understudied exposed referents have high level of As and lower Se contents as compared to referents subjects of non-exposed area (p<0.01). The higher concentration of As and lower levels of Se in biological samples of cancerous patients are consisted with reported studies.

  1. Scanning transmission ion microscopy mass measurements for quantitative trace element analysis within biological samples and validation using atomic force microscopy thickness measurements

    NASA Astrophysics Data System (ADS)

    Devès, Guillaume; Cohen-Bouhacina, Touria; Ortega, Richard

    2004-10-01

    We used the nuclear microprobe techniques, micro-PIXE (particle-induced X-ray emission), micro-RBS (Rutherford backscattering spectrometry) and scanning transmission ion microscopy (STIM) in order to perform the characterization of trace element content and spatial distribution within biological samples (dehydrated cultured cells, tissues). The normalization of PIXE results was usually expressed in terms of sample dry mass as determined by micro-RBS recorded simultaneously to micro-PIXE. However, the main limit of RBS mass measurement is the sample mass loss occurring during irradiation and which could be up to 30% of the initial sample mass. We present here a new methodology for PIXE normalization and quantitative analysis of trace element within biological samples based on dry mass measurement performed by mean of STIM. The validation of STIM cell mass measurements was obtained in comparison with AFM sample thickness measurements. Results indicated the reliability of STIM mass measurement performed on biological samples and suggested that STIM should be performed for PIXE normalization. Further information deriving from direct confrontation of AFM and STIM analysis could as well be obtained, like in situ measurements of cell specific gravity within cells compartment (nucleolus and cytoplasm).

  2. On the petrological, geochemical, and geophysical characterization of a returned Mars surface sample and the impact of biological sterilization on the analyses

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A study was conducted: to identify those experiments that could and should be done on a returned Martian sample in order to characterize its inorganic properties; to evaluate, insofar as can be done, the effects of potential biological sterilization of the sample by heating prior to its return; to identify particular analytical techniques needing further improvement in order to make optimum use of a returned sample; and to identify experiments to be done on simulants, with and without sterilization, that better define the limits of information available about the planet from analyses of returned samples.

  3. Exploring the cellular and tissue uptake of nanomaterials in a range of biological samples using multimodal nonlinear optical microscopy.

    PubMed

    Johnston, Helinor J; Mouras, Rabah; Brown, David M; Elfick, Alistair; Stone, Vicki

    2015-12-18

    The uptake of nanomaterials (NMs) by cells is critical in determining their potential biological impact, whether beneficial or detrimental. Thus, investigation of NM internalization by cells is a common consideration in hazard and efficacy studies. There are currently a number of approaches that are routinely used to investigate NM-cell interactions, each of which have their own advantages and limitations. Ideally, imaging modalities used to investigate NM uptake by cells should not require the NM to be labelled (e.g. with fluorophores) to facilitate its detection. We present a multimodal imaging approach employing a combination of label-free microscopies that can be used to investigate NM-cell interactions. Coherent anti-Stokes Raman scattering microscopy was used in combination with either two-photon photoluminescence or four-wave mixing (FWM) to visualize the uptake of gold or titanium dioxide NMs respectively. Live and fixed cell imaging revealed that NMs were internalized by J774 macrophage and C3A hepatocyte cell lines (15-31 μg ml(-1)). Sprague Dawley rats were exposed to NMs (intratracheal instillation, 62 μg) and NMs were detected in blood and lung leucocytes, lung and liver tissue, demonstrating that NMs could translocate from the exposure site. Obtained data illustrate that multimodal nonlinear optical microscopy may help overcome current challenges in the assessment of NM cellular uptake and biodistribution. It is therefore a powerful tool that can be used to investigate unlabelled NM cellular and tissue uptake in three dimensions, requires minimal sample preparation, and is applicable to live and fixed cells. PMID:26584818

  4. Exploring the cellular and tissue uptake of nanomaterials in a range of biological samples using multimodal nonlinear optical microscopy

    NASA Astrophysics Data System (ADS)

    Johnston, Helinor J.; Mouras, Rabah; Brown, David M.; Elfick, Alistair; Stone, Vicki

    2015-12-01

    The uptake of nanomaterials (NMs) by cells is critical in determining their potential biological impact, whether beneficial or detrimental. Thus, investigation of NM internalization by cells is a common consideration in hazard and efficacy studies. There are currently a number of approaches that are routinely used to investigate NM-cell interactions, each of which have their own advantages and limitations. Ideally, imaging modalities used to investigate NM uptake by cells should not require the NM to be labelled (e.g. with fluorophores) to facilitate its detection. We present a multimodal imaging approach employing a combination of label-free microscopies that can be used to investigate NM-cell interactions. Coherent anti-Stokes Raman scattering microscopy was used in combination with either two-photon photoluminescence or four-wave mixing (FWM) to visualize the uptake of gold or titanium dioxide NMs respectively. Live and fixed cell imaging revealed that NMs were internalized by J774 macrophage and C3A hepatocyte cell lines (15-31 μg ml-1). Sprague Dawley rats were exposed to NMs (intratracheal instillation, 62 μg) and NMs were detected in blood and lung leucocytes, lung and liver tissue, demonstrating that NMs could translocate from the exposure site. Obtained data illustrate that multimodal nonlinear optical microscopy may help overcome current challenges in the assessment of NM cellular uptake and biodistribution. It is therefore a powerful tool that can be used to investigate unlabelled NM cellular and tissue uptake in three dimensions, requires minimal sample preparation, and is applicable to live and fixed cells.

  5. Matrix effects break the LC behavior rule for analytes in LC-MS/MS analysis of biological samples

    PubMed Central

    Fang, Nianbai; Yu, Shanggong; Ronis, Martin JJ

    2015-01-01

    High-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are generally accepted as the preferred techniques for detecting and quantitating analytes of interest in biological matrices on the basis of the rule that one chemical compound yields one LC-peak with reliable retention time (Rt.). However, in the current study, we have found that under the same LC-MS conditions, the Rt. and shape of LC-peaks of bile acids in urine samples from animals fed dissimilar diets differed significantly among each other. To verify this matrix effect, 17 authentic bile acid standards were dissolved in pure methanol or in methanol containing extracts of urine from pigs consuming either breast milk or infant formula and analyzed by LC-MS/MS. The matrix components in urine from piglets fed formula significantly reduced the LC-peak Rt. and areas of bile acids. This is the first characterization of this matrix effect on Rt. in the literature. Moreover, the matrix effect resulted in an unexpected LC behavior: one single compound yielded two LC-peaks, which broke the rule of one LC-peak for one compound. The three bile acid standards which exhibited this unconventional LC behavior were chenodeoxycholic acid, deoxycholic acid, and glycocholic acid. One possible explanation for this effect is that some matrix components may have loosely bonded to analytes, which changed the time analytes were retained on a chromatography column and interfered with the ionization of analytes in the MS ion source to alter the peak area. This study indicates that a comprehensive understanding of matrix effects is needed towards improving the use of HPLC and LC-MS/MS techniques for qualitative and quantitative analyses of analytes in pharmacokinetics, proteomics/metabolomics, drug development, and sports drug testing, especially when LC-MS/MS data are analyzed by automation software where identification of an analyte is based on its exact molecular weight and Rt

  6. On the effect of experimental noise on the classification of biological samples using Raman micro-spectroscopy

    NASA Astrophysics Data System (ADS)

    Barton, Sinead J.; Kerr, Laura T.; Domijan, Katarina; Hennelly, Bryan M.

    2016-04-01

    Raman micro-spectroscopy is an optoelectronic technique that can be used to evaluate the chemical composition of biological samples and has been shown to be a powerful diagnostic tool for the investigation of various cancer related diseases including bladder, breast, and cervical cancer. Raman scattering is an inherently weak process with approximately 1 in 107 photons undergoing scattering and for this reason, noise from the recording system can have a significant impact on the quality of the signal, and its suitability for diagnostic classification. The main sources of noise in the recorded signal are shot noise, CCD dark current, and CCD readout noise. Shot noise results from the low signal photon count while dark current results from thermally generated electrons in the semiconductor pixels. Both of these noise sources are time dependent; readout noise is time independent but is inherent in each individual recording and results in the fundamental limit of measurement, arising from the internal electronics of the camera. In this paper, each of the aforementioned noise sources are analysed in isolation, and used to experimentally validate a mathematical model. This model is then used to simulate spectra that might be acquired under various experimental conditions including the use of different cameras, different source wavelength, and power etc. Simulated noisy datasets of T24 and RT112 cell line spectra are generated based on true cell Raman spectrum irradiance values (recorded using very long exposure times) and the addition of simulated noise. These datasets are then input to multivariate classification using Principal Components Analysis and Linear Discriminant Analysis. This method enables an investigation into the effect of noise on the sensitivity and specificity of Raman based classification under various experimental conditions and using different equipment.

  7. Applying a low energy HPGe detector gamma ray spectrometric technique for the evaluation of Pu/Am ratio in biological samples.

    PubMed

    Singh, I S; Mishra, Lokpati; Yadav, J R; Nadar, M Y; Rao, D D; Pradeepkumar, K S

    2015-10-01

    The estimation of Pu/(241)Am ratio in the biological samples is an important input for the assessment of internal dose received by the workers. The radiochemical separation of Pu isotopes and (241)Am in a sample followed by alpha spectrometry is a widely used technique for the determination of Pu/(241)Am ratio. However, this method is time consuming and many times quick estimation is required. In this work, Pu/(241)Am ratio in the biological sample was estimated with HPGe detector based measurements using gamma/X-rays emitted by these radionuclides. These results were compared with those obtained from alpha spectroscopy of sample after radiochemical analysis and found to be in good agreement. PMID:26141295

  8. Polymer monolithic capillary microextraction combined on-line with inductively coupled plasma MS for the determination of trace rare earth elements in biological samples.

    PubMed

    Zhang, Lin; Chen, Beibei; He, Man; Hu, Bin

    2013-07-01

    A rapid and sensitive method based on polymer monolithic capillary microextraction combined on-line with microconcentric nebulization inductively coupled plasma MS has been developed for the determination of trace/ultratrace rare earth elements in biological samples. For this purpose, the iminodiacetic acid modified poly(glycidyl methacrylate-trimethylolpropane trimethacrylate) monolithic capillary was prepared and characterized by SEM and FTIR spectroscopy. Factors affecting the extraction efficiency, such as sample pH, sample flow rate, sample/eluent volume, and coexisting ions were investigated in detail. Under the optimal conditions, the LODs for rare earth elements were in the range of 0.08 (Er) to 0.97 ng/L (Nd) with a sampling frequency of 8.5 h(-1), and the RSDs were between 1.5% (Sm) and 7.4% (Nd) (c = 20 ng/L, n = 7). The proposed method was successfully applied to the analysis of trace/ultratrace rare earth elements in human urine and serum samples, and the recoveries for the spiked samples were in the range of 82-105%. The developed method was simple, rapid, sensitive, and favorable for the analysis of trace/ultratrace rare earth elements in biological samples with limited sample volume.

  9. SAMPLE EXTRACTION AND GC-MS ANALYSIS FOR POLAR VOLATILE ORGANIC COMPOUNDS (PVOCS) IN LIQUID BIOLOGICAL MEDIA

    EPA Science Inventory

    Current approaches for assessing the cumulative exposures and effects from broad classes of environmental stressors incorporate the measurement of specific groups of endogenous compounds in human biological fluids. Recent focus has been on interpreting patterns of differentially...

  10. The use of high energy laser-plasma sources in soft X-ray contact microscopy of living biological samples

    NASA Astrophysics Data System (ADS)

    Batani, D.; Botto, C.; Moret, M.; Milani, M.; Lucchini, G.; Eidmann, K.; Cotelli, F.; Lora Lamia Donin, C.; Poletti, G.; Ford, T.; Stead, A.

    2002-11-01

    In this paper the results of an experiment on soft X-ray contact microscopy using a laser-plasma source are presented. A resolution of 50 nm has been achieved imaging pig sperm cells, while other specimens, such as algae and yeast cells, showed internal details, proving the technique to be a powerful tool for biological investigations. Original biological information has been obtained and the conditions for optimal image formation have been studied.

