Science.gov

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. Biological Sampling Variability Study

    SciTech Connect

    Amidan, Brett G.; Hutchison, Janine R.

    2016-11-08

    There are many sources of variability that exist in the sample collection and analysis process. This paper addresses many, but not all, sources of variability. The main focus of this paper was to better understand and estimate variability due to differences between samplers. Variability between days was also studied, as well as random variability within each sampler. Experiments were performed using multiple surface materials (ceramic and stainless steel), multiple contaminant concentrations (10 spores and 100 spores), and with and without the presence of interfering material. All testing was done with sponge sticks using 10-inch by 10-inch coupons. Bacillus atrophaeus was used as the BA surrogate. Spores were deposited using wet deposition. Grime was coated on the coupons which were planned to include the interfering material (Section 3.3). Samples were prepared and analyzed at PNNL using CDC protocol (Section 3.4) and then cultured and counted. Five samplers were trained so that samples were taken using the same protocol. Each sampler randomly sampled eight coupons each day, four coupons with 10 spores deposited and four coupons with 100 spores deposited. Each day consisted of one material being tested. The clean samples (no interfering materials) were run first, followed by the dirty samples (coated with interfering material). There was a significant difference in recovery efficiency between the coupons with 10 spores deposited (mean of 48.9%) and those with 100 spores deposited (mean of 59.8%). There was no general significant difference between the clean and dirty (containing interfering material) coupons or between the two surface materials; however, there was a significant interaction between concentration amount and presence of interfering material. The recovery efficiency was close to the same for coupons with 10 spores deposited, but for the coupons with 100 spores deposited, the recovery efficiency for the dirty samples was significantly larger (65

  5. Biological Environmental Sampling Technologies Assessment

    DTIC Science & Technology

    2015-12-01

    sa ti li ty Types of surfaces Info only Can the device support all types of surface sampling to include but not limited to tile, concrete ...sampling to include but not limited to tile, concrete , wood, glass, stone, plastic, etc. Yes/no Informational only Yes N/A N/A Info only...include but not limited to tile, concrete , wood, glass, stone, plastic, etc. Yes/no Informational only Yes N/A N/A Info only Sampling area size

  6. 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.

  7. 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.

  8. 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…

  9. 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.

  10. [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

  11. Atomic force microscopy of biological samples.

    PubMed

    Allison, David P; Mortensen, Ninell P; Sullivan, Claretta J; Doktycz, Mitchel J

    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).

  12. 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).

  13. Microradiography of biological samples with Timepix

    NASA Astrophysics Data System (ADS)

    Dammer, J.; Weyda, F.; Benes, J.; Sopko, V.; Jakubek, J.; Vondracek, V.

    2011-11-01

    Microradiography is an imaging technique using X-rays in the study of internal structures of objects. This rapid and convenient imaging tool is based on differential X-ray attenuation by various tissues and structures within the biological sample. The non-absorbed radiation is detected with a suitable detector and creates a radiographic image. In order to detect the differential properties of X-rays passing through structures sample with different compositions, an adequate high-quality imaging detector is needed. We describe the recently developed radiographic apparatus, equipped with Timepix semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube FeinFocus with tungsten, copper or molybdenum anode. Thanks to the wide dynamic range, time over threshold mode — counter is used as Wilkinson type ADC allowing direct energy measurement in each pixel of Timepix detector and its high spatial resolution better than 1μm, the setup is particularly suitable for radiographic imaging of small biological samples. We are able to visualize some internal biological processes and also to resolve the details of insects (morphology) using different anodes. These anodes generate different energy spectra. These spectra depend on the anode material. The resulting radiographic images varies according to the selected anode. Tiny live insects are an ideal object for our studies.

  14. Accelerator mass spectrometry of small biological samples.

    PubMed

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2008-12-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive technique for isotopic ratio measurements. In the biomedical field, AMS can be used to measure femtomolar concentrations of labeled drugs in body fluids, with direct applications in early drug development such as Microdosing. Likewise, the regenerative properties of cells which are of fundamental significance in stem-cell research can be determined with an accuracy of a few years by AMS analysis of human DNA. However, AMS nominally requires about 1 mg of carbon per sample which is not always available when dealing with specific body substances such as localized, organ-specific DNA samples. Consequently, it is of analytical interest to develop methods for the routine analysis of small samples in the range of a few tens of microg. We have used a 5 MV Pelletron tandem accelerator to study small biological samples using AMS. Different methods are presented and compared. A (12)C-carrier sample preparation method is described which is potentially more sensitive and less susceptible to contamination than the standard procedures.

  15. 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

  16. Millimeter wave absorption spectra of biological samples

    SciTech Connect

    Gandhi, O.P.; Hagmann, M.J.; Hill, D.W.; Partlow, L.M.; Bush, L.

    1980-01-01

    A solid-state computer-controlled system has been used to make swept-frequency measurements of absorption of biological specimens from 26.5 to 90.0 GHz. A wide range of samples was used, including solutions of DNA and RNA, and suspensions of BHK-21/C13 cells, Candida albicans, C krusei, and Escherichia coli. Sharp spectra reported by other workers were not observed. The strong absorbance of water (10--30 dB/mm) caused the absorbance of all aqueous preparations that we examined to have a water-like dependence on frequency. Reduction of incident power (to below 1.0 microW), elimination of modulation, and control of temperature to assure cell viability were not found to significantly alter the water-dominated absorbance. Frozen samples of BHK-21/C13 cells tested at dry ice and liquid nitrogen temperatures were found to have average insertion loss reduced to 0.2 dB/cm but still showed no reproducible peaks that could be attributed to absorption spectra. It is concluded that the special resonances reported by others are likely to be in error.

  17. 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...

  18. 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.

  19. 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.

  20. Negative staining of thinly spread biological samples.

    PubMed

    Harris, J Robin

    2007-01-01

    Negative staining is widely applicable to isolated viruses, protein molecules, macro-molecular assemblies and fibrils, subcellular membrane fractions, liposomes and artificial membranes, synthetic DNA arrays, and also to polymer solutions. In this chapter, techniques are provided for the preparation of the necessary support films (continuous carbon and holey/perforated carbon). The range of suitable negative stains is presented, with some emphasis on the benefit of using ammonium molybdate and of negative stain-trehalose combinations. Protocols are provided for the single-droplet negative staining technique (on continuous and holey carbon support films), the negative staining-carbon film technique, for randomly dispersed fragile molecules, 2D crystallization of proteins, and for cleavage of cells and organelles. The newly developed cryonegative staining procedure also is included. Immunonegative staining and negative staining of affinity labeled complexes (e.g., biotin-streptavidin) are discussed in some detail. The formation of immune complexes in solution for droplet negative staining is presented, as is the use of carbon-plastic support films as an adsorption surface on which to perform immunolabeling or affinity experiments, before negative staining. Dynamic biological systems can be investigated by negative staining, where the time period is in excess of a few minutes, but there are possibilities to greatly reduce the time by rapid stabilization of molecular systems with uranyl acetate or tannic acid.

  1. 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

  2. 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.

  3. An Assay for Thiaminase I in Complex Biological Samples

    PubMed Central

    Hanes, Jeremiah W.; Kraft, Clifford E.; Begley, Tadhg P.

    2007-01-01

    An alternative method for measuring thiaminase I activity in complex samples is described. This assay is based on the selective consumption of the highly chromophoric 4-nitrothiophenolate by thiaminase I resulting in a large decrease in absorbance at 411 nm. This new assay is simple and sensitive and requires only readily available chemicals and a visible region spectrophotometer. In addition, the assay is optimized for high throughput analysis in 96-well format with complex biological samples. PMID:17603991

  4. Enhanced Sampling Techniques in Molecular Dynamics Simulations of Biological Systems

    PubMed Central

    Bernardi, Rafael C.; Melo, Marcelo C. R.; Schulten, Klaus

    2014-01-01

    Background Molecular Dynamics has emerged as an important research methodology covering systems to the level of millions of atoms. However, insufficient sampling often limits its application. The limitation is due to rough energy landscapes, with many local minima separated by high-energy barriers, which govern the biomolecular motion. Scope of review In the past few decades methods have been developed that address the sampling problem, such as replica-exchange molecular dynamics, metadynamics and simulated annealing. Here we present an overview over theses sampling methods in an attempt to shed light on which should be selected depending on the type of system property studied. Major Conclusions Enhanced sampling methods have been employed for a broad range of biological systems and the choice of a suitable method is connected to biological and physical characteristics of the system, in particular system size. While metadynamics and replica-exchange molecular dynamics are the most adopted sampling methods to study biomolecular dynamics, simulated annealing is well suited to characterize very flexible systems. The use of annealing methods for a long time was restricted to simulation of small proteins; however, a variant of the method, generalized simulated annealing, can be employed at a relatively low computational cost to large macromolecular complexes. General Significance Molecular dynamics trajectories frequently do not reach all relevant conformational substates, for example those connected with biological function, a problem that can be addressed by employing enhanced sampling algorithms. PMID:25450171

  5. [Progress in determination of histamine levels in biological samples].

    PubMed

    Wu, Juan-li; Wang, Zhao-pin; Bao, Ai-min

    2012-11-01

    Neuronal histamine is crucially involved in a number of physiological functions as well as in neuropsychiatric diseases. Determination of histamine in biological samples is thus of importance in the clinical studies. The aim of this review is to summarize the progress or effort made in this field, with focus on the high-performance liquid chromatography.

  6. Stability of glufosfamide in phosphate buffers and in biological samples.

    PubMed

    Sun, Yuming; Chen, Xiaoyan; Xu, Haiyan; Guan, Zhongmin; Zhong, Dafang

    2006-03-07

    Glufosfamide is a new, potential chemotherapeutic agent currently under investigation. Stability of glufosfamide was investigated in sodium phosphate buffers with different pH and temperature and in biological samples. Glufosfamide and isophosphamide mustard were quantified simultaneously using a liquid chromatography-ion trap mass spectrometric method; precision and accuracy were within 15% for each analyte. Glufosfamide was stable in neutral buffers, but decomposed to form isophosphoramide mustard under acidic and basic conditions, which was pH- and temperature-dependent. The stability of glufosfamide varied in different biological samples. Results indicated that glufosfamide was unstable in some biological samples, such as the small intestine, smooth muscles, pancreas and urine, especially in the small intestine homogenate, with a half-life of 1.1 h. But the pH (<8) and beta-glucosidase of the tissue homogenate was found to have negligible contribution to the degradation of glufosfamide. The enzymatic inhibition experiment with the specific inhibitor, saccharo-1,4-lactone, demonstrated that it was glucuronidase that resulted in the degradation of glufosfamide in small intestine homogenate. Methanol was recommended to be used to homogenize the tissue in an ice water bath, and the container for urine collection should also be maintained in an ice water bath, and all the biological samples collected should be preserved in frozen condition until analysis.

  7. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 113.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... market by a Animal and Plant Health Inspection Service representative. (a) Either an employee of the... biological products shall be selected. (2) Comparable samples shall be used by Animal and Plant...

  8. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 113.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... market by a Animal and Plant Health Inspection Service representative. (a) Either an employee of the... biological products shall be selected. (2) Comparable samples shall be used by Animal and Plant...

  9. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 113.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... market by a Animal and Plant Health Inspection Service representative. (a) Either an employee of the... biological products shall be selected. (2) Comparable samples shall be used by Animal and Plant...

  10. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 113.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... market by a Animal and Plant Health Inspection Service representative. (a) Either an employee of the... biological products shall be selected. (2) Comparable samples shall be used by Animal and Plant...

  11. 9 CFR 113.3 - Sampling of biological products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Sampling of biological products. 113.3 Section 113.3 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD...

  12. Analysis of water in Autonomous Biological Systems (ABS) samples.

    PubMed

    Ishikawa, Y; Kobayashi, K; Seki, K; Mizutani, H; Kawasaki, Y; Koike, J; Ijiri, K; Yamashita, M; Sugiura, K; Poynter, J; MacCallum, T; Anderson, G

    1998-12-01

    Several soluble components, peptidase and amino acids, and carbon isotopic ratio in the water retrieved from flight experiments of Autonomous Biological Systems (ABS) as well as ground control samples are analyzed to interpret the condition, dynamics, material balance of the ABS ecosystems. Organic carbons in flight samples were found to be more abundant compared with the control ones, which suggested the uniform ecosystems in low gravity might easily dissolve more soluble components. The Mir-1997 flight sample showed higher C/N ratio probably because of the dissolution of carbon-rich plant materials.

  13. 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.

  14. Development of Sampling and Preservation Techniques to Retard Chemical and Biological Changes in Water Samples

    DTIC Science & Technology

    1983-06-24

    I/ DRXTH-TE-CR-82182 DEVELOPMENT OF SAMPLING AND PRESERVATION TECHNIQUES TO RETARD CHEMICAL AND BIOLOGICAL CHANGES IN WATER SAMPLES by H Rope H...Changes in Water Samples MRI ProjecL No. 7050-A 7. AUTI4OR(c) S. CONTRACT OR GRANT NUM[ER(.) DAAK1l-8l-C-0007 I. PERFORMING ORGANIZATION NAME ANO...Tetryl; Diphenylamine, DPA; Nitrobenzane, NB; 2,6-Dinitrotoluene, 2,6-DNT; Nitroglycerin, NG; and Picric Acid, PA) in water samples. The samples were

  15. Capillary electrophoresis screening of poisonous anions extracted from biological samples.

    PubMed

    Gillette, Robert; Doyle, Janet M; Miller, Mark L; Montgomery, Madeline A; Mushrush, George W

    2006-02-02

    A method was developed for screening human biological samples for poisonous anions using capillary electrophoresis (CE) employing indirect UV detection. The run buffer consisted of 2.25 mM pyromellitic acid, 1.6 mM triethanolamine, 0.75 mM hexamethonium hydroxide and 6.5mM NaOH at pH 7.7. Biological samples were pretreated using solid phase extraction. The method was applied to the analysis of human blood, plasma, urine, and intestinal contents. Twenty-nine different anions were detectable at aqueous concentrations of 1 part per million (ppm) with a typical analysis time less than 20 min. Intraday migration time R.S.D. and peak area R.S.D. for blood samples were less than 1.1% and 6.3%, respectively. Interday migration time R.S.D. for plasma samples ranged from 7.5% to 10.4%. The new method produced efficient separations of various target anions extracted from complex biological matrices.

  16. Using electron microscopy to calculate optical properties of biological samples.

    PubMed

    Wu, Wenli; Radosevich, Andrew J; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K; Szleifer, Igal; Backman, Vadim

    2016-11-01

    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques.

  17. Using electron microscopy to calculate optical properties of biological samples

    PubMed Central

    Wu, Wenli; Radosevich, Andrew J.; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K.; Szleifer, Igal; Backman, Vadim

    2016-01-01

    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques. PMID:27896013

  18. Cryogenic X-Ray Diffraction Microscopy for Biological Samples

    SciTech Connect

    Lima, Enju; Wiegart, Lutz; Pernot, Petra; Howells, Malcolm; Timmins, Joanna; Zontone, Federico; Madsen, Anders

    2009-11-06

    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.

  19. Hadamard transform CE-UV detection for biological samples.

    PubMed

    McReynolds, Jennifer A; Gao, Leyi; Barber-Singh, Jennifer; Shippy, Scott A

    2005-02-01

    A Hadamard transform-capillary electrophoresis-UV (HT-CE-UV) detection technique is described for the analysis of biological samples. Pseudorandom injections of sample and buffer according to a simplex matrix obtained from the corresponding Hadamard matrix is performed with conventional capillaries. Alternating injections are achieved with a novel capillary "T" connector created by drilling conventional capillary dimensions through a 1-cm diameter polycarbonate disc. This connector design coupled with a switching system allows for rapid, electrokinetic injections of solution into alternating sample and buffer capillary arms for UV detection. The standard mixtures of nitric oxide (NO) metabolites, nitrite and nitrate, dissolved in physiological saline solution are injected into the separation capillary according to an 83-element injection sequence to obtain a signal-to-noise ratio (S/N) enhancement of ca. 4.5 over a single injection. Nitrite, being the less concentrated metabolite in NO detection and thereby more difficult to detect, was calibrated with the HT-CE-UV method and a limit of detection (LOD) of 0.56 microM was obtained. Rat blood plasma was analyzed with this detection system and demonstrated to be comparable with NO metabolite concentrations of previously published results. This HT-CE-UV method is described where a unique reservoir tube design that contains 8-microL standard nitrite sample volumes is placed over the end of the capillary arm to explore low volume limits for biological samples.

  20. Surface plasmon resonance biosensing toward real biological sample analysis

    NASA Astrophysics Data System (ADS)

    Cunche, Audrey; Bolduc, Olivier R.; Masson, Jean-Francois

    2009-05-01

    The development of monolayer chemistry based on amino acid and short peptides decreases significantly the nonspecific adsorption from biological samples such as serum. Nonspecific adsorption of proteins onto the surface of biosensors currently limits the applicability of many biosensing techniques in real biological samples. In order to minimize this problem, a methodology to immobilize short peptides on surface plasmon resonance (SPR) biosensors was developed using a short chain alkyl thiol monolayer derived with the selected peptides. The chain length of the alkane thiol linking the amino acid to the gold surface influences the physico-chemical properties of the layer and the amount of nonspecifically adsorbed proteins. Varying the composition of the monolayer with peptides formed from the natural amino acids investigates the physico-chemical properties required to minimize nonspecific adsorption of serum. It was observed from monolayers of single amino acids that the composition of the side chain of the amino acid greatly influences the resistance to nonspecific adsorption, with more polar, ionic and small chains resulting in an improved performance in biological samples. Building peptides of different lengths resulted in a further decrease of the amount of nonspecifically bound proteins from serum. Leaving the terminal carboxylic acid end of the peptide unreacted provides an anchoring point for a molecular receptor in the design of a biosensor. Biosensing will be demonstrated with a model system of β-lactamase.

  1. Injection molded microfluidic devices for biological sample separation and detection

    NASA Astrophysics Data System (ADS)

    Morales, Alfredo M.; Simmons, Blake A.; Wallow, Thomas I.; Campbell, K. Jeffery; Mani, Seethambal S.; Mittal, Brita; Crocker, Robert W.; Cummings, Eric B.; Davalos, Rafael V.; Domeier, Linda A.; Hunter, Marion C.; Krafcik, Karen L.; McGraw, Gregory J.; Mosier, Bruce P.; Sickafoose, Shane M.

    2006-01-01

    We are developing a variety of microsystems for the separation and detection of biological samples. At the heart of these systems, inexpensive polymer microfluidic chips carry out sample preparation and analysis. Fabrication of polymer microfluidic chips involves the creation of a master in etched silicon or glass; plating of the master to produce a nickel stamp; large lot chip replication by injection molding; precision chip sealing; and chemical modification of channel surfaces. Separation chips rely on insulator-based dielectrophoresis for the separation of biological particles. Detection chips carry out capillary electrophoresis to detect fluorescent tags that identify specific biological samples. Since the performance and reliability of these microfluidic chips are very sensitive to fluidic impedance, electromagnetic flux, and zeta potential, the microchannel dimensions, shape, and surface chemistry have to be tightly controlled during chip fabrication and use. This paper will present an overview of chip design, fabrication, and testing. Dimensional metrology data, surface chemistry characterization, and chip performance data will be discussed in detail.

  2. 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.

  3. Chiral speciation of selenoamino acids in biological samples.

    PubMed

    Chen, Beibei; He, Man; Zhong, Cheng; Hu, Bin

    2014-10-10

    In this paper, the "state of the art" of chiral speciation of selenoamino acids (SeAAs) in biological samples is critically reviewed. The significance and the features of such studies are highlighted. A special focus lies on chiral speciation of SeAAs by hyphenation techniques in which a chiral separation method (such as gas chromatography (GC), high performance liquid chromatography (HPLC) and capillary electrophoresis (CE)) is on-line coupled with an elemental specific detector, especially inductively coupled plasma mass spectrometry (ICP-MS). The advances in the development and application of hyphenation techniques in chiral speciation of SeAAs in biological samples are summarized and a perspective for future developments including sophisticated and innovative applications is discussed. Overall, HPLC-ICP-MS is more applicable than GC/CE-ICP-MS for chiral speciation of SeAAs. In the future, more novel chiral HPLC methods with high enantio-resolution, low cost and robustness, and their more applications in real biological samples analysis are expected.

  4. Analysis of flavonoids in foods and biological samples.

    PubMed

    Gonzalez-Paramas, A M; Santos-Buelga, C; Duenas, M; Gonzalez-Manzano, S

    2011-12-01

    Flavonoids are a major class of plant phenolics that are widely distributed in the human diet and have been related to health promotion. They may occur in their natural sources in free forms (aglycones), as glycosylated or acylated derivatives, or as oligomeric and polymerized structures. This structural diversity affects their physicochemical behaviour and complicates their analysis. Thus, there is not a single standardized procedure that can be recommended for all flavonoid groups and/or type of samples, and the procedures have to be optimized depending on the nature of the sample and the target analytes. Furthermore, when dealing with the analysis of flavonoids biological samples (i.e., human and animal fluids and tissues) some differential aspects have to be taken into account; the nature of the compounds that can be found in those samples may differ from that present in plants and food, and flavonoids and metabolites occur in much lower concentrations, which make their analysis still more challenging. In this review the main techniques for extraction and analysis of flavonoids in foodstuffs and biological fluids are revised, as well as their occurrence in foods and beverages and available databases.

  5. Femtosecond digital lensless holographic microscopy to image biological samples.

    PubMed

    Mendoza-Yero, Omel; Calabuig, Alejandro; Tajahuerce, Enrique; Lancis, Jesús; Andrés, Pedro; Garcia-Sucerquia, Jorge

    2013-09-01

    The use of femtosecond laser radiation in digital lensless holographic microscopy (DLHM) to image biological samples is presented. A mode-locked Ti:Sa laser that emits ultrashort pulses of 12 fs intensity FWHM, with 800 nm mean wavelength, at 75 MHz repetition rate is used as a light source. For comparison purposes, the light from a light-emitting diode is also used. A section of the head of a drosophila melanogaster fly is studied with both light sources. The experimental results show very different effects of the pinhole size on the spatial resolution with DLHM. Unaware phenomena on the field of the DLHM are analyzed.

  6. A low temperature scanning force microscope for biological samples

    SciTech Connect

    Gustafsson, Mats Gustaf Lennart

    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.

  7. 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

  8. The use of contrast agent for imaging biological samples

    NASA Astrophysics Data System (ADS)

    Dammer, J.; Weyda, F.; Sopko, V.; Jakubek, J.

    2011-01-01

    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1μm, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  9. 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

  10. 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

  11. 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.

  12. New sensitive assay for cadmium in biological samples

    SciTech Connect

    Bhattacharyya, M.H.; Peterson, D.P.; Sacco-Gibson, N.

    1992-01-01

    OSHA is giving serious consideration to substantially lowering permissible exposure limits (PELs) for air cadmium concentrations in the workplace. Consequently, the issue has been raised that improved methods may be needed to effectively monitor worker populations for cadmium exposure if one of the proposed PELs of 1 or 5 {mu}g/m{sup 3} (down from the current 100 {mu}/gm{sup 3}) is adopted. In this brief report, an assay method is described for accurately and precisely determining cadmium concentrations in blood, urine, or other biological samples that has a detection limit of 0.02 {mu}g/L, considerably lower than methods currently in use. It is straight-forward to carry out and uses commercially available chemicals.

  13. New sensitive assay for cadmium in biological samples

    SciTech Connect

    Bhattacharyya, M.H.; Peterson, D.P.; Sacco-Gibson, N.

    1992-08-01

    OSHA is giving serious consideration to substantially lowering permissible exposure limits (PELs) for air cadmium concentrations in the workplace. Consequently, the issue has been raised that improved methods may be needed to effectively monitor worker populations for cadmium exposure if one of the proposed PELs of 1 or 5 {mu}g/m{sup 3} (down from the current 100 {mu}/gm{sup 3}) is adopted. In this brief report, an assay method is described for accurately and precisely determining cadmium concentrations in blood, urine, or other biological samples that has a detection limit of 0.02 {mu}g/L, considerably lower than methods currently in use. It is straight-forward to carry out and uses commercially available chemicals.

  14. Determination of iron (III) in food, biological and environmental samples.

    PubMed

    Verma, Chitra; Tapadia, Kavita; Soni, Anupam Bala

    2017-04-15

    The nanodrop spectrophotometric (NDS) determination of iron (III) in water samples has been established. The proposed method is simple, selective and highly sensitive. The extraction of Fe (III)-thiocyanate complex was done by novel organic reagents such as N-phenylacetamide, N-alkylacetamide, (alkyl=butyl, hexyl and octyl group) in chloroform. The Fe (III) extract was examined in the strong acidic (HCl+H2SO4) solution. The maximum value of molar absorptivity was found to be 1.8×10(5)Lmol(-1)cm(-1) at λmax, 477nm (⩾9 fold enrichments) for N-octylacetamide (N-OAA). The method obeys the Beers Law within the range of 0.05μgmL(-1)-6.0μgmL(-1). The detection limit and RSD value of the method were found to be 5ppb and 0.5906% respectively. The correlation coefficient, slope and intercept were calculated and found to be 0.9989, 0.1112, and 0.0048, respectively. The proposed method was successfully applied to the determination of trace amount of iron (III) in food, biological and environmental samples.

  15. Scanning Ion Conductance Microscopy for Studying Biological Samples

    PubMed Central

    Happel, Patrick; Thatenhorst, Denis; Dietzel, Irmgard D.

    2012-01-01

    Scanning ion conductance microscopy (SICM) is a scanning probe technique that utilizes the increase in access resistance that occurs if an electrolyte filled glass micro-pipette is approached towards a poorly conducting surface. Since an increase in resistance can be monitored before the physical contact between scanning probe tip and sample, this technique is particularly useful to investigate the topography of delicate samples such as living cells. SICM has shown its potential in various applications such as high resolution and long-time imaging of living cells or the determination of local changes in cellular volume. Furthermore, SICM has been combined with various techniques such as fluorescence microscopy or patch clamping to reveal localized information about proteins or protein functions. This review details the various advantages and pitfalls of SICM and provides an overview of the recent developments and applications of SICM in biological imaging. Furthermore, we show that in principle, a combination of SICM and ion selective micro-electrodes enables one to monitor the local ion activity surrounding a living cell. PMID:23202197

  16. Automated Force Volume Image Processing for Biological Samples

    PubMed Central

    Duan, Junbo; Duval, Jérôme F. L.; Brie, David; Francius, Grégory

    2011-01-01

    Atomic force microscopy (AFM) has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature) which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image. PMID:21559483

  17. Ultrasonic microdevices for integrated on-chip biological sample processing

    NASA Astrophysics Data System (ADS)

    Dougherty, George Michael

    Integrated lab-on-a-chip devices, also known as micro total analysis systems (mu-TAS), are expected to play a leading role in biological research and medicine in the 21st century, and on-chip sample processing is a key function of such devices. A new class of ultrasonic microfluidic sample processing devices is presented, based on a single common fundamental unit---a capacitive micromachined ultrasonic transducer---and fabricated using a single common process. Arrays of the transducers are integrated with fluidic microchannels, allowing devices with different functions to be realized simply by altering the physical arrangement and electrical drive signals of the array elements. The efficient, in-plane manipulation of particle-laden liquids is achieved by the use of phased, co-planar transducers, allowing the generation of in-plane, cavity-mode standing waves in the microchannels, and permitting the efficient manipulation of suspended particles such as cells by acoustic radiation forces. Fabricated prototype devices include several types of ultrasonic particle filters, flow-through particle fractionators, particle collimators for cell alignment, devices for the ultrasonic lysing of cells, ultrasonic pumps and ultrasonic mixers. As part of the development effort, an investigation of the thin film silicon material known as "permeable polysilicon" was performed, resulting in the discovery that the material's liquid-permeability properties are caused by nanoscale pores that form spontaneously within an unusual morphological growth regime. A new, one-step porous polysilicon process is presented that allows the quick and easy fabrication of porous polysilicon films for a wide range of applications. The process is used to fabricate the ultrasonic immersion transducers used in the device arrays, and allows the convenient fabrication of a wide variety of microstructures that would be difficult or impossible to fabricate by other means. In addition, a new simulation code is

  18. 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

  19. Modular Automated Processing System (MAPS) for analysis of biological samples.

    SciTech Connect

    Gil, Geun-Cheol; Chirica, Gabriela S.; Fruetel, Julia A.; VanderNoot, Victoria A.; Branda, Steven S.; Schoeniger, Joseph S.; Throckmorton, Daniel J.; Brennan, James S.; Renzi, Ronald F.

    2010-10-01

    We have developed a novel modular automated processing system (MAPS) that enables reliable, high-throughput analysis as well as sample-customized processing. This system is comprised of a set of independent modules that carry out individual sample processing functions: cell lysis, protein concentration (based on hydrophobic, ion-exchange and affinity interactions), interferent depletion, buffer exchange, and enzymatic digestion of proteins of interest. Taking advantage of its unique capacity for enclosed processing of intact bioparticulates (viruses, spores) and complex serum samples, we have used MAPS for analysis of BSL1 and BSL2 samples to identify specific protein markers through integration with the portable microChemLab{trademark} and MALDI.

  20. Real sample temperature: a critical issue in the experiments of nuclear resonant vibrational spectroscopy on biological samples.

    PubMed

    Wang, Hongxin; Yoda, Yoshitaka; Kamali, Saeed; Zhou, Zhao Hui; Cramer, Stephen P

    2012-03-01

    There are several practical and intertangled issues which make the experiments of nuclear resonant vibrational spectroscopy (NRVS) on biological samples difficult to perform. The sample temperature is one of the most important issues. In NRVS the real sample temperatures can be very different from the readings on the temperature sensors. In this study the following have been performed: (i) citing and analyzing various existing NRVS data to assess the real sample temperatures during the NRVS measurements and to understand their trends with the samples' loading conditions; (ii) designing several NRVS measurements with (Et(4)N)[FeCl(4)] to verify these trends; and (iii) proposing a new sample-loading procedure to achieve significantly lower real sample temperatures and to balance among the intertangled experimental issues in biological NRVS measurements.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Analytical methods for determination of anticoagulant rodenticides in biological samples.

    PubMed

    Imran, Muhammad; Shafi, Humera; Wattoo, Sardar Ali; Chaudhary, Muhammad Taimoor; Usman, Hafiz Faisal

    2015-08-01

    Anticoagulant rodenticides belong to a heterogeneous group of compounds which are used to kill rodents. They bind to enzyme complexes responsible for recycling of vitamin K, thus producing impairment in coagulation process. Rodenticides are among the most common house hold toxicants and exhibit wide variety of toxicities in non-target species especially in human, dogs and cats. This article reviews published analytical methods reported in literature for qualitative and quantitative determination of anticoagulant rodenticides in biological specimens. These techniques include high performance liquid chromatography coupled with ultraviolet and florescence detectors, liquid chromatography electrospray ionization tandem mass spectrometry, liquid chromatography with high resolution tandem mass spectrometry, ultra performance liquid chromatography mass spectrometry, gas chromatography mass spectrometry, ion chromatography with fluorescence detection, ion chromatography electrospray ionization ion trap mass spectrometry and ion chromatography electrospray ionization tandem mass spectrometry.

  6. Simultaneous gas chromatographic determination of dibutyltin and tributyltin compounds in biological and sediment samples

    SciTech Connect

    Tsuda, T.; Nakanishi, H.; Morita, T.; Takebayashi, J.

    1986-11-01

    A method is described for the simultaneous determination of nanogram amounts of dibutyltin and tributyltin compounds in biological and sediment samples. These compounds are converted to the corresponding chlorides with HCl, extracted with ethyl acetate-hexane (3 + 2) for biological samples and with hexane for sediment samples, and hydrogenated with sodium borohydride. The corresponding hydrides, Bu2SnH2 and Bu3SnH, are detected by electron-capture gas chromatography after cleanup by silica gel column chromatography. Detection limits are 1.0-2.0 and 0.5-1.0 ng/g, respectively, for biological and sediment samples.

  7. 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

  8. Micro-differential scanning calorimeter for liquid biological samples

    NASA Astrophysics Data System (ADS)

    Wang, Shuyu; Yu, Shifeng; Siedler, Michael S.; Ihnat, Peter M.; Filoti, Dana I.; Lu, Ming; Zuo, Lei

    2016-10-01

    We developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. This design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. We further demonstrated the performance of the sensor with lysozyme unfolding. The measured transition temperature and enthalpy change were in accordance with the previous literature data. This micro-DSC could potentially raise the prospect of high-throughput biochemical measurement by parallel operation with miniaturized sample consumption.

  9. Micro-differential scanning calorimeter for liquid biological samples

    SciTech Connect

    Wang, Shuyu; Yu, Shifeng; Siedler, Michael S.; Ihnat, Peter M.; Filoti, Dana I.; Lu, Ming; Zuo, Lei

    2016-10-20

    Here, we developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. Our design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. Furthermore, we demonstrated the performance of the sensor with lysozyme unfolding. The measured transition temperature and enthalpy change were in accordance with the previous literature data. This micro-DSC could potentially raise the prospect of high-throughput biochemical measurement by parallel operation with miniaturized sample consumption.

  10. Soft Robotic Grippers for Biological Sampling on Deep Reefs.

    PubMed

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

    2016-03-01

    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.

  11. Deep Penetration of Charged Particles in Biological Samples

    NASA Astrophysics Data System (ADS)

    Wang, Rui-Jin; Xia, Yue-Yuan; Mu, Yu-Guang; Zhao, Ming-Wen; Ma, Yu-Chen; Liu, Xiang-Dong; Zhang, Jian-Hua; Liu, Ji-Tian; Yu, Zeng-Liang

    2001-02-01

    Experimental evidence of abnormally deep penetration in some botanical targets by low-energy ion beams is presented. The energy spectra of 818 keV He+ ions penetrating a 70 µm thick seed coat of maize, fruit peel of grape and of tomato all have a common feature. The leading edges of these broad spectra indicate that some of the penetrating ions pass through the thick targets easily and only lose a small fraction of their initial incident energy. Rutherford backscattering spectrometry and electron microprobe measurements are used to determine the argon concentration in multilayer samples of the seed coat of maize implanted by 200 keV Ar+ ions. The results show that about 10% of the Ar+ ions can penetrate deeper than ~100 µm in these samples.

  12. Micro-differential scanning calorimeter for liquid biological samples

    DOE PAGES

    Wang, Shuyu; Yu, Shifeng; Siedler, Michael S.; ...

    2016-10-20

    Here, we developed an ultrasensitive micro-DSC (differential scanning calorimeter) for liquid protein sample characterization. Our design integrated vanadium oxide thermistors and flexible polymer substrates with microfluidics chambers to achieve a high sensitivity (6 V/W), low thermal conductivity (0.7 mW/K), high power resolutions (40 nW), and well-defined liquid volume (1 μl) calorimeter sensor in a compact and cost-effective way. Furthermore, we demonstrated the performance of the sensor with lysozyme unfolding. The measured transition temperature and enthalpy change were in accordance with the previous literature data. This micro-DSC could potentially raise the prospect of high-throughput biochemical measurement by parallel operation with miniaturizedmore » sample consumption.« less

  13. 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.

  14. 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.

  15. 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.

  16. Characterization and purification of glycosaminoglycans from crude biological samples.

    PubMed

    Davies, N P; Roubin, R H; Whitelock, J M

    2008-01-23

    Chondroitin sulfate (CS) is a glycosaminoglycan derived from cartilage and commonly used to treat osteoarthritis, psoriasis, and other conditions. The dimethylmethylene blue (DMMB) assay has been used often to measure glycosaminoglycan levels in relatively pure samples. In this study, we verified the accuracy of the DMMB assay in measuring CS levels in unpurified extract from bovine trachea and shark cartilage, despite potential interference from salts, proteins, and DNA. We found that the glycosaminoglycan signal obtained was due to CS and not to other glycosaminoglycan species. This was confirmed using fluorophore-assisted carbohydrate electrophoresis, which also revealed that the majority of the CS was monosulfated at the C4 or C6 position. Finally, we used anion-exchange chromatography to purify the bovine extract and obtained complete recovery of the glycosaminoglycans, with no contaminating protein. The results of this study should be very useful for future purification and analysis of this common supplement.

  17. 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.

  18. 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

  19. Magnetic separation techniques in sample preparation for biological analysis: a review.

    PubMed

    He, Jincan; Huang, Meiying; Wang, Dongmei; Zhang, Zhuomin; Li, Gongke

    2014-12-01

    Sample preparation is a fundamental and essential step in almost all the analytical procedures, especially for the analysis of complex samples like biological and environmental samples. In past decades, with advantages of superparamagnetic property, good biocompatibility and high binding capacity, functionalized magnetic materials have been widely applied in various processes of sample preparation for biological analysis. In this paper, the recent advancements of magnetic separation techniques based on magnetic materials in the field of sample preparation for biological analysis were reviewed. The strategy of magnetic separation techniques was summarized. The synthesis, stabilization and bio-functionalization of magnetic nanoparticles were reviewed in detail. Characterization of magnetic materials was also summarized. Moreover, the applications of magnetic separation techniques for the enrichment of protein, nucleic acid, cell, bioactive compound and immobilization of enzyme were described. Finally, the existed problems and possible trends of magnetic separation techniques for biological analysis in the future were proposed.