  11. "Shoot and Sense" Janus Micromotors-Based Strategy for the Simultaneous Degradation and Detection of Persistent Organic Pollutants in Food and Biological Samples.

    PubMed

    Rojas, D; Jurado-Sánchez, B; Escarpa, A

    2016-04-01

    A novel Janus micromotor-based strategy for the direct determination of diphenyl phthalate (DPP) in food and biological samples is presented. Mg/Au Janus micromotors are employed as novel analytical platforms for the degradation of the non-electroactive DPP into phenol, which is directly measured by difference pulse voltammetry on disposable screen-printed electrodes. The self-movement of the micromotors along the samples result in the generation of hydrogen microbubbles and hydroxyl ions for DPP degradation. The increased fluid transport improves dramatically the analytical signal, increasing the sensitivity while lowering the detection potential. The method has been successfully applied to the direct analysis of DPP in selected food and biological samples, without any sample treatment and avoiding any potential contamination from laboratory equipment. The developed approach is fast (∼5 min) and accurate with recoveries of ∼100%. In addition, efficient propulsion of multiple Mg/Au micromotors in complex samples has also been demonstrated. The advantages of the micromotors-assisted technology, i.e., disposability, portability, and the possibility to carry out multiple analysis simultaneously, hold considerable promise for its application in food and biological control in analytical applications with high significance. PMID:26938969

  12. [Micro-determination of fluoride in biological samples by pyrohydrolysis and flow-injection analysis using a fluoride ion-selective electrode].

    PubMed

    Itai, K

    1991-02-01

    An apparatus has been developed for the isolation of fluoride in biological samples through pyrohydrolysis. With this apparatus, it is possible to determine both organic and inorganic fluorocompounds with a recovery close to 100% and precision within 5%. The high recovery rate can be expected even for highly heat-resistant compounds such as CaF2, without using WO3 as a catalyst. For determination of the isolated fluoride, a separate apparatus was developed in which flow-injection analysis was used in conjunction with a fluoride ion-selective electrode as a detector. With this apparatus, fluoride in a sample solution with a volume as small as 0.2 ml, and at a concentration as low as 0.5 microgram/l, can be determined within 3 minutes with a precision of several percent. Combined use of the two apparatuses makes it possible to determine fluoride in different biological samples within 10-15 minutes with a precision of several percent, free from external contamination. By selecting suitable conditions for analysis and using a 1 g sample, it is possible to determine fluoride at a concentration as low as 5 ng/g. By employing these apparatuses, the fluoride content in different biological samples has been determine and the effectiveness of their use confirmed. PMID:2051632

  13. "Shoot and Sense" Janus Micromotors-Based Strategy for the Simultaneous Degradation and Detection of Persistent Organic Pollutants in Food and Biological Samples.

    PubMed

    Rojas, D; Jurado-Sánchez, B; Escarpa, A

    2016-04-01

    A novel Janus micromotor-based strategy for the direct determination of diphenyl phthalate (DPP) in food and biological samples is presented. Mg/Au Janus micromotors are employed as novel analytical platforms for the degradation of the non-electroactive DPP into phenol, which is directly measured by difference pulse voltammetry on disposable screen-printed electrodes. The self-movement of the micromotors along the samples result in the generation of hydrogen microbubbles and hydroxyl ions for DPP degradation. The increased fluid transport improves dramatically the analytical signal, increasing the sensitivity while lowering the detection potential. The method has been successfully applied to the direct analysis of DPP in selected food and biological samples, without any sample treatment and avoiding any potential contamination from laboratory equipment. The developed approach is fast (∼5 min) and accurate with recoveries of ∼100%. In addition, efficient propulsion of multiple Mg/Au micromotors in complex samples has also been demonstrated. The advantages of the micromotors-assisted technology, i.e., disposability, portability, and the possibility to carry out multiple analysis simultaneously, hold considerable promise for its application in food and biological control in analytical applications with high significance.

  14. Some Physical, Chemical, and Biological Parameters of Samples of Scleractinium Coral Aquaculture Skeleton Used for Reconstruction/Engineering of the Bone Tissue.

    PubMed

    Popov, A A; Sergeeva, N S; Britaev, T A; Komlev, V S; Sviridova, I K; Kirsanova, V A; Akhmedova, S A; Dgebuadze, P Yu; Teterina, A Yu; Kuvshinova, E A; Schanskii, Ya D

    2015-08-01

    Physical and chemical (phase and chemical composition, dynamics of resorption, and strength properties), and biological (cytological compatibility and scaffold properties of the surface) properties of samples of scleractinium coral skeletons from aquacultures of three types and corresponding samples of natural coral skeletons (Pocillopora verrucosa, Acropora formosa, and Acropora nobilis) were studied. Samples of scleractinium coral aquaculture skeleton of A. nobilis, A. formosa, and P. verrucosa met the requirements (all study parameters) to materials for osteoplasty and 3D-scaffolds for engineering of bone tissue.

  15. Silver nanoparticles attached to silica gel as a new solid phase adsorbent for preconcentration and determination of iron from biological samples

    NASA Astrophysics Data System (ADS)

    Khajeh, Mostafa; Dastafkan, Kamran

    2012-11-01

    In this study, an easy and fast procedure based on solid phase extraction was developed that is intended to pre-concentrate, separate, and determine trace amounts of Fe(III) ions in biological samples using flame atomic absorption spectrometry (FAAS). Silver nanoparticles coated with silica gel were modified by morin and then used as a sorbent. It was synthesized by mixing slurried silica gel with silver nitrate and sodium citrate. The effects of experimental conditions, including pH, sample and eluent flow rates, and the type and least amount of an eluent to the elute iron from the sorbent were studied, and optimum values of these parameters have been found. Under the optimum conditions, the limit of detection of this procedure for Fe(III) was 67 ng/l. The relative standard deviation (RSD%) was 2.5 % (n = 10, C = 0.5 mg/l). The developed procedure was used to determine iron in biological samples.

  16. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

    PubMed

    Schütz, C L; Brochhausen, C; Hampel, G; Iffland, D; Kuczewski, B; Otto, G; Schmitz, T; Stieghorst, C; Kratz, J V

    2012-10-01

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis.

  17. A microfluidic platform for precision small-volume sample processing and its use to size separate biological particles with an acoustic microdevice

    SciTech Connect

    Fong, Erika J.; Huang, Chao; Hamilton, Julie; Benett, William J.; Bora, Mihail; Burklund, Alison; Metz, Thomas R.; Shusteff, Maxim

    2015-11-23

    Here, a major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15–1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing.

  18. A microfluidic platform for precision small-volume sample processing and its use to size separate biological particles with an acoustic microdevice

    DOE PAGES

    Fong, Erika J.; Huang, Chao; Hamilton, Julie; Benett, William J.; Bora, Mihail; Burklund, Alison; Metz, Thomas R.; Shusteff, Maxim

    2015-11-23

    Here, a major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15–1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection,more » system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing.« less

  19. A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice

    PubMed Central

    Fong, Erika J.; Huang, Chao; Hamilton, Julie; Benett, William J.; Bora, Mihail; Burklund, Alison; Metz, Thomas R.; Shusteff, Maxim

    2015-01-01

    A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15–1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing. PMID:26651055

  20. Cryogenic coherent X-ray diffraction imaging of biological samples at SACLA: a correlative approach with cryo-electron and light microscopy.

    PubMed

    Takayama, Yuki; Yonekura, Koji

    2016-03-01

    Coherent X-ray diffraction imaging at cryogenic temperature (cryo-CXDI) allows the analysis of internal structures of unstained, non-crystalline, whole biological samples in micrometre to sub-micrometre dimensions. Targets include cells and cell organelles. This approach involves preparing frozen-hydrated samples under controlled humidity, transferring the samples to a cryo-stage inside a vacuum chamber of a diffractometer, and then exposing the samples to coherent X-rays. Since 2012, cryo-coherent diffraction imaging (CDI) experiments have been carried out with the X-ray free-electron laser (XFEL) at the SPring-8 Ångstrom Compact free-electron LAser (SACLA) facility in Japan. Complementary use of cryo-electron microscopy and/or light microscopy is highly beneficial for both pre-checking samples and studying the integrity or nature of the sample. This article reports the authors' experience in cryo-XFEL-CDI of biological cells and organelles at SACLA, and describes an attempt towards reliable and higher-resolution reconstructions, including signal enhancement with strong scatterers and Patterson-search phasing. PMID:26919369

  1. Cryogenic coherent X-ray diffraction imaging of biological samples at SACLA: a correlative approach with cryo-electron and light microscopy.

    PubMed

    Takayama, Yuki; Yonekura, Koji

    2016-03-01

    Coherent X-ray diffraction imaging at cryogenic temperature (cryo-CXDI) allows the analysis of internal structures of unstained, non-crystalline, whole biological samples in micrometre to sub-micrometre dimensions. Targets include cells and cell organelles. This approach involves preparing frozen-hydrated samples under controlled humidity, transferring the samples to a cryo-stage inside a vacuum chamber of a diffractometer, and then exposing the samples to coherent X-rays. Since 2012, cryo-coherent diffraction imaging (CDI) experiments have been carried out with the X-ray free-electron laser (XFEL) at the SPring-8 Ångstrom Compact free-electron LAser (SACLA) facility in Japan. Complementary use of cryo-electron microscopy and/or light microscopy is highly beneficial for both pre-checking samples and studying the integrity or nature of the sample. This article reports the authors' experience in cryo-XFEL-CDI of biological cells and organelles at SACLA, and describes an attempt towards reliable and higher-resolution reconstructions, including signal enhancement with strong scatterers and Patterson-search phasing.

  2. Matrix effects break the LC behavior rule for analytes in LC-MS/MS analysis of biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) are generally accepted as the preferred techniques for detecting and quantitating analytes of interest in biological matrices on the basis of the rule that one chemical compound yields one LC-...

  3. Integrating Math & Computer Skills in the Biology Classroom: An Example Using Spreadsheet Simulations to Teach Fundamental Sampling Concepts

    ERIC Educational Resources Information Center

    Ray, Darrell L.

    2013-01-01

    Students often enter biology programs deficient in the math and computational skills that would enhance their attainment of a deeper understanding of the discipline. To address some of these concerns, I developed a series of spreadsheet simulation exercises that focus on some of the mathematical foundations of scientific inquiry and the benefits…

  4. Measurement of X-ray mass attenuation coefficients in biological and geological samples in the energy range of 7-12keV.

    PubMed

    Trunova, Valentina; Sidorina, Anna; Kriventsov, Vladimir

    2014-10-17

    Information about X-ray mass attenuation coefficients in different materials is necessary for accurate X-ray fluorescent analysis. The X-ray mass attenuation coefficients for energy of 7-12keV were measured in biological (Mussel and Oyster tissues, blood, hair, liver, and Cabbage leaves) and geological (Baikal sludge, soil, and Alaskite granite) samples. The measurements were carried out at the EXAFS Station of Siberian Synchrotron Radiation Center (VEPP-3). Obtained experimental mass attenuation coefficients were compared with theoretical values calculated for some samples. PMID:25464176

  5. Measurement of X-ray mass attenuation coefficients in biological and geological samples in the energy range of 7-12keV.

    PubMed

    Trunova, Valentina; Sidorina, Anna; Kriventsov, Vladimir

    2014-10-17

    Information about X-ray mass attenuation coefficients in different materials is necessary for accurate X-ray fluorescent analysis. The X-ray mass attenuation coefficients for energy of 7-12keV were measured in biological (Mussel and Oyster tissues, blood, hair, liver, and Cabbage leaves) and geological (Baikal sludge, soil, and Alaskite granite) samples. The measurements were carried out at the EXAFS Station of Siberian Synchrotron Radiation Center (VEPP-3). Obtained experimental mass attenuation coefficients were compared with theoretical values calculated for some samples.

  6. Estimation of lead in biological samples of oral cancer patients chewing smokeless tobacco products by ionic liquid-based microextraction in a single syringe system.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Arain, Asma J; Afridi, Hassan I; Arain, Muhammad B; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Arain, Mariam S

    2015-08-01

    Several studies have reported that the chewing habit of smokeless tobacco (SLT) has been associated with oral cancer. The aim of the present study was to evaluate the trace levels of lead (Pb) in biological samples (blood, scalp hair) of oral cancer patients and referents of the same age group (range 30-60 years). As the concentrations of Pb are very low in biological samples, so a simple and efficient ionic liquid-based microextraction in a single syringe system has been developed, as a prior step to determination by flame atomic absorption spectrometry. In this procedure, the hydrophobic chelates of Pb with ammonium pyrrolidinedithiocarbamate (APDC) were extracted into fine droplets of 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] within a syringe while using Triton X-114 as a dispersant. Factors influencing the microextraction efficiency and determination, such as pH of the sample, volume of [C4MIM][PF6] and Triton X-114, ligand concentration, and incubation time, were studied. To validate the proposed method, certified reference materials were analyzed and the results of Pb(2+) were in good agreement with certified values. At optimum experimental values of significant variables, detection limit and enhancement factor were found to be 0.412 μg/L and 80, respectively. The coexisting ions showed no obvious negative outcome on Pb preconcentration. The proposed method was applied satisfactorily for the preconcentration of Pb(2+) in acid-digested SLT and biological samples of the study population. It was observed that oral cancer patients who consumed different SLT products have 2-3-fold higher levels of Pb in scalp hair and blood samples as compared to healthy referents (p < 0.001). While 31.4-50.8% higher levels of Pb were observed in referents chewing different SLT products as compared to nonconsumers (p < 0.01). PMID:25903188

  7. Estimation of lead in biological samples of oral cancer patients chewing smokeless tobacco products by ionic liquid-based microextraction in a single syringe system.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Arain, Asma J; Afridi, Hassan I; Arain, Muhammad B; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H; Arain, Mariam S

    2015-08-01

    Several studies have reported that the chewing habit of smokeless tobacco (SLT) has been associated with oral cancer. The aim of the present study was to evaluate the trace levels of lead (Pb) in biological samples (blood, scalp hair) of oral cancer patients and referents of the same age group (range 30-60 years). As the concentrations of Pb are very low in biological samples, so a simple and efficient ionic liquid-based microextraction in a single syringe system has been developed, as a prior step to determination by flame atomic absorption spectrometry. In this procedure, the hydrophobic chelates of Pb with ammonium pyrrolidinedithiocarbamate (APDC) were extracted into fine droplets of 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] within a syringe while using Triton X-114 as a dispersant. Factors influencing the microextraction efficiency and determination, such as pH of the sample, volume of [C4MIM][PF6] and Triton X-114, ligand concentration, and incubation time, were studied. To validate the proposed method, certified reference materials were analyzed and the results of Pb(2+) were in good agreement with certified values. At optimum experimental values of significant variables, detection limit and enhancement factor were found to be 0.412 μg/L and 80, respectively. The coexisting ions showed no obvious negative outcome on Pb preconcentration. The proposed method was applied satisfactorily for the preconcentration of Pb(2+) in acid-digested SLT and biological samples of the study population. It was observed that oral cancer patients who consumed different SLT products have 2-3-fold higher levels of Pb in scalp hair and blood samples as compared to healthy referents (p < 0.001). While 31.4-50.8% higher levels of Pb were observed in referents chewing different SLT products as compared to nonconsumers (p < 0.01).

  8. Analysis of sediment, water, and biological samples from the Bay Farm Borrow Area, San Francisco Bay, California

    SciTech Connect

    Thom, R.M.; Lefkovitz, L.F. )

    1991-08-01

    The Bay Farm Borrow Area (BFBA) of San Francisco Bay, California, is under consideration as a dredged-material disposal site by the US Army Corps of Engineers (USACE). As part of the analysis of the site, information is required on the quality of benthic biota, sediment, and water in the BFBA. The objective of this report was to provide data on infauna communities, sediment, and water chemistry from samples collected from the BFBA. The samples were collected, and the data will be analyzed by Science Applications International (SAIC). A total of four samples for sediment chemistry, four samples for water chemistry, and 7 samples for infauna communities were analyzed by the Battelle/Marine Sciences Laboratory (MSL). Water analyses included tests for dissolved organic carbon, total suspended solids, four metals, butyltins, polychlorinated biphenyls (PCBs), chlorinated pesticides, polynuclear aromatic hydrocarbons (PAHs), four phenols, and total phenol. Sediment samples were analyzed for percent solids, total organic carbon, total oil and grease, total petroleum hydrocarbons, grain size, 10 metals, butyltins, PCBs, chlorinated pesticides, PAHs, four phenols, and total phenol. The data along with controls and spike recovery analyses, are presented in tables, and the results are discussed in the text. The quality assurance/quality control criteria were met for the analyses as were the detection limits specified by the sponsor.

  9. Environmental and biological monitoring of persistent organic pollutants in waterbirds by non-invasive versus invasive sampling.

    PubMed

    Kocagöz, Rasih; Onmuş, Ortaç; Onat, İlgen; Çağdaş, Beste; Sıkı, Mehmet; Orhan, Hilmi

    2014-10-15

    Three main groups of persistent organic pollutants (POPs); namely organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) were quantified in water and sediment samples, as well as in various invasive and non-invasive samples from waterbirds in the Büyük Menderes River (BMR). Liver and muscle tissues, blood, and preen gland oil samples of yellow-legged gull (Larus michahellis) and Euroasian coot (Fulica atra) were collected both from the origin (Işıklı Lake) and the estuary (Söke) of the river, blood and preen gland oil samples of grey heron (Ardea cinerea) and pelican (Pelecanus crispus) were collected from the estuary only. In addition, non-hatched eggs from several above species and Mediterranean gull (Larus melanocephalus), in either station were collected. In all samples, POP contamination was measured and the potential usefulness of those invasive and non-invasive sampling for biomonitoring was evaluated. Activities of antioxidant enzymes were measured as potential indicators of POP exposure and of changes in the cellular defence. Venous blood proved to be a promising biomonitor for the concentrations in liver and muscle, especially for PCBs. Activities of antioxidant enzymes were correlated with the liver concentrations of several OCP congeners. The measured egg DDE concentrations were below the established threshold concentrations for the risk of hatch and reproductive success. PMID:24503014

  10. A data standard for sourcing fit-for-purpose biological samples in an integrated virtual network of biobanks.

    PubMed

    Quinlan, Philip R; Mistry, Gita; Bullbeck, Helen; Carter, Anne

    2014-06-01

    Human tissue biobanks are at the epicenter of clinical research, responsible for providing both clinical samples and annotated data. There is a need for large numbers of samples to provide statistical power to research studies, especially since treatment and diagnosis are becoming ever more personalized. A single biobank cannot provide sufficient numbers of samples to capture the full spectrum of any disease. Currently there is no infrastructure in the United Kingdom (UK) to integrate biobanks. Therefore the National Cancer Research Institute (NCRI) Confederation of Cancer Biobanks (CCB) Working Group 3 looked to establish a data standard to enable biobanks to communicate about the samples they hold and so facilitate the formation of an integrated national network of biobanks. The Working Group examined the existing data standards available to biobanks, such as the MIABIS standard, and compared these to the aims of the working group. The CCB-developed data standard has brought many improvements: (1) Where existing data standards have been developed, these have been incorporated, ensuring compatibility with other initiatives; (2) the standard was written with the expectation that it will be extended for specific disease areas, such as the Breast Cancer Campaign Tissue Bank (BCCTB) and the Strategic Tissue Repository Alliances Through Unified Methods (STRATUM) project; and (3) biobanks will be able to communicate about specific samples, as well as aggregated statistics. The development of this data standard will allow all biobanks to integrate and share information about the samples they hold, facilitating the possibility of a national portal for researchers to find suitable samples for research. In addition, the data standard will allow other clinical services, such as disease registries, to communicate with biobanks in a standardized format allowing for greater cross-discipline data sharing.

  11. Determination of plutonium-239, thorium-232, and natural uranium isotopic concentrations in biological samples using photofission track analysis

    NASA Astrophysics Data System (ADS)

    Parry, James Roswell

    Fission track analysis (FTA) has many uses in the scientific community including but not limited to geological dating, neutron flux mapping, and dose reconstruction. The common method of fission for FTA is through neutrons from a nuclear reactor. This dissertation investigates the use of bremsstrahlung radiation produced from an electron linear accelerator to induce fission in FTA samples. This provides a means of simultaneously measuring the amount of Pu-239, U-nat, and Th-232 in a single sample. The benefit of measuring the three isotopes simultaneously is the possible elimination of costly and time consuming chemical processing for dose reconstruction samples. Samples containing the three isotopes were irradiated in two different bremsstrahlung spectra and a neutron spectrum to determine the amount of Pu-239, U-nat, and Th-232 in the samples. The reaction rate from the calibration samples and the counted fission tracks on the samples were used in determining the concentration of each isotope in the samples. The results were accurate to within a factor of two or three, showing that the method can work to predict the concentrations of multiple isotopes in a sample. The limitations of current accelerators and detectors limits the application of this specific procedure to higher concentrations of isotopes. The method detection limits for Pu-239, U-nat, and Th-232 are 20 pCi, 1 fCi, and 0.4 flCI respectively. Analysis of extremely low concentrations of isotopes would require the use of different detectors such as quartz due to the embrittlement encountered in the Lexan at high exposures. Cracking of the Texan detectors started to appear at a fluence of about 2 x 1018 electrons from the accelerator. This may be partly due to the beam stop not being an adequate thickness. The procedure is likely limited to specialty applications for the near term. However, with the world concerns of exposure to depleted uranium, this procedure may find applications in this area since

  12. [Use of solubilization for the preparation of samples for determination of heavy metals in biological materials using atomic absorption spectrophotometry].

    PubMed

    Pfüller, U; Fuchs, V; Golbs, S; Ebert, E; Pfeifer, D

    1980-01-01

    Solubilisation was tested for its suitability to prepare organic samples for metal determination. Flameless atomic-absorption spectrophotometry was used as test method. Copper, manganese, zinc, and chromium levels were determined from various organ systems of Wistar rat, in response to "normal" feeding of pelletised standard feed. A comparison between experimentally established concentrations, on the one hand, and literature data, on the other, suggested that solubilisation was applicable with good success to the preparation of samples from which to determine reliable values, in ppm and ppb, of the above elements. PMID:7436671

  13. Fast quantification of α-lipoic acid in biological samples and dietary supplements using batch injection analysis with amperometric detection.

    PubMed

    Santos Pereira, Laise Nayra Dos; da Silva, Iranaldo Santos; Araújo, Thaylan Pinheiro; Tanaka, Auro Atsushi; Angnes, Lúcio

    2016-07-01

    Batch injection analysis (BIA) with amperometric detection, using a pyrolytic graphite electrode modified with cobalt phthalocyanine (PG/CoPc), was employed for determination of α-lipoic acid (ALA) in pharmaceutical product and in synthetic urine samples. The proposed BIA method is based on the application of a potential of +0.9V vs. Ag/AgCl, KCl sat, enabling quantification of ALA over a concentration range from 1.3×10(-6) to 1.0×10(-4)molL(-1), with a detection limit of 1.5×10(-8)molL(-1). A sampling rate of 180 injections per hour was attained and measurements of the reproducibility of successive injections (100µmolL(-1) ALA on the same electrode) showed a RSD of 2.11% for 40 successive injections. The new sensor was utilised for ALA quantification in a dietary pharmaceutical supplement and in synthetic urine and the results obtained for both samples were compared with parallel analysis using high performance liquid chromatography (HPLC), the method recommended by the United States Pharmacopeia. The results obtained were similar (at a 95% confidence level) and in the case of the synthetic urine sample (prepared with a known amount of ALA) the recovery was situated between 98.0% and 102.6%.