  20. 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.

  1. 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.

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

    EPA Science Inventory

    The Ecological Risk Assessment Support Center (ERASC) announced the release of the final report, Determination of the Biologically Relevant Sampling Depth for Terrestrial and Aquatic Ecological Risk Assessments. This technical paper provides defensible approximations fo...

  3. The Analysis of Cyanide and Its Breakdown Products in Biological Samples

    DTIC Science & Technology

    2010-01-01

    Literature 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE The Analysis of Cyanide and Its Breakdown Products in Biological Samples 5a. CONTRACT... cyanide , thiocyanate, 2-amino-2-thiazoline-4-carboxylic acid (ATCA), chemical warfare agent, exposure, toxicology, analytical methods 16. SECURITY...ISSN: 1040-8347 print / 1547-6510 online DOI: 10.1080/10408340903535315 The Analysis of Cyanide and its Breakdown Products in Biological Samples Brian A

  4. Investigation of reflectance sampling depth in biological tissues for various common illumination/collection configurations.

    PubMed

    Zonios, George

    2014-09-01

    Knowledge of light penetration characteristics is very important in almost all studies in biomedical optics. In this work, the reflectance sampling depth in biological tissues was investigated using Monte Carlo simulations for various common illumination/collection configurations. The analysis shows that the average sampling depth can be described by two simple empirical analytical expressions over the entire typical ranges of absorption and scattering properties relevant to in vivo biological tissue, regardless of the specific illumination/collection configuration details. These results are promising and helpful for the quick, efficient, and accurate design of reflectance studies for various biological tissue applications.

  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.

  6. Procedures for cryogenic X-ray ptychographic imaging of biological samples.

    PubMed

    Yusuf, M; Zhang, F; Chen, B; Bhartiya, A; Cunnea, K; Wagner, U; Cacho-Nerin, F; Schwenke, J; Robinson, I K

    2017-03-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  7. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    DOE PAGES

    Yusuf, M.; Zhang, F.; Chen, B.; ...

    2017-01-12

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  8. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    PubMed Central

    Yusuf, M.; Zhang, F.; Chen, B.; Bhartiya, A.; Cunnea, K.; Wagner, U.; Cacho-Nerin, F.; Schwenke, J.; Robinson, I. K.

    2017-01-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors’ first ptychographic reconstructions using X-rays. PMID:28250953

  9. Improvement of heme oxygenase-1-based heme sensor for quantifying free heme in biological samples.

    PubMed

    Taira, Junichi; Nakashima, Yukinori; Yoshihara, Shun; Koga, Shinya; Sueda, Shinji; Komatsu, Hideyuki; Higashimoto, Yuichiro; Takahashi, Toru; Tanioka, Nohito; Shimizu, Hiroko; Morimatsu, Hiroshi; Sakamoto, Hiroshi

    2015-11-15

    We recently reported a novel heme sensor using fluorescently labeled heme oxygenase-1; however, its inherent enzyme activity would be a potential obstacle in quantifying heme in biological samples. Here, we found that mutation of the catalytically important residue, Asp140, with histidine in the sensor not only diminished the heme degradation activity but also increased heme binding affinity. The sensor with a visible fluorophore was also found to be beneficial to avoid background emission from endogenous substance in biological samples. By using the improved heme sensor, we succeeded in quantifying free heme in rat hepatic samples for the first time.

  10. Non-destructive electron microscopy imaging and analysis of biological samples with graphene coating

    NASA Astrophysics Data System (ADS)

    Park, Jong Bo; Kim, Yong-Jin; Kim, Seong-Min; Yoo, Je Min; Kim, Youngsoo; Gorbachev, Roman; Barbolina, I. I.; Kim, Sang Jin; Kang, Sangmin; Yoon, Myung-Han; Cho, Sung-Pyo; Novoselov, Konstantin S.; Hong, Byung Hee

    2016-12-01

    In electron microscopy (EM), charging of non-conductive biological samples by focused electron beams hinders their high-resolution imaging. Gold or platinum coatings have been commonly used to prevent such sample charging, but it disables further quantitative and qualitative chemical analyses such as energy dispersive spectroscopy (EDS). Here we report that graphene-coating on biological samples enables non-destructive high-resolution imaging by EM as well as chemical analysis by EDS, utilizing graphene’s transparency to electron beams, high conductivity, outstanding mechanical strength and flexibility. We believe that the graphene-coated imaging and analysis would provide us a new opportunity to explore various biological phenomena unseen before due to the limitation in sample preparation and image resolution, which will broaden our understanding on the life mechanism of various living organisms.

  11. Use of nitric acid in sample pretreatment for determination of trace elements in various biological samples by ETAAS.

    PubMed

    Scancar, J; Milacic, R; Falnoga, I; Cemazar, M; Bukovec, P

    2000-07-01

    Trace elements in liquid biological samples may be determined by direct electrothermal atomic absorption spectrometry (ETAAS). In our previous work it was found that samples containing proteins or DNA may leak out of the graphite tube before the drying step, despite the addition of various modifiers. In order to keep the sample to the graphite tube, samples were diluted before analysis 1 + 1 with 32% v/v nitric acid, or 5 microl of 32% v/v nitric acid was added to the graphite tube before ETAAS determination. Applying the proposed procedure, the concentrations of lead in eluted fractions after gel chromatographic separation of human cerebellar nucleus dentatus supernatant and platinum in isolated DNA samples were determined. The use of nitric acid in sample pretreatment prevent sample leakage out of the graphite tube, provided for even drying and considerably reduced nonspecific absorption in lead determination. The repeatability of measurements was better than + 6%. The accuracy of the procedure was checked by spiking samples. The recoveries for both elements lay between 93--104%. Nitric acid was found to be a better modifier than TRITON X-100.

  12. 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.

  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.

  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. NO detection in biological samples: differentiation of 14 NO and 15 NO using infrared laser spectroscopy.

    PubMed

    Fritsch, Thomas; Brouzos, Paris; Heinrich, Kathrin; Kelm, Malte; Rassaf, Tienush; Hering, Peter; Kleinbongard, Petra; Mürtz, Manfred

    2008-08-01

    Accurate characterization of the biochemical pathways of nitric oxide (NO) is essential for investigations in the field of NO research. To analyze the different reaction pathways of enzymatic and non-enzymatic NO formation, determination of the source of NO is crucial. Measuring NO-related products in biological samples distinguishing between (14)NO and (15)NO offers the opportunity to specifically analyze NO signaling in blood and tissue. The aim of this study was to establish a highly sensitive technique for the specific measurement of NO in an isotopologue-selective manner in biological samples. With the cavity leak-out spectroscopy setup (CALOS) a differentiation between (14)NO and (15)NO is feasible. We describe here the employment of this method for measurements in biological samples. Certified gas mixtures of (14)NO/N(2) and (15)NO/N(2) were used to calibrate the system. (14)NO2- and (15)NO2- of aqueous and biological samples were reduced in a triiodide solution, and the NO released was detected via CALOS. Gas-phase chemiluminescence detection (CLD) was used for evaluation. The correlation received for both methods for the detection of NO in the gas phase was r=0.999, p<0.0001. Results obtained using aqueous and biological samples verified that CALOS enables NO measurements with high accuracy (detection limit for (14)NO2- 0.3 pmol and (15)NO2- 0.5 pmol; correlation (14)NO: p<0.0001, r=0.975, (15)NO: p<0.0001, r=0.969). The CALOS assay represents an extension of NO measurements in biological samples, allowing specific investigations of enzymatic and non-enzymatic NO formation and metabolism in a variety of samples.

  16. Development of a Near-Field Scanning Optical Microscope for Imaging Biological Samples in Physiological Buffer

    NASA Astrophysics Data System (ADS)

    Seibel, Eric Jeffrey

    A near-field scanning optical microscope was constructed for imaging intact biological samples in physiological buffer at a resolution beyond the optical diffraction limit. Images are formed by raster scanning the sample within the near -field of the optical probe, which emits collimated light for a limited distance. The technical challenges that were encountered were making the probe, micropositioning the probe and sample with piezoelectrics, and maintaining the sample-probe separation to within the near-field ( <200 nm). By recording the measurement of probe-sample separation during a scan, a topographic image is generated simultaneously with the near-field optical image. The microscope having both imaging modalities was tested and judged fully operational by imaging fluorescently -labeled microspheres under water. The potential of near-field scanning optical microscopy for future biological research was investigated by imaging a fluorescently-labeled, biological test specimen, the single myofibril. Imaging the intact myofibril in buffered saline without chemical fixation provides a challenging, practical test for the microscope. Near-field fluorescence and topographic images of single myofibrils produced image resolution of <=q300 nm, versus ~500 nm for conventional optical microscopy. Interpretation of the images is facilitated by the protein-specific fluorescence labeling. Increasing sample thickness degrades the resolution of the fluorescence images only. Thus, biological samples having > 1 μm thickness, are the practical limit of sample thickness for generating high resolution near-field optical images, when fluorescence is collected in transmission. In contrast, the method of generating the topographic images (called lateral shear-force microscopy), has the advantage of being insensitive to sample thickness. In the topographic images of myofibrils, the change in topography and/or stiffness from the binding of antibodies was detected. The results of this

  17. Solid-phase microextraction (SPME) of drugs and poisons from biological samples.

    PubMed

    Junting, L; Peng, C; Suzuki, O

    1998-11-09

    Solid-phase microextraction (SPME), a new solvent-free sample preparation technique, was invented by C. Arthur and J. Pawliszyn in 1990. This method mainly was applied for the extraction of volatile and semi-volatile organic pollutants in water samples. However, since 1995, SPME has been developed to various biological samples, such as whole blood, plasma, urine, hair and breath, in order to extract drugs and poisons in forensic field. The main advantages of SPME are: high sensitivity, solventless, small sample volume, simplicity and rapidity. We have reviewed the papers published in recent years about SPME in biological samples, and sorted out main experimental conditions, such as fibers, matrixes, the extraction approaches and time, as well as the acceleration method. We would expect SPME technique to have a promising future for toxicological analysis in forensic practice.

  18. Covalent binding of biological samples to solid supports for scanning probe microscopy in buffer solution.

    PubMed Central

    Karrasch, S; Dolder, M; Schabert, F; Ramsden, J; Engel, A

    1993-01-01

    Scanning force microscopy allows imaging of biological molecules in their native state in buffer solution. To this end samples have to be fixed to a flat solid support so that they cannot be displaced by the scanning tip. Here we describe a method to achieve the covalent binding of biological samples to glass surfaces. Coverslips were chemically modified with the photoactivatable cross-linker N-5-azido-2-nitrobenzoyloxysuccinimide. Samples are squeezed between derivatized coverslips and then cross-linked to the glass surface by irradiation with ultraviolet light. Such samples can be imaged repeatedly by the scanning force microscope without loss of image quality, whereas identical but not immobilized samples are pushed away by the stylus. Images FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:8312482

  19. Quantitation of vitamin B6 in biological samples by isotope dilution mass spectrometry

    SciTech Connect

    Hachey, D.L.; Coburn, S.P.; Brown, L.T.; Erbelding, W.F.; DeMark, B.; Klein, P.D.

    1985-11-15

    Methods have been developed for the simultaneous quantitative analysis of vitamin B6 forms in biological samples by isotope dilution mass spectrometry using deuterated forms of pyridoxine, pyridoxal, pyridoxamine, and pyridoxic acid. The biological fluid or tissue sample was homogenized and then treated with a cocktail containing appropriate amounts of each deuterated vitamer, as well as the deuterated, phosphorylated vitamer forms. The individual vitamers were isolated from the homogenate by a complex high-performance liquid chromatographic procedure that provided separate fractions for each of the six vitamers found in biological samples. Aldehydic B6 vitamers were reduced to the alcohol form prior to acetylation and analysis by gas chromatography/mass spectrometry (GC/MS). The three resulting vitamers were analyzed by electron ionization GC/MS using a silicone capillary column. The methods have been applied to analysis of vitamin B6 in liver, milk, urine, and feces at levels as low as 0.02 nmol/ml.

  20. Determination of cadmium and lead in human biological samples by spectrometric techniques: a review.

    PubMed

    Lemos, Valfredo Azevedo; de Carvalho, Anaildes Lago

    2010-12-01

    The analysis of human biological samples, such as blood, urine, nails, and hair, is generally used for the verification of human exposure to toxic metals. In this review, various spectrometric methods for the determination of cadmium and lead in biological samples are discussed and compared. Several spectrometric techniques are presented and discussed with respect to various characteristics such as sensitivity, selectivity, and cost. Special attention is drawn to the procedures for digestion prior to the determination of cadmium and lead in hair, nails, blood, and urine.

  1. Analytical protocol for identification of BMAA and DAB in biological samples.

    PubMed

    Spácil, Zdenek; Eriksson, Johan; Jonasson, Sara; Rasmussen, Ulla; Ilag, Leopold L; Bergman, Birgitta

    2010-01-01

    Beta-N-methylamino-L-alanine (BMAA) is a non-protein amino acid, thought to be inflicting neurodegenerative diseases related to ALS/PDC in human beings. Due to conflicting data concerning the presence of BMAA in various biological matrixes, we present a robust and sensitive method for high confidence identification of BMAA after derivatization by 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC). The efficient sample pretreatment in combination with LC-MS/MS SRM enables chromatographic separation of BMAA from the isomer 2,3-diaminobutyric acid (DAB). The method is applicable for selective BMAA/DAB detection in various biological samples ranging from a prokaryotic cyanobacterium to eukaryotic fish.

  2. 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

  3. Association of environmental toxic elements in biological samples of myocardial infarction patients at different stages.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed; Kandhro, Ghulam Abbas; Baig, Jameel Ahmed; Jamali, Mohammad Khan; Arain, Mohammad Balal; Shah, Abdul Qadir; Shah, Faheem; Khan, Sumaira; Kolachi, Nida Fatima

    2011-06-01

    The exposure of toxic elements may directly or indirectly associate with different pathogenesis of heart diseases. In the present study, the association of arsenic (As), cadmium (Cd), cobalt (Co), lead (Pb), and nickel (Ni) in biological samples (whole blood and urine) and mortality from myocardial infarction (MI) patients at first, second, and third heart attacks was carried out. Both biological samples of 130 MI patients (77 male and 53 female), with ages ranging from 45 to 60 years, and 61 healthy persons (33 male and 28 female) of the same age group were collected. The elements in biological samples were assessed by electrothermal atomic absorption spectrophotometer, prior to microwave-assisted acid digestion. The validity of methodology was checked by the biological certified reference materials. During this study, 78% of 32 patients aged above 50 years, registered after third MI attack, died. In these subjects, the levels of As, Cd, Co, Ni, and Pb in blood samples were higher in MI patients as compared with referents (p < 0.05), while increased by 11.7%, 12.2%, 5.55%, and 7.2%, respectively, in the blood samples of those patients who tolerated the third MI attack (p = 0.12). The high level of understudied toxic elements may play a role in the mortality of MI patients.

  4. American Indian/Alaska Native willingness to provide biological samples for research purposes.

    PubMed

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

    2012-06-01

    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.

  5. Ballast water sampling as a critical component of biological invasions risk management.

    PubMed

    David, Matej; Perkovic, Marko

    2004-08-01

    The human mediated transfer of harmful organisms via shipping, specifically via ballast water transport, leading to the loss of biodiversity, alteration of ecosystems, negative impacts on human health and in some regions economic loss, has raised considerable attention especially in the last decade. Ballast water sampling is very important for biological invasions risk management. The complexity of ballast water sampling is a result of both the variety of organism diversity and behaviour, as well as ship design including availability of ballast water sampling points. Furthermore, ballast water sampling methodology is influenced by the objectives of the sampling study. In the course of research conducted in Slovenia, new sampling equipment for ships' ballast water was developed and tested. In this paper new ballast water sampling methods and equipment together with practical shipboard testing results are presented.

  6. Proton-induced X-ray and gamma ray emission analysis of biological samples

    NASA Astrophysics Data System (ADS)

    Hall, Gene S.; Navon, Eliahu

    1986-04-01

    A 4.1 MeV external proton beam was employed to simultaneously induce X-ray emission (PIXE) and gamma ray emission (PIGE) in biological samples that included human colostrum, spermatozoa, teeth, tree-rings, and follicular fluids. The analytical method was developed to simultaneously determine the elements lithium (Z = 3) through uranium (Z = 92) in the samples. PIXE-PIGE experimental design is described as well as applications in environmental and medical fields.

  7. 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.

  8. 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.

  9. Selective determination of methyl mercury in biological samples by means of programmed temperature gas chromatography.

    PubMed

    Lorenzo, R A; Carro, A; Rubí, E; Casais, C; Cela, R

    1993-01-01

    A programmed temperature gas chromatographic method is presented by which it is possible to carry out routine analysis of methyl mercury in biological samples prepared according to the AOAC official first action recommendations without the need for preliminary treatment of the columns. This method greatly extends the life of the columns as well as the useful time for analysis; it has good linearity and repeatability. With the proposed method a total of 36 samples can be analyzed daily.

  10. 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.

  11. 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

  12. Two-dimensional measurement of the nonlinearity parameter B/A in excised biological samples.

    PubMed

    Saito, Shigemi; Kim, Jung-Ho

    2011-06-01

    The method previously developed for measuring the acoustic nonlinearity parameter B/A in a liquid sample with a volume as small as 0.1 ml [S. Saito, J. Acoust. Soc. Am. 127, 51(2010)] has been automated and applied to two-dimensional measurements of excised biological samples using a LabVIEW program. The focus of the sound beam is laterally shifted on the 3 × 3 mm(2) area of the sample while measuring the B/A successively. By displaying the result of 256 time repeated measurements with an interval of 0.2 mm in two dimensions, a C-mode image was generated for B/A. The images of linear properties such as density, sound speed, and attenuation coefficient are also obtained. The image, whose pattern can be different from those of the density and sound speed, has the capability to reveal the detailed structure of the B/A, which varies from region to region in a single biological sample. The application of the method to small samples is also demonstrated by measuring a thermally coagulated biological sample.

  13. Two-dimensional measurement of the nonlinearity parameter B/A in excised biological samples

    NASA Astrophysics Data System (ADS)

    Saito, Shigemi; Kim, Jung-Ho

    2011-06-01

    The method previously developed for measuring the acoustic nonlinearity parameter B/A in a liquid sample with a volume as small as 0.1 ml [S. Saito, J. Acoust. Soc. Am. 127, 51(2010)] has been automated and applied to two-dimensional measurements of excised biological samples using a LabVIEW program. The focus of the sound beam is laterally shifted on the 3 × 3 mm2 area of the sample while measuring the B/A successively. By displaying the result of 256 time repeated measurements with an interval of 0.2 mm in two dimensions, a C-mode image was generated for B/A. The images of linear properties such as density, sound speed, and attenuation coefficient are also obtained. The image, whose pattern can be different from those of the density and sound speed, has the capability to reveal the detailed structure of the B/A, which varies from region to region in a single biological sample. The application of the method to small samples is also demonstrated by measuring a thermally coagulated biological sample.

  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. 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 ...

  16. 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...

  17. 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

  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. 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

  20. 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.

  1. Lead Assessment in Biological Samples of Children with Different Gastrointestinal Disorders.

    PubMed

    Shah, Faheem; Ullah, Naeem; Kazi, Tasneem Gul; Khan, Ajmal; Kandhro, Ghulam Abbas; Afridi, Hassan Imran; Arain, Mohammad Balal; Khan, Zahid; Farooq, Umar

    2016-01-01

    Lead (Pb) levels have been evaluated in the biological samples of children with different gastrointestinal disorders. Blood, scalp hair, and urine samples of children (of age 4-10 years) complaining about different gastrointestinal disorders were analyzed. For comparison, age matched healthy subjects were also included in this study. Biological samples were digested in a microwave oven prior to Pb determination by graphite furnace atomic absorption spectrometry. Significant differences in Pb profile were found between the diseased and referent children. Elevated Pb contents were observed in case of diseased children than WHO permissible limit, while normal results were obtained for healthy referents. The results were compared with those of healthy children having the same age, socioeconomic status, and residential areas.

  2. Development of a capillary isoelectric focusing immunoassay to measure DJ-1 isoforms in biological samples.

    PubMed

    Besong Agbo, D; Klafki, H; Poschmann, G; Seyfarth, K; Genius, J; Janßen, C; Stühler, K; Wurst, W; Meyer, H E; Klingenspor, M; Wiltfang, J

    2013-12-15

    We report on the development of a novel assay protocol for the separation and detection of charge isoforms of DJ-1 in biological samples by automated capillary isoelectric focusing followed by immunological detection. DJ-1 (PARK7) is considered as a biomarker candidate for Parkinson's disease and may potentially support the differentiation of clinical subtypes of the disease. The new method allows for separation and subsequent relative quantitative comparison of different isoforms of DJ-1 in biological samples. The assay was successfully applied to the analysis of DJ-1 isoform patterns in brains from mice subjected to normal or high-fat diet and revealed statistically significant group differences. Furthermore, in a pooled and concentrated sample of human cerebrospinal fluid that was depleted of albumin and immunoglobulin G, four different charge variants of DJ-1 could be detected. Taken together, the capillary isoelectric focusing immunoassay for DJ-1 represents a promising tool that may ultimately serve in clinical biomarker studies.

  3. 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.

  4. 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

  5. Nanocharacterization of soft biological samples in shear mode with quartz tuning fork probes.

    PubMed

    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.

  6. Synthesis of New Sulfated and Glucuronated Metabolites of Dietary Phenolic Compounds Identified in Human Biological Samples.

    PubMed

    Almeida, A Filipa; Santos, Cláudia N; Ventura, M Rita

    2017-02-23

    (Poly)phenols are a large group of dietary compounds present in fruits and vegetables; their consumption is associated with health beneficial effects. After ingestion, (poly)phenols suffer extensive metabolization, and the identification of their metabolites is an emerging area, because these metabolites are considered the effective bioactive molecules in the human organism. However, a lack of commercially available standards has hampered the study of metabolite bioactivity and the exact structural confirmation in biological samples. New (poly)phenol metabolites previously identified in human samples after the intake of berry juice were chemically synthesized. Efficient chemical reactions were performed with moderate to excellent yields and selectivities. These new compounds could be used as standard chemicals for confirmation of the structure of metabolites in biological samples and will also allow mechanistic studies in cellular models.

  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. 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

  9. 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.

  10. 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

  11. Improved preparation of small biological samples for mercury analysis using cold vapor atomic absorption spectroscopy.

    PubMed

    Adair, B M; Cobb, G P

    1999-05-01

    Concentrations of mercury in biological samples collected for environmental studies are often less than 0.1 microgram/g. Low mercury concentrations and small organ sizes in many wildlife species (approximately 0.1 g) increase the difficulty of mercury determination at environmentally relevant concentrations. We have developed a digestion technique to extract mercury from small (0.1 g), biological samples at these relevant concentrations. Mean recoveries (+/- standard error) from validation trials of mercury fortified tissue samples using cold vapor atomic absorption spectroscopy for analysis ranged from 102 +/- 4.3% (2.5 micrograms/L, n = 15) to 108 +/- 1.4% (25 micrograms/L, n = 15). Recoveries of inorganic mercury were 99 +/- 5 (n = 19) for quality assurance samples analyzed during environmental evaluations conducted during a 24 month period. This technique can be used to determine total mercury concentrations of 60 ng Hg/g sample. Samples can be analyzed in standard laboratories in a short time, at minimal cost. The technique is versatile and can be used to determine mercury concentrations in several different matrices, limiting the time and expense of method development and validation.

  12. Shifted-excitation Raman difference spectroscopy for in vitro and in vivo biological samples analysis

    PubMed Central

    da Silva Martins, Mário Augusto; Ribeiro, Dayana Gonçalves; Pereira dos Santos, Edson Aparecido; Martin, Airton Abrahão; Fontes, Adriana; da Silva Martinho, Herculano

    2010-01-01

    The contamination of the Raman scattering signal with luminescence is a well-known problem when dealing with biological media excited by visible light. The viability of the shifted-excitation Raman difference spectroscopy (SERDS) technique for luminescence suppression on Raman spectra of biological samples was studied in this work. A tunable Lithrow-configuration diode laser (λ = 785 and 830 nm) coupled (directly or by optical fiber) to a dispersive Raman spectrometer was employed to study two sets of human tissues (tooth and skin) in order to determine the set of experimental parameters suitable for luminescence rejection. It was concluded that systematic and reproducible spectra of biological interest can be acquired by SERDS. PMID:21258495

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Comparison of two digestion methods for the determination of selenium in biological samples.

    PubMed

    Ducros, V; Ruffieux, D; Belin, N; Favier, A

    1994-08-01

    Two digestion methods for the determination of selenium in biological samples have been compared: a classic digestion in a heating block by means of wet acid-ashing (HNO3-HClO4) and a microwave digestion in an open-vessel system by heating under reflux with HNO3-H2O2. The two methods were used to determine Se in plasma samples and different reference materials. There was no difference between the mean results, and the correlation coefficient for wet acid-ashing versus microwave digestion was 0.94. The two methods yielded accurate results for the certified materials analysed.

  18. Convergent Synthesis of a Deuterium Labeled Serine Dipeptide Lipid for Analysis of Biological Samples.

    PubMed

    Dietz, Christopher; Clark, Robert B; Nichols, Frank C; Smith, Michael B

    2017-03-08

    Bacterial serine dipeptide lipids are known to promote inflammatory processes and are detected in human tissues associated with periodontal disease or atherosclerosis. Accurate quantification of bacterial serine lipid, specifically lipid 654 [((S)-15-methyl-3-((13-methyltetradecanoyl)oxy)hexadecanoyl)glycyl-L-serine, (3S)-L-serine] isolated from Porphyromonas gingivalis,(1) in biological samples requires the preparation of a stable isotope internal standard for sample supplementation and subsequent mass spectrometric analysis. This report describes the convergent synthesis of a deuterium-substituted serine dipeptide lipid, which is an isotopically labeled homologue that represents a dominant form of serine dipeptide lipid recovered in bacteria.

  19. Immunoassays for Identification of Biological Agents in Sample Unknowns: NATO SlBCA Exercise VI

    DTIC Science & Technology

    2005-12-01

    I• * Dufr+ D Rý sarch aid Rpecherche e1 developpement Svlýlrrnl CaIanada pour la deeonse Canada DEFENCE DEFENSE Immunoassays for Identification of...Biological Agents in Sample Unknowns: NATO SIBCA Exercise VI H.G. Thompson and R.E. Fulton DRDC Suffield D ,,T-iUT O!M STA7’! !r;1T A AiyrVw for P 7 s c...in Sample Unknowns: NATO SIBCA Exercise VI H.G. Thompson and R.E. Fulton Defence R& D Canada - Suffield Defence R& D Canada - Suffield Technical

  20. 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.

  1. A review of surface wipe sampling compared to biologic monitoring for occupational exposure to antineoplastic drugs.

    PubMed

    Kibby, Thomas

    2017-03-01

    The potential for adverse health effects from occupational exposure to antineoplastic drugs (AD) is well known. Control measures recommended by the NIOSH Alert ([3]) include medical and biologic monitoring, and environmental monitoring where available. At present no guidelines or published best practices exist to guide EHS managers on how to carry out this biologic or environmental monitoring. Studies investigating surface wipe sampling for AD have been numerous in the past decade, but very limited research exists to correlate surface contamination with actual absorption by pharmacists and nurses. This article reviews the studies with concurrent surface wipe sampling and urine monitoring for the same AD, and tests their correlation. Methodologic limitations are reviewed. Twenty-one studies were identified that concurrently measured surface contamination by AD by wipe sampling and AD absorption by urine monitoring. Two studies directly evaluated the AD by wipe sampling and urine levels and neither found a statistically significant correlation. Six studies reported a decrease in both surface and urine levels following interventions to reduce contamination or exposure. Only one study directly evaluated the personal protective equipment and handling techniques employed by the studied workers, which can be viewed as a major confounder of absorption. While no statistically significant correlation was found between wipe sampling and urine monitoring for AD, decreases in urine and wipe levels following interventions to reduce exposure were noted. Limitations in the data and recommendations for future research are reviewed.

  2. 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.

  3. 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

  4. RNA SAMPLE PREPARATION APPLIED TO GENE EXPRESSION PROFILING FOR THE HORSE BIOLOGICAL PASSPORT.

    PubMed

    Bailly-Chouriberry, Ludovic; Baudoin, Florent; Cormant, Florence; Glavieux, Yohan; Loup, Benoit; Garcia, Patrice; Popot, Marie-Agnès; Bonnaire, Yves

    2017-04-05

    The improvement of doping control is an on-going race. Techniques to fight against doping are usually based on the direct detection of drugs or their metabolites by analytical methods such as chromatography hyphenated to mass spectrometry after ad hoc sample preparation. Nowadays, omic methods constitute an attractive development and advances have been achieved particularly by application of molecular biology tools for detection of anabolic androgenic steroids (AAS), erythropoiesis-stimulating agent (ESA) or to control human growth hormone misuses. These interesting results across different animal species have suggested that modification of gene expression offers promising new methods of improving the window of detection of banned substances by targeting their effects on blood cell gene expression. In this context, the present study describes the possibility of using a modified version of the dedicated Human IVD (in vitro Diagnostics) PAXgene® Blood RNA Kit for horse gene expression analysis in blood collected on PAXgene® tubes applied to the Horse Biological Passport. The commercial kit was only approved for human blood samples and has required an optimization of specific technical requirements for equine blood samples. Improvements and recommendations were achieved for sample collection, storage and RNA extraction procedure. Following these developments, RNA yield and quality were demonstrated to be suitable for downstream gene expression analysis by qPCR techniques.

  5. 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.

  6. Coherent imaging of biological samples with femtosecond pulses at the free-electron laser FLASH

    NASA Astrophysics Data System (ADS)

    Mancuso, A. P.; Gorniak, Th; Staier, F.; Yefanov, O. M.; Barth, R.; Christophis, C.; Reime, B.; Gulden, J.; Singer, A.; Pettit, M. E.; Nisius, Th; Wilhein, Th; Gutt, C.; Grübel, G.; Guerassimova, N.; Treusch, R.; Feldhaus, J.; Eisebitt, S.; Weckert, E.; Grunze, M.; Rosenhahn, A.; Vartanyants, I. A.

    2010-03-01

    Coherent x-ray imaging represents a new window to imaging non-crystalline, biological specimens at unprecedented resolutions. The advent of free-electron lasers (FEL) allows extremely high flux densities to be delivered to a specimen resulting in stronger scattered signal from these samples to be measured. In the best case scenario, the diffraction pattern is measured before the sample is destroyed by these intense pulses, as the processes involved in radiation damage may be substantially slower than the pulse duration. In this case, the scattered signal can be interpreted and reconstructed to yield a faithful image of the sample at a resolution beyond the conventional radiation damage limit. We employ coherent x-ray diffraction imaging (CXDI) using the free-electron LASer in Hamburg (FLASH) in a non-destructive regime to compare images of a biological sample reconstructed using different, single, femtosecond pulses of FEL radiation. Furthermore, for the first time, we demonstrate CXDI, in-line holography and Fourier transform holography (FTH) of the same unicellular marine organism using an FEL and present diffraction data collected using the third harmonic of FLASH, reaching into the water window. We provide quantitative results for the resolution of the CXDI images as a function of pulse intensity, and compare this with the resolutions achieved with in-line holography and FTH.

  7. 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.

  8. Quantitation of Cytokinins in Biological Samples Using Antibodies Against Zeatin Riboside

    PubMed Central

    Badenoch-Jones, Jane; Letham, David S.; Parker, Charles W.; Rolfe, Barry G.

    1984-01-01

    The cross-reactivity of antibodies elicited in rabbits against zeatin riboside, to a wide range of naturally occurring cytokinins, was examined. As well as to zeatin riboside, the antisera cross-reacted to a considerable extent with zeatin, lupinic acid, zeatin-9-glucoside, zeatin riboside 5′-monophosphate and to a much lesser, but measurable extent, with dihydrozeatin riboside and dihydrozeatin. Chromatographic methods were devised which allowed separation of all these cross-reactive compounds. Four biological samples, extracts of immature Zea mays kernels, immature seeds of Lupinus luteus, and Datura innoxia crown gall tumor tissue, and a sample of Agrobacterium tumefaciens culture supernatant, were purified by these chromatographic methods, using [3H]zeatin riboside as a recovery marker, and at each stage of the purification process, were subjected to radioimmunoassay over a range of dilutions. At each stage of sample purification, sample dilution curves were found to be parallel to the standard curve. Sample cytokinin levels estimated by radioimmunoassay were in close agreement to those available in the literature for similar samples assayed by alternative methods. However, in some samples, unknown cross-reacting compounds were detected. PMID:16663745

  9. Challenges of biological sample preparation for SIMS imaging of elements and molecules at subcellular resolution

    NASA Astrophysics Data System (ADS)

    Chandra, Subhash

    2008-12-01

    Secondary ion mass spectrometry (SIMS) based imaging techniques capable of subcellular resolution characterization of elements and molecules are becoming valuable tools in many areas of biology and medicine. Due to high vacuum requirements of SIMS, the live cells cannot be analyzed directly in the instrument. The sample preparation, therefore, plays a critical role in preserving the native chemical composition for SIMS analysis. This work focuses on the evaluation of frozen-hydrated and frozen freeze-dried sample preparations for SIMS studies of cultured cells with a CAMECA IMS-3f dynamic SIMS ion microscope instrument capable of producing SIMS images with a spatial resolution of 500 nm. The sandwich freeze-fracture method was used for fracturing the cells. The complimentary fracture planes in the plasma membrane were characterized by field-emission secondary electron microscopy (FESEM) in the frozen-hydrated state. The cells fractured at the dorsal surface were used for SIMS analysis. The frozen-hydrated SIMS analysis of individual cells under dynamic primary ion beam (O 2+) revealed local secondary ion signal enhancements correlated with the water image signals of 19(H 3O) +. A preferential removal of water from the frozen cell matrix in the Z-axis was also observed. These complications render the frozen-hydrated sample type less desirable for subcellular dynamic SIMS studies. The freeze-drying of frozen-hydrated cells, either inside the instrument or externally in a freeze-drier, allowed SIMS imaging of subcellular chemical composition. Morphological evaluations of fractured freeze-dried cells with SEM and confocal laser scanning microscopy (CLSM) revealed well-preserved mitochondria, Golgi apparatus, and stress fibers. SIMS analysis of fractured freeze-dried cells revealed well-preserved chemical composition of even the most highly diffusible ions like K + and Na + in physiologically relevant concentrations. The high K-low Na signature in individual cells

  10. High-resolution monochromator for iron nuclear resonance vibrational spectroscopy of biological samples

    NASA Astrophysics Data System (ADS)

    Yoda, Yoshitaka; Okada, Kyoko; Wang, Hongxin; Cramer, Stephen P.; Seto, Makoto

    2016-12-01

    A new high-resolution monochromator for 14.4-keV X-rays has been designed and developed for the Fe nuclear resonance vibrational spectroscopy of biological samples. In addition to high resolution, higher flux and stability are especially important for measuring biological samples, because of the very weak signals produced due to the low concentrations of Fe-57. A 24% increase in flux while maintaining a high resolution better than 0.9 meV is achieved in the calculation by adopting an asymmetric reflection of Ge, which is used as the first crystal of the three-bounce high-resolution monochromator. A 20% increase of the exit beam size is acceptable to our biological applications. The higher throughput of the new design has been experimentally verified. A fine rotation mechanics that combines a weak-link hinge with a piezoelectric actuator was used for controlling the photon energy of the monochromatic beam. The resulting stability is sufficient to preserve the intrinsic resolution.

  11. 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.

  12. 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.

  13. Matrix effect marker for multianalyte analysis by LC-MS/MS in biological samples.

    PubMed

    Tudela, Eva; Muñoz, Gloria; Muñoz-Guerra, Jesús A

    2012-07-15

    Matrix effects (ion suppression/enhancement) are a well-observed phenomenon in analyses of biological matrices by high-performance liquid chromatography-mass spectrometry (LC-MS). However, few simple solutions for detecting and minimizing these adverse effects have been described so far in multianalyte analysis, especially in the field of doping control. This study describes an exhaustive characterization of matrix effects in one hundred urine samples fortified with 41 analytes (glucocorticoids and diuretics). It introduces a novel marker to identify samples in which the reliability of the results is compromised because of acute ion suppression. This new strategy strengthens the rigor of the analysis for screening purposes. Once the matrix effect is identified, a selective sample preparation is introduced to minimize the adverse ion suppression effect. That selective extraction together with the use of a deuterated internal standard permits enhancing the ruggedness of the estimation of glucocorticoid concentration in urine.

  14. 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.

  15. Spectrochemical analysis of powdered biological samples using transversely excited atmospheric carbon dioxide laser plasma excitation

    NASA Astrophysics Data System (ADS)

    Zivkovic, Sanja; Momcilovic, Milos; Staicu, Angela; Mutic, Jelena; Trtica, Milan; Savovic, Jelena

    2017-02-01

    The aim of this study was to develop a simple laser induced breakdown spectroscopy (LIBS) method for quantitative elemental analysis of powdered biological materials based on laboratory prepared calibration samples. The analysis was done using ungated single pulse LIBS in ambient air at atmospheric pressure. Transversely-Excited Atmospheric pressure (TEA) CO2 laser was used as an energy source for plasma generation on samples. The material used for the analysis was a blue-green alga Spirulina, widely used in food and pharmaceutical industries and also in a few biotechnological applications. To demonstrate the analytical potential of this particular LIBS system the obtained spectra were compared to the spectra obtained using a commercial LIBS system based on pulsed Nd:YAG laser. A single sample of known concentration was used to estimate detection limits for Ba, Ca, Fe, Mg, Mn, Si and Sr and compare detection power of these two LIBS systems. TEA CO2 laser based LIBS was also applied for quantitative analysis of the elements in powder Spirulina samples. Analytical curves for Ba, Fe, Mg, Mn and Sr were constructed using laboratory produced matrix-matched calibration samples. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used as the reference technique for elemental quantification, and reasonably well agreement between ICP and LIBS data was obtained. Results confirm that, in respect to its sensitivity and precision, TEA CO2 laser based LIBS can be successfully applied for quantitative analysis of macro and micro-elements in algal samples. The fact that nearly all classes of materials can be prepared as powders implies that the proposed method could be easily extended to a quantitative analysis of different kinds of materials, organic, biological or inorganic.

  16. 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.

  17. Indonesia: statistical sampling technique in validation of radiation sterilisation dose of biological tissue.

    PubMed

    Hilmy, N; Basril, A; Febrida, A

    2003-01-01

    The aim of the work is to find the best solution for statistical sampling technique in validation of radiation sterilization dose (RSD) for biological tissues, according to ISO standard. As a model for sampling are biological tissues retrieved from one cadaver donor which consist of frozen bone grafts (18 packets), lyophilized allografts (68 packets) and demineralized bone powder grafts (40 packets). The size and type of products vary from long bones, cancellous chips to bone powders, tendons and facia lata, that make the number of bioburden per product could not be treated equally. Frozen samples could not be considered as the same production batch with lyophilized samples, because of different processing and irradiation temperature. The minimum number of uniformed samples needed for validation per production batch size, according to ISO 13409, is from 20 to 79 and 20 of them will be used for the test sample size, i.e. 10 for bio-burden determination and the remaining 10 for verification dose. Based on the number of uniformed grafts, statistical sampling can be carried out on lyophilized and demineralized bone grafts, but not on frozen bone grafts. Bioburden determinations were carried out and validated according to ISO 11737-1. Results of average bioburden determination (cfu/per packet), using sample item portion (SIP) = 1, are 5 cfu/packet for lyophilized bone grafts and 4 cfu/packet for demineralized bone powder grafts. Verification doses obtained were 2.40 kGy for lyophilized grafts and 2.24 kGy for demineralized bone powder grafts. The results of verification dose were accepted and the RSD of 25 kGy is substantiated It can be concluded that a statistical sampling technique can be applied if all the grafts produced in the same process such as lyophilized, demineralized as well as frozen are assumed to be in one production batch regardless of sample uniformity such as size, type and weight; for this ISO 13409 can be applied for the validation of RSD.

  18. General guidelines for safe and expeditious international transport of samples subjected to biological dosimetry assessment.

    PubMed

    Di Giorgio, Marina; Radl, Analía; Taja, María R; Bubniak, Ruth; Deminge, Mayra; Sapienza, Carla; Vázquez, Marina; Baciu, Florian; Kenny, Pat

    2014-06-01

    It has been observed that victims of accidental overexposures show better chance of survival if they receive medical treatment early. The increased risk of scenarios involving mass casualties has stimulated the scientific community to develop tools that would help the medical doctors to treat victims. The biological dosimetry has become a routine test to estimate the dose, supplementing physical and clinical dosimetry. In case of radiation emergencies, in order to provide timely and effectively biological dosimetry assistance it is essential to guarantee an adequate transport of blood samples in principal, for providing support to countries that do not have biodosimetry laboratories. The objective of the present paper is to provide general guidelines, summarised in 10 points, for timely and proper receiving and sending of blood samples under National and International regulations, for safe and expeditious international transport. These guidelines cover the classification, packaging, marking, labelling, refrigeration and documentation requirements for the international shipping of blood samples and pellets, to provide assistance missions with a tool that would contribute with the preparedness for an effective biodosimetric response in cases of radiological or nuclear emergencies.

  19. Multiplex coherent anti-Stokes Raman scattering microspectroscopy for monitoring molecular structural change in biological samples

    NASA Astrophysics Data System (ADS)

    Ohta, Takayuki; Hashizume, Hiroshi; Takeda, Keigo; Ishikawa, Kenji; Ito, Masafumi; Hori, Masaru

    2014-10-01

    Biological applications employing non-equilibrium plasma processing has been attracted much attention. It is essential to monitor the changes in an intracellular structure of the cell during the plasma exposure. In this study, we have analyzed the molecular structure of biological samples using multiplex coherent anti-Stokes Raman scattering (CARS) microspectroscopy. Two picosecond pulse lasers with fundamental (1064 nm) or the supercontinuum (460-2200 nm) were employed as a pump and Stokes beams of multiplex CARS microspectroscopy, respectively. The pump and the Stokes laser beams were collinearly overlapped and tightly focused into a sample using an objective lens of high numerical aperture. The CARS signal was collected by another microscope objective lens which is placed facing the first one. After passing through a short pass filter, the signal was dispersed by a polychromator, and was detected by a charge-coupled device camera. The sample was sandwiched by a coverslip and a glass bottom dish for the measurements and was placed on a piezo stage. The CARS signals of the quinhydrone crystal at 1655, 1584, 1237 and 1161 cm-1 were assigned to the C-C, C =O stretching, O-H and C-O stretching vibrational modes, respectively.

  20. 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…

  1. 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.

  2. 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.

  3. 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).

  4. Determination of selenium in biological samples by slurry sampling-electrothermal vaporization-in situ fusion-isotope dilution-microwave-induced nitrogen plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kawano, Takafumi; Nishide, Akifumi; Okutsu, Kentaro; Minami, Hirotsugu; Zhang, Qiangbin; Inoue, Sadanobu; Atsuya, Ikuo

    2005-03-01

    Determination of selenium in certified reference biological materials by slurry sampling electrothermal vaporization (ETV)-isotope dilution (ID)-microwave-induced nitrogen plasma mass spectrometry (MIP-MS) was performed. Several parameters such as the heating conditions were studied in order to obtain optimal conditions. A special heating stage called the in situ fusion stage was applied just before the pyrolysis stage in the electrothermal vaporization process in order to fuse the biological sample and to achieve selenium isotope-equilibration between selenium in the sample and the 78Se spike solution. The slurry sample containing an appropriate amount of biological sample, 78Se spike solution, and sodium hydroxide as an alkaline flux was injected into the electrothermal vaporization unit. The slurry sample was in situ fused, pyrolyzed, and then vaporized. The ion counts at m/ z=78 and 80, the spike and reference isotopes, respectively, could be measured accurately without interference caused by argon since nitrogen plasma was used. The analytical utility of the proposed slurry sampling-electrothermal vaporization-in situ fusion-microwave-induced nitrogen plasma mass spectrometry was evaluated by determining the selenium concentration in certified reference biological materials, and the analytical results obtained were in good agreement with the certified values. The limit of detection for selenium was 90 ng g -1. The relative standard deviation of the determination of selenium was 8-15% with a high sample throughput (less than 30 min per sample including a slurry preparation.)

  5. Thickness determination of biological samples with a zeta-calibrated scanning tunneling microscope.

    PubMed Central

    Wang, Z H; Hartmann, T; Baumeister, W; Guckenberger, R

    1990-01-01

    A single-tube scanning tunneling microscope has been zeta-calibrated by using atomic steps of crystalline gold and was used for measuring the thickness of two biological samples, metal-coated as well as uncoated. The hexagonal surface layer of the bacterium Deinococcus radiodurans with an open network-type structure shows thickness values that are strongly influenced by the substrate and the preparation method. In contrast, the thickness of the purple membrane of Halobacterium halobium with its densely packed less-corrugated structure exhibits very little variation in thickness in coated preparations and the values obtained are in good agreement with x-ray data. Images PMID:2251276

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

    NASA Astrophysics Data System (ADS)

    Hong, Seok Min; Lee, Hoonsoo; Baek, Insuck; Kim, Moon S.

    2016-05-01

    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) array detector, and a custom-designed illumination source. The system has an effective imaging range from 900 nm to 2500 nm. In this paper, we present SWIR hyperspectral images of plant leaves and fruits, and preliminary SWIR image analysis results.

  7. 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.

  8. On the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBS

    SciTech Connect

    Falcon-Gonzalez, J. M.; Bernal-Alvarado, J.; Sosa, M.; Garcia-Leon, M.; Morilla Garcia, Y.; Garcia-Tenorio, R.

    2008-08-11

    The analytical techniques based on ion beams or IBA techniques give quantitative information on elemental concentration in samples of a wide variety of nature. In this work, we focus on PIXE technique, analyzing thick target biological specimens (TTPIXE), using 3 MeV protons produced by an electrostatic accelerator. A nuclear microprobe was used performing PIXE and RBS simultaneously, in order to solve the uncertainties produced in the absolute PIXE quantifying. The advantages of using both techniques and a nuclear microprobe are discussed. Quantitative results are shown to illustrate the multielemental resolution of the PIXE technique; for this, a blood standard was used.

  9. On the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBS

    NASA Astrophysics Data System (ADS)

    Falcón-González, J. M.; Bernal-Alvarado, J.; García-León, M.; García-Tenorio, R.; García, Y. Morilla; Sosa, M.

    2008-08-01

    The analytical techniques based on ion beams or IBA techniques give quantitative information on elemental concentration in samples of a wide variety of nature. In this work, we focus on PIXE technique, analyzing thick target biological specimens (TTPIXE), using 3 MeV protons produced by an electrostatic accelerator. A nuclear microprobe was used performing PIXE and RBS simultaneously, in order to solve the uncertainties produced in the absolute PIXE quantifying. The advantages of using both techniques and a nuclear microprobe are discussed. Quantitative results are shown to illustrate the multielemental resolution of the PIXE technique; for this, a blood standard was used.

  10. Selective extraction of proteins and other macromolecules from biological samples using molecular imprinted polymers.

    PubMed

    Stevenson, Derek; El-Sharif, Hazim F; Reddy, Subrayal M

    2016-11-01

    The accurate determination of intact macromolecules in biological samples, such as blood, plasma, serum, urine, tissue and feces is a challenging problem. The increased interest in macromolecules both as candidate drugs and as biomarkers for diagnostic purposes means that new method development approaches are needed. This review charts developments in the use of molecularly imprinted polymers first for small-molecular-mass compounds then for proteins and other macromolecules. Examples of the development of molecularly imprinted polymers for macromolecules are highlighted. The two main application areas to date are sensors and separation science, particularly SPE. Examples include peptides and polypeptides, lysozyme, hemoglobin, ovalbumin, bovine serum albumin and viruses.

  11. Chlorinated and brominated persistent organic compounds in biological samples from the environment

    SciTech Connect

    Jansson, B.; Andersson, R.; Asplund, L.; Litzen, K.; Nylund, K.; Sellstroem, U.; Uvemo, U.; Wahlberg, C.; Wideqvist, U. . Inst. of Applied Environmental Research); Odsjoe, T.; Olsson, M. . Section for Vertebrate Zoology)

    1993-07-01

    Eleven selected biological samples representing different ecosystems, trophic levels, and areas mainly in Sweden have been analyzed for 31 halogenated organic compounds or compound groups. The multiresidue analytical method provides a good opportunity to compare the concentrations of the different compounds in the investigated samples. By the use of ratios of these concentrations, comparisons can be done between species and areas. An attempt to describe an environmental distribution profile is demonstrated for some of the compounds using the concentration ratio between these compounds and 2,2[prime],4,4[prime],5,5[prime]-hexachlorobiphenyl (PCB 153). Chlorinated paraffins (CPs) were found in all samples and in some of them at higher concentrations than the polychlorinated biphenyls (PCBs). The ratio of CP to PCB 153 is higher in the investigated terrestrial species than in the aquatic, which is not the case for the other compounds. Polybrominated diphenyl ethers were also found in all but one sample. The concentrations were highest in industrialized areas but were also present in samples from background areas. Seven major cogeners of PCBs were determined; the sum ranged from 50 to 200,000 ng/g lw in the investigated samples. Three coplanar PCB congeners were also analyzed as well as polychlorinated naphthalenes, which were found at levels between 0.038 and 50 ng/g lw. The latter two groups do not seem to biomagnify in the foot chain of herring to grey seal to the same extent as the major PCB compounds. Pentachlorobenzene was found in only three of the samples, whereas hexachlorobenzene was present in all samples.

  12. A multipurpose scanning near-field optical microscope: Reflectivity and photocurrent on semiconductor and biological samples

    NASA Astrophysics Data System (ADS)

    Cricenti, A.; Generosi, R.; Barchesi, C.; Luce, M.; Rinaldi, M.

    1998-09-01

    A multipurpose scanning near field optical microscope (SNOM) operating at ambient pressure is described with the aim of characterizing the inner parts of biological molecules and any semiconductor or metal microstructure. Therefore, in addition to the requirements of reliability and mechanical stability we have carefully considered analyzing a sample with all available geometries for input/output of photons, in order to get as much information as possible. The SNOM unit consists of two separable cylindrical supports; the lower one contains the sample holder mounted on top of a piezoelectric scanner which is contained in a motor controlled x-y-z stage. A piezo-modulated stretched optical fiber with a few tens of nanometer pinhole and a shear-force apparatus mounted inside the top cylinder allow for topography measurements. The reflectivity of the sample can be measured by applying different methods: the sample can be illuminated on top by an external source, as well as by the optical fiber used for the detection of the reflectivity signal. An aperture in the lower cylinder allows for illumination of the sample on the back: in this case the fiber collects the evanescent wave induced at the top of the sample. Another aperture in the lower cylinder allows measurement of the reflected light which includes a contribution due to the interaction with the fiber. Also photocurrent experiments can be easily performed by illuminating the sample with the fiber and detecting the transmitted signal using a current-voltage converter mounted inside the top cylinder. A video-camera that can reach 170 enlargements is mounted on the top cylinder for positioning the fiber on particular regions of the sample. Reflectivity and photocurrent measurements have been performed on uncoated neurons, CsI compound, Au/GaAs, and PtSi/Si systems, reaching a resolution well below the diffraction limit.

  13. Availability of MudPIT data for classification of biological samples

    PubMed Central

    2013-01-01

    Background Mass spectrometry is an important analytical tool for clinical proteomics. Primarily employed for biomarker discovery, it is increasingly used for developing methods which may help to provide unambiguous diagnosis of biological samples. In this context, we investigated the classification of phenotypes by applying support vector machine (SVM) on experimental data obtained by MudPIT approach. In particular, we compared the performance capabilities of SVM by using two independent collection of complex samples and different data-types, such as mass spectra (m/z), peptides and proteins. Results Globally, protein and peptide data allowed a better discriminant informative content than experimental mass spectra (overall accuracy higher than 87% in both collection 1 and 2). These results indicate that sequencing of peptides and proteins reduces the experimental noise affecting the raw mass spectra, and allows the extraction of more informative features available for the effective classification of samples. In addition, proteins and peptides features selected by SVM matched for 80% with the differentially expressed proteins identified by the MAProMa software. Conclusions These findings confirm the availability of the most label-free quantitative methods based on processing of spectral count and SEQUEST-based SCORE values. On the other hand, it stresses the usefulness of MudPIT data for a correct grouping of sample phenotypes, by applying both supervised and unsupervised learning algorithms. This capacity permit the evaluation of actual samples and it is a good starting point to translate proteomic methodology to clinical application. PMID:23317455

  14. Biological and biomedical (14)C-accelerator mass spectrometry and graphitization of carbonaceous samples.

    PubMed

    Chung, Ill-Min; Kim, Seung-Hyun

    2013-06-21

    Accelerator mass spectrometry (AMS) is the ultimate technique for measuring rare isotopes in small samples. Biological and biomedical applications of (14)C-AMS (bio-(14)C-AMS) commenced in the early 1990s and are now widely used in many research fields including pharmacology, toxicology, food, and nutrition. For accurate, precise, and reproducible bio-(14)C-AMS analysis, the graphitization step in sample preparation is the most critical step. So, various sample preparation methods for a process called graphitization have been reported for specific applications. Catalytic graphitization using either a flame-sealed borosilicate tube or a septa-sealed vial is a popular sample preparation method for bio-(14)C-AMS. In this review, we introduce the AMS system, especially for bio-(14)C-AMS. In addition, we also review the graphitization method for bio-(14)C-AMS to promote further understanding and improvement of sample preparation for this technique. Examples of catalytic graphitization methods over the past two decades are described.

  15. 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

    2013-03-07

    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.

  16. 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

  17. Electrochemical DNA hybridization sensors applied to real and complex biological samples.

    PubMed

    Tosar, J P; Brañas, G; Laíz, J

    2010-12-15

    DNA hybridization biosensors, also known as genosensors, are analytical devices for the detection of specific DNA "target" sequences in solution, upon hybridization of the targets with complementary "probes" immobilized on a solid substrate. Electrochemical genosensors hold great promise to serve as devices suitable for point-of-care diagnostics and multiplexed platforms for fast, simple and inexpensive nucleic acids analysis. Although a lot of progress has been made in the past few years, the performance of genosensors in complex biological samples has been assayed in only a small fraction of published research articles. This review covers such a group of reports, from the year 2000 onwards. Special attention is played in the nature and complexity of the samples and in the way matrix effects were treated and specificity controls were performed.

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

    DOE PAGES

    Anderson, Aaron S.; Mukundan, Harshini; Mcinroy, Rhonda E.; ...

    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

  19. 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.

  20. Biobanks for research. Ethical and legal aspects in human biological samples collections in France.

    PubMed

    Noiville, Christine

    2012-06-01

    Because they gather huge quantities of human biological samples and information allowing for better understanding of diseases, biobanks appear as a very powerful tool for boosting both medical research and public health as a whole. Although France does not really appear as a leader in biobanking compared to China or UK, biobanks and other samples collections abound in our country and have then been regulated, even though french law does not use the term biobank as such. The present article gives an overview of the current legal framework and explores the remaining ethical and legal issues, concerning particularly the protection of donors, the sharing of biobanks content and the sharing of biobanks benefits. The article explains how these universal questions arise in this country and what answers (sometimes specific) they get or could get in the following years.

  1. 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

  2. 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.

  3. Proton Transmitting Energy Spectra and Transmission Electron Microscope Examinations of Biological Samples

    NASA Astrophysics Data System (ADS)

    Tan, Chun-yu; Xia, Yue-yuan; Zhang, Jian-hua; Mu, Yu-guang; Wang, Rui-jin; Liu, Ji-tian; Liu, Xiang-dong; Yu, Zeng-liang

    1999-02-01

    Transmission energy spectra of 530 keV H+ ion penetrating 140 μm thick seed coat of maize and fruit peel of grape with thickness of 100 μm were measured. The result indicates that these thick biological targets, as seen by the penetrating ions, are inhomogeneous, and there are open "channel like" paths along which the incident ions can transmit the targets easily. While most of the incident ions are stopped in the targets, some of the transmitting ions only lose a small fraction of their initial incident energy. The transmission energy spectra show a pure electronic stopping feature. Transmission electron microscope (TEM) micrographes taken from the samples of seed coat of maize and fruit peel of tomato with thickness of 60 μm indicate that 150 keV electron beam from the TEM can penetrate the thick samples to give very good images with clear contrasts.

  4. Colorimetric estimation of inorganic phosphate in colored and/or turbid biological samples: assay of phosphohydrolases.

    PubMed

    Upreti, G C

    1984-03-01

    A simple method of inorganic phosphate determination for colored and/or turbid biological samples is described. The procedure is mild, and so is suitable for routine phosphohydrolase assays. Following deproteinization by ice-cold trichloroacetic (or silicotungstic) acid, the sample was treated with acid-washed charcoal to remove interference due to color. The phosphate in the colorless supernatant was assayed either by measuring the phosphomolybdate spectrophotometrically at 310 nm, following its extraction in organic solvents or by a modified Fiske and Subbarow method. The turbidity interference in the latter case was eliminated either by centrifugation, by sodium dodecyl sulfate treatment, or by extraction of reduced phosphomolybdate blue color by cyclohexanone. Though deproteinization by silicotungstic acid eliminated the turbidity problem, its use in conjunction with charcoal treatment was not convenient.

  5. 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

  6. A round-robin determination of boron in botanical and biological samples.

    PubMed

    Downing, R G; Strong, P L

    1998-01-01

    The accurate determination of boron (B) at trace and ultratrace concentrations is an important step toward establishing the role of B in biological functions. However, low-level B concentrations are difficult to determine accurately, especially for many botanical and biological matrices. A round-robin study was conducted to assess analytical agreement for low-level B determinations. Ten experienced research groups from analytical laboratories extending across Europe, Asia, and the US participated in this study. These groups represent a cross-section of academic, commercial, and government facilities. The researchers employed both ion-coupled plasma and neutron techniques in the study. Results from this round-robin study indicate good agreement between participating laboratories at the mg/kg level, but at the lowest levels, microg/kg, only three laboratories participated, and agreement was poor. By encouraging discussion among scientists over these data, the secondary goal of this round-robin study is to stimulate continued improvement in analytical procedures and techniques for accurate low-level B determinations. Furthermore, it is intended to encourage the development of a variety of low-level (low mg/kg and microg/kg) B certified reference samples in biological and botanical matrices. The results from the round-robin analyses were compiled and are summarized in this article.

  7. 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.

  8. Micro-electromembrane extraction across free liquid membranes. Extractions of basic drugs from undiluted biological samples.

    PubMed

    Kubáň, Pavel; Boček, Petr

    2014-04-11

    This contribution describes properties and utilization of free liquid membranes (FLMs) in micro-electromembrane extraction (μ-EME) of analytes from samples with complex matrices. An FLM was formed as a plug of a selected organic solvent, 1-ethyl-2-nitrobenezene (ENB) or 2-nitrophenyloctyl ether, in a narrow bore polymeric tubing and was sandwiched between a plug of aqueous donor and aqueous acceptor solution. The FLM acted as a phase interface that enabled selective transfer of analytes from donor into acceptor solution. Acceptor solution after μ-EME was analysed by capillary electrophoresis (CE). Fundamental characteristics of FLMs were depicted and discussed by presenting experimental data on their performance for various basic operational parameters, such as composition and volume of donor/acceptor solution, applied extraction voltage, thickness of FLM and extraction time. Positively charged basic drugs (nortriptyline, haloperidol and loperamide) and their solutions in water, urine and blood serum served as model samples. It was shown that FLMs may offer fast, efficient and selective pretreatment of crude biological samples providing that basic operational parameters of μ-EME are set properly. At optimised conditions, basic drugs in 1.5μL of a biological sample were transferred across 1.5μL of FLM (ENB) into 1.5μL of acceptor solution in about 5min at an extraction voltage of 100V. Repeatability values of μ-EMEs and CE-UV analyses of the three basic drugs were better than 7.7% for peak areas, recoveries ranged between 19 and 52% and linear relationship was obtained for analytical signal vs. concentration in 1-50mgL(-1) range (r(2) better than 0.996). Limits of detection, defined as 3×S/N, were below 1mgL(-1) for all examined matrices.

  9. Direct measurement of lipid-soluble arsenic species in biological samples with HPLC-ICPMS.

    PubMed

    Schmeisser, Ernst; Goessler, Walter; Kienzl, Norbert; Francesconi, Kevin A

    2005-06-01

    Lipid-soluble arsenicals (arsenolipids) occur in a wide range of biological samples where they may play a key role in the biosynthesis of organoarsenic compounds from inorganic arsenic. The study of these compounds has been hindered, however, by the lack of a suitable analytical technique able to separate and measure the various lipid species. As a source of arsenolipids, we used 10 crude fish oils from various regions of the world. Total arsenic analyses on the fish oils, performed with ICPMS following acid digestion with microwave-assisted heating, gave concentrations from 4.3 to 10.5 mg As kg(-1). All of the arsenic was soluble in non-polar solvents such as hexane. Analysis of the fish oils for arsenolipids was performed by normal phase HPLC-ICPMS with various mixtures of organic solvents as mobile phases. Inherent problems of instability associated with the introduction of organic solvents to the plasma were overcome by the use of reduced column flow, a chilled spray chamber, and the addition of oxygen directly to the plasma. All ten fish oils appeared to contain the same 4-6 major arsenolipids, but in varying amounts depending on the origin of the fish. Further chromatography with both normal phase and reversed-phase conditions on some of the oils indicated the presence of many more minor arsenolipids. Quantification was achieved by external calibration against triphenylarsine oxide or triphenylarsine sulfide, and the sum of species following HPLC of the oils matched well the total arsenic results (92-107%). The method was applied to samples of food supplements (fish oil capsules) and a packaged food product (cod liver) whereby arsenolipids were measured and found to be significant arsenic constituents. This study represents the first attempt to directly measure intact arsenolipids and, with appropriate sample preparation, may be suitable for quantitative measurement of these arsenicals in a range of biological samples, including foodstuffs.

  10. Testosterone and progesterone concentrations in blow samples are biologically relevant in belugas (Delphinapterus leucas).

    PubMed

    Richard, Justin T; Robeck, Todd R; Osborn, Steven D; Naples, Lisa; McDermott, Alexa; LaForge, Robert; Romano, Tracy A; Sartini, Becky L

    2016-12-16

    Steroid hormone analysis in blow (respiratory vapor) may provide a minimally invasive way to assess the reproductive status of wild cetaceans. Biological validation of the method is needed to allow for the interpretation of hormone measurements in blow samples. Utilizing samples collected from trained belugas (Delphinapterus leucas, n=20), enzyme immunoassays for testosterone and progesterone were validated for use with beluga blow samples. Testosterone concentrations in 40 matched blood and blow samples collected from 4 male belugas demonstrated a positive correlation (R(2)=0.52, p<0.0001). Progesterone concentrations in 64 matching blood and blow samples from 11 females were also positively correlated (R(2)=0.60, p<0.0001). Testosterone concentrations (mean±SD) in blow samples collected from adult males (119.3±14.2pg/ml) were higher (p<0.01) than that of a juvenile male (<8years) (59.4±6.5pg/ml) or female belugas (54.1±25.7pg/ml). Among adult males, testosterone concentrations in blow demonstrated a seasonal pattern of secretion, with peak secretion occurring during the breeding season (February-April, 136.95±33.8pg/ml). Progesterone concentrations in blow varied by reproductive status; pregnant females (410.6±87.8pg/ml) and females in the luteal phase of the estrous cycle (339.5±51.0pg/ml) had higher (p<0.0001) blow progesterone concentrations than non-pregnant females without a corpus luteum (242.5±27.3pg/ml). Results indicate that blow sample analysis can be used to detect variation in reproductive states associated with large differences in circulating testosterone or progesterone in belugas.

  11. 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.

  12. [The biomonitoring of toxic substances in biological samples of general population].

    PubMed

    Ibarluzea, Jesús; Aurrekoetxea, Juan José; Porta, Miquel; Sunyer, Jordi; Ballester, Ferran

    2016-11-01

    Many of the world's most developed countries have adopted biomonitoring of toxic substances in order to ascertain their levels in biological samples. These substances get into the body through different environmental exposures. Monitoring toxic substances in biological samples should allow us to ascertain their levels in vulnerable groups, assess their evolution over time, make comparisons with levels observed in other countries, identify groups at risk or with high toxic levels and promote research. The main objective of biomonitoring is to act as a policy design tool to facilitate the implementation of particular measures in various sectors: health, environmental, agricultural and livestock or food industry sectors. In Spain, information on levels of toxic substances of environmental origin is provided by specific studies on health effects from environmental sources, such as the INMA project (INfancia y Medio Ambiente [childhood and environment]). In addition, biomonitoring projects have been implemented in Catalonia and the Canary Islands, together with a national biomonitoring programme in the adult working population. However, further progress is needed to develop a system that covers the general population as well as subgroups at risk, which relies on the collaboration of the involved authorities and the participation of professionals from different sectors and citizen organisations interested in the relationship between health and the environment.

  13. 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

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

    PubMed

    Killinger, Bryan A; Moszczynska, Anna

    2016-04-05

    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.

  15. Performance tuning non-uniform sampling for sensitivity enhancement of signal-limited biological NMR

    PubMed Central

    Palmer, Melissa R.; Wenrich, Broc R.; Stahlfeld, Phillip

    2014-01-01

    Non-uniform sampling (NUS) has been established as a route to obtaining true sensitivity enhancements when recording indirect dimensions of decaying signals in the same total experimental time as traditional uniform incrementation of the indirect evolution period. Theory and experiments have shown that NUS can yield up to two-fold improvements in the intrinsic signal-to-noise ratio (SNR) of each dimension, while even conservative protocols can yield 20–40 % improvements in the intrinsic SNR of NMR data. Applications of biological NMR that can benefit from these improvements are emerging, and in this work we develop some practical aspects of applying NUS nD-NMR to studies that approach the traditional detection limit of nD-NMR spectroscopy. Conditions for obtaining high NUS sensitivity enhancements are considered here in the context of enabling 1H,15N-HSQC experiments on natural abundance protein samples and 1H,13C-HMBC experiments on a challenging natural product. Through systematic studies we arrive at more precise guidelines to contrast sensitivity enhancements with reduced line shape constraints, and report an alternative sampling density based on a quarter-wave sinusoidal distribution that returns the highest fidelity we have seen to date in line shapes obtained by maximum entropy processing of non-uniformly sampled data. PMID:24682944

  16. 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.

  17. Exploring Earth's Atmospheric Biology using a Platform-Extensible Sampling Payload

    NASA Astrophysics Data System (ADS)

    Gentry, D.; Rothschild, L.

    2012-12-01

    The interactions between Earth's atmosphere and its biosphere, or aerobiology, remain a significant unknown. What few studies have been done conclusively show that Earth's atmosphere has a rich and dynamic microbial presence[Bowers et al., 2010]; that microbes suspended in air survive over long times (1-2 weeks)[Smith et al., 2010] and travel great distances (>5000 km)[Kellogg and Griffin, 2006]; that some airborne bacteria actively nucleate ice crystals, affecting meteorology[Delort et al., 2010]; and that the presence of microbes in the atmosphere has other planetary-scale effects[Delort et al., 2010]. Basic questions, however, such as the number of microbes present, their activity level and state, the different species present and their variance over time and space, remain largely unquantified. Compounding the significant physical and environmental challenges of reliable aerobiological sampling, collection and analysis of biological samples at altitudes above ~10-20 km has traditionally used ad hoc instrumentation and techniques, yielding primarily qualitative analytical results that lack a common basis for comparison[Bowers et al., 2010]. There is a strong need for broad-basis, repeatable, reliably comparable data about aerobiological basics. We describe here a high-altitude environmental and biological sampling project designed specifically to address these issues. The goal is a robust, reliable, re-usable sampling system, with open reproducibility and adaptability for multiple low-cost flight platforms (including ground-tethered systems, high-altitude balloons, and suborbital sounding rockets); by establishing a common modular payload structure for high-altitude sampling with appeal to a broad user base, we hope to encourage widespread collection of comparable aerobiological data. We are on our third prototype iteration, with demonstrated function of two sample capture modules, a support backbone (tracking, data logging, event response, etc.), a simple ground

  18. 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.

  19. Beta camera for static and dynamic imaging of charged-particle emitting radionuclides in biologic samples.

    PubMed

    Ljunggren, K; Strand, S E

    1990-12-01

    A detection system based on microchannel plates has been constructed to image charged particles emitted by radionuclides in biomedical samples. This technique has significant advantages over conventional film autoradiography for investigating the distribution of radiolabeled compounds: shorter acquisition times due to the high sensitivity, easier sample handling, direct quantification and the ability to perform dynamic studies. The detector performance shows a spatial resolution of 0.9 mm for carbon-14 (14C) (0.156 MeV), good linearity and homogeneity. The noise level is below 50/(cm2.sec). Successful imaging with this system has been performed with beta-emitters 14C, sulfur-35 (35S), iodine-131 (131I), yttrium-90 (90Y), and positron emitters gallium-68 (68Ga), and fluorine-18 (18F). Dynamic studies of axonal transport of 35S-methionine in a nerve, and static images of 90Y-labeled monoclonal antibodies in slices of tumors are presented. The system shows promise for rapid quantitative imaging of charged-particle emitting radionuclides in small biologic samples.

  20. Origin and temperature dependence of radiation damage in biological samples at cryogenic temperatures.

    PubMed

    Meents, Alke; Gutmann, Sascha; Wagner, Armin; Schulze-Briese, Clemens

    2010-01-19

    Radiation damage is the major impediment for obtaining structural information from biological samples by using ionizing radiation such as x-rays or electrons. The knowledge of underlying processes especially at cryogenic temperatures is still fragmentary, and a consistent mechanism has not been found yet. By using a combination of single-crystal x-ray diffraction, small-angle scattering, and qualitative and quantitative radiolysis experiments, we show that hydrogen gas, formed inside the sample during irradiation, rather than intramolecular bond cleavage between non-hydrogen atoms, is mainly responsible for the loss of high-resolution information and contrast in diffraction experiments and microscopy. The experiments that are presented in this paper cover a temperature range between 5 and 160 K and reveal that the commonly used temperature in x-ray crystallography of 100 K is not optimal in terms of minimizing radiation damage and thereby increasing the structural information obtainable in a single experiment. At 50 K, specific radiation damage to disulfide bridges is reduced by a factor of 4 compared to 100 K, and samples can tolerate a factor of 2.6 and 3.9 higher dose, as judged by the increase of R(free) values of elastase and cubic insulin crystals, respectively.

  1. 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.

  2. 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.

  3. Developmental validation of the PrepFiler Forensic DNA Extraction Kit for extraction of genomic DNA from biological samples.

    PubMed

    Brevnov, Maxim G; Pawar, Hemant S; Mundt, Janna; Calandro, Lisa M; Furtado, Manohar R; Shewale, Jaiprakash G

    2009-05-01

    The PrepFiler Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples. The kit facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials: 0.1 and 40 microL of human blood (donor 2) provided 14 and 2883 ng of DNA, respectively. Following the revised SWGDAM guidelines, performance of the developed method was investigated using different sample types including saliva on swabs, semen stains on cotton fabric, samples exposed to environment, samples with polymerase chain reaction (PCR) inhibitors, blood stains (on denim, cotton cloth, and FTA paper), and touch evidence-type samples. DNA yields for all samples tested were equal or better than those obtained by both phenol-chloroform extraction and commercial kits tested. DNA obtained from these samples was free of detectable PCR inhibitors. Short tandem repeat profiles were complete, conclusive, and devoid of PCR artifacts.

  4. Performance of selective and differential media in the primary isolation of yeasts from different biological samples.

    PubMed

    Silva, Jaqueline Otero; Franceschini, Silvio Antônio; Lavrador, Marco Aurélio Sicchiroli; Candido, Regina Célia

    2004-01-01

    In view of the increase in yeast infections, especially polymicrobial ones, differential culture media have acquired increasing importance. The present study evaluated the Sabouraud chloramphenicol, Biggy agar, Pagano Levin agar and CHROMagar Candida media in terms of isolation, number of yeast colony forming units per plate, and inhibition of bacteria and filamentous fungi. To this end, we used 223 biological samples, including feces, and oral, vaginal and anal mucosae from 86 patients presenting or not symptoms of fungal infections. The four media did not differ significantly in terms of detection of yeast-positive cultures. The number of colony forming units per plate ranged from zero to 2.380, with a predominance of counts of 1 to 9 colonies per plate. No significant differences were observed among the four culture media in terms of number of colonies counted, for each kind of biological material. Fifteen species belonging to the genera Candida, Saccharomyces, Cryptococcus, Trichosporon and Rhodotorula were isolated, with C. albicans being the predominant species, followed by C. parapsilosis and R. rubra. CHROMagar Candida and Biggy agar were complementary in the isolation of the different species and favored a greater recovery of polymicrobial cultures. Pagano Levin agar isolated the smallest variety of species. Sabouraud chloramphenicol agar was the least effective in terms of bacterial inhibition and favored a greater development of filamentous fungi. The results suggest that more than one culture medium should be used for an adequate primary isolation.

  5. Methods for using 3-D ultrasound speckle tracking in biaxial mechanical testing of biological tissue samples.

    PubMed

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

    2015-04-01

    Being multilayered and anisotropic, biological tissues such as cardiac and arterial walls are structurally complex, making the 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.

  6. Direct and selective spectrophotometric method for the determination of vanadium in steel, environmental and biological samples

    NASA Astrophysics Data System (ADS)

    Mathew, Sunitha B.; Pataila, Girija; Pillai, Ajai K.; Gupta, V. K.