  14. Fast quantification of α-lipoic acid in biological samples and dietary supplements using batch injection analysis with amperometric detection.

    PubMed

    Santos Pereira, Laise Nayra Dos; da Silva, Iranaldo Santos; Araújo, Thaylan Pinheiro; Tanaka, Auro Atsushi; Angnes, Lúcio

    2016-07-01

    Batch injection analysis (BIA) with amperometric detection, using a pyrolytic graphite electrode modified with cobalt phthalocyanine (PG/CoPc), was employed for determination of α-lipoic acid (ALA) in pharmaceutical product and in synthetic urine samples. The proposed BIA method is based on the application of a potential of +0.9V vs. Ag/AgCl, KCl sat, enabling quantification of ALA over a concentration range from 1.3×10(-6) to 1.0×10(-4)molL(-1), with a detection limit of 1.5×10(-8)molL(-1). A sampling rate of 180 injections per hour was attained and measurements of the reproducibility of successive injections (100µmolL(-1) ALA on the same electrode) showed a RSD of 2.11% for 40 successive injections. The new sensor was utilised for ALA quantification in a dietary pharmaceutical supplement and in synthetic urine and the results obtained for both samples were compared with parallel analysis using high performance liquid chromatography (HPLC), the method recommended by the United States Pharmacopeia. The results obtained were similar (at a 95% confidence level) and in the case of the synthetic urine sample (prepared with a known amount of ALA) the recovery was situated between 98.0% and 102.6%. PMID:27154671

  15. Mouse skin tumor initiation-promotion and complete carcinogenesis bioassays: mechanisms and biological activities of emission samples.

    PubMed Central

    Nesnow, S; Triplett, L L; Slaga, T J

    1983-01-01

    Extracts of soots obtained from various sources were applied to the skin of mice in an effort to identify carcinogens in these mixtures and to link these materials to the etiology of human cancer. Samples of coal chimney soot, coke oven materials, industrial carbon black, oil shale soot, and gasoline vehicle exhaust materials have been examined by this method. The studies reported here have been constructed to compare the carcinogenic and tumorigenic potency of extracts from various particulate emissions: coke ovens, diesel and gasoline vehicles and a roofing tar pot. Automobile emission samples were obtained by collecting the diluted and cooled exhaust on Teflon-coated glass fiber filters. Coke oven and roofing tar samples were particulate emission samples collected by impaction and filtration. The organic components associated with each of the particles were extracted with dichloromethane and dermally applied to SENCAR mice. All agents were applied as tumor initiators by using a five-dose protocol. Selected extracts were also applied as complete carcinogens and as tumor promotors. Statistical analyses of the resulting tumor data were performed by using nonlinear Poisson and probit models. The results from these experiments provide a suitable data base for comparative potency estimation of complex mixtures. PMID:6825618

  16. Dissolution of biological samples in deep eutectic solvents: an approach for extraction of polycyclic aromatic hydrocarbons followed by liquid chromatography-fluorescence detection.

    PubMed

    Helalat-Nezhad, Zahra; Ghanemi, Kamal; Fallah-Mehrjardi, Mehdi

    2015-05-15

    A novel sample preparation method based on the complete dissolution of marine biological samples in choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent was developed for fast and efficient extraction of eight polycyclic aromatic hydrocarbons (PAHs) using minimum volumes of cyclohexane. The extracted PAHs were purified and then measured by high-performance liquid chromatography-fluorescence detection (HPLC-FL). The effect of key parameters on extraction recoveries and precision was investigated. At optimized conditions, the studied samples were dissolved under atmospheric pressure in ChCl-Ox (1:2) at 55°C for 30min, which is considerably lower than the temperature used in the classical and current methods. After dissolution, it took approximately 20min to quantitatively extract the PAHs from ChCl-Ox using 5mL cyclohexane. Depending on the analyte, the developed method was linear over the calibration range 1.0-250, 2.0-250, and 5.0-250ngg(-1), with r(2)>0.996. The detection limits of the method were between 0.50 and 3.08ngg(-1). The intra-day and inter-day precisions (based on the relative standard deviation, n=5) of the spiked PAHs at a concentration level of 50ngg(-1) were better than 12.6% and 13.3%, respectively. Individual PAH recoveries from spiked marine fish and macroalgae samples were in the range of 71.6% to 109.6%. For comparison, the spiked samples were also subjected to the Soxhlet extraction method. The simplicity of the procedure, high extraction efficiency, short analysis time, and use of safe and inexpensive components suggest the proposed method has a high potential for utilization in routine trace PAH analysis in biological samples.

  17. Dissolution of biological samples in deep eutectic solvents: an approach for extraction of polycyclic aromatic hydrocarbons followed by liquid chromatography-fluorescence detection.

    PubMed

    Helalat-Nezhad, Zahra; Ghanemi, Kamal; Fallah-Mehrjardi, Mehdi

    2015-05-15

    A novel sample preparation method based on the complete dissolution of marine biological samples in choline chloride-oxalic acid (ChCl-Ox) deep eutectic solvent was developed for fast and efficient extraction of eight polycyclic aromatic hydrocarbons (PAHs) using minimum volumes of cyclohexane. The extracted PAHs were purified and then measured by high-performance liquid chromatography-fluorescence detection (HPLC-FL). The effect of key parameters on extraction recoveries and precision was investigated. At optimized conditions, the studied samples were dissolved under atmospheric pressure in ChCl-Ox (1:2) at 55°C for 30min, which is considerably lower than the temperature used in the classical and current methods. After dissolution, it took approximately 20min to quantitatively extract the PAHs from ChCl-Ox using 5mL cyclohexane. Depending on the analyte, the developed method was linear over the calibration range 1.0-250, 2.0-250, and 5.0-250ngg(-1), with r(2)>0.996. The detection limits of the method were between 0.50 and 3.08ngg(-1). The intra-day and inter-day precisions (based on the relative standard deviation, n=5) of the spiked PAHs at a concentration level of 50ngg(-1) were better than 12.6% and 13.3%, respectively. Individual PAH recoveries from spiked marine fish and macroalgae samples were in the range of 71.6% to 109.6%. For comparison, the spiked samples were also subjected to the Soxhlet extraction method. The simplicity of the procedure, high extraction efficiency, short analysis time, and use of safe and inexpensive components suggest the proposed method has a high potential for utilization in routine trace PAH analysis in biological samples. PMID:25857544

  18. Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples.

    PubMed

    Hou, Xiaolin; Roos, Per

    2008-02-11

    The radiometric methods, alpha (alpha)-, beta (beta)-, gamma (gamma)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include (3)H, (14)C, (36)Cl, (41)Ca, (59,63)Ni, (89,90)Sr, (99)Tc, (129)I, (135,137)Cs, (210)Pb, (226,228)Ra, (237)Np, (241)Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed.

  19. Towards tender X-rays with Zernike phase-contrast imaging of biological samples at 50 nm resolution.

    PubMed

    Vartiainen, Ismo; Warmer, Martin; Goeries, Dennis; Herker, Eva; Reimer, Rudolph; David, Christian; Meents, Alke

    2014-07-01

    X-ray microscopy is a commonly used method especially in material science application, where the large penetration depth of X-rays is necessary for three-dimensional structural studies of thick specimens with high-Z elements. In this paper it is shown that full-field X-ray microscopy at 6.2 keV can be utilized for imaging of biological specimens with high resolution. A full-field Zernike phase-contrast microscope based on diffractive optics is used to study lipid droplet formation in hepatoma cells. It is shown that the contrast of the images is comparable with that of electron microscopy, and even better contrast at tender X-ray energies between 2.5 keV and 4 keV is expected.

  20. Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples.

    PubMed

    Hou, Xiaolin; Roos, Per

    2008-02-11

    The radiometric methods, alpha (alpha)-, beta (beta)-, gamma (gamma)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include (3)H, (14)C, (36)Cl, (41)Ca, (59,63)Ni, (89,90)Sr, (99)Tc, (129)I, (135,137)Cs, (210)Pb, (226,228)Ra, (237)Np, (241)Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed. PMID:18215644

  1. Beyond nC60: strategies for identification of transformation products of fullerene oxidation in aquatic and biological samples

    PubMed Central

    Pycke, Benny F. G.; Chao, Tzu-Chiao; Herckes, Pierre; Westerhoff, Paul

    2013-01-01

    Owing to their exceptional properties and versatility, fullerenes are in widespread use for numerous applications. Increased production and use of fullerenes will inevitably result in accelerated environmental release. However, study of the occurrence, fate, and transport of fullerenes in the environment is complicated because a variety of surface modifications can occur as a result of either intentional functionalization or natural processes. To gain a better understanding of the effect and risk of fullerenes on environmental health, it is necessary to acquire reliable data on the parent compounds and their congeners. Whereas currently established quantification methods generally focus on analysis of unmodified fullerenes, we discuss in this review the occurrence and analysis of oxidized fullerene congeners (i.e., their corresponding epoxides and polyhydroxylated derivatives) in the environment and in biological specimens. We present possible strategies for detection and quantification of parent nanomaterials and their various derivatives. PMID:22644149

  2. Atomization characteristics and direct determination of manganese and magnesium in biological samples using a magnetically altered thin-film plasma

    SciTech Connect

    Brewer, S.W. Jr.; Sacks, R.D.

    1988-09-01

    A magnetic field with peak value of 3.7 kG is used to improve the atomization characteristics of an electrically vaporized thin-film plasma for the direct determination of Mg and Mn in solid biological materials. Plasmas are generated by high-current capacitive discharges through 350-..mu..g Ag or Au thin films formed on polypropylene substrates. Radiation intensity vs time plots are compared with and without the magnetic field for the NBS materials bovine liver, oyster tissue, orchard leaves, citrus leaves, tomato leaves, and pine needles. Analytical standard for Mg are prepared from suspensions of MgO powder, and standards for Mn are prepared from aqueous solutions of Mn(NO/sub 3/)/sub 2/ or MnSO/sub 4/. Analytical accuracy usually is improved with the presence of the magnetic field.

  3. Direct online HPLC-CV-AFS method for traces of methylmercury without derivatisation: a matrix-independent method for urine, sediment and biological tissue samples.

    PubMed

    Brombach, Christoph-Cornelius; Gajdosechova, Zuzana; Chen, Bin; Brownlow, Andrew; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2015-01-01

    Mercury (Hg) is a global pollutant which occurs in different species, with methylmercury (MeHg) being the critical compound due to its neurotoxicity and bioaccumulation through the food chain. Methods for trace speciation of MeHg are therefore needed for a vast range of sample matrices, such as biological tissues, fluids, soils or sediments. We have previously developed an ultra-trace speciation method for methylmercury in water, based on a preconcentration HPLC cold vapour atomic fluorescence spectrometry (HPLC-CV-AFS) method. The focus of this work is mercury speciation in a variety of sample matrices to assess the versatility of the method. Certified reference materials were used where possible, and samples were spiked where reference materials were not available, e.g. human urine. Solid samples were submitted for commonly used digestion or extraction processes to obtain a liquid sample for injection into the analytical system. For MeHg in sediment samples, an extraction procedure was adapted to accommodate MeHg separation from high amounts of Hg(2+) to avoid an overload of the column. The recovery for MeHg determination was found to be in the range of 88-104% in fish reference materials (DOLT-2, DOLT-4, DORM-3), lobster (TORT-2), seaweed (IAEA-140/TM), sediments (ERM(®)-CC580) and spiked urine and has been proven to be robust, reliable, virtually matrix-independent and relatively cost-effective. Applications in the ultra-trace concentration range are possible using the preconcentration up to 200 mL, while for higher MeHg-containing samples, lower volumes can be applied. A comparison was carried out between species-specific isotope dilution gas chromatography inductively coupled plasma mass spectrometry (SSID-GC-ICP-MS) as the gold standard and HPLC-CV-AFS for biological tissues (liver, kidney and muscle of pilot whales), showing a slope of 1.008 and R (2) = 0.97, which indicates that the HPLC-CV-AFS method achieves well-correlated results for MeHg in

  4. Direct online HPLC-CV-AFS method for traces of methylmercury without derivatisation: a matrix-independent method for urine, sediment and biological tissue samples.