    2011-10-01

    A simple, direct and selective spectrophotometric method for determination of vanadium is described. The present methodology is based on the strong oxidizing power of vanadium (V). Vanadium (V) selectively oxidizes leucocrystal violet (LCV) to crystal violet in the presence of phosphoric acid. The violet colored dye obtained shows maximum absorbance at 590 nm. Beer's law is obeyed in the concentration range 0.06-0.6 μg ml -1. The molar absorptivity and Sandell's sensitivity are found to be 6.78 × 10 4 l mol -1 cm -1 and 0.0044 μg cm -2, respectively. The proposed method is simple, direct, and sensitive. It has been successfully applied for the determination of vanadium in various environmental, biological and steel samples.

  7. Ethics and law in research with human biological samples: a new approach.

    PubMed

    Petrini, Carlo

    2014-01-01

    During the last century a large number of documents (regulations, ethical codes, treatises, declarations, conventions) were published on the subject of ethics and clinical trials, many of them focusing on the protection of research participants. More recently various proposals have been put forward to relax some of the constraints imposed on research by these documents and regulations. It is important to distinguish between risks deriving from direct interventions on human subjects and other types of risk. In Italy the Data Protection Authority has acted in the question of research using previously collected health data and biological samples to simplify the procedures regarding informed consent. The new approach may be of help to other researchers working outside Italy.

  8. Use of self-actuating and self-sensing cantilevers for imaging biological samples in fluid

    PubMed Central

    Barbero, R J; Deutschinger, A; Todorov, V; Gray, D S; Belcher, A M; Rangelow, I W; Youcef-Toumi, K

    2014-01-01

    In this paper, we present a detailed investigation into the suitability of atomic force microscopy (AFM) cantilevers with integrated deflection sensor and micro-actuator for imaging of soft biological samples in fluid. The Si cantilevers are actuated using a micro-heater at the bottom end of the cantilever. Sensing is achieved through p-doped resistors connected in a Wheatstone bridge. We investigated the influence of the water on the cantilever dynamics, the actuation and the sensing mechanisms, as well as the crosstalk between sensing and actuation. Successful imaging of yeast cells in water using the integrated sensor and actuator shows the potential of the combination of this actuation and sensing method. This constitutes a major step towards the automation and miniaturization required to establish AFM in routine biomedical diagnostics and in vivo applications. PMID:19801750

  9. A micro flow-meter for closed-loop management of biological samples.

    PubMed

    Accoto, Dino; Damiani, Francesco; Campisi, Michele; Castrataro, Piero; Campolo, Domenico; Guglielmelli, Eugenio; Dario, Paolo

    2005-01-01

    The closed-loop management of biological samples in μTAS requires proper flow-sensors to be inserted in the hydraulic path. The optimal choice between hybrid mounting and monolithic fabrication depends on several design variables, one of which is the technological compatibility between the sensor and the pumping mechanism. Monolithic integration appears to be the eligible solution if both pumps and sensors can be fabricated with the same technological process. In this paper we show that it is actually possible to fabricate a flow-sensor, based on streaming potential detection, with the same soft-lithographic process used for the fabrication of electroosmotic pumps. The device has been fabricated in PDMS and experimentally tested, showing a good linearity. Finally, its time-varying response, related to the aging of the PDMS surface, is discussed.

  10. Blood, sweat, and tears: embedding biological samples in social science research on children.

    PubMed

    Kall, Denise

    2008-01-01

    In the first decade of the 21st Century, calls for interdisciplinary research are commonplace. Yet, relatively few papers discuss how to complete such research successfully. In this paper, I describe the details of data collection focused on five, six and seven-year old children. The project examined the effect of environmental contaminants on children's educational outcomes. It included a primary caregiver interview, a skill test with the child, and a venous blood draw from the child to test for lead, mercury, cadmium, arsenic, nicotine, and cotinine. This paper describes key issues and the solutions I adopted. Challenges discussed here include navigating the Institutional Review Board Process, analyzing the blood, obtaining the supplies needed to draw blood, banking blood for future research, hiring a phlebotomist, and recruiting subjects. While not all details will apply directly to other research projects, this paper provides some perspective on the current realities facing social scientists who decide to collect biological samples.

  11. 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.

  12. TLC-spectrophometric separation and trace determination of monocrotophos and dichlorvos in enviromental and biological samples.

    PubMed

    Janghel, Etesh K; Rai, J K; Khan, S; Rai, M K; Gupta, V K

    2007-04-01

    Organophosphorus insecticides, monocrotophos and dichlrovos are increasingly being used in agriculture to control insects on a wide range of crops. Their ready access has resulted in misuse in many instances of homicidal and suicidal poisoning cases. This paper describes about a chromogenic spray reagent for the detection/determination of monocrophos and dichlrovos in environmental and biological samples by TLC and spectrophotometric method. Monocrotophos and dichlorvos on alkaline hydrolysis yield N-methyl acetoacetamide and dichlroacetaldehyde respectively, which in turn react with diazotized p-amino acetophenone to give red-violet and red coloured compounds. Other organophosphorus insecticides do not give this reaction. Moreover, organochlorine and synthetic pyrethroid insecticides and constituents of viscera (amino acids, peptides, proteins etc), which are generally coextracted with the insecticides, do not interfere. However, phenolic compounds and hydrolysed product of carbamate insecticides may interfere and differentiate from monocrotophos and dichlrovos by Rf values. The lower limit of detection is 0.2 mg for monocrotophos and 0.1 mg for dichlorovos. The absorption maxima of the reddish-violet and red colour formed by monocrotophos and dichlrovos, are measured at 560 nm and 540 nm respectively. Beer's Law is obeyed over the concentration range of 1.2 to 6.8 mg and 6.2 to 35 mg in the final solution volume of 25 mL. The molar absorptivity and Sandell's sensitivity of monocrotophos and dichlrovos were found to be 7.1 x 10(5) (+100) 1 mole(-1) cm(-1) and 0.008 mg cm(-2), 1.2 x 10(5) 1 mole(-1) cm(-1) and 0.003 mg cm(-2) respectively. The standard deviation and relative standard deviation were found be +/- 0.005 and 2.05% +/- 0.007 and 2.02% respectively. The developed method has been successfully applied to the detection and determination of monocrotophos and dichlrovos in environmental and biological samples.

  13. Molecularly Imprinted Plasmonic Substrates for Specific and Ultrasensitive Immunoassay of Trace Glycoproteins in Biological Samples.

    PubMed

    Muhammad, Pir; Tu, Xueying; Liu, Jia; Wang, Yijia; Liu, Zhen

    2017-04-05

    Assays of glycoproteins hold significant biological importance and clinical values, for which immunoassay has been the workhorse tool. As immunoassays are associated with disadvantages such as poor availability of high-specificity antibodies, limited stability of biological reagents, and tedious procedure, innovative alternatives that can overcome these drawbacks are highly desirable. Plasmonic immunosandwich assay (PISA) has emerged as an appealing alternative to immunoassay for fast and sensitive determination of trace glycoproteins in biosamples. Plasmonic substrates play key roles in PISA, not only in determining the specificity but also in greatly influencing the detection sensitivity. Herein, we report a new type of molecularly imprinted plasmonic substrates for rapid and ultrasensitive PISA assay of trace glycoproteins in complex real samples. The substrates were fabricated from glass slides, first coated with self-assembled monolayer (SAM) of gold nanoparticles (AuNPs) and then molecularly imprinted with organo-siloxane polymer in the presence of template glycoproteins. The prepared molecularly imprinted substrates exhibited not only a significant plasmonic effect but also excellent binding properties, ensuring the sensitivity as well as the specificity of the assay. Alkaline phosphatase (ALP) and α-fetoprotein (AFP), glycoproteins that are routinely used as disease markers in clinical diagnosis, were used as representative targets. The limit of detection (LOD) was 3.1 × 10(-12) M for ALP and 1.5 × 10(-14) M for AFP, which is the best among the PISA approaches reported. The sample volume required was only 5 μL, and the total time required was within 30 min for each assay. Specific and ultrasensitive determination of ALP and AFP in human serum was demonstrated. Because many disease biomarkers are glycoproteins, the developed PISA approach holds great promise in disease diagnostics.

  14. Determination of 9-cis beta-carotene and zeta-carotene in biological samples.

    PubMed

    Qin, Jian; Yeum, Kyung-Jin; Johnson, Elizabeth J; Krinsky, Norman I; Russell, Robert M; Tang, Guangwen

    2008-09-01

    Concentrations of 9-cis beta-carotene (9-cis betaC) and zeta-carotene (zetaC) in biological samples may provide crucial information on the biological activities of these carotenoids. However, in high-performance liquid chromatography (HPLC) these carotenoids are often co-eluted. Therefore, there is an urgent need to develop a method for 9-cis betaC and zetaC quantitation. Both 9-cis betaC and zetaC have peak absorbance at 400 and 450 nm, respectively, whereas only 9-cis betaC has peak absorbance at 475 nm. We developed a HPLC method to quantitate 9-cis betaC and zetaC by using peak absorbance ratios. The 9-cis betaC/zetaC peak area was monitored at 475, 450 and 400 nm. The 9-cis betaC was quantified by using absorbance value at 475 nm; zetaC was then calculated from the 9-cis betaC/zetaC peak at 400 nm by subtracting 9-cis betaC contribution at 400 nm using the 400-nm/475-nm peak absorbance ratio of 9-cis betaC (0.39). This method was applied to determine 9-cis betaC and zetaC concentrations in serum and breast milk samples (n=12) from American lactating women and serum and breast adipose tissue samples (n=16) from Korean women with either benign or malignant breast tumors. 9-cis betaC concentrations in serum and breast milk of American women, and serum and adipose tissue of Korean women were 7.1+/-0.8 and 1.1+/-0.2 nM, and 15.6+/-1.1 nM and 0.2+/-0.1 nmol/g, respectively. zetaC concentrations in the above samples were 54.2+/-7.2 and 8.3+/-1.8 nM, and 49.0+/-3.9 nM and 0.3+/-0.1 nmol/g, respectively.

  15. Highly sensitive disposable nucleic acid biosensors for direct bioelectronic detection in raw biological samples

    PubMed Central

    Kuralay, Filiz; Campuzano, Susana; Haake, David A.; Wang, Joseph

    2015-01-01

    The development of rapid, low-cost and reliable diagnostic methods is crucial for the identification and treatment of many diseases. Screen-printed gold electrodes (Au/SPEs), coated with a ternary monolayer interface, involving hexanedithiol (HDT), a specific thiolated capture probe (SHCP), and 6-mercapto-1 hexanol (MCH) (SHCP/HDT/MCH) are shown here to offer direct and sensitive detection of nucleic acid hybridization events in untreated raw biological samples (serum, urine and crude bacterial lysate solutions). The composition of the ternary monolayer was modified and tailored to the surface of the Au/SPE. The resulting SHCP/HDT/MCH monolayer has demonstrated to be extremely useful for enhancing the performance of disposable nucleic acid sensors based on screen-printed electrodes. Compared to common SHCP/MCH binary interfaces, the new ternary self-assembled monolayer (SAM) resulted in a 10-fold improvement in the signal (S)-to-noise (N) ratio (S/N) for 1 nM target DNA. The SHCP/HDT/MCH-modified Au/SPEs allowed the direct quantification of the target DNA down to 25 pM (0.25 fmol) and 100 pM (1 fmol) in undiluted/untreated serum and urine samples, respectively, and of 16S rRNA Escherichia coli (E. coli) corresponding to 3000 CFU μL−1 in raw cell lysate samples. The new SAM-coated screen-printed electrodes also displayed favorable non-fouling properties after a 24 h exposure to raw human serum and urine samples, offering great promise as cost-effective nucleic acid sensors for a wide range of decentralized genetic tests. PMID:21807191

  16. 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

  17. 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

  18. Simultaneous neutron-activation determination of selenium and mercury in biological samples by volatilization.

    PubMed

    Byrne, A R; Kosta, L

    1974-10-01

    A method is described for the determination of selenium together with mercury in biological samples by neutron-activation analysis based on quantitative volatilization of both elements. The technique originally developed for mercury, based on pyrolysis with filtration of undesirable impurities and selective trapping from the gas phase, is now extended to selenium. The radionuclides (197)Hg and (75)Se, from one sample, are trapped separately and counted in a well-type NaI(Tl) detector and gamma-spectrometer for maximum sensitivity. The method has been tested by comparative analyses and analyses of standard biological materials, and gives good results. It is simple and is especially effective in studies of the interaction of mercury and selenium in biological systems; a positive correlation for these elements was found for human tissues. On décrit une méthode pour le dosage du sélénium conjointement au mercure dans les échantillons biologiques par analyse par activation de neutrons basée sur la volatilisation quantitative des deux éléments. La techniqu initialement développée pour le mercure, basée sur la pyrolyse avec filtration des impuretés indésirables et captage sélectif de la phase gazeuse, est maintenant étendue au sélénium. Les radionuclides (197)Hg et (75)Se, d'un échantillon, sont captés séparément dans un détecteur NaI(Tl) du type puits et un spectromètre gamma pour la sensibilité maximale. La méthode a été essayée par des analyses comparatives et des analyses de produits biologiques étalons, et donne de bons résultats. Elle est simple et particulièrement efficace dans les études de l'interaction du mercure et du sélénium dans des systèmes biologiques; on a trouvé une corrélation positive pour ces éléments pour des tissus humains.

  19. A user-friendly robotic sample preparation program for fully automated biological sample pipetting and dilution to benefit the regulated bioanalysis.

    PubMed

    Jiang, Hao; Ouyang, Zheng; Zeng, Jianing; Yuan, Long; Zheng, Naiyu; Jemal, Mohammed; Arnold, Mark E

    2012-06-01

    Biological sample dilution is a rate-limiting step in bioanalytical sample preparation when the concentrations of samples are beyond standard curve ranges, especially when multiple dilution factors are needed in an analytical run. We have developed and validated a Microsoft Excel-based robotic sample preparation program (RSPP) that automatically transforms Watson worklist sample information (identification, sequence and dilution factor) to comma-separated value (CSV) files. The Freedom EVO liquid handler software imports and transforms the CSV files to executable worklists (.gwl files), allowing the robot to perform sample dilutions at variable dilution factors. The dynamic dilution range is 1- to 1000-fold and divided into three dilution steps: 1- to 10-, 11- to 100-, and 101- to 1000-fold. The whole process, including pipetting samples, diluting samples, and adding internal standard(s), is accomplished within 1 h for two racks of samples (96 samples/rack). This platform also supports online sample extraction (liquid-liquid extraction, solid-phase extraction, protein precipitation, etc.) using 96 multichannel arms. This fully automated and validated sample dilution and preparation process has been applied to several drug development programs. The results demonstrate that application of the RSPP for fully automated sample processing is efficient and rugged. The RSPP not only saved more than 50% of the time in sample pipetting and dilution but also reduced human errors. The generated bioanalytical data are accurate and precise; therefore, this application can be used in regulated bioanalysis.

  20. A capillary zone electrophoresis for determination of thiolic peptides in biological samples.

    PubMed

    Pérez-Rama, Mónica; Abalde, Julio; Herrero, Concepción; Suárez, Cristina; Torres, Enrique

    2009-06-01

    A new method to improve the analyses of thiolic peptides (cysteine, gammaGlu-Cys, glutathione, phytochelatins and desglycyl-phytochelatins) derivatized with monobromobimane (mBrB) in complex biological samples by CZE is described. The method involves a SPE using Sep-Pak Light C18 Cartridges after derivatization and a later CZE analysis. Elution of mBrB-thiols was achieved with 10 mM HCl + 70% methanol v/v in deionised water. Electrophoretic parameters, such as BGE pH and concentration, different organic additives (methanol and trifluoroethanol), applied voltage and capillary length were studied in order to establish suitable analytical conditions. Optimum separation of the mBrB-thiolic peptides was obtained with 100 mM sodium borate buffer at pH 7.60. The electrophoretic conditions were +15 kV, capillary length of 90 cm from inlet to detector (98 cm total length, 50 microm ID), samples were loaded into the capillary by hydrodynamic injection (50 mbar, 20 s) and detection was performed at 390 nm. The improved method showed good reproducibility, linearity and sensitivity. The LODs and LOQs estimated using a standard of GSH were 1.41 and 4.69 microM respectively.

  1. 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.

  2. 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

  3. Estimation of angiotensin peptides in biological samples by LC/MS method.

    PubMed

    Ali, Quaisar; Wu, Yonnie; Nag, Sourashish; Hussain, Tahir

    2014-01-21

    The low abundance of angiotensin peptides in biological tissues such as the kidney cortex, adipose tissue, urine and plasma makes their detection and quantification a challenge. A few available methods used to quantify these peptides involve lengthy processes of sample preparation and are hardly quantitative. Here, we report a mass spectrometry approach for quantifying angiotensin peptides [Ang II, Ang-(1-7)] in the kidney cortex, epididymal white adipose tissue (eWAT), urine and plasma of male mice. Tissue homogenates, urine and plasma samples were solid-phase extracted with C18 Sep-Pak cartridges and eluted off proteinaceous compounds. These extracted peptide samples were separated on C18 column with a linear acetonitrile gradient and detected by Q-ToF mass analyzer in ESI+-MS ion mode based on their retention time, accurate mass measurement of peptides, the isotope pattern of doubly charged molecular ion, and quantitation of peak area (or ion count) when referencing to the angiotensin peptide standards. The lower limit of quantitation for each angiotensin peptide was 10 pgmg(-1) with the percent recovery at 100.6%. The intra-batch precision for Ang-(1-7) and Ang II were 24.0 and 12.7%, accuracy 84.0-123.0% and 100.2-116.0% respectively. Using this method, we determined the levels of Ang II and Ang-(1-7) in the kidney cortex, eWAT, urine and plasma. Quantification of angiotensin peptides could help target subtle therapeutics changes against pathophysiological conditions such as obesity, kidney disease and hypertension.

  4. 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

  5. Copper, chromium, manganese, iron, nickel, and zinc levels in biological samples of diabetes mellitus patients.

    PubMed

    Kazi, Tasneem Gul; Afridi, Hassan Imran; Kazi, Naveed; Jamali, Mohammad Khan; Arain, Mohammad Bilal; Jalbani, Nussarat; Kandhro, Ghulam Abbas

    2008-04-01

    There is accumulating evidence that the metabolism of several trace elements is altered in diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progress of this disease. The aim of present study was to compare the level of essential trace elements, chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn) in biological samples (whole blood, urine, and scalp hair) of patients who have diabetes mellitus type 2 (n = 257), with those of nondiabetic control subjects (n = 166), age ranged (45-75) of both genders. The element concentrations were measured by means of an atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet-acid-digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of (97.60-99.49%) of certified values. The results of this study showed that the mean values of Zn, Mn, and Cr were significantly reduced in blood and scalp-hair samples of diabetic patients as compared to control subjects of both genders (p < 0.001). The urinary levels of these elements were found to be higher in the diabetic patients than in the age-matched healthy controls. In contrast, high mean values of Cu and Fe were detected in scalp hair and blood from patients versus the nondiabetic subjects, but the differences found in blood samples was not significant (p < 0.05). These results are consistent with those obtained in other studies, confirming that deficiency and efficiency of some essential trace metals may play a role in the development of diabetes mellitus.

  6. Evaluation of arsenic, cobalt, copper and manganese in biological Samples of Steel mill workers by electrothermal atomic absorption Spectrometry.

    PubMed

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

    2009-02-01

    The determination of trace and toxic elements in biological samples (blood, urine and scalp hair samples) of human beings is an important clinical test. The aim of our present study was to determine the concentration of arsenic (As), copper (Cu), cobalt (Co) and manganese (Mn), in biological samples of male production workers (PW) and quality control workers (QW) of steel mill, with aged 25-55 years, to assess the possible influence of environmental exposure. For comparison purpose, the same biological samples of unexposed healthy males of same age group were collected as control subjects. The determination of all elements in biological samples was carried out by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The accuracy of the As, Cu, Co and Mn measurements was tested by simultaneously analyzing certified reference materials (CRMs) and for comparative purposes conventional wet acid digestion method was used on the same CRMs. No significant differences were observed between the analytical results and the certified values, using both methods (paired t-test at P > 0.05). The results indicate that concentrations of As, Cu, Co and Mn in all three biological samples of the exposed workers (QW and PW) were significantly higher than those of the controls. The possible correlation of these elements with the etiology of different physiological disorders is discussed. The results were also demonstrated the need of attention for improvements in workplace, ventilation and industrial hygiene practices.

  7. 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.

  8. Depletion of cells and abundant proteins from biological samples by enhanced dielectrophoresis✩

    PubMed Central

    Gupta, C.; Provine, J.; Davis, R.W.; Howe, R.T.

    2016-01-01

    Platforms that are sensitive and specific enough to assay low-abundance protein biomarkers, in a high throughput multiplex format, within a complex biological fluid specimen, are necessary to enable protein biomarker based diagnostics for diseases such as cancer. The signal from an assay for a low-abundance protein biomarker in a biological fluid sample like blood is typically buried in a background that arises from the presence of blood cells and from high-abundance proteins that make up 90% of the assayed protein mass. We present an automated on-chip platform for the depletion of cells and highly abundant serum proteins in blood. Our platform consists of two components, the first of which is a microfluidic mixer that mixes beads containing antibodies against the highly abundant proteins in the whole blood. This complex mixture (consisting of beads, cells, and serum proteins) is then injected into the second component of our microfluidic platform, which comprises a filter trench to capture all the cells and the beads. The size-based trapping of the cells and beads into the filter trench is significantly enhanced by leveraging additional negative dielectrophoretic forces to push the micron sized particles (cells and beads which have captured the highly abundant proteins) down into the trench, allowing the serum proteins of lower abundance to flow through. In general, dielectrophoresis using bare electrodes is incapable of producing forces beyond the low piconewton range that tend to be insufficient for separation applications. However, by using electrodes passivated with atomic layer deposition, we demonstrate the application of enhanced negative DEP electrodes together with size-based flltration induced by the filter trench, to deplete 100% of the micron sized particles in the mixture. PMID:26924893

  9. Preparation of polysulfone materials on nickel foam for solid-phase microextraction of floxacin in water and biological samples.

    PubMed

    Guan, Xiujuan; Cheng, Ting; Wang, Shuxia; Liu, Xiaoyan; Zhang, Haixia

    2017-03-01

    Solid-phase microextraction with polysulfone and molecularly imprinted polymers as coating on nickel foam were used to adsorb and enrich floxacin drugs. The preparation method is simple and reproducible to obtain the materials with controlled thickness. After evaluation by scanning electron microscope and various adsorption experiments, the materials were used to adsorb analytes in water samples and biological samples. Coupling with chromatographic analysis, the method recoveries are satisfactory with 90.0-104.8% and 79.31-107.1% for water and biological samples. The method repeatability by intra- and interday experiments shows that the RSD values for water and biological samples were 1.0-9.9% and 1.7-10.3%, with the quantitative limits of three floxacin drugs as 3.0-6.2 μg L(-1). Graphical Abstract Preparation diagram of polysulfone material.

  10. 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.

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

    PubMed

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

    2011-05-13

    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.

  12. Analysis of six relevant toxaphene congeners in biological samples using ion trap MS/MS.

    PubMed

    Gouteux, Bruno; Lebeuf, Michel; Trottier, Steve; Gagné, Jean-Pierre

    2002-10-01

    The quantification of six polychlorinated bornanes (CHBs) was studied using ion trap MS/MS. The significance of the selection of parent ions (Ip) and daughter ions (Id) on the detection of these toxaphene congeners was assessed in standard solution and biological samples. Our results indicate that different Ip and Id, selected at either low or high mass-to-charge (m/z) ratios, influence drastically the response factor of the CHBs and the chemical noise observed. For the octachlorinated toxaphene congeners (Parlar-26 (P-26), Parlar-40/41 (P-40/41), Parlar-44 (P-44)), the detection performance of the ion trap MS/MS is similar whether Ip and Id were chosen at low or high m/z ratios. However, the selection of Ip and Id at high m/z ratios clearly enhances the detection of the nonachlorinated toxaphene congeners (Parlar-50 (P-50), Parlar-62 (P-62)). The improved method, which selects Ip and Id at low m/z ratios for P-26, P-40/41 and P-44 and at high m/z ratios for P-50 and P-62, permitted to obtain low detection limits as well as repeatable and accurate results.

  13. 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.

  14. 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.

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

    SciTech Connect

    Chang, Huan -Tsung

    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.

  16. Substrate-zymography: a still worthwhile method for gelatinases analysis in biological samples.

    PubMed

    Ricci, Serena; D'Esposito, Vittoria; Oriente, Francesco; Formisano, Pietro; Di Carlo, Angelina

    2016-08-01

    Matrix metallo-proteinases (MMPs) are a family of zinc-dependent endopeptidases, capable of degrading all the molecular components of extracellular matrix. A class of MMPs is gelatinases which includes gelatinase A or MMP-2 (72 kDa) and gelatinase B or MMP-9 (92 kDa), which have been shown to play critical roles in pathophysiology of many human disease and, in particular, cancer progression. For these reasons they obtained a great interest as potential non-invasive biomarker in providing useful clinical information in cancer diagnosis and therapy. A sensitive and unexpensive method for analysis of gelatinases is the gelatine zymography, which allows to measure the relative amounts of active and inactive enzymes in body fluids and tissue extracts. The procedure involves the electrophoretic separation of proteins under denaturing but non reducing conditions through a polyacrylamide gel containing a synthetic substrate (gelatin). The aim of this mini-review has been to describe the general principles of gelatine zymography technique, underling the main advantages and disadvantages. Even though an improvement of this method is necessary for a better applicability in laboratory medicine, gelatine zymography represents the most convenient method to detect the activity of the different gelatinases from a wide range of biological samples.

  17. Microwave-accelerated bioassay technique for rapid and quantitative detection of biological and environmental samples.

    PubMed

    Mohammed, Muzaffer; Syed, Maleeha F; Aslan, Kadir

    2016-01-15

    Quantitative detection of molecules of interest from biological and environmental samples in a rapid manner, particularly with a relevant concentration range, is imperative to the timely assessment of human diseases and environmental issues. In this work, we employed the microwave-accelerated bioassay (MAB) technique, which is based on the combined use of circular bioassay platforms and microwave heating, for rapid and quantitative detection of Glial Fibrillary Acidic Protein (GFAP) and Shiga like toxin (STX 1). The proof-of-principle use of the MAB technique with the circular bioassay platforms for the rapid detection of GFAP in buffer based on colorimetric and fluorescence readouts was demonstrated with a 900W kitchen microwave. We also employed the MAB technique with a new microwave system (called the iCrystal system) for the detection of GFAP from mice with brain injuries and STX 1 from a city water stream. Control bioassays included the commercially available gold standard bioassay kits run at room temperature. Our results show that the lower limit of detection (LLOD) of the colorimetric and fluorescence based bioassays for GFAP was decreased by ~1000 times using the MAB technique and our circular bioassay platforms as compared to the commercially available bioassay kits. The overall bioassay time for GFAP and STX 1 was reduced from 4h using commercially available bioassay kits to 10min using the MAB technique.

  18. Ozone degradation of residual carbon in biological samples using microwave irradiation.

    PubMed

    Jiang, W; Chalk, S J; Kingston, H M

    1997-03-01

    In an attempt to produce complete oxidation of a biological matrix, bovine liver, ozone was investigated as an additional, potentially non-contaminating, oxidizing reagent after nitric acid digestion. Experiments were carried out to determine the decomposition efficiency of residual carbon species, primarily o-, m- and p-nitrobenzoic acids (NBAs), using ozone. The NBAs were degraded by purging sample digests with ozone, while heating the solutions with microwave energy at atmospheric pressure. The effects of the degradation temperature and solution pH on the ozonation of NBAs were determined. Solid phase extraction (C18) was used to extract NBAs from the acid digestate solutions prior to HPLC analysis. Reversed phase HPLC was used to determine NBA concentrations in digest solutions. After 2.5 h of purging ozone at 80 degrees C, 33.65 +/- 3.80% o-NBA degradation, 19.39 +/- 1.74% m-NBA degradation, and 26.47 +/- 3.36% p-NBA degradation were obtained.

  19. Wet ashing in biological samples in a microwave oven under pressure using poly(tetrafluoroethylene) vessels

    SciTech Connect

    Aysola, P.; Anderson, P.; Langford, C.H.

    1987-06-01

    Gorsuch has described the problems associated with the oxidation of organic matter in biological samples. This is a step that must precede trace metal determination by atomic spectroscopy. Treatment with acid on a hot plate typically requires 1-2 h. The use of a microwave oven is an attractive possibility for acceleration of the process. Koirtyohann et al. and Barrett et al. modified microwave ovens by adding an exhaust port. Nadkarni exploited an unmodified oven by using a Pyrex vacuum desiccator as a pressurizable vessel. They report significant losses of Cu (26%) and Pb (20%). Matts et al. tried polycarbonate pressurizable vessels, but the plastic quickly became opaque and brittle. The authors have reevaluated the prospects for use of an unmodified microwave oven with pressurized vessels. They found that Pyrex vessels gain heat in the glass quickly. The authors substituted Teflon TFA brand fluorocarbon resin for polycarbonate and find it has superior chemical and mechanical properties. They now report a 60-s pressure vessel procedure using an unmodified commercial oven.

  20. Microwave-Accelerated Bioassay Technique for Rapid and Quantitative Detection of Biological and Environmental Samples

    PubMed Central

    Mohammed, Muzaffer; Syed, Maleeha F.; Aslan, Kadir

    2015-01-01

    Quantitative detection of molecules of interest from biological and environmental samples in a rapid manner, particularly with a relevant concentration range, is imperative to the timely assessment of human diseases and environmental issues. In this work, we employed the microwave-accelerated bioassay (MAB) technique, which is based on the combined use of circular bioassay platforms and microwave heating, for rapid and quantitative detection of Glial Fibrillary Acidic Protein (GFAP) and Shiga like toxin (STX 1). The proof-of-principle use of the MAB technique with the circular bioassay platforms for the rapid detection of GFAP in buffer based on colorimetric and fluorescence readouts was demonstrated with a 900 W kitchen microwave. We also employed the MAB technique with a new microwave system (called the iCrystal system) for the detection of GFAP from mice with brain injuries and STX 1 from a city water stream. Control bioassays included the commercially available gold standard bioassay kits run at room temperature. Our results show that the lower limit of detection (LLOD) of the colorimetric and fluorescence based bioassays for GFAP was decreased by ~1,000 times using the MAB technique and our circular bioassay platforms as compared to the commercially available bioassay kits. The overall bioassay time for GFAP and STX 1 was reduced from 4 hours using commercially available bioassay kits to 10 minutes using the MAB technique. PMID:26356762

  1. 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.

  2. 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.

  3. In-focus electron microscopy of frozen-hydrated biological samples with a Boersch phase plate.

    PubMed

    Barton, B; Rhinow, D; Walter, A; Schröder, R; Benner, G; Majorovits, E; Matijevic, M; Niebel, H; Müller, H; Haider, M; Lacher, M; Schmitz, S; Holik, P; Kühlbrandt, W

    2011-12-01

    We report the implementation of an electrostatic Einzel lens (Boersch) phase plate in a prototype transmission electron microscope dedicated to aberration-corrected cryo-EM. The combination of phase plate, C(s) corrector and Diffraction Magnification Unit (DMU) as a new electron-optical element ensures minimal information loss due to obstruction by the phase plate and enables in-focus phase contrast imaging of large macromolecular assemblies. As no defocussing is necessary and the spherical aberration is corrected, maximal, non-oscillating phase contrast transfer can be achieved up to the information limit of the instrument. A microchip produced by a scalable micro-fabrication process has 10 phase plates, which are positioned in a conjugate, magnified diffraction plane generated by the DMU. Phase plates remained fully functional for weeks or months. The large distance between phase plate and the cryo sample permits the use of an effective anti-contaminator, resulting in ice contamination rates of <0.6 nm/h at the specimen. Maximal in-focus phase contrast was obtained by applying voltages between 80 and 700 mV to the phase plate electrode. The phase plate allows for in-focus imaging of biological objects with a signal-to-noise of 5-10 at a resolution of 2-3 nm, as demonstrated for frozen-hydrated virus particles and purple membrane at liquid-nitrogen temperature.

  4. [New methods and technologies expandable to the laser detection of biological and medical samples].

    PubMed

    Shi, Gui-zhen; Du, Hai; Ge, Liao-hai; Tian, Yu; Huang, Mao-cheng; Wang, Wen-yun

    2011-07-01

    The multicolour three-photon resonant photoionization spectra and high-time-resolved laser spectrum of UI were measured with a setup composed of a Nd:YAG-laser (532 nm, operated at 10 Hz)-pumped pulsed tunable dye laser system, a time-of-flight mass spectrometer, including micro-channel plate components, ns-oscilloscope, boxcar integrator, and so on. Creative inventions of this paper are for the first time by laser-induced quantum population of the graphic method, the causes for single-colour and two-colour three-photon resonant photoionization spectra peak were given in the three-colour three-photon resonant photoionization experiment; The question how to avoid producing single-colour and two-colour three-photon resonant photoionization spectra peak was solved, That is, how to solve the problem to avoid "false peaks", so that multicolour three-photon resonant photoionization purity was raised remarkably; On this basis, not only in close proximity to energy level position with just a difference 0.642 cm, the isotopes A and B of uranium, which are difficult to distinguish, were well resolved, but the two excited state lifetime values were obtained respectively. This technology is not limited to uranium spectrum, but more importantly, it's versatile. The new methods and technologies of basic research can be expanded to samples of biological and medical research fields with laser detecting and analysis.

  5. 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

  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. Awareness of Biologically Confirmed HCV Among a Community Residing Sample of Drug Users in Baltimore City

    PubMed Central

    Hearn, Lauren E.; Marsiske, Michael; Kahn, Maria R.; Latimer, William W.

    2014-01-01

    The present study sought to examine: (1) the prevalence and correlates of biologically confirmed Hepatitis C (HCV) and (2) the prevalence and correlates of prior HCV diagnosis and an unmet need for HCV treatment, among a community residing sample of drug users. The current study used a subset of HCV tested participants from the larger NEURO-HIV Epidemiologic Study from Baltimore, Maryland (Mage = 34.81, SD = 9.25; 46 % female). All participants were tested for HCV at baseline. Self-report was used to assess awareness of an HCV diagnosis and participation in treatment. Of the 782 participants tested for HCV, 19 % reported having received an HCV diagnosis in the past while 48 % tested positive for HCV. Only 6 % reported having received treatment for any form of hepatitis. Of those who tested HCV positive, 63 % reported never being diagnosed, and only 13 % received any treatment for HCV. We found that only 35 % of those who reported a prior HCV diagnosis received any treatment. The findings regarding lack of HCV awareness and diagnosis were considerable as expected. These deficits suggest that there are numerous gaps in patients' knowledge and beliefs regarding HCV that may interfere at multiple steps along the path from diagnosis to treatment. This study clearly demonstrates that a critical need exists to improve public knowledge of HCV risk factors, the need for testing, and the availability of effective treatment. PMID:24173529

  8. 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

  9. 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.

  10. 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

    2016-01-07

    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.

  11. Determination of lead and manganese in biological samples and sediment using slurry sampling and flame atomic absorption spectrometry.

    PubMed

    Vieira, Daniel Rodrigues; Castro, Jacira Teixeira; Lemos, Valfredo Azevedo

    2011-01-01

    A procedure was developed for the determination of lead (Pb) and manganese (Mn) using slurry sampling. The two elements were detected using flame atomic absorption spectrometry with a slotted tube atom trap. Slurries were prepared by adding nitric acid solution (0.30%, w/v) to a powdered sample (0.10 g). After homogenization by ultrasonic bath for 15 min, the slurries were introduced directly into the detection equipment. Some conditions of the procedure were evaluated, such as acid concentration, presence of surfactants, and sonication time. Under optimized conditions, the LODs and LOQs achieved were 0.8 and 2.6 microg/g for Pb and 0.5 and 1.6 microg/g for Mn, respectively. The precision obtained varied between 3.1 and 5.8% (Mn), and 2.6 and 5.4% (Pb) for slurries of shrimp and sediment. The analytical curves were established using aqueous standards in nitric acid solutions. The accuracy of the method was assessed through the determination of Pb and Mn in the following certified reference materials: ERM-CE 278 (mussel tissue), CRM 397 (human hair), and SRM 1646a (estuarine sediment). The proposed procedure was successfully applied to the determination of Pb and Mn in six samples of shrimp powder, seasoning, and river sediment. The levels of Mn detected varied from 2.2 to 71.3 microg/g; Pb was detected in only one sediment sample (4.3 microg/g).

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

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

    PubMed Central

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

    2008-01-01

    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 617 adoptive and biological families, adjusting for sample restriction of SES range. Controlling for gender, parenting, parental expectations for educational attainment (PEEA), IQ, engagement in school, and genetic and shared environmental influences on sibling pairs, SES still made a small but significant nonshared environmental contribution to school grades. IQ, PEEA, and SES had collinear associations with school grades, as did engagement and parenting. The associations of IQ and engagement with school grades were largely independent of each other. The link between PEEA and IQ was stronger in adoptive than biological offspring. We discuss the implications of these findings. PMID:19081832

  18. 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

  19. 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.

  20. Semiquantitative multielemental analysis of biological samples by a laser ionization orthogonal time-of-flight mass spectrometer.

    PubMed

    Chen, Lizhi; Lin, Lin; Yu, Quan; Yan, Xiaomei; Hang, Wei; He, Jian; Huang, Benli

    2009-07-01

    Semiquantitative multielemental analyses of biological samples (tea leaf standard, Laminaria japonica, and pig skin) were demonstrated with a newly developed laser ionization orthogonal time-of-flight mass spectrometer (LI-O-TOFMS). The sample was directly ablated and ionized with high irradiance after simple sample preparation. Relative sensitivity coefficients (RSC) were calculated and evaluated for sensitivity differences. Due to the employment of a collisional cooling device and the orthogonal geometry of the TOF system, high resolving power can be obtained, such that elemental peaks and interferential peaks with the same nominal mass can be distinguished. The detection limit of microg g(-1) levels can be commonly achieved for elemental determination.

  1. A microfluidic platform for precision small-volume sample processing and its use to size separate biological particles with an acoustic microdevice [Precision size separation of biological particles in small-volume samples by an acoustic microfluidic system

    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.

  2. A microfluidic platform for precision small-volume sample processing and its use to size separate biological particles with an acoustic microdevice [Precision size separation of biological particles in small-volume samples by an acoustic microfluidic system

    DOE PAGES

    Fong, Erika J.; Huang, Chao; Hamilton, Julie; ...

    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

  3. Sample Preparation and Identification of Biological, Chemical and Mid-Spectrum Agents

    DTIC Science & Technology

    2005-10-01

    mL sterile PBS. Form a suspension by vigorous agitation using a vortex mixer for 10-15 seconds. Soil and Other Solid Environmental Samples. To 5...grams of sample add two equivalent volumes of sterile PBS. Form a suspension by vigorous agitation on vortex mixer for 10-15 seconds. Filter sample...Micro-Extraction Solid phase microextraction (SPME) is a relatively new analytical technique. It can combine sample preparation and GC or LC analysis in

  4. Chiral analysis of amphetamines, methadone and metabolites in biological samples by electrodriven methods.

    PubMed

    Mandrioli, Roberto; Mercolini, Laura; Raggi, Maria A

    2011-10-01

    Amphetamines and methadone are synthetic chiral drugs with a high potential for abuse. As such, several analytical methods have been developed for their enantioseparation and analysis in biological tissues, and some of these are based on electrodriven techniques. In this review, the most important and recent of these latter methods are reviewed and their main advantages and disadvantages are discussed. Particular attention is paid to the suitability of each method for the application to the biological matrix of interest: while all methods have been successfully applied for one or more biological tissues, to reach this goal they must overcome the sensitivity problem that is common to almost all capillary electrophoretic techniques. Most methods use one or more cyclodextrin derivatives as the chiral selector, thus the separation mechanism is not particularly complicated or unusual.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Photoelectron dynamics in x-ray free-electron-laser diffractive imaging of biological samples.

    PubMed

    Hau-Riege, Stefan P

    2012-06-08

    X-ray free electron lasers hold the promise of enabling atomic-resolution diffractive imaging of single biological molecules. We develop a hybrid continuum-particle model to describe the x-ray induced damage and find that the photoelectron dynamics and electrostatic confinement strongly affect the time scale of the damage processes. These phenomena are not fully captured in hydrodynamic modeling approaches.

  10. 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,…

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

    ERIC Educational Resources Information Center

    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…

  13. Biological Fieldwork in a Sample of Secondary Schools in England and Wales.

    ERIC Educational Resources Information Center

    Gayford, C. G.

    1984-01-01

    Discusses results from a survey of teachers and students in 133 schools concerning uses of fieldwork in biology. These results (given for A-level and pre-A-level responses) focus on the importance, location, times, and types of fieldwork, and student attitudes toward fieldwork. (DH)

  14. Preparing monodisperse macromolecular samples for successful biological small-angle X-ray and neutron-scattering experiments.

    PubMed

    Jeffries, Cy M; Graewert, Melissa A; Blanchet, Clément E; Langley, David B; Whitten, Andrew E; Svergun, Dmitri I

    2016-11-01

    Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) are techniques used to extract structural parameters and determine the overall structures and shapes of biological macromolecules, complexes and assemblies in solution. The scattering intensities measured from a sample contain contributions from all atoms within the illuminated sample volume, including the solvent and buffer components, as well as the macromolecules of interest. To obtain structural information, it is essential to prepare an exactly matched solvent blank so that background scattering contributions can be accurately subtracted from the sample scattering to obtain the net scattering from the macromolecules in the sample. In addition, sample heterogeneity caused by contaminants, aggregates, mismatched solvents, radiation damage or other factors can severely influence and complicate data analysis, so it is essential that the samples be pure and monodisperse for the duration of the experiment. This protocol outlines the basic physics of SAXS and SANS, and it reveals how the underlying conceptual principles of the techniques ultimately 'translate' into practical laboratory guidance for the production of samples of sufficiently high quality for scattering experiments. The procedure describes how to prepare and characterize protein and nucleic acid samples for both SAXS and SANS using gel electrophoresis, size-exclusion chromatography (SEC) and light scattering. Also included are procedures that are specific to X-rays (in-line SEC-SAXS) and neutrons, specifically preparing samples for contrast matching or variation experiments and deuterium labeling of proteins.

  15. A high performance liquid chromatographic method of analysis of 4'-O-tetrahydropyranyladriamycin and their metabolites in biological samples.

    PubMed

    Matsushita, Y; Iguchi, H; Kiyosaki, T; Tone, H; Ishikura, T; Takeuchi, T; Umezawa, H

    1983-07-01

    A method for measuring 4'-O-tetrahydropyranyladriamycin (THP) and its metabolites in biological samples are described. By reversed-phase high performance liquid chromatography using fluorescence detection, THP and its metabolites were all separated on a single chromatogram within 18 minutes. A linear calibration curve was obtained up to 2,000 ng/ml of THP in plasma. The recovery of THP in the analysis was more than 95% above 5 ng/ml and 87.1% even at 1.25 ng/ml. Thus the lower limit was 1.25 ng/ml in biological samples. Blood levels and urinary excretion in mice and dogs were satisfactory measured by this analytical method.

  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. Prompt gamma neutron activation analysis of 10B and Gd in biological samples at the MEPhI reactor.

    PubMed

    Khokhlov, V F; Zaitsev, K N; Beliayev, V N; Kulakov, V N; Lipengolts, A A; Portnov, A A

    2009-07-01

    The purpose of the work was to build a prompt gamma neutron activation analysis (PGNAA) facility at the MEPhI reactor for analyzing the content of various elements for NCT. The facility was implemented on a monochromatic neutron beam. Methods of quantitative (10)B and Gd measurement have been developed for pharmacokinetic studies. The facility is capable of measuring 1 microg of (10)B and 10 microg of Gd in biological samples with an error less than 10%. The detection limit of the facility is 0.3 microg of (10)B and 2 microg of Gd. Neutron flux attenuation within biological tissue samples was estimated and a new system for determining the elemental concentration was suggested.

  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.

  19. An Activity To Demonstrate the Concept of Sampling Error for the Introductory Biology Classroom.

    ERIC Educational Resources Information Center

    Rutledge, Michael L.

    2001-01-01

    This activity makes students a part of an investigation that determines the frequency of a particular plant variety in a simulated population. Provides an opportunity for students to observe the inherent variability of estimates, observe the relationship between sample size and sampling error, and consider aspects of research design. (Author/SAH)

  20. Environmental Sampling Procedures and Methods to Respond to Biological Contamination (White Powder)

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Matzke, Brett D.

    2008-11-01

    This is a contribution to the annual report for the DHS Standards Office. It summarizes statistics-focused work associated with developing validated sampling procedures and methods. The main focus is on the experimental and sampling design constructed for contamination and decontamination field tests conducted during September 2007 in a remote, unused office building on the Idaho National Laboratory site.

  1. Electrical manipulation of biological samples in glass-based electrofluidics fabricated by 3D femtosecond laser processing

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2014-03-01

    Electrical manipulation of biological samples using glass-based electrofluidics fabricated by femtosecond laser, in which the microfluidic structures are integrated with microelectric components, is presented. Electro-orientation of movement of living cells with asymmetric shapes such as Euglena gracilis of aquatic microorganisms in microfluidic channels is demonstrated using the fabricated electrofluidics. By integrating the properly designed microelectrodes into microfluidic channels, the orientation direction of Euglena cells can be well controlled.

  2. Substrate interferences in identifying flammable liquids in food, environmental and biological samples: case studies.

    PubMed

    Borusiewicz, Rafal

    2015-05-01

    The analysis of samples for traces of ignitable liquids is most often connected with suspected arson cases. In such cases, samples taken from the point of origin of the fire are analyzed for the presence of ignitable liquids. However, sometimes, in cases not connected with arson, there is a need to detect and identify traces of ignitable liquids. Three examples of such cases are given in this paper. Aqueous samples (polluted water, juice and blood) were analyzed using a procedure routinely used in the analyses of fire debris. The procedure consists of passive adsorption of volatile organic compounds on Tenax, followed by thermal desorption and chromatographic analysis. Results showed that analysis of such untypical samples may be connected with unusual matrix effects, not frequently encountered in fire debris samples.

  3. 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.

  4. Comparison of high-performance liquid chromatography with radioimmunoassay for the determination of domoic acid in biological samples.

    PubMed

    Lawrence, J F; Cleroux, C; Truelove, J F

    1994-02-18

    A reversed-phase liquid chromatographic method employing UV absorption detection at 242 nm was compared to a radioimmunoassay technique for the determination of the marine toxin, domoic acid, in several types of seafood and biological samples. Agreement between the two methods for spiked samples of mussels and rat serum was very good over a range of concentrations of 0.15-7.3 micrograms/g domoic acid. Also, a very good correlation was observed between the two methods for naturally incurred residues of domoic acid in razor clams, anchovies and crab meat over a concentration range of 0.6-43 micrograms/g domoic acid.

  5. Characterization of carbon nanotubes and analytical methods for their determination in environmental and biological samples: a review.

    PubMed

    Herrero-Latorre, C; Álvarez-Méndez, J; Barciela-García, J; García-Martín, S; Peña-Crecente, R M

    2015-01-01

    In the present paper, a critical overview of the most commonly used techniques for the characterization and the determination of carbon nanotubes (CNTs) is given on the basis of 170 references (2000-2014). The analytical techniques used for CNT characterization (including microscopic and diffraction, spectroscopic, thermal and separation techniques) are classified, described, and illustrated with applied examples. Furthermore, the performance of sampling procedures as well as the available methods for the determination of CNTs in real biological and environmental samples are reviewed and discussed according to their analytical characteristics. In addition, future trends and perspectives in this field of work are critically presented.

  6. Automated sample preparation techniques for the determination of drug enantiomers in biological fluids using liquid chromatography with chiral stationary phases.

    PubMed

    Ceccato, A; Toussaint, B; Chiap, P; Hubert, P; Crommen, J

    1999-01-01

    The determination of drug enantiomers has become of prime importance in the field of pharmaceutical and biomedical analysis. Liquid chromatography (LC) is one of the most frequently used techniques for achieving the separation and quantitation of the enantiomers of drug compounds. In the bioanalytical field, the integrated systems present an interesting alternative to time-consuming sample preparation techniques such as liquid-liquid extraction. Solid phase extraction (SPE) on disposable cartridges, dialysis or column switching are sample preparation techniques that can be fully automated and applied to enantioselective analysis in biological fluids. The selection of the most appropriate LC mode and chiral stationary phase for enantioseparations in bioanalysis is discussed and some aspects of these automated sample preparation procedures are compared, such as selectivity, detectability, elution of the analytes from the extraction sorbent, sample volume and analyte stability.

  7. Stability of heroin, 6-monoacetylmorphine, and morphine in biological samples and validation of an LC-MS assay for delayed analyses of pharmacokinetic samples in rats.

    PubMed

    Jones, Jessica M; Raleigh, Michael D; Pentel, Paul R; Harmon, Theresa M; Keyler, Daniel E; Remmel, Rory P; Birnbaum, Angela K

    2013-02-23

    Degradation of heroin to 6-monoacetylmorphine (6-MAM) and then morphine happens rapidly in vivo and in vitro. The rates of heroin and 6-MAM degradation depend on the type of biological samples, and the duration and conditions of storage. In order to optimize conditions for measuring heroin and its metabolites in samples collected for pharmacokinetic studies in rats, we investigated the time course of degradation of heroin, 6-MAM, and morphine in four biological matrices: rat blood, rat brain homogenate, bovine serum, and human plasma under various conditions. Analyte concentrations were measured by LC-MS. The goal was to identify conditions that allow maximum flexibility in scheduling sample collection and analysis, as well as gain more information on the stability of heroin in blood and tissue samples. A solid-phase extraction method with ice-cold solvents, sodium fluoride (NaF) and a low pH (3.0) maintained sample stability. Quality controls were within 94.0-105% of the target value. Variability was 4.0-8.9% for all analytes within the range of 5-200 ng/mL for heroin, 5-1000 ng/mL for 6-MAM, and 10-200 ng/mL for morphine. Heroin degradation to 6-MAM was faster in rat whole blood than in plasma, and faster in rat plasma than in rat brain homogenate. Maintaining NaF at 4 mg/mL throughout processing enhanced stability; higher NaF concentrations added to whole blood caused hemolysis. Samples processed through solid phase extraction and stored as dried pellets at 80°C constituted the most stable environment for heroin, and was superior to the storing of samples in solution prior to or after extraction. Nevertheless, post-extraction heroin and 6-MAM levels declined by 6.7-8.3% over one week in rat plasma under these conditions, and by <1-4.7% in bovine serum or human plasma.

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

    SciTech Connect

    Britton, L.J.; Greeson P.E.

    1989-01-01

    Chapter A4 contains methods used by the US Geological Survey to collect, preserve, and analyze waters to determine their 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; Part 2 consists of a glossary; and Part 3 is a list of taxonomic references.

  9. Testing biological liquid samples using modified m-line spectroscopy method

    NASA Astrophysics Data System (ADS)

    Augusciuk, Elzbieta; Rybiński, Grzegorz

    2005-09-01

    Non-chemical method of detection of sugar concentration in biological (animal and plant source) liquids has been investigated. Simplified set was build to show the easy way of carrying out the survey and to make easy to gather multiple measurements for error detecting and statistics. Method is suggested as easy and cheap alternative for chemical methods of measuring sugar concentration, but needing a lot effort to be made precise.

  10. 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

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

    PubMed

    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.

  12. 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.

  13. Impact of Processing Method on Recovery of Bacteria from Wipes Used in Biological Surface Sampling

    PubMed Central

    Olson, Nathan D.; Filliben, James J.; Morrow, Jayne B.

    2012-01-01

    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. PMID:22706055

  14. 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.

  15. 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.

  16. The Evaluation of Carpet Steam/Heat Cleaners as Biological Sampling Device

    DTIC Science & Technology

    2011-12-08

    2.10.0 12. DISTRIBUTION/ AVAILABILITY STATEMENT Approved for public release, distribution unlimited 13. SUPPLEMENTARY NOTES The original document...Increased availability of sampling methods and resources to support rapid recovery and cleanup following wide-area release and contamination...will be performed in building E5951. Coupon extraction, sample analysis, and quantitative assessment will be performed in lab 307 located in the

  17. 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.

  18. Use of semiconductor nanocrystals to encode microbeads for multiplexed analysis of biological samples

    NASA Astrophysics Data System (ADS)

    Berestovoy, Mikhail A.; Bilan, Regina S.; Krivenkov, Victor; Nabiev, Igor; Sukhanova, Alyona

    2017-01-01

    Microbeads encoded with semiconductor quantum dots (QDs) are suitable tools for multiplexed analyses of various biological markers using flow cytometry. We have prepared a panel of microbeads encoded with QDs of different colors emitting with different luminescence intensities using the layer-by-layer deposition technique, which consists in layering of alternately charged polyelectrolytes and negatively charged QDs onto the surface of microbeads. This method allows QDs to be separated with one or several polymer layers in order to prevent Förster resonance energy transfer (FRET) and the resultant quenching of QD fluorescence in multicolor microbeads.

  19. The latest advancements in proteomic two-dimensional gel electrophoresis analysis applied to biological samples.

    PubMed

    Santucci, Laura; Bruschi, Maurizio; Ghiggeri, Gian Marco; Candiano, Giovanni

    2015-01-01

    Two-dimensional gel electrophoresis (2DE) is one of the fundamental approaches in proteomics for the separation and visualization of complex protein mixtures. Proteins can be analyzed by 2DE using isoelectric focusing (IEF) in the first dimension, combined to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension, gel staining (silver and Coomassie), image analysis, and 2DE gel database. High-resolution 2DE can resolve up to 5,000 different proteins simultaneously (∼2,000 proteins routinely), and detect and quantify <1 ng of protein per spot. Here, we describe the latest developments for a more complete analysis of biological fluids.

  20. Integrating clinical and biological information in a shanghai biobank: an introduction to the sample repository and information sharing platform project.

    PubMed

    Cui, Wenbin; Zheng, Peiyong; Yang, Jiahong; Zhao, Rong; Gao, Jiechun; Yu, Guangjun

    2015-02-01

    Biobanks are important resources and central tools for translational medicine, which brings scientific research outcomes to clinical practice. The key purpose of biobanking in translational medicine and other medical research is to provide biological samples that are integrated with clinical information. In 2008, the Shanghai Municipal Government launched the "Shanghai Tissue Bank" in an effort to promote research in translational medicine. Now a sharing service platform has been constructed to integrate clinical practice and biological information that can be used in diverse medical and pharmaceutical research studies. The platform collects two kinds of data: sample data and clinical data. The sample data are obtained from the hospital biobank management system, and mainly include the donors' age, gender, marital status, sample source, sample type, collection time, deposit time, and storage method. The clinical data are collected from the "Hospital-Link" system (a medical information sharing system that connects 23 tertiary hospitals in Shanghai). The main contents include donors' corresponding medication information, test reports, inspection reports, and hospital information. As of the end of September 2014, the project has a collection of 16,020 donors and 148,282 samples, which were obtained from 12 medical institutions, and automatically acquired donors' corresponding clinical data from the "Hospital-Link" system for 6830 occurrences. This project will contribute to scientific research at medical institutions in Shanghai, and will also support the development of the biopharmaceutical industry. In this article, we will describe the significance, the construction phases, the application prospects, and benefits of the sample repository and information sharing service platform.

  1. High-performance liquid chromatographic determination of histamine in biological samples: the cerebrospinal fluid challenge--a review.

    PubMed

    Wang, Zhaopin; Wu, Juanli; Wu, Shihua; Bao, Aimin

    2013-04-24

    Histamine, a neurotransmitter crucially involved in a number of basic physiological functions, undergoes changes in neuropsychiatric disorders. Detection of histamine in biological samples such as cerebrospinal fluid (CSF) is thus of clinical importance. The most commonly used method for measuring histamine levels is high performance liquid chromatography (HPLC). However, factors such as very low levels of histamine, the even lower CSF-histamine and CSF-histamine metabolite levels, especially in certain neuropsychiatric diseases, rapid formation of histamine metabolites, and other confounding elements during sample collection, make analysis of CSF-histamine and CSF-histamine metabolites a challenging task. Nonetheless, this challenge can be met, not only with respect to HPLC separation column, derivative reagent, and detector, but also in terms of optimizing the CSF sample collection. This review aims to provide a general insight into the quantitative analyses of histamine in biological samples, with an emphasis on HPLC instruments, methods, and hyphenated techniques, with the aim of promoting the development of an optimal and practical protocol for the determination of CSF-histamine and/or CSF-histamine metabolites.

  2. Collections of human biological samples for scientific purposes. Why do current regulation need to be clarified and how?

    PubMed

    Deplanque, Dominique; Birraux, Guillaume; Bertoye, Pierre-Henri; Postaire, Eric

    2009-01-01

    The collection of human biological samples is of major importance for future research in France and Europe. In recent years, new regulatory procedures have been designed to monitor these activities; but they are somewhat complex and some clarifications are needed. The law needs also to be amended. The definition of biobanking activities should be clarified, and regulatory procedures, including consultation of the Ethics Committee, declarations to the Ministry of Research and the protection of personal data, should be simplified. It is also of great importance to correctly define the modalities in which Biobanks are granted their authorisations. The role of Ethics Committees regarding the evaluation of information and the consent procedures should also be clarified, particularly when samples from children are used, or when the samples are used for genetic analyses. As well as scientific and public health aspects, the storage of human biological samples may also have important economic consequences. It is hence crucial to adapt the procedure for submitting patents, particularly when several public or private partners are working together. The possible changes to both French and European laws planned in the next months would be an ideal time to introduce these changes.

  3. 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).

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

    PubMed

    Ogura, Toshihiko

    2009-08-07

    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.

  5. Adventitious agents and live viral vectored vaccines: Considerations for archiving samples of biological materials for retrospective analysis.

    PubMed

    Klug, Bettina; Robertson, James S; Condit, Richard C; Seligman, Stephen J; Laderoute, Marian P; Sheets, Rebecca; Williamson, Anna-Lise; Gurwith, Marc; Kochhar, Sonali; Chapman, Louisa; Carbery, Baevin; Mac, Lisa M; Chen, Robert T

    2016-12-12

    Vaccines are one of the most effective public health medicinal products with an excellent safety record. As vaccines are produced using biological materials, there is a need to safeguard against potential contamination with adventitious agents. Adventitious agents could be inadvertently introduced into a vaccine through starting materials used for production. Therefore, extensive testing has been recommended at specific stages of vaccine manufacture to demonstrate the absence of adventitious agents. Additionally, the incorporation of viral clearance steps in the manufacturing process can aid in reducing the risk of adventitious agent contamination. However, for live viral vaccines, aside from possible purification of the virus or vector, extensive adventitious agent clearance may not be feasible. In the event that an adventitious agent is detected in a vaccine, it is important to determine its origin, evaluate its potential for human infection and pathology, and discern which batches of vaccine may have been affected in order to take risk mitigation action. To achieve this, it is necessary to have archived samples of the vaccine and ancillary components, ideally from developmental through to current batches, as well as samples of the biological materials used in the manufacture of the vaccine, since these are the most likely sources of an adventitious agent. The need for formal guidance on such vaccine sample archiving has been recognized but not fulfilled. We summarize in this paper several prior major cases of vaccine contamination with adventitious agents and provide points for consideration on sample archiving of live recombinant viral vector vaccines for use in humans.

  6. 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.

  7. Structural Study of Heterogeneous Biological Samples by Cryoelectron Microscopy and Image Processing.

    PubMed

    White, H E; Ignatiou, A; Clare, D K; Orlova, E V

    2017-01-01

    In living organisms, biological macromolecules are intrinsically flexible and naturally exist in multiple conformations. Modern electron microscopy, especially at liquid nitrogen temperatures (cryo-EM), is able to visualise biocomplexes in nearly native conditions and in multiple conformational states. The advances made during the last decade in electronic technology and software development have led to the revelation of structural variations in complexes and also improved the resolution of EM structures. Nowadays, structural studies based on single particle analysis (SPA) suggests several approaches for the separation of different conformational states and therefore disclosure of the mechanisms for functioning of complexes. The task of resolving different states requires the examination of large datasets, sophisticated programs, and significant computing power. Some methods are based on analysis of two-dimensional images, while others are based on three-dimensional studies. In this review, we describe the basic principles implemented in the various techniques that are currently used in the analysis of structural conformations and provide some examples of successful applications of these methods in structural studies of biologically significant complexes.

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

    PubMed

    Cifra, Michal; Pospíšil, Pavel

    2014-10-05

    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.

  9. Structural Study of Heterogeneous Biological Samples by Cryoelectron Microscopy and Image Processing

    PubMed Central

    White, H. E.; Ignatiou, A.; Clare, D. K.

    2017-01-01

    In living organisms, biological macromolecules are intrinsically flexible and naturally exist in multiple conformations. Modern electron microscopy, especially at liquid nitrogen temperatures (cryo-EM), is able to visualise biocomplexes in nearly native conditions and in multiple conformational states. The advances made during the last decade in electronic technology and software development have led to the revelation of structural variations in complexes and also improved the resolution of EM structures. Nowadays, structural studies based on single particle analysis (SPA) suggests several approaches for the separation of different conformational states and therefore disclosure of the mechanisms for functioning of complexes. The task of resolving different states requires the examination of large datasets, sophisticated programs, and significant computing power. Some methods are based on analysis of two-dimensional images, while others are based on three-dimensional studies. In this review, we describe the basic principles implemented in the various techniques that are currently used in the analysis of structural conformations and provide some examples of successful applications of these methods in structural studies of biologically significant complexes. PMID:28191458

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

    PubMed

    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

    2016-10-19

    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.

  11. 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

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

    NASA Astrophysics Data System (ADS)

    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

    2016-10-01

    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.

  13. [Blood sampling using "dried blood spot": a clinical biology revolution underway?].

    PubMed

    Hirtz, Christophe; Lehmann, Sylvain

    2015-01-01

    Blood testing using the dried blood spot (DBS) is used since the 1960s in clinical analysis, mainly within the framework of the neonatal screening (Guthrie test). Since then numerous analytes such as nucleic acids, small molecules or lipids, were successfully measured on the DBS. While this pre-analytical method represents an interesting alternative to classic blood sampling, its use in routine is still limited. We review here the different clinical applications of the blood sampling on DBS and estimate its future place, supported by the new methods of analysis as the LC-MS mass spectrometry.

  14. Mapping Chemical and Structural Composition of Pharmaceutical and Biological Samples by Raman, Surface-Enhanced Raman and Fluorescence Spectral Imaging

    NASA Astrophysics Data System (ADS)

    Chourpa, Igor; Cohen-Jonathan, Simone; Dubois, Pierre

    Raman spectroscopy is an analytical technique recognised for its structural and conformational specificity. The efficient discrimination of molecular species by Raman is particularly potent for multidimensional microscopic imaging of complex biological environment, as demonstrated in the present book. The commonly admitted problem of Raman, low sensitivity, can often be circumvented due to high output instruments and via approaches like RRS (resonance Raman scattering), SERS (surface-enhanced Raman scattering), TERS (tip-enhanced Raman scattering) or CARS (coherent anti-Stokes Raman scattering). In contrast to the latter, RRS and SERS are realizable with less sophisticated set-up based on common Raman systems. Although more invasive than RRS, SERS provides better sensitivity and quenching of fluorescence. SERRS (surface-enhanced resonance Raman scattering) spectroscopy can be used in coupling with fluorescence and competes in selectivity and sensitivity with spectrofluorimetry. In the chapter below, we use recent applications made in our group to illustrate the use of Raman and SERRS spectral imaging for characterization of biological samples (animal subcutaneous tissue, human cancer cells) and pharmaceutical samples (microparticles for drug delivery, fibres for wound dressing). After a brief description of experimental details on spectral imaging, the chapter will focus on results concerning (i) biocompatible pharmaceutical materials made of alginates and (ii) anticancer drugs in pharmaceutical forms and in biological systems.

  15. Determination of amines as pentafluoropropionic acid anhydride derivatives in biological samples using liquid chromatography and tandem mass spectrometry.

    PubMed

    Marand, Asa; Karlsson, Daniel; Dalene, Marianne; Skarping, Gunnar

    2004-06-01

    Determination of amines in biological samples as markers of exposure to the amines or the corresponding isocyanates is an important tool for industrial exposure assessment. In this study, a liquid chromatography and tandem mass spectrometry (LC-MS/MS) method for determination of amines in biological samples as perfluorofatty amides derivatives is presented. The method enables determination of diamines such as methylene diamine (MDA), toluene diamine (TDA), naphthalene diamine (NDA), hexamethylene diamine (HDA), isophorone diamine (IPDA), methylenedi(cyclohexylamine)(HMDA) and 4,4'-methylene-(2-chloroaniline)(MOCA) in human urine and plasma. The work-up procedure included hydrolysis of the biological samples with 3 M H(2)SO(4) at 100 degrees C for 16 h and extraction of the amines into toluene, where derivatisation of the amines with perfluorofatty acid anhydride was performed. Following removal of excess reagent and the acid formed and an exchange of solvent, the derivatives were analysed using gradient elution with an acetonitrile/water mobile phase composition and electrospray ionisation (ESI) with multiple reaction monitoring (MRM) of [M - H](-)-->[M - H - 120](-) or [119](-). Several perfluorofatty acid anhydrides were evaluated as derivatisation reagents, but the LC chromatographic properties of the pentafluoropropionic acid anhydride (PFPA) derivatives were favourable. Quantification of amine-PFPA derivatives was performed using deuterium labelled amine-PFPA derivatives as internals standards with good precision and linearity in the investigated range of 0-20 ng ml(-1) urine. The instrumental detection limits for the amine-PFPA derivatives were 0.2-3 fmol for MRM of [M - H](-)-->[119](-) and 0.3-8 fmol for [M - H](-)-->[M - H - 120](-). In 10 urine and 6 plasma samples from workers exposed to isocyanates, determination of TDA and MDA as PFPA derivatives was performed using LC-MS/MS and a reference GC-MS method. No significant difference between the two

  16. Set-up and calibration of a method to measure 10B concentration in biological samples by neutron autoradiography

    NASA Astrophysics Data System (ADS)

    Gadan, M. A.; Bortolussi, S.; Postuma, I.; Ballarini, F.; Bruschi, P.; Protti, N.; Santoro, D.; Stella, S.; Cansolino, L.; Clerici, A.; Ferrari, C.; Zonta, A.; Zonta, C.; Altieri, S.

    2012-03-01

    A selective uptake of boron in the tumor is the base of Boron Neutron Capture Therapy, which can destroy the tumor substantially sparing the normal tissue. In order to deliver a lethal dose to the tumor, keeping the dose absorbed by normal tissues below the tolerance level, it is mandatory to know the 10B concentration present in each kind of tissue at the moment of irradiation. This work presents the calibration procedure adopted for a boron concentration measurement method based on neutron autoradiography, where biological samples are deposited on sensitive films and irradiated in the thermal column of the TRIGA reactor (University of Pavia). The latent tracks produced in the film by the charged particles coming from the neutron capture in 10B are made visible by a proper etching, allowing the measurement of the track density. A calibration procedure with standard samples provides curves of track density as a function of boron concentration, to be used in the measurement of biological samples. In this paper, the bulk etch rate parameter and the calibration curves obtained for both liquid samples and biological tissues with known boron concentration are presented. A bulk etch rate value of (1.64 ± 0.02) μm/h and a linear dependence with etching time were found. The plots representing the track density versus the boron concentration in a range between 5 and 50 μg/g (ppm) are linear, with an angular coefficient of (1.614 ± 0.169)·10-3 tracks/(μm2 ppm) for liquids and (1.598 ± 0.097)·10-2 tracks/(μm2 ppm) for tissues.

  17. Recent trends in microdialysis sampling integrated with conventional and microanalytical systems for monitoring biological events: A review

    PubMed Central

    Nandi, Pradyot; Lunte, Susan M.

    2013-01-01

    Microdialysis (MD) is a sampling technique that can be employed to monitor biological events both in vivo and in vitro. When it is coupled to an analytical system, microdialysis can provide near realtime information on the time-dependent concentration changes of analytes in the extracellular space or other aqueous environments. Online systems for the analysis of microdialysis samples enable fast, selective and sensitive analysis while preserving the temporal information. Analytical methods employed for online analysis include liquid chromatography (LC), capillary (CE) and microchip electrophoresis and flow-through biosensor devices. This review article provides an overview of microdialysis sampling and online analysis systems with emphasis on in vivo analysis. Factors that affect the frequency of analysis and, hence, the temporal resolution of these systems are also discussed. PMID:19733728

  18. 1H NMR determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental and biological samples.

    PubMed

    Moura, Sidnei; Ultramari, Mariah de Almeida; de Paula, Daniela Mendes Louzada; Yonamine, Mauricio; Pinto, Ernani

    2009-04-01

    A nuclear magnetic resonance (1H NMR) method for the determination of beta-N-methylamino-L-alanine (L-BMAA) in environmental aqueous samples was developed and validated. L-BMAA is a neurotoxic modified amino acid that can be produced by cyanobacteria in aqueous environments. This toxin was extracted from samples by means of solid-phase extraction (SPE) and identified and quantified by 1H NMR without further derivatization steps. The lower limit of quantification (LLOQ) was 5 microg/mL. Good inter and intra-assay precision was also observed (relative standard deviation <8.5%) with the use of 4-nitro-DL-phenylalanine as an internal standard (IS). This method of 1H NMR analysis is not time consuming and can be readily utilized to monitor L-BMAA and confirm its presence in environmental and biological samples.

  19. Substrate contributions in micro-ATR of thin samples: implications for analysis of cells, tissue and biological fluids.

    PubMed

    Bassan, Paul; Sachdeva, Ashwin; Lee, Joe; Gardner, Peter

    2013-07-21

    Low-e microscope slides are a common substrate for biological samples. Typically they are used for transflection infrared microspectroscopy but increasingly they are also being used for micro-ATR experiments since it is assumed that the FTIR-ATR absorbance spectra of cells and tissue on low-e substrates will not contain any spectral contributions from the substrate materials. This, in part, is due to the expectation that all the infrared light will be reflected at the highly reflective surface. At low sample thicknesses, however (e.g. less than 2 μm) the electric field does indeed penetrate through the substrate layers and undergoes absorption, from the glass supporting layer making up the majority of the slide. In this paper we show experimental evidence of the substrate contributions in ATR spectra and also a theoretical model giving insight into the spectral contributions of the substrate as a function of sample thickness.

  20. 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.

  1. 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.

  2. High-performance liquid chromatography using electrochemical detection for the determination of prazosin in biological samples.

    PubMed

    Rathinavelu, A; Malave, A

    1995-08-04

    For the quantitation of prazosin a sensitive high-performance liquid chromatographic (HPLC) method was developed. This HPLC analysis method uses an electrochemical detection technique for the identification and quantitation of prazosin. In this assay the serum samples were deproteinized by using a simple acetonitrile precipitation technique that was followed by n-hexane extraction. Prazosin in the deproteinized serum sample was separated by an isocratic elution with an ODS Hypersil HPLC column (150 x 4.6 mm) using a mobile phase consisting of 0.05 M Na2HPO4-acetonitrile (60:40), pH 8.4. Prazosin that was eluted from the column was detected using a Coulochem II electrochemical detector. The precision of this assay method was assessed by performing inter- and intra-assay analyses by spiking prazosin free fetal bovine serum samples with 20 and 40 ng/ml concentrations of prazosin. In the intra-assay the recovery was 95.40 +/- 4.82% and 97.80 +/- 3.40%, respectively, for 20 and 40 ng/ml concentrations of prazosin that were used to spike the serum samples. This electrochemical detection HPLC assay method could be very useful in monitoring plasma levels of prazosin.

  3. Determination of total magnesium in biological samples using electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Hulanicki, Adam; Godlewska, Beata; Brzóska, Malgorzata

    1995-11-01

    Magnesium content is an important diagnostic parameter in medicine. It is recognized that its determination in one compartment is not sufficient for reliable information about the magnesium status in the body. In addition to the common procedures of magnesium determination in blood by flame atomic absorption spectrometry, the procedure of electrothermal atomization has also been developed and applied to the analysis of blood fractions, mononuclear cells and isolated nuclei of liver cells. Electrothermal atomization is preferred in cases where the sample size is limited and the magnesium content low. The total errors are in the order of 3-4%. Various techniques of sample pretreatment have been tested and direct dilution with 0.05 mol l -1 nitric acid was optimal when the samples were not mineralized. The calibration graph based on standards containing albumin was found to give the best results, as the form of magnesium in the samples may influence the ashing and atomization processes. Good agreement was obtained for determination of magnesium in standard serum. The results are compared with those obtained by the standard flame atomization technique.

  4. Micellar electrokinetic chromatographic method for the dabrafenib determination in biological samples.

    PubMed

    Rodríguez, Juana; Castañeda, Gregorio; Muñoz, Lorena; Lizcano, Isabel; Berciano, Miguel A

    2016-05-01

    Two different micellar electrokinetic chromatographic methods to determine dabrafenib in urine and serum, both using borate buffer (pH 9.2, 20 mM) and SDS as separation electrolyte, are developed and validated. The analyses were carried out in a fused-silica capillary of 75 μm of internal diameter and total length of 47 and 37 cm for urine and serum determination, respectively. The detection of the target compound was performed at 227 nm in urine samples and at 251 nm in serum samples. The linearity range was from 1 to 21 mg/L of dabrafenib in urine and from 2 to 40 mg/L in serum. In all cases, inter- and intraday RSDs were <4%. Sample preparation of serum samples consists of an only step of 1:1 dilution with water before its injection in the electrophoretic system. These simple, sensitive, accurate, and cost-effective methods can be used in routine clinical practice to monitor dabrafenib concentrations in urine and serum of metastatic melanoma skin cancer patients.