    PubMed

    Brombach, Christoph-Cornelius; Gajdosechova, Zuzana; Chen, Bin; Brownlow, Andrew; Corns, Warren T; Feldmann, Jörg; Krupp, Eva M

    2015-01-01

    Mercury (Hg) is a global pollutant which occurs in different species, with methylmercury (MeHg) being the critical compound due to its neurotoxicity and bioaccumulation through the food chain. Methods for trace speciation of MeHg are therefore needed for a vast range of sample matrices, such as biological tissues, fluids, soils or sediments. We have previously developed an ultra-trace speciation method for methylmercury in water, based on a preconcentration HPLC cold vapour atomic fluorescence spectrometry (HPLC-CV-AFS) method. The focus of this work is mercury speciation in a variety of sample matrices to assess the versatility of the method. Certified reference materials were used where possible, and samples were spiked where reference materials were not available, e.g. human urine. Solid samples were submitted for commonly used digestion or extraction processes to obtain a liquid sample for injection into the analytical system. For MeHg in sediment samples, an extraction procedure was adapted to accommodate MeHg separation from high amounts of Hg(2+) to avoid an overload of the column. The recovery for MeHg determination was found to be in the range of 88-104% in fish reference materials (DOLT-2, DOLT-4, DORM-3), lobster (TORT-2), seaweed (IAEA-140/TM), sediments (ERM(®)-CC580) and spiked urine and has been proven to be robust, reliable, virtually matrix-independent and relatively cost-effective. Applications in the ultra-trace concentration range are possible using the preconcentration up to 200 mL, while for higher MeHg-containing samples, lower volumes can be applied. A comparison was carried out between species-specific isotope dilution gas chromatography inductively coupled plasma mass spectrometry (SSID-GC-ICP-MS) as the gold standard and HPLC-CV-AFS for biological tissues (liver, kidney and muscle of pilot whales), showing a slope of 1.008 and R (2) = 0.97, which indicates that the HPLC-CV-AFS method achieves well-correlated results for MeHg in

  5. Monitoring of chlorsulfuron in biological fluids and water samples by molecular fluorescence using rhodamine B as fluorophore.

    PubMed

    Alesso, Magdalena; Escudero, Luis A; Talio, María Carolina; Fernández, Liliana P

    2016-11-01

    A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL(-1) CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259µgL(-1) and a limit of quantification of 0.866µgL(-1) were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories. PMID:27591634

  6. Speciation of inorganic and organometallic compounds in solid biological samples by thermal vaporization and plasma emission spectrometry

    SciTech Connect

    Hanamura, S.; Smith, B.W.; Winefordner, J.D.

    1983-11-01

    By means of thermal vaporization, inorganic, organic, and metallorganic species are separated and elemental emission in a microwave plasma is detected as a function of vaporization temperature. Solid samples of 250 mg or more are used to avoid problems with sample heterogeneity. The precision of characteristic appearance temperatures is +/-2/sup 0/C. The single electrode atmosphere pressure microwave plasma system is extremely tolerant to the introduction of water, organic solvents, and air. The measurement system contained a repetition wavelength scan device to allow background correction. The plasma temperature was 5500 K. The system was used to measure C, H, N, O, and Hg in orchard leaves and in tuna fish. 9 figures, 5 tables.

  7. Monitoring of chlorsulfuron in biological fluids and water samples by molecular fluorescence using rhodamine B as fluorophore.

    PubMed

    Alesso, Magdalena; Escudero, Luis A; Talio, María Carolina; Fernández, Liliana P

    2016-11-01

    A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL(-1) CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259µgL(-1) and a limit of quantification of 0.866µgL(-1) were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories.

  8. Estimated neutron-activation data for TFTR. Part II. Biological dose rate from sample-materials activation

    SciTech Connect

    Ku, L.; Kolibal, J.G.

    1982-06-01

    The neutron induced material activation dose rate data are summarized for the TFTR operation. This report marks the completion of the second phase of the systematic study of the activation problem on the TFTR. The estimations of the neutron induced activation dose rates were made for spherical and slab objects, based on a point kernel method, for a wide range of materials. The dose rates as a function of cooling time for standard samples are presented for a number of typical neutron spectrum expected during TFTR DD and DT operations. The factors which account for the variations of the pulsing history, the characteristic size of the object and the distance of observation relative to the standard samples are also presented.

  9. [Logistics of collection and transportation of biological samples and the organization of the central laboratory in the ELSA-Brasil].

    PubMed

    Fedeli, Ligia G; Vidigal, Pedro G; Leite, Claudia Mendes; Castilhos, Cristina D; Pimentel, Robércia Anjos; Maniero, Viviane C; Mill, Jose Geraldo; Lotufo, Paulo A; Pereira, Alexandre C; Bensenor, Isabela M

    2013-06-01

    The ELSA (Estudo Longitudinal de Saúde do Adulto - Brazilian Longitudinal Study for Adult Health) is a multicenter cohort study which aims at the identification of risk factors associated with type 2 diabetes and cardiovascular diseases in the Brazilian population. The paper describes the strategies for the collection, processing, transportation, and quality control of blood and urine tests in the ELSA. The study decided to centralize the tests at one single laboratory. The processing of the samples was performed at the local laboratories, reducing the weight of the material to be transported, and diminishing the costs of transportation to the central laboratory at the Universidade de São Paulo Hospital. The study included tests for the evaluation of diabetes, insulin resistance, dyslipidemia, electrolyte abnormalities, thyroid hormones, uric acid, hepatic enzyme abnormalities, inflammation, and total blood cell count. In addition, leukocyte DNA, urine, plasma and serum samples were stored. The central laboratory performed approximately 375,000 tests.

  10. Existing and emerging technologies for measuring stable isotope labelled retinol in biological samples: isotope dilution analysis of body retinol stores.

    PubMed

    Preston, Tom

    2014-01-01

    This paper discusses some of the recent improvements in instrumentation used for stable isotope tracer measurements in the context of measuring retinol stores, in vivo. Tracer costs, together with concerns that larger tracer doses may perturb the parameter under study, demand that ever more sensitive mass spectrometric techniques are developed. GCMS is the most widely used technique. It has high sensitivity in terms of sample amount and uses high resolution GC, yet its ability to detect low isotope ratios is limited by background noise. LCMSMS may become more accessible for tracer studies. Its ability to measure low level stable isotope tracers may prove superior to GCMS, but it is isotope ratio MS (IRMS) that has been designed specifically for low level stable isotope analysis through accurate analysis of tracer:tracee ratios (the tracee being the unlabelled species). Compound-specific isotope analysis, where GC is interfaced to IRMS, is gaining popularity. Here, individual 13C-labelled compounds are separated by GC, combusted to CO2 and transferred on-line for ratiometric analysis by IRMS at the ppm level. However, commercially-available 13C-labelled retinol tracers are 2 - 4 times more expensive than deuterated tracers. For 2H-labelled compounds, GC-pyrolysis-IRMS has now become more generally available as an operating mode on the same IRMS instrument. Here, individual compounds are separated by GC and pyrolysed to H2 at high temperature for analysis by IRMS. It is predicted that GC-pyrolysis-IRMS will facilitate low level tracer procedures to measure body retinol stores, as has been accomplished in the case of fatty acids and amino acids. Sample size requirements for GC-P-IRMS may exceed those of GCMS, but this paper discusses sample preparation procedures and predicts improvements, particularly in the efficiency of sample introduction.

  11. Public views on the donation and use of human biological samples in biomedical research: a mixed methods study

    PubMed Central

    Lewis, Celine; Clotworthy, Margaret; Hilton, Shona; Magee, Caroline; Robertson, Mark J; Stubbins, Lesley J; Corfield, Julie

    2013-01-01

    Objective A mixed methods study exploring the UK general public's willingness to donate human biosamples (HBSs) for biomedical research. Setting Cross-sectional focus groups followed by an online survey. Participants Twelve focus groups (81 participants) selectively sampled to reflect a range of demographic groups; 1110 survey responders recruited through a stratified sampling method with quotas set on sex, age, geographical location, socioeconomic group and ethnicity. Main outcome measures (1) Identify participants’ willingness to donate HBSs for biomedical research, (2) explore acceptability towards donating different types of HBSs in various settings and (3) explore preferences regarding use and access to HBSs. Results 87% of survey participants thought donation of HBSs was important and 75% wanted to be asked to donate in general. Responders who self-reported having some or good knowledge of the medical research process were significantly more likely to want to donate (p<0.001). Reasons why focus group participants saw donation as important included: it was a good way of reciprocating for the medical treatment received; it was an important way of developing drugs and treatments; residual tissue would otherwise go to waste and they or their family members might benefit. The most controversial types of HBSs to donate included: brain post mortem (29% would donate), eyes post mortem (35%), embryos (44%), spare eggs (48%) and sperm (58%). Regarding the use of samples, there were concerns over animal research (34%), research conducted outside the UK (35%), and research conducted by pharmaceutical companies (56%), although education and discussion were found to alleviate such concerns. Conclusions There is a high level of public support and willingness to donate HBSs for biomedical research. Underlying concerns exist regarding the use of certain types of HBSs and conditions under which they are used. Improved education and more controlled forms of consent for

  12. Use of the 1‐mm micro‐probe for metabolic analysis on small volume biological samples

    PubMed Central

    Serkova, Natalie J.; Freund, Amy S.; Brown, Jaimi L.

    2008-01-01

    Abstract Endogenous metabolites are promising diagnostic end‐points in cancer research. Clinical application of high‐resolution NMR spectroscopy is often limited by extremely low volumes of human specimens. In the present study, the use of the Bruker 1‐mm high‐resolution TXI micro‐probe was evaluated in the elucidation of metabolic profiles for three different clinical applications with limited sample sizes (body fluids, isolated cells and tissue biopsies). Sample preparation and 1H‐NMR metabolite quantification protocols were optimized for following oncology‐oriented applications: (i) to validate the absolute concentrations of citrate and spermine in human expressed prostatic specimens (EPS volumes 5 to 10 μl: prostate cancer application); (ii) to establish the metabolic profile of isolated human lymphocytes (total cell count 4 = 106: chronic myelogenous leukaemia application); (iii) to assess the metabolic composition of human head‐and‐neck cancers from mouse xenografts (biopsy weights 20 to 70 mg: anti‐cancer treatment application). In this study, the use of the Bruker 1‐mm micro‐probe provides a convenient way to measure and quantify endogenous metabolic profiles of samples with a very low volume/weight/cell count. PMID:19267884

  13. Liquid scintillation based quantitative measurement of dual radioisotopes (3H and 45Ca) in biological samples for bone remodeling studies

    PubMed Central

    Hui, Susanta K; Sharma, M; Bhattacharyya, M H

    2011-01-01

    Acute and prolonged bone complications associated with radiation and chemotherapy in cancer survivors underscore the importance of establishing a laboratory-based complementary dual-isotope tool to evaluate short- as well as long-term bone remodeling in an in vivo model. To address this need, a liquid scintillation dual-label method was investigated using different scintillation cocktails for quantitative measurement of 3H-tetracycline (3H-TC) and 45Ca as markers of bone turnover in mice. Individual samples were prepared over a wide range of known 45Ca/3H activity ratios. Results showed that 45Ca/3H activity ratios determined experimentally by the dual-label method were comparable to the known activity ratios (percentage difference ~2%), but large variations were found in samples with 45Ca/3H activity ratios in range of 2–10 (percentage difference ~ 20–30%). Urine and fecal samples from mice administered with both 3H-TC and 45Ca were analyzed with the dual-label method. Positive correlations between 3H and 45Ca in urine (R = 0.93) and feces (R = 0.83) indicate that 3H-TC and 45Ca can be interchangeably used to monitor longitudinal in vivo skeletal remodeling. PMID:21900015

  14. Determination of noble metals in biological samples by electrothermal vaporization inductively coupled plasma mass spectrometry, following cloud point extraction

    NASA Astrophysics Data System (ADS)

    Andreia Mesquita da Silva, Márcia; Lúcia Azzolin Frescura, Vera; José Curtius, Adilson

    2001-10-01

    A simple separation procedure for noble metals based on cloud point extraction is proposed. The analyte ions in aqueous acidic solution, obtained by the acid digestion of the samples, were complexed with O, O-diethyl-dithiophosphate and Triton X-114 was added as a non-ionic surfactant. By increasing the temperature up to the cloud point, a phase separation occurs, resulting in an aqueous phase and a surfactant-rich phase containing most of the analytes that were complexed. The metals in the surfactant-rich phase were determined by electrothermal vaporization inductively coupled plasma mass spectrometry. The extraction conditions as well as the instrumental parameters were optimized. Enrichment factors ranging from 7 (Rh) to 60 (Pt) and limits of detection from 0.6 (Pt) to 3.0 ng l -1 (Rh) were obtained in the digested samples. The extraction was not efficient for Ir. Among the reference materials analyzed in this work, only one (SRM 2670, urine) presented recommended values for Au and Pt. Due to the non-availability of adequate CRMs, accuracy was assessed by spiking known analyte amounts to the acid digests. Recoveries close to 100% were observed for all the studied elements but Ru. Poor agreement between found and recommended values was observed for non-digested urine sample, probably due to the carrier effect of co-extracted residual matrix components. However, good agreement was reached after urine acid mineralization.

  15. Biological Sampling and Analysis in Sinclair and Dyes Inlets, Washington: Chemical Analyses for 2007 Puget Sound Biota Study

    SciTech Connect

    Brandenberger, Jill M.; Suslick, Carolynn R.; Johnston, Robert K.

    2008-10-09

    Evaluating spatial and temporal trends in contaminant residues in Puget Sound fish and macroinvertebrates are the objectives of the Puget Sound Ambient Monitoring Program (PSAMP). In a cooperative effort between the ENVironmental inVESTment group (ENVVEST) and Washington State Department of Fish and Wildlife, additional biota samples were collected during the 2007 PSAMP biota survey and analyzed for chemical residues and stable isotopes of carbon (δ13C) and nitrogen (δ15N). Approximately three specimens of each species collected from Sinclair Inlet, Georgia Basin, and reference locations in Puget Sound were selected for whole body chemical analysis. The muscle tissue of specimens selected for chemical analyses were also analyzed for δ13C and δ15N to provide information on relative trophic level and food sources. This data report summarizes the chemical residues for the 2007 PSAMP fish and macro-invertebrate samples. In addition, six Spiny Dogfish (Squalus acanthias) samples were necropsied to evaluate chemical residue of various parts of the fish (digestive tract, liver, embryo, muscle tissue), as well as, a weight proportional whole body composite (WBWC). Whole organisms were homogenized and analyzed for silver, arsenic, cadmium, chromium, copper, nickel, lead, zinc, mercury, 19 polychlorinated biphenyl (PCB) congeners, PCB homologues, percent moisture, percent lipids, δ13C, and δ15N.

  16. On-line preconcentration/determination of zinc from water, biological and food samples using synthesized chelating resin and flame atomic absorption spectrometry.

    PubMed

    Yılmaz, Sibel; Tokalıoğlu, Serife; Sahan, Serkan; Ulgen, Ahmet; Sahan, Ahmet; Soykan, Cengiz

    2013-04-01

    An on-line flow injection pre-concentration-flame atomic absorption spectrometry method was developed to determine trace zinc in water (tap, dam, and well water), biological (hair and nail), and liver samples. As a solid phase extractant, a synthesized new chelating resin, poly(2-thiozylmethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was used. The resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, and surface area by nitrogen sorption. A pre-concentration factor of 40-fold for a sample volume of 12.6 mL was obtained by using the time-based technique. The detection limit for the pre-concentration method was found to be 2.2 μg L(-1). The precision (as RSD,%) for 10 replicate determinations at the 0.04 μg mL(-1) Zn concentration was 1.2%. The calibration graph using the pre-concentration system for zinc was linear with a correlation coefficient of 0.998 in the concentration range from 0.005 to 0.05 μg mL(-1). The applicability and accuracy of the developed method were estimated by the analysis spiked water, biological, liver samples (83-105%), and also certified reference material TMDA-70 (fortified lake water) and SPS-WW1 Batch 111-Wastewater. The results were in agreement with the certified values.

  17. Versatile sample environments and automation for biological solution X-ray scattering experiments at the P12 beamline (PETRA III, DESY)

    PubMed Central

    Blanchet, Clement E.; Spilotros, Alessandro; Schwemmer, Frank; Graewert, Melissa A.; Kikhney, Alexey; Jeffries, Cy M.; Franke, Daniel; Mark, Daniel; Zengerle, Roland; Cipriani, Florent; Fiedler, Stefan; Roessle, Manfred; Svergun, Dmitri I.

    2015-01-01

    A high-brilliance synchrotron P12 beamline of the EMBL located at the PETRA III storage ring (DESY, Hamburg) is dedicated to biological small-angle X-ray scattering (SAXS) and has been designed and optimized for scattering experiments on macromolecular solutions. Scatterless slits reduce the parasitic scattering, a custom-designed miniature active beamstop ensures accurate data normalization and the photon-counting PILATUS 2M detector enables the background-free detection of weak scattering signals. The high flux and small beam size allow for rapid experiments with exposure time down to 30–50 ms covering the resolution range from about 300 to 0.5 nm. P12 possesses a versatile and flexible sample environment system that caters for the diverse experimental needs required to study macromolecular solutions. These include an in-vacuum capillary mode for standard batch sample analyses with robotic sample delivery and for continuous-flow in-line sample purification and characterization, as well as an in-air capillary time-resolved stopped-flow setup. A novel microfluidic centrifugal mixing device (SAXS disc) is developed for a high-throughput screening mode using sub-microlitre sample volumes. Automation is a key feature of P12; it is controlled by a beamline meta server, which coordinates and schedules experiments from either standard or nonstandard operational setups. The integrated SASFLOW pipeline automatically checks for consistency, and processes and analyses the data, providing near real-time assessments of overall parameters and the generation of low-resolution models within minutes of data collection. These advances, combined with a remote access option, allow for rapid high-throughput analysis, as well as time-resolved and screening experiments for novice and expert biological SAXS users. PMID:25844078

  18. Simultaneous determination of trace levels of ethylmercury and methylmercury in biological samples and vaccines using sodium tetra(n-propyl)borate as derivatizing agent.

    PubMed

    Gibicar, Darija; Logar, Martina; Horvat, Nusa; Marn-Pernat, Andreja; Ponikvar, Rafael; Horvat, Milena

    2007-05-01

    Because of increasing awareness of the potential neurotoxicity of even low levels of organomercury compounds, analytical techniques are required for determination of low concentrations of ethylmercury (EtHg) and methylmercury (MeHg) in biological samples. An accurate and sensitive method has been developed for simultaneous determination of methylmercury and ethylmercury in vaccines and biological samples. MeHg and EtHg were isolated by acid leaching (H2SO4-KBr-CuSO4), extraction of MeHg and EtHg bromides into an organic solvent (CH2Cl2), then back-extraction into Milli-Q water. MeHg and EtHg bromides were derivatized with sodium tetrapropylborate (NaBPr4), collected at room temperature on Tenax, separated by isothermal gas chromatography (GC), pyrolysed, and detected by cold-vapour atomic fluorescence spectrometry (CV AFS). The repeatability of results from the method was approximately 5-10% for EtHg and 5-15% for MeHg. Detection limits achieved were 0.01 ng g-1 for EtHg and MeHg in blood, saliva, and vaccines and 5 ng g-1 for EtHg and MeHg in hair. The method presented has been shown to be suitable for determination of background levels of these contaminants in biological samples and can be used in studies related to the health effects of mercury and its species in man. This work illustrates the possibility of using hair and blood as potential biomarkers of exposure to thiomersal.

  19. Temperature-controlled micro-TLC: a versatile green chemistry and fast analytical tool for separation and preliminary screening of steroids fraction from biological and environmental samples.

    PubMed

    Zarzycki, Paweł K; Slączka, Magdalena M; Zarzycka, Magdalena B; Bartoszuk, Małgorzata A; Włodarczyk, Elżbieta; Baran, Michał J

    2011-11-01

    This paper is a continuation of our previous research focusing on development of micro-TLC methodology under temperature-controlled conditions. The main goal of present paper is to demonstrate separation and detection capability of micro-TLC technique involving simple analytical protocols without multi-steps sample pre-purification. One of the advantages of planar chromatography over its column counterpart is that each TLC run can be performed using non-previously used stationary phase. Therefore, it is possible to fractionate or separate complex samples characterized by heavy biological matrix loading. In present studies components of interest, mainly steroids, were isolated from biological samples like fish bile using single pre-treatment steps involving direct organic liquid extraction and/or deproteinization by freeze-drying method. Low-molecular mass compounds with polarity ranging from estetrol to progesterone derived from the environmental samples (lake water, untreated and treated sewage waters) were concentrated using optimized solid-phase extraction (SPE). Specific bands patterns for samples derived from surface water of the Middle Pomerania in northern part of Poland can be easily observed on obtained micro-TLC chromatograms. This approach can be useful as simple and non-expensive complementary method for fast control and screening of treated sewage water discharged by the municipal wastewater treatment plants. Moreover, our experimental results show the potential of micro-TLC as an efficient tool for retention measurements of a wide range of steroids under reversed-phase (RP) chromatographic conditions. These data can be used for further optimalization of SPE or HPLC systems working under RP conditions. Furthermore, we also demonstrated that micro-TLC based analytical approach can be applied as an effective method for the internal standard (IS) substance search. Generally, described methodology can be applied for fast fractionation or screening of the

  20. Temperature-controlled micro-TLC: a versatile green chemistry and fast analytical tool for separation and preliminary screening of steroids fraction from biological and environmental samples.

    PubMed

    Zarzycki, Paweł K; Slączka, Magdalena M; Zarzycka, Magdalena B; Bartoszuk, Małgorzata A; Włodarczyk, Elżbieta; Baran, Michał J

    2011-11-01

    This paper is a continuation of our previous research focusing on development of micro-TLC methodology under temperature-controlled conditions. The main goal of present paper is to demonstrate separation and detection capability of micro-TLC technique involving simple analytical protocols without multi-steps sample pre-purification. One of the advantages of planar chromatography over its column counterpart is that each TLC run can be performed using non-previously used stationary phase. Therefore, it is possible to fractionate or separate complex samples characterized by heavy biological matrix loading. In present studies components of interest, mainly steroids, were isolated from biological samples like fish bile using single pre-treatment steps involving direct organic liquid extraction and/or deproteinization by freeze-drying method. Low-molecular mass compounds with polarity ranging from estetrol to progesterone derived from the environmental samples (lake water, untreated and treated sewage waters) were concentrated using optimized solid-phase extraction (SPE). Specific bands patterns for samples derived from surface water of the Middle Pomerania in northern part of Poland can be easily observed on obtained micro-TLC chromatograms. This approach can be useful as simple and non-expensive complementary method for fast control and screening of treated sewage water discharged by the municipal wastewater treatment plants. Moreover, our experimental results show the potential of micro-TLC as an efficient tool for retention measurements of a wide range of steroids under reversed-phase (RP) chromatographic conditions. These data can be used for further optimalization of SPE or HPLC systems working under RP conditions. Furthermore, we also demonstrated that micro-TLC based analytical approach can be applied as an effective method for the internal standard (IS) substance search. Generally, described methodology can be applied for fast fractionation or screening of the

  1. Analytical approaches for MCPD esters and glycidyl esters in food and biological samples: a review and future perspectives.