  5. Profiling the biological effects of wastewater samples via bioluminescent bacterial biosensors combined with estrogenic assays.

    PubMed

    Bazin, Ingrid; Seo, Ho Bin; Suehs, Carey M; Ramuz, Marc; De Waard, Michel; Gu, Man Bock

    2017-01-01

    Various water samples were successfully evaluated using a panel of different recombinant bioluminescent bacteria and estrogenic activity analysis. The bioluminescent bacteria strains induced by oxidative (superoxide radical or hydroxyl radical), protein damage, cell membrane damage, or cellular toxicity were used. Estrogenic activities were examined by using the yeast strain BY4741, which carries the β-galactosidase reporter gene under the control of the estrogen-responsive element (ERE). A total of 14 samples from three wastewater treatment plants, one textile factory, and seawater locations in Tunisia were analyzed. A wide range of bio-responses were described. Site/sample heterogeneity was prevalent, in combination with generally high relative bioluminescence scores for oxidative stress (OH•). Estrogenic activity was detected at all sites and was particularly elevated at certain sites. Our perspectives include the future exploration of the variation detected in relation to treatment plant operations and environmental impacts. In conclusion, this new multi-experimental method can be used for rapid bio-response profile monitoring and the evaluation of environmental samples spanning a wide range of domains. This study confirms that bio-reactive wastewater treatment plant (WWTP) effluents are discharged into seawater, where they may impact coastal populations.

  6. Comparative quantification of Campylobacter jejuni from environmental samples using traditional and molecular biological techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter jejuni (C. jejuni) is one of the most common causes of gastroenteritis in the world. Given the potential risks to human, animal and environmental health the development and optimization of methods to quantify this important pathogen in environmental samples is essential. Two of the mos...

  7. 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.

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

    PubMed Central

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

    2008-01-01

    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 influence, and very modest shared environmental influence. No gender differences were evident. There were significant genetic influences common to IQ and parental expectations of educational attainment, parenting and engagement in school, school grades and engagement in school, parental expectations for offspring educational attainment and school grades, and IQ and school grades. A possible interpretation of the common genetic influences involving parenting is that parents use their own experience with school in shaping the ways in which they parent their offspring. PMID:19081831

  9. FRET and Flow Cytometry Assays to Measure Proteopathic Seeding Activity in Biological Samples.

    PubMed

    Furman, Jennifer L; Diamond, Marc I

    2017-01-01

    Transcellular propagation of protein aggregates-or seeds-is increasingly implicated as a mechanism for disease progression in many neurodegenerative disorders, including Alzheimer's disease and the related tauopathies. While neuropathology generally originates in one discrete brain region, pathology progresses as disease severity advances, often along discrete neural networks. The stereotypical spread of tau pathology suggests that cell-to-cell transfer of toxic protein aggregates could underlie disease progression, and recent studies implicate seeding as a proximal marker of disease, as compared to standard histological and biochemical analyses. Commonly used metrics for protein aggregation detection, however, lack sensitivity, are not quantitative, and/or undergo subjective classification. Here, we describe a FRET and flow cytometry cell-based assay that allows for rapid and quantitative detection of protein aggregates from human and rodent biological specimens.

  10. 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.

  11. A self-contained polymeric cartridge for automated biological sample preparation.

    PubMed

    Xu, Guolin; Lee, Daniel Yoke San; Xie, Hong; Chiew, Deon; Hsieh, Tseng-Ming; Ali, Emril Mohamed; Lun Looi, Xing; Li, Mo-Huang; Ying, Jackie Y

    2011-09-01

    Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis.

  12. Competitive ELISA: An Accurate, Quick and Effective Tool to Monitor Brevetoxins in Environmental and Biological Sample

    PubMed Central

    Naar, Jerome; Weidner, Allison; Baden, Daniel G.

    2010-01-01

    A competitive Enzyme-Linked Immuno-Sorbent Assay (competitive ELISA) has been developed for analyzing brevetoxins (PbTxs). Antibodies to brevetoxins were used in combination with a multi-step signal amplification procedure for the detection of toxins. This procedure minimizes non-specific signals and background noise often observed in complex matrices. Therefore, analysis can be performed with various samples (seawater, air filter, mammalian body fluids, shellfish, etc.) without the need for extensive extraction and/or purification steps. Brevetoxin analysis in liquid samples like seawater, urine and serum can be performed without pretreatment, dilution or purification. The limit of quantification of PbTxs is 2 ng mL−1 in any of the liquid sample matrices tested. For shellfish monitoring, analyses are performed after homogenization of shellfish meat (5 g) with brevetoxin-ELISA buffer (200 mL) and can be performed on tissue from a single mollusk as well as on a pool of shellfish meat. Comparative quantification of PbTxs achieved in buffer, seawater, mammalian body fluid and shellfish homogenate spiked with equal amounts of toxin (10 ng mL−1 sample) varied by no more than 5%. These data suggest that the matrix composition of the sample does not affect the performance of the assay. Because this assay is not affected by matrix composition and can be performed in shellfish homogenate, this procedure can be used to prevent or diagnose human exposure to PbTxs and has the potential to replace the currently used mouse bioassay for monitoring PbTxs in shellfish. PMID:26436142

  13. 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.

  14. 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

  15. Chip-based magnetic cytometer for high-throughput cellular profiling in unprocessed biological samples

    NASA Astrophysics Data System (ADS)

    Issadore, David; Chung, Jaehoon; Shao, Huilin; Liong, Monty; Weissleder, Ralph; Lee, Hakho

    2012-02-01

    Quantitative, high-throughput measurement of biomarkers in individual cells is a cornerstone of biomedical research, but prohibitive size, cost, and requisite sample processing have kept this technology from being more widely adapted in the clinic. We have developed a miniaturized magnetic cytometer (μMCM), a hybrid semiconductor / microfluidic chip, to rapidly measure the magnetic moments of individual immunomagnetically tagged cells. The use of magnetic detection enables measurements to be done on native specimens, thus decreasing the loss of rare cells and removing the need for expensive sample processing equipment. Benefiting from the high speed and sensitivity of semiconductor technology, the μMCM offers high-throughput operation (upwards of 10^7 cells/sec) with a detection resolution of ˜2000 magnetic nanoparticles/cell. The clinical utility of the μMCM was demonstrated by detecting scant tumor cells (20 cells) in whole blood and by molecularly profiling cells from solid tumor to monitor longitudinal drug efficacy.

  16. Determination of trace lead in biological and water samples with dispersive liquid-liquid microextraction preconcentration.

    PubMed

    Liang, Pei; Sang, Hongbo

    2008-09-01

    A new method for the determination of trace lead was developed by dispersive liquid-liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry. In the proposed approach, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was used as a chelating agent, and carbon tetrachloride and ethanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of lead and its subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent, and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of this method for lead was reached at 78. The detection limit for lead was 39 ng L(-1) (3 sigma), and the relative standard deviation (RSD) was 3.2% (n=7, c=10 ng mL(-1)). The method was successfully applied to the determination of trace amounts of lead in human urine and water samples.

  17. 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.

  18. Demonstration of a Sample Preparation Method for Biological Detection Based on a Novel Membrane Fractionation Technology

    DTIC Science & Technology

    2008-12-31

    oftarget nucleic acid in the sample) Deoxyribonucleic acid kilo Dalton Leonard Wood Institute Midwest Research Institute Quantitative Polymerase...membranes. Desalination 227: 111-119. 7) Kong S, Titchener- Hooker N, Levy MS, 2006. Plasmid DNA processing for gene therapy and vaccination: Studies on...Computerized Helical Scanning Technique. JAm Soc Nephrol, 13: S53-S61. 15. Bricefio, M.I. , Joseph , D.D. 2003. Self-lubricated transport of aqueous

  19. Experimental set up for the irradiation of biological samples and nuclear track detectors with UV C

    PubMed Central

    Portu, Agustina Mariana; Rossini, Andrés Eugenio; Gadan, Mario Alberto; Bernaola, Omar Alberto; Thorp, Silvia Inés; Curotto, Paula; Pozzi, Emiliano César Cayetano; Cabrini, Rómulo Luis; Martin, Gisela Saint

    2016-01-01

    Aim In this work we present a methodology to produce an “imprint” of cells cultivated on a polycarbonate detector by exposure of the detector to UV C radiation. Background The distribution and concentration of 10B atoms in tissue samples coming from BNCT (Boron Neutron Capture Therapy) protocols can be determined through the quantification and analysis of the tracks forming its autoradiography image on a nuclear track detector. The location of boron atoms in the cell structure could be known more accurately by the simultaneous observation of the nuclear tracks and the sample image on the detector. Materials and Methods A UV C irradiator was constructed. The irradiance was measured along the lamp direction and at different distances. Melanoma cells were cultured on polycarbonate foils, incubated with borophenylalanine, irradiated with thermal neutrons and exposed to UV C radiation. The samples were chemically attacked with a KOH solution. Results A uniform irradiation field was established to expose the detector foils to UV C light. Cells could be seeded on the polycarbonate surface. Both imprints from cells and nuclear tracks were obtained after chemical etching. Conclusions It is possible to yield cellular imprints in polycarbonate. The nuclear tracks were mostly present inside the cells, indicating a preferential boron uptake. PMID:26933396

  20. Antigen recovery and preservation using the microwave irradiation of biological samples for transmission electron microscopy analysis.

    PubMed

    Aïoun, Josiane; Chat, Sophie; Bordat, Christian; Péchoux, Christine

    2013-01-01

    Most studies using microwave irradiation (MWI) for the preparation of tissue samples have reported an improvement in structural integrity. However, there have been few studies on the effect of microwave (MW) on antigen preservation during sample preparation prior to immunolocalization. This report documents our experience of specimen preparation using an automatic microwave apparatus to obtain antigen preservation and retrieval. We tested the effects of MW processing vs. conventional procedures on the morphology and antigenicity of two different tissues: the brain and mammary gland, whose chemical composition and anatomical organization are quite different. We chose to locate the transcription factor PPARβ/δ using immunocytochemistry on brain tissue sections from hamsters. Antigen retrieval protocols involving MWI were used to restore immunoreactivity. We also studied the efficiency of the ultrastructural immunolocalization of both PPARγ and caveolin-1 following MWI vs. conventional treatment, on mammary gland tissue from mice at 10 days of lactation. Our findings showed that the treatment of tissue samples with MWI, in the context of a process lasting just a few hours from fixation to immunolocalization, enabled similar, or even better, results than conventional protocols. The quantification of immunolabeling for cav-1 indicated an increase in density of up to three-fold in tissues processed in the microwave oven. Furthermore, MW treatment permitted the localization of PPARβ/δ in glutaraldehyde-fixed specimens, which was impossible in the absence of MWI. This study thus showed that techniques involving the use of microwaves could largely improve both ultrastructure and immunodetection.

  1. 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.

  2. Economic Hardship and Biological Weathering: The Epigenetics of Aging in a U.S. Sample of Black Women

    PubMed Central

    Lei, Man Kit; Beach, Steven R.H.; Philibert, Robert A.; Cutrona, Carolyn E.; Gibbons, Frederick X.; Barr, Ashley

    2016-01-01

    Background Past research has linked low socio-economic status (SES) to inflammation, metabolic dysregulation, and various chronic and age-related diseases such as type 2 diabetes, coronary heart disease, stroke, and dementia. These studies suggest that the challenges and adversities associated with low SES may result in premature aging and increased risk of morbidity and mortality. Objective Building upon this research, the present study investigates additional avenues whereby low income might accelerate biological aging. Methods Structural equation modeling and longitudinal data from a sample of 100 Black, middle-aged women residing in the United States was used to investigate the effect of income on a recently developed epigenetic measure of biological aging. This measure can be used as a “biological clock” to assess, at any point during adulthood, the extent to which an individual is experiencing accelerated or decelerated biological aging. Results Low income displayed a robust association with accelerated aging that was unaffected after controlling for other SES-related factors such as education, marital status, and childhood adversity. Further, our analyses indicated that the association between income and biological aging was not explained by health-related behaviors such as diet, exercise, smoking, alcohol consumption, or having health insurance. Rather, in large measure, it was financial pressure (difficulty paying bills, buying necessities, or meeting daily expenses) that accounted for the association between low income and accelerated aging. Conclusions These findings support the view that chronic financial pressures associated with low income exerts a weathering effect that results in premature aging. PMID:26765221

  3. 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.

  4. 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

  5. Simultaneous multielemental analysis of some environmental and biological samples by inductively coupled plasma atomic emission spectrometry

    SciTech Connect

    Hee, S.S.Q.; Boyle, J.R.

    1988-05-15

    The Parr bomb technique is found to be the preferred acid digestion method for multielemental analysis by simultaneous inductively coupled plasma atomic emission spectroscopy (ICP-AES) when compared with microwave and hot plate methods for many environmental and biological specimens, but especially for the latter. One digestion alone often did not produce quantitative results compared with a sequential digestion scheme. The digestions were then refined to be as similar as possible for the various substrates studied. The interference of carbon on As and Se had to be corrected at less than or equal to 3000 ..mu..g of C/mL in the analysis solution, and thus the C content had to be monitored to assess the efficiency of the digestions and to determine if interelemental correction for C presence was required. The C correction was adequate in the range 3000-10,000 ..mu..g of C/ml. The use of modified k values was demonstrated to provide accuracy and had to be used for ICP-AES spectrometers where background corrections were performed first for fixed channels. The results on Cincinnati soils and feces of Cincinnati children showed that Si and Ti were possible tracer elements for soil ingestion by the children.

  6. Concentration of prion protein from biological samples to increase the limits of detection by immunoassay.

    PubMed

    Davidowitz, Eliot; Eljuga, Lucy; Dover, Katarzyna; Tian, Jean; Grossman, Abraham

    2005-06-01

    An RNA-ligand-based adsorbent has been shown to concentrate prion protein (PrP) from solutions in a model system. The work presented here extends the utility of the RNA-based adsorbent to brain homogenates of cow, sheep, mule deer (Odocoileus hemionus) and elk (Cervus elaphus). Brain homogenates were diluted either in buffer, representing specimens used in post-mortem tests, or in serum, modelling specimens used in biological-fluid-based tests. The RNA adsorbent was effective in binding PrPC (cellular PrP,) and PrPres (proteinase K-resistant PrP) from the brain homogenates of all the species tested in both model systems. The three antibodies against PrP used in the experiments identified PrP in immunoblot analysis after concentrating PrP from brain homogenates with the adsorbent, indicating the general applicability of this technology for improving the detection of PrP in immunoassays. Utilization of RNA adsorbent increased the level of detection of PrPres by immunoblot over several-hundredfold. The results obtained suggest that this RNA adsorbent can be used to increase detection in current post-mortem immunoassays and for the development of a blood-based ante-mortem test.

  7. 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.

  8. 3-Dimensional quantitative detection of nanoparticle content in biological tissue samples after local cancer treatment

    NASA Astrophysics Data System (ADS)

    Rahn, Helene; Alexiou, Christoph; Trahms, Lutz; Odenbach, Stefan

    2014-06-01

    X-ray computed tomography is nowadays used for a wide range of applications in medicine, science and technology. X-ray microcomputed tomography (XμCT) follows the same principles used for conventional medical CT scanners, but improves the spatial resolution to a few micrometers. We present an example of an application of X-ray microtomography, a study of 3-dimensional biodistribution, as along with the quantification of nanoparticle content in tumoral tissue after minimally invasive cancer therapy. One of these minimal invasive cancer treatments is magnetic drug targeting, where the magnetic nanoparticles are used as controllable drug carriers. The quantification is based on a calibration of the XμCT-equipment. The developed calibration procedure of the X-ray-μCT-equipment is based on a phantom system which allows the discrimination between the various gray values of the data set. These phantoms consist of a biological tissue substitute and magnetic nanoparticles. The phantoms have been studied with XμCT and have been examined magnetically. The obtained gray values and nanoparticle concentration lead to a calibration curve. This curve can be applied to tomographic data sets. Accordingly, this calibration enables a voxel-wise assignment of gray values in the digital tomographic data set to nanoparticle content. Thus, the calibration procedure enables a 3-dimensional study of nanoparticle distribution as well as concentration.

  9. 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.

  10. 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.

  11. Enhanced methods for unbiased deep sequencing of Lassa and Ebola RNA viruses from clinical and biological samples.

    PubMed

    Matranga, Christian B; Andersen, Kristian G; Winnicki, Sarah; Busby, Michele; Gladden, Adrianne D; Tewhey, Ryan; Stremlau, Matthew; Berlin, Aaron; Gire, Stephen K; England, Eleina; Moses, Lina M; Mikkelsen, Tarjei S; Odia, Ikponmwonsa; Ehiane, Philomena E; Folarin, Onikepe; Goba, Augustine; Kahn, S Humarr; Grant, Donald S; Honko, Anna; Hensley, Lisa; Happi, Christian; Garry, Robert F; Malboeuf, Christine M; Birren, Bruce W; Gnirke, Andreas; Levin, Joshua Z; Sabeti, Pardis C

    2014-01-01

    We have developed a robust RNA sequencing method for generating complete de novo assemblies with intra-host variant calls of Lassa and Ebola virus genomes in clinical and biological samples. Our method uses targeted RNase H-based digestion to remove contaminating poly(rA) carrier and ribosomal RNA. This depletion step improves both the quality of data and quantity of informative reads in unbiased total RNA sequencing libraries. We have also developed a hybrid-selection protocol to further enrich the viral content of sequencing libraries. These protocols have enabled rapid deep sequencing of both Lassa and Ebola virus and are broadly applicable to other viral genomics studies.

  12. Advancements in mass spectrometry for biological samples: Protein chemical cross-linking and metabolite analysis of plant tissues

    SciTech Connect

    Klein, Adam

    2015-01-01

    This thesis presents work on advancements and applications of methodology for the analysis of biological samples using mass spectrometry. Included in this work are improvements to chemical cross-linking mass spectrometry (CXMS) for the study of protein structures and mass spectrometry imaging and quantitative analysis to study plant metabolites. Applications include using matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) to further explore metabolic heterogeneity in plant tissues and chemical interactions at the interface between plants and pests. Additional work was focused on developing liquid chromatography-mass spectrometry (LC-MS) methods to investigate metabolites associated with plant-pest interactions.

  13. 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.

  14. Peak Fitting to Resolve CN- isotope Ratios in Biological and Environmental Samples Using TOF-SIMS.

    SciTech Connect

    Cliff, John B.; Gaspar, Dan J.; Bottomley, Peter J.; Myrold, David D.; Alfred Benninghoven

    2004-06-15

    Our research has focused on developing TOF-SIMS in order to measure organic 15N isotopes in environmental samples [1]. Our goal was to develop a peak-fitting algorithm that would successfully remove the isobaric interferences Al- and 13C14N- from 12C15N-ions under conditions of low mass resolution inherent in environmental samples. We tested a variety of peak fitting models and found that the EMG+GMG model performed better than the standard peak shape shifting method under conditions of high mass resolution unless Al was present as an interference. Under conditions of Al interference and low 15N content, the shape shifting method performed better than the analytical model. As 15N content increased, the analytical model worked comparably or better than the standard method. However, neither method worked satisfactorily when organic 15N standards were analyzed on kaolin clay. Nevertheless, these data emphasize the potential utility of using analytical models to resolve isobaric interferences in TOF-SIMS.

  15. Benefits and Limitations of Low-kV Macromolecular Imaging of Frozen-Hydrated Biological Samples

    PubMed Central

    Majorovits, Endre; Angert, Isabel; Kaiser, Ute; Schröder, Rasmus R.

    2016-01-01

    Object contrast is one of the most important parameters of macromolecular imaging. Low-voltage transmission electron microscopy has shown an increased atom contrast for carbon materials, indicating that amplitude contrast contributions increase at a higher rate than phase contrast and inelastic scattering. Here, we studied image contrast using ice-embedded tobacco mosaic virus particles as test samples at 20–80 keV electron energy. The particles showed the expected increase in contrast for lower energies, but at the same time the 2.3-nm-resolution measure decayed more rapidly. We found a pronounced signal loss below 60 keV, and therefore we conclude that increased inelastic scattering counteracts increased amplitude contrast. This model also implies that as long as the amplitude contrast does not increase with resolution, beam damage and multiple scattering will always win over increased contrast at the lowest energies. Therefore, we cannot expect that low-energy imaging of conventionally prepared samples would provide better data than state-of-the-art 200–300 keV imaging. PMID:26910420

  16. 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.

  17. Targeted quantitative analysis of eicosanoid lipids in biological samples using liquid chromatography-tandem mass spectrometry

    PubMed Central

    Mesaros, Clementina; Lee, Seon Hwa; Blair, Ian A.

    2009-01-01

    The eicosanoids are a large family of arachidonic acid oxidation products that contain twenty carbon atoms. Cyclooxygenase (COX)-derived eicosanoids have important roles as autacoids involved in the regulation of cardiovascular function and tumor progression. Lipoxygenase (LO)-derived eicosanoids have been implicated as important mediators of inflammation, asthma, cardiovascular disease and cancer. Cytochrome P-450 (P450)-derived eicosanoids are both vasodilators and vasoconstrictors. There is intense interest in the analysis of reactive oxygen species (ROS)-derived isoprostanes (isoPs) because of their utility as biomarkers of oxidative stress. Enzymatic pathways of eicosanoid formation are regioselective and enantioselective, whereas ROS-mediated eicosanoid formation proceeds with no stereoselectivity. Many of the eicosanoids are also present in only pM concentrations in biological fluids. This presents a formidable analytical challenge because methodology is required that can separate enantiomers and diastereomers with high sensitivity and specificity. However, the discovery of atmospheric pressure ionization (API)/MS methodology of electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and electron capture (EC) APCI has revolutionized our ability to analyze endogenous eicosanoids. LC separations of eicosanoids can now be readily coupled with API ionization, collision induced dissociation (CID) and tandem MS (MS/MS). This makes it possible to efficiently conduct targeted eicosanoid analyses using LC-multiple reaction motoring (MRM)/MS. Several examples of targeted eicosanoid lipid analysis using conventional LC-ESI/MS have been discussed and some new data on the analysis of eicosanoids using chiral LC-ECAPCI/MS has been presented. PMID:19345647

  18. 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.

  19. 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.

  20. A simple method for overcoming some problems when observing thick reflective biological samples with a confocal scanning laser microscope.

    PubMed

    Rumio, C; Morini, M; Miani, A; Barajon, I; Castano, P

    1995-01-01

    A simple device is described, which allows the range of depth of scanning to be reduced when observing thick reflecting biological samples with a confocal scanning laser microscope (CSLM). Thick histological sections of human skin and rat brain stem were mounted between two coverslips ('sandwich' style) and the optical tomography was performed from both sides by turning the 'sandwich' upside-down. The samples were impregnated using standard Golgi-Cox, 'rapid Golgi' or other silver methods. The ability to turn the 'sandwich' upside-down is particularly useful when the reflective structure inspected is deep inside the section, i.e., near the lower surface of the specimen, or when it is opaque to the laser beam or excessively reflective.

  1. High-resolution, high-transmission soft x-ray spectrometer for the study of biological samples.

    PubMed

    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 x 3000) microm2, 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.

  2. Review of methods for determination of total protein and peptide concentration in biological samples.

    PubMed

    Sapan, Christine V; Lundblad, Roger L

    2015-04-01

    Clinical proteomics can be defined as the use of proteomic technologies to identify and measure biomarkers in fluids and tissues. The current work is intended to review various methods used for the determination of the total concentration of protein or peptide in fluids and tissues and the application of such methods to clinical proteomics. Specifically, this article considers the approaches to the measurement of total protein concentration, not the measurement of the concentration of a specific protein or group of proteins in a larger mixture of proteins. The necessity of understanding various concepts such as fit-for-use, quality-by-design, and other regulatory elements is discussed, as is the significance of using suitable standards for the protein quality of various samples.

  3. 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.

  4. Integrating silicon nanowire field effect transistor, microfluidics and air sampling techniques for real-time monitoring biological aerosols.

    PubMed

    Shen, Fangxia; Tan, Miaomiao; Wang, Zhenxing; Yao, Maosheng; Xu, Zhenqiang; Wu, Yan; Wang, Jindong; Guo, Xuefeng; Zhu, Tong

    2011-09-01

    Numerous threats from biological aerosol exposures, such as those from H1N1 influenza, SARS, bird flu, and bioterrorism activities necessitate the development of a real-time bioaerosol sensing system, which however is a long-standing challenge in the field. Here, we developed a real-time monitoring system for airborne influenza H3N2 viruses by integrating electronically addressable silicon nanowire (SiNW) sensor devices, microfluidics and bioaerosol-to-hydrosol air sampling techniques. When airborne influenza H3N2 virus samples were collected and delivered to antibody-modified SiNW devices, discrete nanowire conductance changes were observed within seconds. In contrast, the conductance levels remained relatively unchanged when indoor air or clean air samples were delivered. A 10-fold increase in virus concentration was found to give rise to about 20-30% increase in the sensor response. The selectivity of the sensing device was successfully demonstrated using H1N1 viruses and house dust allergens. From the simulated aerosol release to the detection, we observed a time scale of 1-2 min. Quantitative polymerase chain reaction (qPCR) tests revealed that higher virus concentrations in the air samples generally corresponded to higher conductance levels in the SiNW devices. In addition, the display of detection data on remote platforms such as cell phone and computer was also successfully demonstrated with a wireless module. The work here is expected to lead to innovative methods for biological aerosol monitoring, and further improvements in each of the integrated elements could extend the system to real world applications.

  5. Simultaneous analysis of antibiotics in biological samples by ultra high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Cazorla-Reyes, Rocío; Romero-González, Roberto; Frenich, Antonia Garrido; Rodríguez Maresca, Manuel Angel; Martínez Vidal, José Luis

    2014-02-01

    A rapid and reliable multiclass method was developed for the simultaneous analysis of 21 antibiotics (beta-lactams, aminoglycosides, penicillins, cephalosporins, carbapenems or quinolones) in urine, serum, cerebrospinal fluid (CSF) and bronchial aspirations by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Prior to chromatographic determination, the analytes were extracted from human biological fluids by simple sample treatments, which imply dilution, liquefaction, or protein precipitation. Several chromatographic conditions were optimized in order to obtain a fast separation (<6min for each chromatographic run). MS/MS conditions were evaluated in order to increase selectivity and sensitivity and all compounds were detected in electrospray (ESI) positive ion mode, except clavulanic acid and sulbactam, which were monitored in negative ion mode. The developed method was validated in terms of linearity, selectivity, limits of detection (LODs) and quantification (LOQs), trueness, repeatability and interday precision. The LOQs ranged from 0.01 to 1.00mg/L for urine, serum and CSF. In case of bronchial aspirations, the LOQs were between 0.02 and 0.67mg/kg. In all matrices the recovery results were in the range 70-120% and interday precision was lower than 25%. Finally, the optimized method was applied to the analysis of biological samples from 10 patients in the intensive care unit (ICU) of a hospital located in Almeria (Spain). Several antibiotics (e.g., amoxicillin, tobramycin, levofloxacin, or linezolid) were found in the studied samples, observing that the highest concentrations were obtained in urine samples.

  6. 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.

  7. 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.

  8. Tip in-light on: Advantages, challenges, and applications of combining AFM and Raman microscopy on biological samples.

    PubMed

    Prats-Mateu, Batirtze; Gierlinger, Notburga

    2017-01-01

    Scanning probe microscopies and spectroscopies, especially AFM and Confocal Raman microscopy are powerful tools to characterize biological materials. They are both non-destructive methods and reveal mechanical and chemical properties on the micro and nano-scale. In the last years the interest for increasing the lateral resolution of optical and spectral images has driven the development of new technologies that overcome the diffraction limit of light. The combination of AFM and Raman reaches resolutions of about 50-150 nm in near-field Raman and 1.7-50 nm in tip enhanced Raman spectroscopy (TERS) and both give a molecular information of the sample and the topography of the scanned surface. In this review, the mentioned approaches are introduced, the main advantages and problems for application on biological samples discussed and some examples for successful experiments given. Finally the potential of colocated AFM and Raman measurements is shown on a case study of cellulose-lignin films: the topography structures revealed by AFM can be related to a certain chemistry by the colocated Raman scan and additionally the mechanical properties be revealed by using the digital pulsed force mode. Microsc. Res. Tech. 80:30-40, 2017. © 2016 Wiley Periodicals, Inc.

  9. Trace level determination of molybdenum in environmental and biological samples using surfactant-mediated liquid-liquid extraction.

    PubMed

    Shrivas, Kamlesh; Agrawal, Kavita; Harmukh, Neetu

    2009-01-15

    A novel and sensitive spectrophotometric method for the determination of molybdenum at trace levels in environmental and biological samples is proposed. The method is based on the reaction of Mo (V) with thiocyanate (SCN(-)) and methyltrioctyl ammonium chloride (MTOAC) in acidic medium. The red colored complex of molybdenum is extracted with N-phenylbenzimidoyl thiourea (PBITU) in 1-pentanol for its determination by spectrophotometry. The sensitivity of the present method is higher than other conventional thiocyanate method, due to the use of MTOAC in liquid-liquid extraction. The value of molar absorptivity of the complex with respect to molybdenum is 7.6x10(4)Lmol(-1)cm(-1) at 470nm. The limit of detection of the metal is 5ngmL(-1). The system obeys Beer's law between 20 and 1000ngmL(-1) with slope, intercept and correlation coefficient values of 0.81, 2.5x10(-3) and +0.999, respectively. Most of the metal ions tested did not interfere in the determination of molybdenum. The proposed method has been successfully applied for the determination of the molybdenum in environmental and biological samples.

  10. Selective recognition of Triamterene in biological samples by molecularly imprinted monolithic column with a pseudo template employed.

    PubMed

    Zhao, Xiao-Yun; Zhang, Hong-Wu; Liang, Zhen-Jie; Shu, Ya-Ping; Liang, Yong

    2013-05-01

    Melamine (MAM) was employed as a pseudo template to prepare a molecularly imprinted polymer monolithic column which presents the ability of selective recognition to Triamterene (TAT), whose structure was similar to that of MAM. Methacrylic acid and ethylene glycol dimethacrylate were applied as functional monomer and cross-linker, respectively, during the in situ polymerization process. Chromatographic behaviors were evaluated, the results indicated that the molecularly imprinted polymer monolithic column possessed excellent affinity and selectivity for TAT, and the imprinting factor was high up to 3.99 when 7:3 of ACN/water v/v was used as mobile phase. In addition, the dissociation constant and the binding sites were also determined by frontal chromatography as 134.31 μmol/L and 132.28 μmol/g, respectively, which demonstrated that the obtained molecularly imprinted polymer monolith had a high binding capacity and strong affinity ability to TAT. Furthermore, biological samples could be directly injected into the column and TAT was enriched with the optimized mobile phase. These assays gave recovery values higher than 91.60% with RSD values that were always less than 3.5%. The molecularly imprinted monolithic column greatly simplified experiment procedure and can be applied to preconcentration, purification, and analysis of TAT in biological samples.

  11. Amino Nitrogen Quantum Dots-Based Nanoprobe for Fluorescence Detection and Imaging of Cysteine in Biological Samples.

    PubMed

    Tang, Zhijiao; Lin, Zhenhua; Li, Gongke; Hu, Yuling

    2017-03-20

    Fluorescent amino nitrogen quantum dots (aN-dots) were synthesized by microwave-assisted method using 2-azidoimidazole and aqueous ammonia. The aN-dots have a nitrogen component up to 40%, which exhibit high fluorescence quantum yield, good photostability, and excellent biocompatibility. We further explored the use of the aN-dots combined with AuNPs as a nanoprobe for detecting fluorescently and imaging of cysteine (Cys) in complex biological samples. In this sensing system, the fluorescence of aN-dots was quenched significantly by gold nanoparticles (AuNPs), while the addition of Cys can lead to the fluorescence signal recovery. Furthermore, we have demonstrated that this strategy can offer a rapid and selective detection of Cys with a good linear relationship in the range of 0.3-3.0 μmol/L. As expected, this assay was successfully applied to the detection of Cys in human serum and plasma samples with recoveries ranging from 90.0% to 106.7%. Especially, the nanoprobe exhibits good cell membrane permeability and excellent biocompatibility by CCK-8 assay, which is favorable for bioimaging applications. Therefore, this fluorescent probe ensemble was further used for imaging of Cys in living cells, which suggests our proposed method has strong potential for clinical diagnosis. As a novel member of the quantum-dot family, the aN-dots hold great promise to broaden applications in biological systems.

  12. 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.

  13. 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

  14. Tip in–light on: Advantages, challenges, and applications of combining AFM and Raman microscopy on biological samples

    PubMed Central

    Gierlinger, Notburga

    2016-01-01

    Abstract Scanning probe microscopies and spectroscopies, especially AFM and Confocal Raman microscopy are powerful tools to characterize biological materials. They are both non‐destructive methods and reveal mechanical and chemical properties on the micro and nano‐scale. In the last years the interest for increasing the lateral resolution of optical and spectral images has driven the development of new technologies that overcome the diffraction limit of light. The combination of AFM and Raman reaches resolutions of about 50–150 nm in near‐field Raman and 1.7–50 nm in tip enhanced Raman spectroscopy (TERS) and both give a molecular information of the sample and the topography of the scanned surface. In this review, the mentioned approaches are introduced, the main advantages and problems for application on biological samples discussed and some examples for successful experiments given. Finally the potential of colocated AFM and Raman measurements is shown on a case study of cellulose‐lignin films: the topography structures revealed by AFM can be related to a certain chemistry by the colocated Raman scan and additionally the mechanical properties be revealed by using the digital pulsed force mode. Microsc. Res. Tech. 80:30–40, 2017. © 2016 Wiley Periodicals, Inc. PMID:27514318

  15. SILAC-Based Quantitative Strategies for Accurate Histone Posttranslational Modification Profiling Across Multiple Biological Samples.

    PubMed

    Cuomo, Alessandro; Soldi, Monica; Bonaldi, Tiziana

    2017-01-01

    Histone posttranslational modifications (hPTMs) play a key role in regulating chromatin dynamics and fine-tuning DNA-based processes. Mass spectrometry (MS) has emerged as a versatile technology for the analysis of histones, contributing to the dissection of hPTMs, with special strength in the identification of novel marks and in the assessment of modification cross talks. Stable isotope labeling by amino acid in cell culture (SILAC), when adapted to histones, permits the accurate quantification of PTM changes among distinct functional states; however, its application has been mainly confined to actively dividing cell lines. A spike-in strategy based on SILAC can be used to overcome this limitation and profile hPTMs across multiple samples. We describe here the adaptation of SILAC to the analysis of histones, in both standard and spike-in setups. We also illustrate its coupling to an implemented "shotgun" workflow, by which heavy arginine-labeled histone peptides, produced upon Arg-C digestion, are qualitatively and quantitatively analyzed in an LC-MS/MS system that combines ultrahigh-pressure liquid chromatography (UHPLC) with new-generation Orbitrap high-resolution instrument.

  16. Identification of food-derived bioactive peptides in blood and other biological samples.

    PubMed

    Sato, Kenji; Iwai, Koji; Aito-Inoue, Misako

    2008-01-01

    Recent studies have demonstrated the presence of food-derived peptides in human blood after ingestion of enzymatic hydrolysates of food proteins, while most peptides in food are degraded into amino acids during digestion and absorption. To capture and clarify the food-derived peptides in blood, solid-phase extraction (SPE) using a mini-spin column packed with a strong cation exchanger was developed. This technique allows the use of a nonvolatile acid such as trichloroacetic acid, a strong protein denaturant, for the deproteinizing procedure. To improve resolution of hydrophilic peptide and increase specificity and sensitivity in the detection of peptide by reversed-phase high-performance liquid chromatography (RP-HPLC) after subfractionation by size-exclusion chromatography (SEC), peptides are derivatized with phenyl isothiocyanate. The resultant phenyl thiocarbamyl (PTC)-peptides can be resolved with high resolution and sensitivity by RP-HPLC. By comparing chromatograms of PTC derivatives from blood before and after ingestion of a peptide sample, food-derived peptide can be detected. The isolated PTC-peptide can be applied to a peptide sequencer based on the Edman degradation reaction.

  17. 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.

  18. Determination of colistin in human plasma, urine and other biological samples using LC-MS/MS.

    PubMed

    Ma, Zheng; Wang, Jiping; Gerber, Jacobus P; Milne, Robert W

    2008-02-01

    A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed to quantify colistin in human plasma and urine, and perfusate and urine from the isolated perfused rat kidney (IPK). Solid phase extraction (SPE) preceded chromatography on a Synergi Fusion-RP column with a mobile phase of acetonitrile, water and acetic acid (80/19/1) at 0.2mL/min. Ions were generated using electrospray ionization and detected in the positive-ion mode. Multiple reaction monitoring was performed using precursor-product ion combinations. Calibration curves were linear from 0.028microg/mL (human plasma, IPK perfusate and urine)/0.056microg/mL (human urine) to 1.78microg/mL (all four media) for colistin A sulfate; corresponding values for colistin B sulfate were 0.016/0.032 to 1.01microg/mL. Accuracy and precision were within 10%. The LLOQ for colistin A sulfate was 0.028microg/mL in human plasma, IPK perfusate and urine and 0.056microg/mL in human urine; corresponding values for colistin B sulfate were 0.016 and 0.032microg/mL. The low sample volume, short analysis time and low LLOQ are ideal for pre-clinical and human pharmacokinetic studies of colistin.

  19. 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.

  20. 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.

  1. 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 (

  2. Application of picosecond laser-induced breakdown spectroscopy to quantitative analysis of boron in meatballs and other biological samples.

    PubMed

    Hedwig, Rinda; Lahna, Kurnia; Lie, Zener Sukra; Pardede, Marincan; Kurniawan, Koo Hendrik; Tjia, May On; Kagawa, Kiichiro

    2016-11-10

    This report presents the results of laser-induced breakdown spectroscopy (LIBS) study on biological and food samples of high water content using a picosecond (ps) laser at low output energy of 10 mJ and low-pressure helium ambient gas at 2 kPa. Evidence of excellent emission spectra of various analyte elements with very low background is demonstrated for a variety of samples without the need of sample pretreatment. Specifically, limits of detection in the range of sub-ppm are obtained for hazardous Pb and B impurities in carrots and meatballs. This study also shows the inferior performance of LIBS using a nanosecond laser and atmospheric ambient air for a soft sample of high water content and thereby explains its less successful applications in previous attempts. The present result has instead demonstrated the feasibility and favorable results of employing LIBS with a ps laser and low-pressure helium ambient gas as a less costly and more practical alternative to inductively coupled plasma for regular high sensitive inspection of harmful food preservatives and environmental pollutants.

  3. 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

  4. Prediction uncertainty assessment of a systems biology model requires a sample of the full probability distribution of its parameters.

    PubMed

    van Mourik, Simon; Ter Braak, Cajo; Stigter, Hans; Molenaar, Jaap

    2014-01-01

    Multi-parameter models in systems biology are typically 'sloppy': some parameters or combinations of parameters may be hard to estimate from data, whereas others are not. One might expect that parameter uncertainty automatically leads to uncertain predictions, but this is not the case. We illustrate this by showing that the prediction uncertainty of each of six sloppy models varies enormously among different predictions. Statistical approximations of parameter uncertainty may lead to dramatic errors in prediction uncertainty estimation. We argue that prediction uncertainty assessment must therefore be performed on a per-prediction basis using a full computational uncertainty analysis. In practice this is feasible by providing a model with a sample or ensemble representing the distribution of its parameters. Within a Bayesian framework, such a sample may be generated by a Markov Chain Monte Carlo (MCMC) algorithm that infers the parameter distribution based on experimental data. Matlab code for generating the sample (with the Differential Evolution Markov Chain sampler) and the subsequent uncertainty analysis using such a sample, is supplied as Supplemental Information.

  5. Recent advances in the development of extraction chromatographic materials for the isolation of radionuclides from biological and environmental samples.

    SciTech Connect

    Dietz, M. L.

    1998-11-30

    The determination of low levels of radionuclides in environmental and biological samples is often hampered by the complex and variable nature of the samples. One approach to circumventing this problem is to incorporate into the analytical scheme a separation and preconcentration step by which the species of interest can be isolated from the major constituents of the sample. Extraction chromatography (EXC), a form of liquid chromatography in which the stationary phase comprises an extractant or a solution of an extractant in an appropriate diluent coated onto an inert support, provides a simple and efficient means of performing a wide variety of metal ion separations. Recent advances in extractant design, in particular the development of extractants capable of metal ion recognition or of strong complex formation even in acidic media, have substantially improved the utility of the method. For the preconcentration of actinides, for example, an EXC resin consisting of a liquid diphosphonic acid supported on a polymeric substrate has been shown to exhibit extraordinarily strong retention of these elements from acidic chloride media. This resin, together with other related materials, can provide the basis of a number of efficient and flexible schemes for the separation and preconcentration of radionuclides form a variety of samples for subsequent determination.

  6. Evaluation of cadmium, chromium, nickel, and zinc in biological samples of psoriasis patients living in Pakistani cement factory area.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed; Kandhro, Ghulam Abbas; Baig, Jameel Ahmed; Shah, Abdul Qadir; Khan, Sumaira; Kolachi, Nida Fatima; Wadhwa, Sham Kumar; Shah, Faheem; Jamali, Mohammad Khan; Arain, Mohammad Balal

    2011-09-01

    Psoriasis is a noncontiguous common and chronic skin disorder. The aim of the present study was to compare the level of trace elements cadmium (Cd), chromium (Cr), Nickel (Ni), and zinc (Zn) in biological samples (whole blood, urine, and scalp hair) of psoriasis patients of both gender age ranged (25-55 years) at mild, moderate severe, and more severe stage (n = 418) living in the vicinity of cement factory. For comparison purposes, healthy age-matched referent subjects, residents of industrial and non-industrial area, of both gender were also selected (n = 241). The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of methodology was checked by using certified reference materials (CRMs) and conventional wet acid digestion method on same CRMs and real samples. The results of this study showed that the mean values of Cd, Cr, Ni, and Pb were significantly higher in scalp hair, blood, and urine samples of mild and severe psoriasis patients as compared to referents (p < 0.001), while the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of psoriasis patients. The deficiency of Zn in psoriasis patients may be undoubtedly caused by the toxic element exposures via cement factory.

  7. 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

  8. 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

  9. 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.

  10. Gay and Bisexual Men's Perceptions of the Donation and Use of Human Biological Samples for Research: A Qualitative Study.

    PubMed

    Patterson, Chris; McDaid, Lisa M; Hilton, Shona

    2015-01-01

    Human biological samples (biosamples) are increasingly important in diagnosing, treating and measuring the prevalence of illnesses. For the gay and bisexual population, biosample research is particularly important for measuring the prevalence of human immunodeficiency virus (HIV). By determining people's understandings of, and attitudes towards, the donation and use of biosamples, researchers can design studies to maximise acceptability and participation. In this study we examine gay and bisexual men's attitudes towards donating biosamples for HIV research. Semi-structured telephone interviews were conducted with 46 gay and bisexual men aged between 18 and 63 recruited in commercial gay scene venues in two Scottish cities. Interview transcripts were analysed thematically using the framework approach. Most men interviewed seemed to have given little prior consideration to the issues. Participants were largely supportive of donating tissue for medical research purposes, and often favourable towards samples being stored, reused and shared. Support was often conditional, with common concerns related to: informed consent; the protection of anonymity and confidentiality; the right to withdraw from research; and ownership of samples. Many participants were in favour of the storage and reuse of samples, but expressed concerns related to data security and potential misuse of samples, particularly by commercial organisations. The sensitivity of tissue collection varied between tissue types and collection contexts. Blood, urine, semen and bowel tissue were commonly identified as sensitive, and donating saliva and as unlikely to cause discomfort. To our knowledge, this is the first in-depth study of gay and bisexual men's attitudes towards donating biosamples for HIV research. While most men in this study were supportive of donating tissue for research, some clear areas of concern were identified. We suggest that these minority concerns should be accounted for to develop

  11. A direct comparison of methods used to measure oxidized glutathione in biological samples: 2-vinylpyridine and N-ethylmaleimide.

    PubMed

    Mcgill, Mitchell R; Jaeschke, Hartmut

    2015-01-01

    The ratio of glutathione disulfide (GSSG) to reduced glutathione (GSH) in biological samples is a frequently used parameter of oxidative stress. As a result, many methods are developed to measure GSSG. The most popular and convenient of these relies on enzymatic cycling following the chemical masking of GSH in the sample using 2-vinylpyridine (2VP). However, 2VP is a slow reactant and its use may result in artificially high GSSG values due to oxidation of the sample over time. Fast-reacting reagents such as N-ethylmaleimide (NEM) may provide more accurate results. We performed a direct comparison of methods using 2VP and NEM. With 2VP, the percentage of total glutathione (GSH+GSSG) in the oxidized form was significantly higher in all tested tissues (kidney, lung and liver) compared to the same procedure performed using NEM. We conclude that NEM, when coupled with a simple solid-phase extraction procedure, is more accurate for the determination of GSSG. We also tested the effects of various handling and storage conditions on GSSG. A detailed description and a discussion of other methods are also included.

  12. A direct comparison of methods used to measure oxidized glutathione in biological samples: 2-vinylpyridine and N-ethylmaleimide

    PubMed Central

    McGill, Mitchell R.; Jaeschke, Hartmut

    2016-01-01

    The ratio of glutathione disulfide (GSSG) to reduced glutathione (GSH) in biological samples is a frequently used parameter of oxidative stress. As a result, many methods have been developed to measure GSSG. The most popular and convenient of these relies on enzymatic cycling following the chemical masking of GSH in the sample using 2-vinylpyridine (2VP). However, 2VP is a slow reactant and its use may result in artificially high GSSG values due to oxidation of the sample over time. Faster-reacting reagents like N-ethylmaleimide (NEM) may provide more accurate results. We have performed a direct comparison of methods using 2VP and NEM. With 2VP, the percentage of total glutathione (GSH+GSSG) in the oxidized form was significantly higher in all tested tissues (kidney, lung, and liver) compared to the same procedure performed using NEM. We conclude that NEM, when coupled with a simple solid phase extraction procedure, is more accurate for determination of GSSG. We also tested the effects of various handling and storage conditions on GSSG. A detailed description and a discussion of other methods are also included. PMID:26461121

  13. Sensitive determination of terazosin in pharmaceutical formulations and biological samples by ionic-liquid microextraction prior to spectrofluorimetry.

    PubMed

    Zeeb, Mohsen; Sadeghi, Mahdi

    2012-01-01

    An efficient and environmentally friendly sample preparation method based on the application of hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF(6)] ionic liquid (IL) as a microextraction solvent was proposed to preconcentrate terazosin. The performance of the microextraction method was improved by introducing a common ion of pyridinium IL into the sample solution. Due to the presence of the common ion, the solubility of IL significantly decreased. As a result, the phase separation successfully occurred even at high ionic strength, and the volume of the settled IL-phase was not influenced by variations in the ionic strength (up to 30% w/v). After preconcentration step, the enriched phase was introduced to the spectrofluorimeter for the determination of terazosin. The obtained results revealed that this system did not suffer from the limitations of that in conventional ionic-liquid microextraction. Under optimum experimental conditions, the proposed method provided a limit of detection (LOD) of 0.027 μg L(-1) and a relative standard deviation (R.S.D.) of 2.4%. The present method was successfully applied to terazosin determination in actual pharmaceutical formulations and biological samples. Considering the large variety of ionic liquids, the proposed microextraction method earns many merits, and will present a wide application in the future.

  14. Sensitive Determination of Terazosin in Pharmaceutical Formulations and Biological Samples by Ionic-Liquid Microextraction Prior to Spectrofluorimetry

    PubMed Central

    Zeeb, Mohsen; Sadeghi, Mahdi

    2012-01-01

    An efficient and environmentally friendly sample preparation method based on the application of hydrophobic 1-Hexylpyridinium hexafluorophosphate [Hpy][PF6] ionic liquid (IL) as a microextraction solvent was proposed to preconcentrate terazosin. The performance of the microextraction method was improved by introducing a common ion of pyridinium IL into the sample solution. Due to the presence of the common ion, the solubility of IL significantly decreased. As a result, the phase separation successfully occurred even at high ionic strength, and the volume of the settled IL-phase was not influenced by variations in the ionic strength (up to 30% w/v). After preconcentration step, the enriched phase was introduced to the spectrofluorimeter for the determination of terazosin. The obtained results revealed that this system did not suffer from the limitations of that in conventional ionic-liquid microextraction. Under optimum experimental conditions, the proposed method provided a limit of detection (LOD) of 0.027 μg L−1 and a relative standard deviation (R.S.D.) of 2.4%. The present method was successfully applied to terazosin determination in actual pharmaceutical formulations and biological samples. Considering the large variety of ionic liquids, the proposed microextraction method earns many merits, and will present a wide application in the future. PMID:22505920

  15. 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.

  16. Neighbourhood Socioeconomic Status and Biological “Wear & Tear” in a Nationally Representative Sample of US Adults

    PubMed Central

    Bird, Chloe E; Seeman, Teresa; Escarce, José J; Basurto-Dávila, Ricardo; Finch, Brian K; Dubowitz, Tamara; Heron, Melonie; Hale, Lauren; Merkin, Sharon Stein; Weden, Margaret; Lurie, Nicole; Alcoa, Paul O’Neill

    2012-01-01

    Objective To assess whether neighbourhood socioeconomic status (NSES) is independently associated with disparities in biological “wear and tear”—measured by allostatic load (AL)—in a nationally representative sample of U.S. adults. Design Cross-sectional study. Setting Population-based U.S. survey, the Third National Health and Nutrition Examination Survey (NHANES III), merged with U.S. Census data describing respondents’ neighbourhoods. Participants 13,184 adults from 83 counties and 1,805 census tracts who completed NHANES III interviews and medical examinations and whose residential addresses could be reliably geocoded to census tracts. Main Outcome Measures A summary measure of biological risk, incorporating nine biomarkers that together represent AL across metabolic, cardiovascular, and inflammatory subindices. Results Being male, older, having lower income, less education, being Mexican-American, and being both Black and female were all independently associated with worse AL. After adjusting for these characteristics, living in a lower SES neighbourhood was associated with worse AL (coeff. = −0.46; CI −0.079, −0.012). The relationship between NSES and AL did not vary significantly by gender or race/ethnicity. Conclusions Living in a lower SES neighbourhood in the United States is associated with significantly greater biological wear and tear as measured by AL, and this relationship is independent of individual SES characteristics. Our findings demonstrate that where one lives is independently associated with AL, thereby suggesting that policies that improve NSES may also yield health returns. PMID:19759056

  17. Spectrofluorimetric determination of buparvaquone in biological fluids, food samples and a pharmaceutical formulation by using terbium-deferasirox probe.

    PubMed

    Manzoori, Jamshid L; Jouyban, Abolghasem; Amjadi, Mohammad; Panahi-Azar, Vahid; Karami-Bonari, Amir Reza; Tamizi, Elnaz

    2011-06-15

    A simple spectrofluorimetric method is described for the determination of buparvaquone (BPQ), based on its quenching effect on the fluorescence intensity of Tb(3+)-deferasirox (DFX) complex as a fluorescent probe. The excitation and emission wavelengths were 328 and 545nm, respectively. The optimum conditions for determination of BPQ were investigated considering the effects of various affecting parameters. The variations in fluorescence intensity of the system showed a good linear relationship with the concentration of BPQ in the range of 10-1500μgL(-1), its correlation coefficient was 0.999 with the detection and quantification limits of 1.1 and 3.4μgL(-1), respectively. Linearity, reproducibility, recovery, limits of detection and quantification made the method suitable for BPQ assay in biological fluids, meat, dairy products and BPQ parenteral solutions (vials). The method was applied to real samples of serum and milk of three cows receiving BPQ.

  18. 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.

  19. Simultaneous determination of gallium and zinc in biological samples, wine, drinking water, and wastewater by derivative synchronous fluorescence spectrometry

    SciTech Connect

    Pozo, M.E.U.; de Torres, A.G.; Pavon, J.M.C.

    1987-04-15

    A simple, rapid, sensitive, and selective method for the simultaneous determination of gallium and zinc using derivative synchronous fluorescence spectrometry has been studied. This determination is based upon the formation of fluorescent complexes with salicylaldehyde thiocarbohydrazone (SATCH). The reaction is carried out at pH 4.7 in aqueous-ethanol medium (52% (v/v) ethanol). The use of second-derivative synchronous fluorescence spectrometry permits the simultaneous determination of gallium and zinc in the concentration intervals of 2-40 and 20-1500 ng/mL, respectively. The effect of interferences was studied. The method has been applied to the determination of gallium and zinc in biological samples (after destruction of the organic matter by using a HNO/sub 3/-H/sub 2/O/sub 2/ mixture), wine, drinking water, and wastewater.

  20. Graphene-Based Materials as Solid Phase Extraction Sorbent for Trace Metal Ions, Organic Compounds, and Biological Sample Preparation.

    PubMed

    Ibrahim, Wan Aini Wan; Nodeh, Hamid Rashidi; Sanagi, Mohd Marsin

    2016-07-03

    Graphene is a new carbon-based material that is of interest in separation science. Graphene has extraordinary properties including nano size, high surface area, thermal and chemical stability, and excellent adsorption affinity to pollutants. Its adsorption mechanisms are through non-covalent interactions (π-π stacking, electrostatic interactions, and H-bonding) for organic compounds and covalent interactions for metal ions. These properties have led to graphene-based material becoming a desirable adsorbent in a popular sample preparation technique known as solid phase extraction (SPE). Numerous studies have been published on graphene applications in recent years, but few review papers have focused on its applications in analytical chemistry. This article focuses on recent preconcentration of trace elements, organic compounds, and biological species using SPE-based graphene, graphene oxide, and their modified forms. Solid phase microextraction and micro SPE (µSPE) methods based on graphene are discussed.

  1. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Sardans, Jordi; Montes, Fernando; Peñuelas, Josep

    2010-02-01

    this technique that reaches figures of merit equivalent to Inductively coupled plasma mass spectrometry (ICP-MS). Herein is presented an overview of recent advances and applications of (ETAAS) for the determination of As, Cd, Cu, Hg and Pb in biological samples drawn from studies over the last decade.

  2. Selective LC-MS/MS method for the identification of BMAA from its isomers in biological samples.

    PubMed

    Jiang, Liying; Aigret, Benoit; De Borggraeve, Wim M; Spacil, Zdenek; Ilag, Leopold L

    2012-06-01

    Algal blooms are well-known sources of acute toxic agents that can be lethal to aquatic organisms. However, one such toxin, β-N-methylamino-L-alanine (BMAA) is also believed to cause amyotrophic lateral sclerosis, also known as Lou Gehrig's disease. The detection and identification of BMAA in natural samples were challenging until the recent introduction of reliable methods. However, the issue of potential interference from unknown isomers of BMAA present in samples has not yet been thoroughly investigated. Based on a systematic database search, we generated a list of all theoretical BMAA structural isomers, which was subsequently narrowed down to seven possible interfering compounds for further consideration. The seven possible candidates satisfied the requirements of chemical stability and also shared important structural domains with BMAA. Two of the candidates, 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl) glycine (AEG) have recently been studied in the context of BMAA. A further isomer, β-amino-N-methyl-alanine (BAMA), has to be considered because it can potentially yield the fragment ion, which is diagnostic for BMAA. Here, we report the synthesis and analysis of BAMA, together with AEG, DAB, and other isomers that are of interest in the separation and detection of BMAA in biological samples by using either high-performance liquid chromatography or ultra-high-performance liquid chromatography coupled with tandem mass spectrometry. We detected for the first time BAMA in blue mussel and oyster samples. This work extends the previously developed liquid chromatography-tandem mass spectrometry platform Spacil et al. (Analyst 135:127, 2010) to allow BMAA isomers to be distinguished, improving the detection and identification of this important amino acid.

  3. X-ray holographic microscopy with zone plates applied to biological samples in the water window using 3rd harmonic radiation from the free-electron laser FLASH.

    PubMed

    Gorniak, T; Heine, R; Mancuso, A P; Staier, F; Christophis, C; Pettitt, M E; Sakdinawat, A; Treusch, R; Guerassimova, N; Feldhaus, J; Gutt, C; Grübel, G; Eisebitt, S; Beyer, A; Gölzhäuser, A; Weckert, E; Grunze, M; Vartanyants, I A; Rosenhahn, A

    2011-06-06

    The imaging of hydrated biological samples - especially in the energy window of 284-540 eV, where water does not obscure the signal of soft organic matter and biologically relevant elements - is of tremendous interest for life sciences. Free-electron lasers can provide highly intense and coherent pulses, which allow single pulse imaging to overcome resolution limits set by radiation damage. One current challenge is to match both the desired energy and the intensity of the light source. We present the first images of dehydrated biological material acquired with 3rd harmonic radiation from FLASH by digital in-line zone plate holography as one step towards the vision of imaging hydrated biological material with photons in the water window. We also demonstrate the first application of ultrathin molecular sheets as suitable substrates for future free-electron laser experiments with biological samples in the form of a rat fibroblast cell and marine biofouling bacteria Cobetia marina.

  4. 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.

  5. 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.

  6. 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.

  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. Antisera specific for carcinogen-DNA adducts and carcinogen-modified DNA: applications for detection of xenobiotics in biological samples.

    PubMed

    Poirier, M C

    1993-07-01

    The development of immunoassays and immunoaffinity chromatography methods for determination of carcinogen-DNA adducts and carcinogen-modified DNA samples rests upon eliciting and characterizing polyclonal and monoclonal antisera against these haptens. The use of such antisera has widespread application in investigating chronic carcinogen administration in animal models and in monitoring human tissues for evidence of carcinogen exposure. Radioimmunoassays and enzyme-linked immunosorbent assays developed with carcinogen-DNA adduct antisera are exceedingly sensitive, measuring 1 adduct in 10(8) nucleotides. Not only can DNA damage be quantified directly by immunoassay, but the antisera have also been used to isolate DNA adducts of a particular chemical class by immunoaffinity chromatography before application of more chemically-specific end-points. Both of these methodological approaches have made seminal contributions to the newly-emerging field of molecular epidemiology. This chapter will focus on methods for preparing immunogens, the establishment of immunoassays, characterization of antisera and specific problems encountered with biological samples in addition, the use of immunoaffinity chromatography for preparative concentration of DNA adducts of a particular class will be included.

  10. 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

  11. Spectrophotometric determination of Sb(III) and Sb(V) in biological samples after micelle-mediated extraction.

    PubMed

    Madrakian, Tayyebeh; Bozorgzadeh, Elaheh

    2009-10-30

    This work presents a micelle-mediated extraction method for simultaneous preconcentration and determination of Sb(III) and Sb(V) species in biological samples as a prior preconcentration step to their spectrophotometric determination. The analytical system is based on the selective reaction between Sb(III) and bromopyrogallol red (BPR) in the presence of cetyltrimethylammonium bromide (CTAB) and potassium iodide at pH 6.4. Total Sb concentration was determined after reduction of Sb(V) to Sb(III) in the presence of potassium iodide and ascorbic acid. The optimal extraction and reaction conditions were studied and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration factor, and improvement factors) were obtained. Linearity for Sb(III) and Sb(V) were obeyed in the range of 0.2-20.0 ng mL(-1) and 0.4-25.0 ng mL(-1), respectively. The detection limit for the determination of Sb(III) and Sb(V) were 0.05 ng mL(-1) and 0.08 ng mL(-1), respectively. 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 and urine samples.

  12. 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.

  13. Highly selective ionic liquid-based microextraction method for sensitive trace cobalt determination in environmental and biological samples.

    PubMed

    Berton, Paula; Wuilloud, Rodolfo G

    2010-03-10

    A simple and rapid dispersive liquid-liquid microextraction procedure based on an ionic liquid (IL-DLLME) was developed for selective determination of cobalt (Co) with electrothermal atomic absorption spectrometry (ETAAS) detection. Cobalt was initially complexed with 1-nitroso-2-naphtol (1N2N) reagent at pH 4.0. The IL-DLLME procedure was then performed by using a few microliters of the room temperature ionic liquid (RTIL) 1-hexyl-3-methylimidazolium hexafluorophosphate [C(6)mim][PF(6)] as extractant while methanol was the dispersant solvent. After microextraction procedure, the Co-enriched RTIL phase was solubilized in methanol and directly injected into the graphite furnace. The effect of several variables on Co-1N2N complex formation, extraction with the dispersed RTIL phase, and analyte detection with ETAAS, was carefully studied in this work. An enrichment factor of 120 was obtained with only 6 mL of sample solution and under optimal experimental conditions. The resultant limit of detection (LOD) was 3.8 ng L(-1), while the relative standard deviation (RSD) was 3.4% (at 1 microg L(-1) Co level and n=10), calculated from the peak height of absorbance signals. The accuracy of the proposed methodology was tested by analysis of a certified reference material. The method was successfully applied for the determination of Co in environmental and biological samples.

  14. Determination of haloperidol in biological samples using molecular imprinted polymer nanoparticles followed by HPLC-DAD detection.

    PubMed

    Ebrahimzadeh, Homeira; Dehghani, Zahra; Asgharinezhad, Ali Akbar; Shekari, Nafiseh; Molaei, Karam

    2013-09-10

    In this study an extraction procedure using molecular imprinted polymer nanoparticles for the determination of haloperidol in biological samples is proposed. The haloperidol imprinted polymer nanoparticles were synthesized successfully by precipitation polymerization in a flask containing haloperidol as a template, ethyleneglycoldimethacrylate as a crosslinking agent, methacrylic acid as a functional monomer, and 2,2'-azobisisobutyronitrile as an initiator. The leached and unleached polymer nanoparticles have been characterized by infrared spectroscopy and scanning electron microscopy. The effect of different variables such as the pH of solution, uptake and elution time, type, and the least amount of eluent for elution of haloperidol from polymer was evaluated. Extraction efficiencies more than 97% were obtained by elution of the polymer with 1.5 mL of methanol-acetic acid-trifluoroacetic acid 79.9:20:0.1. Under optimal conditions maximum adsorption capacity was obtained 153.84 mg g(-1). The detection limit of the proposed procedure was between 0.2 and 0.35 μg L(-1). Finally this method was applied to the determination of haloperidol in plasma and urine samples and satisfactory results were achieved (RSD<6.9%).

  15. HPLC-FLD and spectrofluorometer apparatus: How to best detect fluorescent probe-loaded niosomes in biological samples.

    PubMed

    Primavera, Rosita; Di Francesco, Martina; De Cola, Antonella; De Laurenzi, Vincenzo; Paolino, Donatella; Ciancaioni, Matteo; Carafa, Maria; Celia, Christian; Di Ilio, Carmine; Di Stefano, Antonio; Fresta, Massimo; Locatelli, Marcello; Di Marzio, Luisa

    2015-11-01

    The analytical tools allow the detection of bioactive compounds, diagnostic agents and chemotherapeutics. Recently, new methods have been developed to analyze pharmaceutical samples and ingredients. In this attempt, analytical parameters, e.g., the lack of trueness, robustness and sensitivity, play a pivotal role to quantify and analyze molecules, both for diagnostic applications as well as therapeutic treatments. Spectrophotometers and spectrofluorometers are apparatus for easy and rapid quantification of molecular probes and chemotherapeutics into cells, plasma and tissues. However, they lack accuracy and precision. Conversely, HPLC provides the maximum resolution to detect and separate fluorescent probes and chemotherapeutics after their incubation in cells, plasma and tissues. The aim of this work was to develop an HPLC method that easily detects molecular and fluorescent probes, e.g., Nile Red, in biological samples. To improve the robustness of the method, Nile Red was analyzed before and after loading into niosomes made from Tween 20 and 21, respectively. A significant difference was further obtained by comparing the entrapment efficacy percentage of niosomes made from Tween 21 (42.23%) and Tween 20 (53.25%). The comparison between HPLC and spectrofluorometer assays showed differences between the two methods in terms of limit of detection, linearity and accuracy. The resulting data demonstrated that the HPLC-FLD provides a limit of detection for Nile Red of 0.1 ng/mL, and a good linearity up to 62.5 ng/mL. The HPLC-FLD analysis showed a limit of quantification value for a total mass of Nile Red 1200-folds better than data previously reported in studies; and 312-folds better than the spectrofluorometer analysis. Additionally, results show that the HPLC-FLD increases the sensitivity for biological samples compared to the spectrofluorometer. The Nile Red-loaded niosomes were also incubated at different times with HEK-293 cells. In vitro results demonstrated

  16. 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

  17. 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

  18. 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

  19. Detection of chemical warfare agent simulants and hydrolysis products in biological samples by paper spray mass spectrometry.

    PubMed

    McKenna, Josiah; Dhummakupt, Elizabeth S; Connell, Theresa; Demond, Paul S; Miller, Dennis B; Michael Nilles, J; Manicke, Nicholas E; Glaros, Trevor

    2017-03-24

    Paper spray ionization coupled to a high resolution tandem mass spectrometer (a quadrupole orbitrap) was used to identify and quantitate chemical warfare agent (CWA) simulants and their hydrolysis products in blood and urine. Three CWA simulants, dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), and diisopropyl methylphosphonate (DIMP), and their isotopically labeled standards were analyzed in human whole blood and urine. Calibration curves were generated and tested with continuing calibration verification standards. Limits of detection for these three compounds were in the low ng mL(-1) range for the direct analysis of both blood and urine samples. Five CWA hydrolysis products, ethyl methylphosphonic acid (EMPA), isopropyl methylphosphonic acid (IMPA), isobutyl methylphosphonic acid (iBuMPA), cyclohexyl methylphosphonic acid (CHMPA), and pinacolyl methylphosphonic acid (PinMPA), were also analyzed. Calibration curves were generated in both positive and negative ion modes. Limits of detection in the negative ion mode ranged from 0.36 ng mL(-1) to 1.25 ng mL(-1) in both blood and urine for the hydrolysis products. These levels were well below those found in victims of the Tokyo subway attack of 2 to 135 ng mL(-1). Improved stability and robustness of the paper spray technique in the negative ion mode was achieved by the addition of chlorinated solvents. These applications demonstrate that paper spray mass spectrometry (PS-MS) can be used for rapid, sample preparation-free detection of chemical warfare agents and their hydrolysis products at physiologically relevant concentrations in biological samples.

  20. 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,…

  1. 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

  2. HPLC and TLC methods for analysis of [(18)F]FDG and its metabolites from biological samples.

    PubMed

    Rokka, Johanna; Grönroos, Tove J; Viljanen, Tapio; Solin, Olof; Haaparanta-Solin, Merja

    2017-03-24

    The most used positron emission tomography (PET) tracer, 2-[(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG), is a glucose analogue that is used to measure tissue glucose consumption. Traditionally, the Sokoloff model is the basis for [(18)F]FDG modeling. According to this model, [(18)F]FDG is expected to be trapped in a cell in the form of [(18)F]FDG-6-phosphate ([(18)F]FDG-6-P). However, several studies have shown that in tissues, [(18)F]FDG metabolism goes beyond [(18)F]FDG-6-P. Our aim was to develop radioHPLC and radioTLC methods for analysis of [(18)F]FDG metabolites from tissue samples. The radioHPLC method uses a sensitive on-line scintillation detector to detect radioactivity, and the radioTLC method employs digital autoradiography to detect the radioactivity distribution on a TLC plate. The HPLC and TLC methods were developed using enzymatically in vitro-produced metabolites of [(18)F]FDG as reference standards. For this purpose, three [(18)F]FDG metabolites were synthesized: [(18)F]FDG-6-P, [(18)F]FD-PGL, and [(18)F]FDG-1,6-P2. The two methods were evaluated by analyzing the [(18)F]FDG metabolic profile from rodent ex vivo tissue homogenates. The HPLC method with an on-line scintillation detector had a wide linearity in a range of 5Bq-5kBq (LOD 46Bq, LOQ 139Bq) and a good resolution (Rs ≥1.9), and separated [(18)F]FDG and its metabolites clearly. The TLC method combined with digital autoradiography had a high sensitivity in a wide range of radioactivity (0.1Bq-2kBq, LOD 0.24Bq, LOQ 0.31Bq), and multiple samples could be analyzed simultaneously. As our test and the method validation with ex vivo samples showed, both methods are useful, and at best they complement each other in analysis of [(18)F]FDG and its radioactive metabolites from biological samples.

  3. 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.

  4. 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.

  5. Simple determination of fluoride in biological samples by headspace solid-phase microextraction and gas chromatography-tandem mass spectrometry.

    PubMed

    Kwon, Sun-Myung; Shin, Ho-Sang

    2015-08-14

    A simple and convenient method to detect fluoride in biological samples was developed. This method was based on derivatization with 2-(bromomethyl)naphthalene, headspace solid phase microextraction (HS-SPME) in a vial, and gas chromatography-tandem mass spectrometric detection. The HS-SPME parameters were optimized as follows: selection of CAR/PDMS fiber, 0.5% 2-(bromomethyl)naphthalene, 250 mg/L 15-crown-5-ether as a phase transfer catalyst, extraction and derivatization temperature of 95 °C, heating time of 20 min and pH of 7.0. Under the established conditions, the lowest limits of detection were 9 and 11 μg/L in 1.0 ml of plasma and urine, respectively, and the intra- and inter-day relative standard deviation was less than 7.7% at concentrations of 0.1 and 1.0 mg/L. The calibration curve showed good linearity of plasma and urine with r=0.9990 and r=0.9992, respectively. This method is simple, amenable to automation and environmentally friendly.

  6. 33S nuclear magnetic resonance spectroscopy of biological samples obtained with a laboratory model 33S cryogenic probe.

    PubMed

    Hobo, Fumio; Takahashi, Masato; Saito, Yuta; Sato, Naoki; Takao, Tomoaki; Koshiba, Seizo; Maeda, Hideaki

    2010-05-01

    (33)S nuclear magnetic resonance (NMR) spectroscopy is limited by inherently low NMR sensitivity because of the quadrupolar moment and low gyromagnetic ratio of the (33)S nucleus. We have developed a 10 mm (33)S cryogenic NMR probe, which is operated at 9-26 K with a cold preamplifier and a cold rf switch operated at 60 K. The (33)S NMR sensitivity of the cryogenic probe is as large as 9.8 times that of a conventional 5 mm broadband NMR probe. The (33)S 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 SO(4)(2-) anions and -SO(3)(-) groups using the (33)S cryogenic probe, as the (33)S 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 (33)S cryogenic probe, as the (33)S 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.

  7. Evaluation of status of trace and toxic metals in biological samples (scalp hair, blood, and urine) of normal and anemic children of two age groups.

    PubMed

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

    2011-06-01

    Anemia affects a substantial portion of the world's population, provoking severe health problems as well as important economic losses to the region in which this condition is found. This study was designed to compare the levels of essential trace and toxic elements in scalp hair, blood, and urine samples of anemic children (n = 132) with age range 1-5 and 6-10 years of both genders. For a comparative study, 134 non-anemic age- and sex-matched children as control subjects, residing in the same city, were selected. The metals in the biological samples were measured by flame atomic absorption spectrophotometry/electrothermal atomic absorption spectrometry prior to microwave-assisted acid digestion. The proposed method was validated using certified reference samples of hair, blood, and urine. The results indicated significantly lower levels of iron, copper, and zinc in the biological samples as compared to the control children of both genders (p = 0.01-0.008). The mean values of lead and cadmium were significantly high in all three biological samples of anemic children as compared to non-anemic children of both age groups (p = 0.005-0.001). The ratios of essential metal to toxic metals in the biological samples of anemic children of both age groups were significantly lower than that of controls. Deficiency of essential trace metals and high level of toxic metals may play a role in the development of anemia in the subjects under study.

  8. Application of self-organizing maps for PCDD/F pattern recognition of environmental and biological samples to evaluate the impact of a hazardous waste incinerator.

    PubMed

    Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

    2010-04-15

    Kohonen's self-organizing maps (SOM) is one of the most popular artificial neural network models. In this study, SOM were used to assess the potential relationships between polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) congener profiles in environmental (soil, herbage, and ambient air) and biological (plasma, adipose tissue, and breast milk) samples, and the emissions of a hazardous waste incinerator (HWI) in Spain. The visual examination of PCDD/F congener profiles of most environmental and biological samples did not allow finding out any differences between monitors. However, the global SOM analysis of environmental and biological samples showed that the weight of the PCDD/F stack emissions of the HWI on the environmental burden and on the exposure of the individuals living in the surroundings was not significant in relation to the background levels. The results confirmed the small influence of the HWI emissions of PCDD/Fs on the environment and the population living in the neighborhood.

  9. Three-dimensional temperature fields of the North Patagonian Sea recorded by Magellanic penguins as biological sampling platforms

    NASA Astrophysics Data System (ADS)

    Sala, Juan E.; Pisoni, Juan P.; Quintana, Flavio

    2017-04-01

    Temperature is a primary determinant of biogeographic patterns and ecosystem processes. Standard techniques to study the ocean temperature in situ are, however, particularly limited by their time and spatial coverage, problems which might be partially mitigated by using marine top predators as biological platforms for oceanographic sampling. We used small archival tags deployed on 33 Magellanic penguins (Spheniscus magellanicus), and obtained 21,070 geo-localized profiles of water temperature, during late spring of 2008, 2011, 2012 and 2013; in a region of the North Patagonian Sea with limited oceanographic records in situ. We compared our in situ data of sea surface temperature (SST) with those available from satellite remote sensing; to describe the three-dimensional temperature fields around the area of influence of two important tidal frontal systems; and to study the inter-annual variation in the three-dimensional temperature fields. There was a strong positive relationship between satellite- and animal-derived SST data although there was an overestimation by remote-sensing by a maximum difference of +2 °C. Little inter-annual variability in the 3-dimensional temperature fields was found, with the exception of 2012 (and to a lesser extent in 2013) where the SST was significantly higher. In 2013, we found weak stratification in a region which was unexpected. In addition, during the same year, a warm small-scale vortex is indicated by the animal-derived temperature data. This allowed us to describe and better understand the dynamics of the water masses, which, so far, have been mainly studied by remote sensors and numerical models. Our results highlight again the potential of using marine top predators as biological platforms to collect oceanographic data, which will enhance and accelerate studies on the Southwest Atlantic Ocean. In a changing world, threatened by climate change, it is urgent to fill information gaps on the coupled ocean-atmosphere system

  10. 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.