    PubMed

    Crews, C; Chiodini, A; Granvogl, M; Hamlet, C; Hrnčiřík, K; Kuhlmann, J; Lampen, A; Scholz, G; Weisshaar, R; Wenzl, T; Jasti, P R; Seefelder, W

    2013-01-01

    Esters of 2 - and 3-monochloropropane-1,2-diol (MCPD) and glycidol esters are important contaminants of processed edible oils used as foods or food ingredients. This review describes the occurrence and analysis of MCPD esters and glycidol esters in vegetable oils and some other foods. The focus is on the analytical methods based on both direct and indirect methods. Methods of analysis applied to oils and lipid extracts of foods have been based on transesterification to free MCPD and determination by gas chromatography-mass spectrometry (indirect methods) and by high-performance liquid chromatography-mass spectrometry (direct methods). The evolution and performance of the different methods is described and their advantages and disadvantages are discussed. The application of direct and indirect methods to the analysis of foods and to research studies is described. The metabolism and fate of MCPD esters and glycidol esters in biological systems and the methods used to study these in body tissues studies are described. A clear understanding of the chemistry of the methods is important when choosing those suitable for the desired application, and will contribute to the mitigation of these contaminants.

  2. A specific method for measurement of equine active myeloperoxidase in biological samples and in in vitro tests.

    PubMed

    Franck, Thierry; Kohnen, S; Deby-Dupont, G; Grulke, S; Deby, C; Serteyn, D

    2006-07-01

    An original method called SIEFED (specific immunological extraction followed by enzymatic detection) was developed for the specific detection of the activity of equine myeloperoxidase (MPO). The method consists of the extraction of MPO from aqueous solutions by immobilized anti-MPO antibodies followed by washing (to eliminate proteins and interfering molecules) and measurement of MPO activity using a detection system containing a fluorogenic substrate, hydrogen peroxide, and nitrite as reaction enhancer. The SIEFED technique was applied to study active MPO in horse biological fluids and the effects of 2 polyphenolic molecules, curcumin and resveratrol, on MPO activity. The detection limit of the SIEFED was 0.23 mU/ml. The SIEFED exhibited good precision with intra-assay and interassay coefficients of variation below 10% and 20%, respectively, for MPO activities ranging from 0.25 to 6.4 mU/ml. The activity of MPO was generally higher than 1 mU/ml in the fluids collected from horses with inflammatory diseases. Curcumin and resveratrol exerted a dose-dependent inhibition on MPO activity and, as they were removed before the enzymatic detection of MPO, the results suggest a direct drug-nzyme interaction or an enzyme structure modification by the drug. The SIEFED is a new tool that would be useful for specific detection of active MPO in complex media and for selection of MPO activity modulators.

  3. Spatially Localized Two-Dimensional J-Resolved NMR Spectroscopy via Intermolecular Double-Quantum Coherences for Biological Samples at 7 T

    PubMed Central

    Tan, Chunhua; Cai, Shuhui; Huang, Yuqing

    2015-01-01

    Background and Purpose Magnetic resonance spectroscopy (MRS) constitutes a mainstream technique for characterizing biological samples. Benefiting from the separation of chemical shifts and J couplings, spatially localized two-dimensional (2D) J-resolved spectroscopy (JPRESS) shows better identification of complex metabolite resonances than one-dimensional MRS does and facilitates the extraction of J coupling information. However, due to variations of macroscopic magnetic susceptibility in biological samples, conventional JPRESS spectra generally suffer from the influence of field inhomogeneity. In this paper, we investigated the implementation of the localized 2D J-resolved spectroscopy based on intermolecular double-quantum coherences (iDQCs) on a 7 T MRI scanner. Materials and Methods A γ-aminobutyric acid (GABA) aqueous solution, an intact pig brain tissue, and a whole fish (Harpadon nehereus) were explored by using the localized iDQC J-resolved spectroscopy (iDQCJRES) method, and the results were compared to those obtained by using the conventional 2D JPRESS method. Results Inhomogeneous line broadening, caused by the variations of macroscopic magnetic susceptibility in the detected biological samples (the intact pig brain tissue and the whole fish), degrades the quality of 2D JPRESS spectra, particularly when a large voxel is selected and some strongly structured components are included (such as the fish spinal cord). By contrast, high-resolution 2D J-resolved information satisfactory for metabolite analyses can be obtained from localized 2D iDQCJRES spectra without voxel size limitation and field shimming. From the contrastive experiments, it is obvious that the spectral information observed in the localized iDQCJRES spectra acquired from large voxels without field shimming procedure (i.e. in inhomogeneous fields) is similar to that provided by the JPRESS spectra acquired from small voxels after field shimming procedure (i.e. in relatively homogeneous fields

  4. Digital Radiography of Mammographic Phantoms and Biologic Samples Using a 64 Microstrips Crystalline Silicon Detector Coupled to the RX64 ASIC

    SciTech Connect

    Leyva, A.; Cabal, A.; Pinera, I.; Abreu, Y.; Cruz, C. M.; Montano, L. M.; Diaz, C. C.; Fontaine, M.; Ortiz, C. M.; Padilla, F.; Mora, R. de la

    2008-08-11

    The present paper synthesizes the results obtained in the evaluation of a 64 microstrips crystalline silicon detector coupled to RX64 ASIC, designed for high-energy physics experiments, as a useful X-ray detector in advanced medical radiography, specifically in digital mammography. Research includes the acquisition of two-dimensional radiography of a mammography phantom using the scanning method, and the comparison of experimental profile with mathematically simulated one. The paper also shows the experimental images of three biological samples taken from breast biopsies, where it is possible to identify the presence of possible pathological tissues.

  5. Determination of androgens and progestogens in environmental and biological samples using fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Guedes-Alonso, Rayco; Ciofi, Lorenzo; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Bubba, Massimo Del; Kabir, Abuzar; Furton, Kenneth G

    2016-03-11

    Androgens and progestogens are two important groups of endocrine disrupting compounds (EDCs) which are implicated to produce severe detrimental impact over aquatic biota, even at very low concentrations of ngL(-1). For this reason, one of the major challenges to analytical chemists is the development of sensitive and selective extraction processes which allow the rapid and green determination of these emerging pollutants at low concentrations in environmental samples. Fabric phase sorptive extraction is a new, highly sensitive, efficient and solvent minimized technique which combine the advantages of sol-gel derived microextraction sorbents and the rich surface chemistry of cellulose fabric substrate. This process has several advantages such as minimum usage of organic solvents, short extraction times, small sample volumes and high analyte preconcentration factors. In this study, an extraction method based on sorptive fabric phase coupled to ultra-high-performance liquid chromatography tandem mass spectrometry detection (FPSE-UHPLC-MS/MS) has been developed for the determination of four progestogens and six androgens in environmental and biological samples. All the parameters involved in the extraction, such as sample volume, extraction and desorption times, desorption solvent volume and sample pH values have been optimized. The developed method provides satisfactory limits of detection (between 1.7 and 264ngL(-1)), good recoveries and low relative standard deviations (below 10% in tap and osmosis water and below 20% in wastewater and urine). Subsequently, the method was used to analyse tap water, wastewater treated with different processing technologies and urine samples. The concentrations of the detected hormones ranged from 28.3 to 227.3 ngL(-1) in water samples and from 1.1 to 3.7μgL(-1) in urine samples.

  6. Determination of androgens and progestogens in environmental and biological samples using fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Guedes-Alonso, Rayco; Ciofi, Lorenzo; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Bubba, Massimo Del; Kabir, Abuzar; Furton, Kenneth G

    2016-03-11

    Androgens and progestogens are two important groups of endocrine disrupting compounds (EDCs) which are implicated to produce severe detrimental impact over aquatic biota, even at very low concentrations of ngL(-1). For this reason, one of the major challenges to analytical chemists is the development of sensitive and selective extraction processes which allow the rapid and green determination of these emerging pollutants at low concentrations in environmental samples. Fabric phase sorptive extraction is a new, highly sensitive, efficient and solvent minimized technique which combine the advantages of sol-gel derived microextraction sorbents and the rich surface chemistry of cellulose fabric substrate. This process has several advantages such as minimum usage of organic solvents, short extraction times, small sample volumes and high analyte preconcentration factors. In this study, an extraction method based on sorptive fabric phase coupled to ultra-high-performance liquid chromatography tandem mass spectrometry detection (FPSE-UHPLC-MS/MS) has been developed for the determination of four progestogens and six androgens in environmental and biological samples. All the parameters involved in the extraction, such as sample volume, extraction and desorption times, desorption solvent volume and sample pH values have been optimized. The developed method provides satisfactory limits of detection (between 1.7 and 264ngL(-1)), good recoveries and low relative standard deviations (below 10% in tap and osmosis water and below 20% in wastewater and urine). Subsequently, the method was used to analyse tap water, wastewater treated with different processing technologies and urine samples. The concentrations of the detected hormones ranged from 28.3 to 227.3 ngL(-1) in water samples and from 1.1 to 3.7μgL(-1) in urine samples. PMID:26858117

  7. Surfactant assisted pulsed two-phase electromembrane extraction followed by GC analysis for quantification of basic drugs in biological samples.

    PubMed

    Zahedi, Pegah; Davarani, Saied Saeed Hosseiny; Moazami, Hamid Reza; Nojavan, Saeed

    2016-01-01

    In this work, a simple and efficient surfactant assisted pulsed two-phase electromembrane extraction (SA-PEME) procedure combined with gas chromatography (GC) has been developed for the determination of alfentanil, sufentanil and methadone in various samples. It has been found that the addition of anionic surfactant causes the accumulation of the cationic analytes at the SLM/solution interface resulting in an easier transfer of the analytes into the organic phase. The method was accomplished with 1-octanol as the acceptor phase and supported liquid membrane (SLM) by means of an 80 V pulsed electrical driving force and the extraction time of 20 min. The model analytes were extracted from 3.0 mL sample solution (pH 4.0) containing 0.02% w/v surfactant (sodium dodecyl sulfate). The duty cycle of 92% and frequency of 0.357 Hz gave the best performance. Extraction recoveries in the range of 70.5-95.2% and satisfactory repeatability (7.6samples. PMID:26469297

  8. Three-dimensional X-ray observation of atmospheric biological samples by linear-array scanning-electron generation X-ray microscope system.

    PubMed

    Ogura, Toshihiko

    2011-01-01

    Recently, we developed a soft X-ray microscope called the scanning-electron generation X-ray microscope (SGXM), which consists of a simple X-ray detection system that detects X-rays emitted from the interaction between a scanning electron beam (EB) and the thin film of the sample mount. We present herein a three-dimensional (3D) X-ray detection system that is based on the SGXM technology and designed for studying atmospheric biological samples. This 3D X-ray detection system contains a linear X-ray photodiode (PD) array. The specimens are placed under a CuZn-coated Si₃N₄ thin film, which is attached to an atmospheric sample holder. Multiple tilt X-ray images of the samples are detected simultaneously by the linear array of X-ray PDs, and the 3D structure is calculated by a new 3D reconstruction method that uses a simulated-annealing algorithm. The resulting 3D models clearly reveal the inner structure of the bacterium. In addition, the proposed method can easily be used for diverse samples in a broad range of scientific fields.

  9. Direct analysis of environmental and biological samples for total mercury with comparison of sequential atomic absorption and fluorescence measurements from a single combustion event

    NASA Astrophysics Data System (ADS)

    Cizdziel, James V.; Tolbert, Candice; Brown, Garry

    2010-02-01

    A Direct Mercury Analyzer (DMA) based on sample combustion, concentration of mercury by amalgamation with gold, and cold vapor atomic absorption spectrometry (CVAAS) was coupled to a mercury-specific cold vapor atomic fluorescence spectrometer (CVAFS). The purpose was to evaluate combustion-AFS, a technique which is not commercially available, for low-level analysis of mercury in environmental and biological samples. The experimental setup allowed for comparison of dual measurements of mercury (AAS followed by AFS) for a single combustion event. The AFS instrument control program was modified to properly time capture of mercury from the DMA, avoiding deleterious combustion products from reaching its gold traps. Calibration was carried out using both aqueous solutions and solid reference materials. The absolute detection limits for mercury were 0.002 ng for AFS and 0.016 ng for AAS. Recoveries for reference materials ranged from 89% to 111%, and the precision was generally found to be <10% relative standard deviation (RSD). The two methods produced similar results for samples of hair, finger nails, coal, soil, leaves and food stuffs. However, for samples with mercury near the AAS detection limit (e.g., filter paper spotted with whole blood and segments of tree rings) the signal was still quantifiable with AFS, demonstrating the lower detection limit and greater sensitivity of AFS. This study shows that combustion-AFS is feasible for the direct analysis of low levels of mercury in solid samples that would otherwise require time-consuming and contamination-prone digestion.

  10. Three-Dimensional X-ray Observation of Atmospheric Biological Samples by Linear-Array Scanning-Electron Generation X-ray Microscope System

    PubMed Central

    Ogura, Toshihiko

    2011-01-01

    Recently, we developed a soft X-ray microscope called the scanning-electron generation X-ray microscope (SGXM), which consists of a simple X-ray detection system that detects X-rays emitted from the interaction between a scanning electron beam (EB) and the thin film of the sample mount. We present herein a three-dimensional (3D) X-ray detection system that is based on the SGXM technology and designed for studying atmospheric biological samples. This 3D X-ray detection system contains a linear X-ray photodiode (PD) array. The specimens are placed under a CuZn-coated Si3N4 thin film, which is attached to an atmospheric sample holder. Multiple tilt X-ray images of the samples are detected simultaneously by the linear array of X-ray PDs, and the 3D structure is calculated by a new 3D reconstruction method that uses a simulated-annealing algorithm. The resulting 3D models clearly reveal the inner structure of the bacterium. In addition, the proposed method can easily be used for diverse samples in a broad range of scientific fields. PMID:21731770

  11. Chromosome aberrations in peripheral blood lymphocytes of welders and characterization of their exposure by biological samples analysis.

    PubMed

    Elias, Z; Mur, J M; Pierre, F; Gilgenkrantz, S; Schneider, O; Baruthio, F; Danière, M C; Fontana, J M

    1989-05-01

    Chromosomal aberrations in cultured lymphocytes obtained from 55 welders and 55 matched controls were analyzed. Depending on the welding techniques and the nature of the consumables and metals welded, three separate groups of welders were examined. Chromium, nickel, and manganese levels in serum and urine were measured to assess the exposure to welding fumes. A statistically significant increase of chromosomal aberrations was found in one of the three analyzed groups of welders. This group used the semi-automatic metal active gas welding process with cored wire containing nickel for welding mild steel. These welders had significantly higher concentrations of serum and urine manganese and, unlike the other welders, significantly elevated concentrations of nickel, both in serum and urine. However, no significant correlations between nickel or manganese levels and the frequency of chromosomal aberrations were found. There was a significant correlation between the length of welding employment of these welders and the frequency of chromosomal breaks, although there was no significant correlation between age and the frequency of chromosomal aberrations. The other two groups of welders, for which the analyses of biologic fluids proved chromium and manganese exposure, had no statistically significant higher frequency of chromosomal aberrations. One of these groups used the manual metal arc welding process with coated electrodes for welding mainly mild steel and the other group used the tungsten inert gas welding process for welding stainless steel. A significant correlation between the daily amount of cigarettes smoked and the frequency of chromosomal breakages, in controls as in welders, was observed. The present data indicate that certain welding processes may generate fumes that seem to have a clastogenic activity. PMID:2715858

  12. Chromosome aberrations in peripheral blood lymphocytes of welders and characterization of their exposure by biological samples analysis

    SciTech Connect

    Elias, Z.; Mur, J.M.; Pierre, F.; Gilgenkrantz, S.; Schneider, O.; Baruthio, F.; Daniere, M.C.; Fontana, J.M.

    1989-05-01

    Chromosomal aberrations in cultured lymphocytes obtained from 55 welders and 55 matched controls were analyzed. Depending on the welding techniques and the nature of the consumables and metals welded, three separate groups of welders were examined. Chromium, nickel, and manganese levels in serum and urine were measured to assess the exposure to welding fumes. A statistically significant increase of chromosomal aberrations was found in one of the three analyzed groups of welders. This group used the semi-automatic metal active gas welding process with cored wire containing nickel for welding mild steel. These welders had significantly higher concentrations of serum and urine manganese and, unlike the other welders, significantly elevated concentrations of nickel, both in serum and urine. However, no significant correlations between nickel or manganese levels and the frequency of chromosomal aberrations were found. There was a significant correlation between the length of welding employment of these welders and the frequency of chromosomal breaks, although there was no significant correlation between age and the frequency of chromosomal aberrations. The other two groups of welders, for which the analyses of biologic fluids proved chromium and manganese exposure, had no statistically significant higher frequency of chromosomal aberrations. One of these groups used the manual metal arc welding process with coated electrodes for welding mainly mild steel and the other group used the tungsten inert gas welding process for welding stainless steel. A significant correlation between the daily amount of cigarettes smoked and the frequency of chromosomal breakages, in controls as in welders, was observed. The present data indicate that certain welding processes may generate fumes that seem to have a clastogenic activity.

  13. Relation between sources of particulate air pollution and biological effect parameters in samples from four European cities: An exploratory study

    SciTech Connect

    Steerenberg, P.A.; van Amelsvoort, L.; Lovik, M.; Hetland, R.B.; Alberg, T.; Halatek, T.; Bloemen, H.J.T.; Rydzynski, K.; Swaen, G.; Schwarze, P.; Dybing, E.; Cassee, F.R.

    2006-05-15

    Given that there are widely different prevalence rates of respiratory allergies and asthma between the countries of Europe and that exposure to ambient particulate matter (PM) is substantial in urban environments throughout Europe, an EU project entitled 'Respiratory Allergy and Inflammation Due to Ambient Particles' (RAIAP) was set up. The project focused on the role of physical and chemical composition of PM on release of cytokines of cells in vitro, on respiratory inflammation in vivo, and on adjuvant potency in allergy animal models. Coarse (2.5 - 10 {mu}m) and fine (0.15 - 2.5 {mu}m) particles were collected during the spring, summer and winter in Rome ( I), Oslo (N), Lodz (PL), and Amsterdam (NL). Markers within the same model were often well correlated. Markers of inflammation in the in vitro and in vivo models also showed a high degree of correlation. In contrast, correlation between parameters in the different allergy models and between allergy and inflammation markers was generally poor. This suggests that various bioassays are needed to assess the potential hazard of PM. The present study also showed that by clustering chemical constituents of PM based on the overall response pattern in the bioassays, five distinct groups could be identified. The clusters of traffic, industrial combustion and/or incinerators, and combustion of black and brown coal/wood smoke were associated primarily with adjuvant activity for respiratory allergy, whereas clusters of crustal of material and sea spray are predominantly associated with measures for inflammation and acute toxicity. The present study has shown that biological effect of PM can be linked to one or more PM emission sources and that this linkage requires a wide range of bioassays.

  14. Precision and accuracy in the quantitative analysis of biological samples by accelerator mass spectrometry: application in microdose absolute bioavailability studies.

    PubMed

    Gao, Lan; Li, Jing; Kasserra, Claudia; Song, Qi; Arjomand, Ali; Hesk, David; Chowdhury, Swapan K

    2011-07-15

    Determination of the pharmacokinetics and absolute bioavailability of an experimental compound, SCH 900518, following a 89.7 nCi (100 μg) intravenous (iv) dose of (14)C-SCH 900518 2 h post 200 mg oral administration of nonradiolabeled SCH 900518 to six healthy male subjects has been described. The plasma concentration of SCH 900518 was measured using a validated LC-MS/MS system, and accelerator mass spectrometry (AMS) was used for quantitative plasma (14)C-SCH 900518 concentration determination. Calibration standards and quality controls were included for every batch of sample analysis by AMS to ensure acceptable quality of the assay. Plasma (14)C-SCH 900518 concentrations were derived from the regression function established from the calibration standards, rather than directly from isotopic ratios from AMS measurement. The precision and accuracy of quality controls and calibration standards met the requirements of bioanalytical guidance (U.S. Department of Health and Human Services, Food and Drug Administration, Center for Drug Evaluation and Research, Center for Veterinary Medicine. Guidance for Industry: Bioanalytical Method Validation (ucm070107), May 2001. http://www.fda.gov/downloads/Drugs/GuidanceCompilanceRegulatoryInformation/Guidances/ucm070107.pdf ). The AMS measurement had a linear response range from 0.0159 to 9.07 dpm/mL for plasma (14)C-SCH 900158 concentrations. The CV and accuracy were 3.4-8.5% and 94-108% (82-119% for the lower limit of quantitation (LLOQ)), respectively, with a correlation coefficient of 0.9998. The absolute bioavailability was calculated from the dose-normalized area under the curve of iv and oral doses after the plasma concentrations were plotted vs the sampling time post oral dose. The mean absolute bioavailability of SCH 900518 was 40.8% (range 16.8-60.6%). The typical accuracy and standard deviation in AMS quantitative analysis of drugs from human plasma samples have been reported for the first time, and the impact of these

  15. Dithizone chloroform single drop microextraction system combined with electrothermal atomic absorption spectrometry using Ir as permanent modifier for the determination of Cd in water and biological samples

    NASA Astrophysics Data System (ADS)

    Fan, Zhefeng; Zhou, Wei

    2006-07-01

    A simple and sensitive method using dithizone-chloroform single drop microextraction has been developed for separation and preconcentration of trace Cd prior to its determination by electrothermal atomic absorption spectrometry with Ir as permanent modifier. Parameters, such as pyrolysis and atomization temperature, solvent type, pH, dithizone concentration, extraction time, organic drop volume, stirring rate and sample volume were investigated. Under the optimized conditions, a detection limit (3 σ) of 0.7 ng/l and enrichment factor of 65 were achieved. The relative standard deviation was 7.4% ( c = 0.2 μg/l, n = 5). The developed method has been applied to the determination of trace Cd in water samples and biological reference materials with satisfactory results.

  16. Development of a novel carbon paste sensor for determination of micromolar amounts of sulfaquinoxaline in pharmaceutical and biological samples.

    PubMed

    Soleymanpour, Ahmad; Rezvani, Seyyed Ahmad

    2016-01-01

    A potentiometric carbon paste sensor was fabricated for determination of sulfaquinoxaline (SQX) based on the use of ion-association complex of sulfaquinoxaline sodium with 2,3,5-triphenyltetrazolium chloride. The proposed sensor exhibited Nernstian slope of 58.4 ± 0.3 mV per decade for sulfaquinoxaline over a wide concentration range of 5.0 × 10(-6) to 1.0 × 10(-2)M, with a low detection limit of 3.0 × 10(-6)M. The sensor manifested advantages of fast response time, satisfactory reproducibility, long life time, high thermal stability and, most importantly, excellent selectivities for sulfaquinoxaline relative to a wide variety of common foreign inorganic cations, anions, sugars and amino acids. The sensor was successfully used for determination of sulfaquinoxaline in pharmaceutical solution, blood serum, urine and milk samples. The isothermal coefficient of the electrode was calculated by the investigation of temperature effects on the electrode potential response.

  17. Automatic simultaneous determination of copper and lead in biological samples by flow injection/stripping voltammetric analysis

    PubMed Central

    Izquierdo, Andrés; de Castro, M. D. Luque; Valcárcel, Miguel

    1993-01-01

    An automatic-continuous method for the simultaneous determination of copper and lead based on flow injection analysis (FIA) and stripping voltammetry (SV) is proposed. The method affords the determination of the analytes at the ng/ml level (linear ranges 0.64 to 64.0 ng/ml and 2.1 to 62.2 ng/ml for copper and lead, respectively) with good precision (r.s.d. values smaller than 4%). The selectivity of SV allows the method to be applied to the determination of these analytes in bovine liver fresh samples and certified reference materials from the National Institute for Standards and Technology and the Community Bureau of Reference. The performance of the method was assessed by repeatability and validation statistical studies. PMID:18924966