  11. Development of the complex permittivity measurement system for high-loss biological samples using the free space method in quasi-millimeter and millimeter wave bands.

    PubMed

    Sasaki, K; Segawa, H; Mizuno, M; Wake, K; Watanabe, S; Hashimoto, O

    2013-03-07

    The free space method using a pair of lens antennas was modified for the complex permittivity measurement of biological samples from 20 to 110 GHz. Two methodologies were used to obtain the complex permittivities by the free space method, which were based on the reflection and transmission coefficients. The measurement results obtained with the two methodologies were compared with each other. The measured complex permittivities of the biological samples from the free space method were then compared with those measured using the coaxial probe method. Finally, the measurement data were also compared with those from measurement methods developed in past literatures.

  12. 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.

  13. High-resolution melting analysis for bird sexing: a successful approach to molecular sex identification using different biological samples.

    PubMed

    Morinha, Francisco; Travassos, Paulo; Seixas, Fernanda; Santos, Nuno; Sargo, Roberto; Sousa, Luís; Magalhães, Paula; Cabral, João A; Bastos, Estela

    2013-05-01

    High-resolution melting (HRM) analysis is a very attractive and flexible advanced post-PCR method with high sensitivity/specificity for simple, fast and cost-effective genotyping based on the detection of specific melting profiles of PCR products. Next generation real-time PCR systems, along with improved saturating DNA-binding dyes, enable the direct acquisition of HRM data after quantitative PCR. Melting behaviour is particularly influenced by the length, nucleotide sequence and GC content of the amplicons. This method is expanding rapidly in several research areas such as human genetics, reproductive biology, microbiology and ecology/conservation of wild populations. Here we have developed a successful HRM protocol for avian sex identification based on the amplification of sex-specific CHD1 fragments. The melting curve patterns allowed efficient sexual differentiation of 111 samples analysed (plucked feathers, muscle tissues, blood and oral cavity epithelial cells) of 14 bird species. In addition, we sequenced the amplified regions of the CHD1 gene and demonstrated the usefulness of this strategy for the genotype discrimination of various amplicons (CHD1Z and CHD1W), which have small size differences, ranging from 2 bp to 44 bp. The established methodology clearly revealed the advantages (e.g. closed-tube system, high sensitivity and rapidity) of a simple HRM assay for accurate sex differentiation of the species under study. The requirements, strengths and limitations of the method are addressed to provide a simple guide for its application in the field of molecular sexing of birds. The high sensitivity and resolution relative to previous real-time PCR methods makes HRM analysis an excellent approach for improving advanced molecular methods for bird sexing.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Efficient synthesis of narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with excellent molecular recognition ability in a real biological sample.

    PubMed

    Zhao, Man; Zhang, Cong; Zhang, Ying; Guo, Xianzhi; Yan, Husheng; Zhang, Huiqi

    2014-02-28

    A facile and highly efficient approach to obtain narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with molecular recognition ability in a real biological sample as good as what they show in the organic solvent-based media is described for the first time.

  19. Evaluation of toxic metals in biological samples (scalp hair, blood and urine) of steel mill workers by electrothermal atomic absorption spectrometry.

    PubMed

    Afridi, Hassan I; Kazi, Tasneem G; Jamali, Mohammad K; Kazi, Gul H; Arain, Mohammad B; Jalbani, Nusrat; Shar, Ghulam Q; Sarfaraz, Raja A

    2006-10-01

    The determination of toxic metals in the biological samples of human beings is an important clinical screening procedure. This study aimed to assess the possible influence of environmental exposure on production workers (PW) and quality control workers (QCW) of a steel mill, all male subjects aged 25-55 years. In this investigation, the concentrations of Pb, Cd, Ni and Cr were determined in biological samples (blood, urine and scalp hair samples) from these steel mill workers in relation to controlled unexposed healthy subjects of the same age group. After pre-treatment with nitric acid-hydrogen peroxide, the samples were digested via a microwave oven, and for comparison purposes, the same samples were digested by the conventional wet acid digestion method. The samples digested were subjected to graphite furnace atomic absorption spectrometry (GFAAS). To assess the reliability of these methods, critical factors, such as detection limit(s), calibration range(s), accuracy and precision, were studied. Quality control for these procedures was established with certified sample of human hair, urine and whole blood. The results indicate that the level of lead, cadmium and nickel in scalp hair, blood and urine samples were significantly higher in both groups of exposed workers (QW and PW) than those of the controls. The possible connection of these elements with the etiology of disease is discussed. The results also show the need for immediate improvements in workplace ventilation and industrial hygiene practices.

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. Polymer monolithic capillary microextraction on-line coupled with inductively coupled plasma-mass spectrometry for the determination of trace Au and Pd in biological samples

    NASA Astrophysics Data System (ADS)

    Liu, Xiaolan; He, Man; Chen, Beibei; Hu, Bin

    2014-11-01

    A novel method based on on-line polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Au and Pd in biological samples. For this purpose, poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was prepared and functionalized with mercapto groups. The prepared monolith exhibited good selectivity to Au and Pd, and good resistance to strong acid with a long life span. Factors affecting the extraction efficiency of CME, such as sample acidity, sample flow rate, eluent conditions and coexisting ion interference were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) were 5.9 ng L- 1 for Au and 8.3 ng L- 1 for Pd, and the relative standard deviations (RSDs, c = 50 ng L -1, n = 7) were 6.5% for Au and 1.1% for Pd, respectively. The developed method was successfully applied to the determination of Au and Pd in human urine and serum samples with the recovery in the range of 84-118% for spiked samples. The developed on-line polymer monolithic CME-ICP-MS method has the advantages of rapidity, simplicity, low sample/reagent consumption, high sensitivity and is suitable for the determination of trace Au and Pd in biological samples with limited amount available and complex matrix.

  5. A Feedfordward Adaptive Controller to Reduce the Imaging Time of Large-Sized Biological Samples with a SPM-Based Multiprobe Station

    PubMed Central

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

    2012-01-01

    The time required to image large samples is an important limiting factor in SPM-based systems. In multiprobe setups, especially when working with biological samples, this drawback can make impossible to conduct certain experiments. In this work, we present a feedfordward controller based on bang-bang and adaptive controls. The controls are based in the difference between the maximum speeds that can be used for imaging depending on the flatness of the sample zone. Topographic images of Escherichia coli bacteria samples were acquired using the implemented controllers. Results show that to go faster in the flat zones, rather than using a constant scanning speed for the whole image, speeds up the imaging process of large samples by up to a 4× factor. PMID:22368491

  6. 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

  7. Evaluation of essential trace and toxic elements 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; Kazi, Naveed; Kandhro, Ghulam Abbas; Baig, Jameel Ahmed; Shah, Abdul Qadir; Wadhwa, Sham Kumar; Khan, Sumaira; Kolachi, Nida Fatima; Shah, Faheem; Jamali, Mohammad Khan; Arain, Mohammad Balal; Sirajuddin

    2011-10-01

    The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. 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 samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb 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 As, Ca, Cd, K, Pb, Mg, Na, and Zn 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 concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p < 0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.

  8. Magnetic metal-organic nanotubes: An adsorbent for magnetic solid-phase extraction of polychlorinated biphenyls from environmental and biological samples.

    PubMed

    Li, Qiu-Lin; Wang, Lei-Lei; Wang, Xia; Wang, Ming-Lin; Zhao, Ru-Song

    2016-06-03

    A new type of three-dimensional, echinus-like magnetic Fe3O4 @ cobalt(Ⅱ)-based metal-organic nanotube (Fe3O4 @ Co-MONT) yolk-shell microspheres, have been designed and synthesized for the first time. Fe3O4 @ Co-MONTs yolk-shell microspheres were characterized by scanning electron micrographs, transmission electron microscopy, Fourier transform infrared spectra, X-ray diffraction, and vibrating sample magnetometry. The feasibility of the new material for use as an absorbent was investigated for magnetic solid phase-extraction (MSPE) of polychlorinated biphenyls (PCBs) from environmental water samples and biological samples. The Plackett-Burman design and Box-Behnken design were used to determine and optimize the extraction parameters influencing the extraction efficiency through response surface methodology. Under the optimized conditions, the developed method showed good linearity within the range of 5-1000ngL(-1), low limits of detection (0.31-0.49ngL(-1)), and good reproducibility (RSD<10%). The proposed method was successfully applied for the analysis of PCBs in real environmental water samples. These results demonstrated that Fe3O4 @ Co-MONTs is a promising adsorbent material for the MSPE of PCBs at trace levels from environmental water samples and biological samples.

  9. 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.

  10. 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…

  11. 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-...

  12. Ultra-Sensitive Elemental Analysis Using Plasmas 5.Speciation of Arsenic Compounds in Biological Samples by High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry System

    NASA Astrophysics Data System (ADS)

    Kaise, Toshikazu

    Arsenic originating from the lithosphere is widely distributed in the environment. Many arsenicals in the environment are in organic and methylated species. These arsenic compounds in drinking water or food products of marine origin are absorbed in human digestive tracts, metabolized in the human body, and excreted viatheurine. Because arsenic shows varying biological a spects depending on its chemical species, the biological characteristics of arsenic must be determined. It is thought that some metabolic pathways for arsenic and some arsenic circulation exist in aqueous ecosystems. In this paper, the current status of the speciation analysis of arsenic by HPLC/ICP-MS (High Performance Liquid Chromatography-Inductively Coupled Plasma Mass spectrometry) in environmental and biological samples is summarized using recent data.

  13. Highly sensitive determination of nitric oxide in biologic samples by a near-infrared BODIPY-based fluorescent probe coupled with high-performance liquid chromatography.

    PubMed

    Zhang, Hui-Xian; Chen, Jian-Bo; Guo, Xiao-Feng; Wang, Hong; Zhang, Hua-Shan

    2013-11-15

    Nitric oxide (NO) acts as an important regulator and mediator in numerous processes of biological systems. In this work, the analytical potential of a novel near-infrared (NIR, >600 nm) BODIPY-based fluorescent probe for NO, 8-(3,4-diaminophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-di(1,2-dihydro) naphtho[b, g]s-indacene (DANPBO-H) has been evaluated in high performance liquid chromatography (HPLC). In 25 mM pH 6.50 borate buffer, DANPBO-H reacted with NO to give the corresponding triazole, DANPBO-H-T, at 35 °C for 20 min. DANPBO-H-T was eluted using a mobile phase of methanol/tetrahydrofuran/50mM pH 7.00 H3Cit-NaOH buffer (81:7:12, v/v/v) in 4 min on a C8 column and detected with fluorescence detection at excitation and emission wavelengths of 621 and 631 nm, respectively. The limit of detection (LOD) (signal-to-noise=3) reached to 5.50×10(-10) M. Excellent selectivity was observed against other reactive oxygen/nitrogen species. Various representative biological matrixes including the whole blood and organs of mice, the pangen and radical of rice, human vascular endothelial (ECV-304) cells and mouse macrophage (RAW 264.7) cells were used to verify the feasibility and resistance to interfering effects from complex biological sample matrixes of the developed DANPBO-H-based HPLC method. Compared to the existing derivatization-based HPLC methods for NO, the proposed method eliminates interfering effects from complex biological sample matrixes efficiently owing to the fluorescence detection in the NIR region, and is more advantageous and robust for the sensitive and selective determination of NO in complex biological samples.

  14. Field comparison of passive sampling and biological approaches for measuring exposure to PAH and alkylphenols from offshore produced water discharges.

    PubMed

    Harman, Christopher; Brooks, Steven; Sundt, Rolf C; Meier, Sonnich; Grung, Merete

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAH) and alkylphenols (AP) that are present in routine discharges of produced water (PW) from the offshore industry continue to cause concern. The suitability of biological methods and chemical based passive samplers to determine exposure to these compounds was tested by deploying them around an oil installation and at reference locations in the North Sea. PAH and AP were analysed either as parent compounds in passive samplers and mussel tissue or as metabolites in fish bile. Generally the pattern of exposure relative to proximity to the discharge was represented by mussels, SPMDs and fish for PAH. Fish and SPMDs showed good correlation for PAH accumulations, whereas some differences were apparent between mussels and SPMDs. POCIS was the only technique tested that could accurately measure the most abundant AP in PW. The advantages of biologically independent measures of exposure for inclusion in discharge monitoring studies are outlined.

  15. Determination of Biological Variance and Validation of a Fluorometric Assay for Measurement of α-l-Iduronidase Activity in Dried Blood Spots Samples: The First Experience in Iran.

    PubMed

    Abdi, Mohammad; Hakhamaneshi, Mohammad Said; Alaei, Mohammad Reza; Azadi, Namam-Ali; Vakili, Rahim; Zamanfar, Daniel; Taghikhani, Mohammad; Khatami, Shohreh

    2015-07-01

    Methods for assaying lysosomal diseases in dried blood samples are very useful today due to its several advantages related to the stability of samples, its transportation, handled and analysis, and its potential use for newborn screening compared to traditional methods in leucocytes samples. For this reason, it is important to validate these assays before being used in routine laboratory. Because of different in biological markers based on ethnicity, we aimed this study to validation a DBS-based fluorometric assay for measurement of α-l-Iduronidase activity for diagnosis of MPS I patients in Iran. DBS samples were collected from 15 MPS I patients and 60 healthy age matched subjects. Diagnostic value, biological variance and α-l-Iduronidase activity were determined. DBS α-l-Iduronidase activity was significantly higher in male subjects than in female group. Using a cut-off level of 1.08 µmol/spot 20 h, sensitivity and specificity were 100 and 98 %. The linearity of test was proved and we showed that within-run and between run precision were 5.6 and 14.66 %. Measurement of α-l-Iduronidase activity in DBS samples is an accurate test for diagnosis of MPS I and because of its rapid shipping and simplicity to keeping, DBS-based enzyme activity could be considered as a useful diagnostic tool in this disease.

  16. Measurement of unlabeled and stable isotope-labeled homoarginine, arginine and their metabolites in biological samples by GC-MS and GC-MS/MS.

    PubMed

    Kayacelebi, Arslan Arinc; Knöfel, Ann-Kathrin; Beckmann, Bibiana; Hanff, Erik; Warnecke, Gregor; Tsikas, Dimitrios

    2015-09-01

    Circulating and excretory L-homoarginine (hArg) and asymmetric dimethylarginine (ADMA) are cardiovascular risk factors. L-Arginine (Arg) is the common precursor of hArg and ADMA. This protocol describes gas chromatography-mass spectrometry (GC-MS) and gas chromatography-mass spectrometry-mass spectrometry (GC-MS/MS) methods for the quantitative determination of hArg, Arg and ADMA in biological samples, including human plasma, urine and sputum. Aliquots (10 µL) of native urine, plasma or serum ultrafiltrate (cutoff, 10 kDa), and acetone-deproteinized sputum samples are evaporated to dryness. Then, amino acids are derivatized to their methyl ester N-pentafluoropropionyl derivatives. In parallel, trideuteromethyl ester N-pentafluoropropionyl derivatives of hArg, Arg and ADMA are de novo synthesized from the unlabelled amino acids and used as internal standards. Alternatively, commercially available stable isotope-labeled analogs of hArg, Arg and ADMA are used as internal standards, and they are added to the native biological samples. Quantification is performed by selected ion monitoring in GC-MS and selected reaction monitoring in GC-MS/MS. By these protocols, unlabelled and stable isotope-labeled hArg, Arg and their metabolites including ADMA and ornithine can be measured equally accurately and precisely by GC-MS and GC-MS/MS in several different biological fluids in experimental and clinical settings.

  17. True non-contact atomic force microscopy imaging of heterogeneous biological samples in liquids: topography and material contrast.

    PubMed

    Almonte, Lisa; Colchero, Jaime

    2017-02-23

    The present work analyses how the tip-sample interaction signals critically determine the operation of an Atomic Force Microscope (AFM) set-up immersed in liquid. On heterogeneous samples, the conservative tip-sample interaction may vary significantly from point to point - in particular from attractive to repulsive - rendering correct feedback very challenging. Lipid membranes prepared on a mica substrate are analyzed as reference samples which are locally heterogeneous (material contrast). The AFM set-up is operated dynamically at low oscillation amplitude and all available experimental data signals - the normal force, as well as the amplitude and frequency - are recorded simultaneously. From the analysis of how the dissipation (oscillation amplitude) and the conservative interaction (normal force and resonance frequency) vary with the tip-sample distance we conclude that dissipation is the only appropriate feedback source for stable and correct topographic imaging. The normal force and phase then carry information about the sample composition ("chemical contrast"). Dynamic AFM allows imaging in a non-contact regime where essentially no forces are applied, rendering dynamic AFM a truly non-invasive technique.

  18. 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.

  19. 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.

  20. Determination of selenium in marine biological tissues by transverse heated electrothermal atomic absorption spectrometry with longitudinal Zeeman background correction and automated ultrasonic slurry sampling.

    PubMed

    Méndez, H; Alava, F; Lavilla, I; Bendicho, C

    2001-01-01

    A fast, sensitive, and reliable method for determination of selenium in marine biological tissues by electrothermal atomic absorption spectrometry with slurry sampling was developed. Slurries were prepared from fresh and frozen seafood samples that were previously homogenized, dried, and ground; particle sizes <100 microm were taken for analysis. A 3% (v/v) HNO3 solution containing 0.01% (v/v) Triton X-100 was used as slurry diluent. Slurries were mixed on an automated ultrasonic slurry sampler at 20% amplitude for 30 s just before an aliquot was injected into the furnace. The method was successfully validated against the following certified reference materials: NRCC CRM DORM-2 (Dogfish muscle); NRCC CRM TORT-2 (Lobster hepatopancreas); NRCC CRM DOLT-2 (Dogfish liver); and BCR CRM 278 (Mussel tissue), and was subsequently applied to determination of Se in 10 marine biological samples. The influences of the drying procedure (oven-, microwave-, and freeze-drying), matrix modifier amount, mass of solid material in cup, and pipetting sequence are discussed. The limit of determination of Se was 0.16 microg/g and the repeatability, estimated as between-batch precision, was in the range of 4-8%. Se contents in the samples ranged from 0.6 to 2.8 microg/g. The proposed method should be useful for fast assessment of the daily dietary intake of Se.

  1. Fabrication of diverse pH-sensitive functional mesoporous silica for selective removal or depletion of highly abundant proteins from biological samples.

    PubMed

    Wang, Jiaojiao; Lan, Jingfeng; Li, Huihui; Liu, Xiaoyan; Zhang, Haixia

    2017-01-01

    In proteomic studies, poor detection of low abundant proteins is a major problem due to the presence of highly abundant proteins. Therefore, the specific removal or depletion of highly abundant proteins prior to analysis is necessary. In response to this problem, a series of pH-sensitive functional mesoporous silica materials composed of 2-(diethylamino)ethyl methacrylate and methacrylic acid units were designed and synthesized via atom transfer radical polymerization. These functional mesoporous silica materials were characterized and their ability for adsorption and separation of proteins was evaluated. Possessing a pH-sensitive feature, the synthesized functional materials showed selective adsorption of some proteins in aqueous or buffer solutions at certain pH values. The specific removal of a particular protein from a mixed protein solution was subsequently studied. The analytical results confirmed that all the target proteins (bovine serum albumin, ovalbumin, and lysozyme) can be removed by the proposed materials from a five-protein mixture in a single operation. Finally, the practical application of this approach was also evaluated by the selective removal of certain proteins from real biological samples. The results revealed that the maximum removal efficiencies of ovalbumin and lysozyme from egg white sample were obtained as 99% and 92%, respectively, while the maximum removal efficiency of human serum albumin from human serum sample was about 80% by the proposed method. It suggested that this treatment process reduced the complexity of real biological samples and facilitated the identification of hidden proteins in chromatograms.

  2. Determination of V, Cr, Cu, As, and Pb Ions in Water and Biological Samples by Combining ICP-MS with Online Preconcentration Using Impregnated Resin.

    PubMed

    Wang, Shuo; Dong, Xv; Dai, Bingye; Pan, Mingfei; He, Shaoyuan; Wang, Junping

    2015-01-01

    A method was developed for detection of V, Cr, Cu, As, and Pb in water and biological samples by combining online flow injection and preconcentration with inductively coupled plasma-MS. The 2-nitroso-1-naphthol-4-sulfonic acid (Nitroso-S) impregnated MCI GEL CHP20P resin was prepared as an enrichment sorbent. Some parameters affecting the efficiency of the preconcentration process were investigated in the experiment, including the pH and volume of sample solution, the flow rate for sample loading, the type and concentration of eluent, and the influence of co-existing ions. Under the optimal experimental conditions, the enrichment factor and LOD (3s) of chosen metal ions V, Cr, Cu, As, and Pb were in the ranges of 71-268 and 4.89-23.76 ng/L, respectively. Based on 11 repeated measurements of standard solutions (1.0 μg/L), the RSD of the ions ranged from 1.2 to 2.9%. The detection procedure was also performed for analyzing two certified reference materials, GBW 08607 (water) and GBW 10052 (green tea), as well as environmental water and biological samples. Good agreement with certified values and high recoveries have demonstrated improved accuracy of the proposed method.

  3. Collection of a Lifetime: A Practical Approach to Developing a Longitudinal Collection of Women’s Healthcare Biological Samples

    PubMed Central

    Santillan, Mark K.; Leslie, Kimberly K.; Hamilton, Wendy S.; Boese, Brenda J.; Ahuja, Monika; Hunter, Stephen K.; Santillan, Donna A.

    2014-01-01

    Objective The objective is to develop a biorepository of samples that represent all stages of a women’s life. Importantly, our goal is to collect longitudinal physical specimens as well as the associated short and long-term clinical information. Study Design The Women’s Health Tissue Repository was established to encompass four tissue banks: Well Women Tissue Bank, Reproductive Endocrinology & Infertility Tissue Bank, Maternal Fetal Tissue Bank, and the long-established Gynecologic Malignancies Tissue Bank. Based on their health status, women being seen in Women’s Health at the University of Iowa are recruited to contribute samples and grant access to their electronic medical record to the biorepository. Samples are coded, processed, and stored for use by investigators. Results The Maternal Fetal Tissue Bank was the first expansion of our department’s biobanking efforts. Approximately 75% of the women approached consent to participate in the Maternal Fetal Tissue Bank. Enrollment has steadily increased. Samples have been used for over 20 projects in the first 3 years and are critical to 7 funded grants and 3 patent applications. Conclusion Patient samples with corresponding clinical data are initially important to women’s health research. Our model demonstrates that many research projects by faculty, fellows, and residents have benefited from the existence of the Women’s Health Tissue Repository. While challenging to achieve, longitudinal sampling allows for the greatest opportunity to study normal and pathological changes throughout all phases of a women’s life, including pregnancy. This bank facilitates and accelerates the development of novel research, technologies, and possible therapeutic options in women’s health. The establishment of more longitudinal biorepositories based on our model would enhance women’s health research. PMID:24965987

  4. Well-defined hydrophilic molecularly imprinted polymer microspheres for efficient molecular recognition in real biological samples by facile RAFT coupling chemistry.

    PubMed

    Zhao, Man; Chen, Xiaojing; Zhang, Hongtao; Yan, Husheng; Zhang, Huiqi

    2014-05-12

    A facile and highly efficient new approach (namely RAFT coupling chemistry) to obtain well-defined hydrophilic molecularly imprinted polymer (MIP) microspheres with excellent specific recognition ability toward small organic analytes in the real, undiluted biological samples is described. It involves the first synthesis of "living" MIP microspheres with surface-bound vinyl and dithioester groups via RAFT precipitation polymerization (RAFTPP) and their subsequent grafting of hydrophilic polymer brushes by the simple coupling reaction of hydrophilic macro-RAFT agents (i.e., hydrophilic polymers with a dithioester end group) with vinyl groups on the "living" MIP particles in the presence of a free radical initiator. The successful grafting of hydrophilic polymer brushes onto the obtained MIP particles was confirmed by SEM, FT-IR, static contact angle and water dispersion studies, elemental analyses, and template binding experiments. Well-defined MIP particles with densely grafted hydrophilic polymer brushes (∼1.8 chains/nm(2)) of desired chemical structures and molecular weights were readily obtained, which showed significantly improved surface hydrophilicity and could thus function properly in real biological media. The origin of the high grafting densities of the polymer brushes was clarified and the general applicability of the strategy was demonstrated. In particular, the well-defined characteristics of the resulting hydrophilic MIP particles allowed the first systematic study on the effects of various structural parameters of the grafted hydrophilic polymer brushes on their water-compatibility, which is of great importance for rationally designing more advanced real biological sample-compatible MIPs.

  5. Development and validation of a single HPLC method for determination of α-tocopherol in cell culture and in human or mouse biological samples.

    PubMed

    Cimadevilla, Henar M; Hevia, David; Miar, Ana; Mayo, Juan C; Lombo, Felipe; Sainz, Rosa M

    2015-06-01

    A straightforward and common analytical method for α-tocopherol (αT) determination in various biological samples, including plasma, red blood cells (RBC), tissues and cultured cell lines, was developed and validated, using a reverse phase-chromatographic method (RP-HPLC). Even though many chromatographic methods for αT determination have been reported, most of them require readjustment when applied to different types of samples. Thus, an effective and simple method for αT determination in different biological matrices is still necessary, specifically for translational research. This method was applied using a C18 column (250 × 4.6 mm, 5 µm particle size) under isocratic elution with MeOH:ACN:H2 O (90:9:1 v/v/v) at a flow rate of 1 mL/min and detected using photodiode array at 293 nm. Linearity (r >0.9997) was observed for standard calibration with inter- and intraday variation of standard <4%. Lower limits of detection and quantification for αT in this assay were 0.091 and 0.305 µg/mL respectively. Validation proved the method to be selective, linear, accurate and precise. The method was successfully applied in great variety of biological samples, that is, human and mouse plasma, RBCs, murine tissues and human/mouse/rat cultured cell lines. More importantly, a single protocol of extraction and detection can be applied, making this method very convenient for standardization of different types of samples.

  6. 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

  7. Liquid chromatography-tandem mass spectrometry determination of baclofen in various biological samples and application to a pharmacokinetic study.

    PubMed

    Kim, Tae Hwan; Shin, Soyoung; Shin, Jeong Cheol; Choi, Jin Ho; Seo, Won Sik; Park, Gi-Young; Kwon, Dong Rak; Yoo, Sun Dong; Lee, Ah-Ram; Joo, Sang Hoon; Min, Byung Sun; Yoo, Won Young; Shin, Beom Soo

    2013-11-01

    Baclofen is a structural analogue of γ-aminobutyric acid (GABA) that has been used for the treatment of spasticity since 1977. This study describes a simple and sensitive LC/MS/MS assay for the quantification of baclofen in rat plasma, urine, as well as various tissue samples. The assay utilized a simple protein precipitation and achieved lower limit of quantification (LLOQ) of 0.25ng/mL for rat plasma and brain samples and 2ng/mL for rat urine, liver and kidney samples. The assay was validated to demonstrate the specificity, linearity, recovery, LLOQ, accuracy, precision, and stability by using matrix matched quality control samples. There is no endogenous or exogenous peaks interfering with the analytes and matrix effects were minimized by optimized separation condition. The assay was linear over a concentration range of 0.25-500ng/mL for rat plasma and brain tissue, and 2-5000ng/mL for rat urine, kidney and liver with correlation coefficients >0.999. The mean intra- and inter-day assay accuracies were 94.6-104.6 and 96.0-103.6%, respectively. The mean intra- and inter-day precisions were 5.71 and 5.70%, respectively. The developed assay was successfully applied to a pharmacokinetic study and examined urinary excretion and tissue distribution of baclofen in rats following intravenous and oral administration.

  8. 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.

  9. Ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet for determination of three antifungal drugs in water and biological samples.

    PubMed

    Ezoddin, Maryam; Shojaie, Mehran; Abdi, Khosrou; Karimi, Mohammad Ali

    2017-03-01

    A novel ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet (UAAD-LLM-SFO) followed by HPLC-UV detection was developed for the analysis of three antifungal drugs in water and biological samples. In this method, 1-dodecanol was used as the extraction solvent. The emulsion was rapidly formed by pulling in and pushing out the mixture of sample solution and extraction solvent for 5 times repeatedly using a 10-mL glass syringe while sonication was performed. Therefore, an organic dispersive solvent required in common microextraction methods was not used in the proposed method. After dispersing, an aliquot of acetonitrile was introduced as a demulsifier solvent into the sample solution to separate two phases. Therefore, some additional steps, such as the centrifugation, ultrasonication, or agitation of the sample solution, are not needed. Parameters influencing the extraction recovery were investigated. The proposed method showed a good linearity for the three antifungal drugs studied with the correlation coefficients (R (2) > 0.9995). The limits of detection (LODs) and the limits of the quantification (LOQs) were between 0.01-0.03 μg L(-1) and 0.03-0.08 μg L(-1), respectively. The preconcentration factors (PFs) were in the range of 107-116, respectively. The precisions, as the relative standard deviations (RSDs) (n = 5), for inter-day and intra-day analysis were in the range of 2.1-4.5% and 6.5-8.5%, respectively. This method was successfully applied to determine the three antifungal drugs in tap water and biological samples. The recoveries of antifungal drugs in these samples were 92.4-98.5%. Graphical abstract Ultrasound-air-assisted demulsified liquid-liquid microextraction by solidification of a floating organic droplet for the analysis of three antifungal drugs prior HPLC-UV.

  10. 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.

  11. 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.

  12. 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

  13. Context Matters: Volunteer Bias, Small Sample Size, and the Value of Comparison Groups in the Assessment of Research-Based Undergraduate Introductory Biology Lab Courses

    PubMed Central

    Brownell, Sara E.; Kloser, Matthew J.; Fukami, Tadashi; Shavelson, Richard J.

    2013-01-01

    The shift from cookbook to authentic research-based lab courses in undergraduate biology necessitates the need for evaluation and assessment of these novel courses. Although the biology education community has made progress in this area, it is important that we interpret the effectiveness of these courses with caution and remain mindful of inherent limitations to our study designs that may impact internal and external validity. The specific context of a research study can have a dramatic impact on the conclusions. We present a case study of our own three-year investigation of the impact of a research-based introductory lab course, highlighting how volunteer students, a lack of a comparison group, and small sample sizes can be limitations of a study design that can affect the interpretation of the effectiveness of a course. PMID:24358380

  14. Ultrasound-assisted extraction followed by disposable pipette purification for the determination of polychlorinated biphenyls in small-size biological tissue samples.

    PubMed

    Pena-Abaurrea, M; García de la Torre, V S; Ramos, L

    2013-11-22

    The use of solid-phase extraction pipette tip (also called disposable pipette extraction, DPX) has been evaluated for the purification of environmentally relevant polychlorinated biphenyls (PCBs) in fatty extracts obtained by ultrasound-assisted extraction with a sonication probe from small-size biological tissues. Complete sample treatment involved only 50 mg of sample and was completed in ca. 15 min with minimal sample manipulation and reagents consumption (i.e., 1.5 mL of n-hexane and 0.8 g of acidic silica). The performance of the proposed methodology for the intended determination was firstly evaluated by determination of the endogenous PCB levels in a naturally contaminated internal reference material. The determined concentrations showed a good agreement with those obtained using a more conventional sample preparation procedure previously validated in our laboratory (recoveries, as compared to levels determined using the latter method, were in the 85-123% range for a large majority of the studied congeners, and the relative standard deviations were in general lower than 14%). Results obtained for the analysis of reference food samples and certified reference materials NIST 1945 and 1947 demonstrated that, when combined with gas chromatography coupled to ion trap mass spectrometry working in the tandem mode, GC-ITD(MS/MS), the proposed methodology allowed accurate determination of most of the investigated PCBs and that 50 mg of sample sufficed for the screening of less abundant toxic congeners.

  15. Development of a double sandwich fluorescent ELISA to detect rattlesnake venom in biological samples from horses with a clinical diagnosis of rattlesnake bite.

    PubMed

    Gilliam, Lyndi L; Ownby, Charlotte L; McFarlane, Dianne; Canida, Amy; Holbrook, Todd C; Payton, Mark E; Krehbiel, Clinton R

    2013-10-01

    Rattlesnake bites in horses are not uncommon and the clinical outcomes are widely variable. Treatment of horses with anti-venom is often cost prohibitive and could have negative consequences; therefore, the development of a quantitative test to determine if anti-venom therapy is indicated would be valuable. The objective of this study was to develop an ELISA to detect rattlesnake venom in biological samples from clinically bitten horses. Nineteen horses were enrolled in the study. Urine was available from 19 horses and bite site samples were available from 9 horses. A double sandwich fluorescent ELISA was developed and venom was detected in 5 of 9 bite site samples and 12 of 19 urine samples. In order to determine if this assay is useful as a guide for treatment, a correlation between venom concentration and clinical outcome needs to be established. For this, first peak venom concentration needs to be determined. More frequent, consistent sample collection will be required to define a venom elimination pattern in horses and determine the ideal sample collection time to best estimate the maximum venom dose. This report describes development of an assay with the ability to detect rattlesnake venom in the urine and at the bite site of horses with a clinical diagnosis of rattlesnake bite.

  16. El Programa Nacional de Estuarios (NEP)

    EPA Pesticide Factsheets

    Información general sobre el Programa Nacional de Estuarios (PNE, por sus siglas en inglés) establecido en el 1987 para restaurar y proteger los estuarios significativos para Estados Unidos, y sus territorios. La Agencia de Protección Ambiental de EE.UU.

  17. [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.

  18. Quantitative Conformationally Sampled Pharmacophore (CSP) for δ Opioid Ligands: Reevaluation of hydrophobic moieties essential for biological activity

    PubMed Central

    Bernard, Denzil; Coop, Andrew; MacKerell, Alexander D.

    2008-01-01

    Recent studies have indicated several therapeutic applications for δ opioid agonists and antagonists. To exploit the therapeutic potential of δ opioids developing a structural basis for the activity of ligands at the δ opioid receptor is essential. The conformationally sampled pharmacophore (CSP) method (Bernard et al., JACS, 125: 3103–3107, 2003) is extended here to obtain quantitative models of δ opioid ligand efficacy and affinity. Quantification is performed via overlap integrals of the conformational space sampled by ligands with respect to a reference compound. Iterative refinement of the CSP model identified hydrophobic groups other than the traditional phenylalanine residues as important for efficacy and affinity in DSLET and ICI 174,864. The obtained models for a structurally diverse set of peptidic and non-peptidic δ opioid ligands offer good predictions with R2 values > 0.9 and the predicted efficacy for a set of test compounds was consistent with the experimental value. PMID:17367120

  19. 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

  20. Enzyme-Linked Immunosorbant Assays for Identification of Biological Agents in Sample Unknowns: NATO SIBCA. Exercise 5

    DTIC Science & Technology

    2004-12-01

    des organismes irradi6 par des rayons gamma Bacillus anthracis, Yersinia pestis. Brucella melitensis , Francisella tularensis, Vibrio cholerae... Brucella melitensis , VEE virus, Burkholderia mallei, Vaccinia virus, and Yellow fever virus were used to screen SIBCA samples for homologous agents...cholerae, Brucella melitensis , le virus EEV, Burkholderia mnallei, le virus de la vaccine et le virus de la fi~vre jaune ont k6 utilis~es pour analyser les

  1. 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.

  2. 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

  3. Liquid scintillation based quantitative measurement of dual radioisotopes (3H and 45Ca) in biological samples for bone remodeling studies.

    PubMed

    Hui, Susanta K; Sharma, M; Bhattacharyya, M H

    2012-01-01

    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 (3)H-tetracycline ((3)H-TC) and (45)Ca as markers of bone turnover in mice. Individual samples were prepared over a wide range of known (45)Ca/(3)H activity ratios. Results showed that (45)Ca/(3)H 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 (45)Ca/(3)H activity ratios in range of 2-10 (percentage difference ∼20-30%). Urine and fecal samples from mice administered with both (3)H-TC and (45)Ca were analyzed with the dual-label method. Positive correlations between (3)H and (45)Ca in urine (R=0.93) and feces (R=0.83) indicate that (3)H-TC and (45)Ca can be interchangeably used to monitor longitudinal in vivo skeletal remodeling.

  4. Determination of the molecular weight of poly(ethylene glycol) in biological samples by reversed-phase LC-MS with in-source fragmentation.

    PubMed

    Warrack, Bethanne M; Redding, Brian P; Chen, Guodong; Bolgar, Mark S

    2013-05-01

    PEGylation has been widely used to improve the biopharmaceutical properties of therapeutic proteins and peptides. Previous studies have used multiple analytical techniques to determine the fate of both the therapeutic molecule and unconjugated poly(ethylene glycol) (PEG) after drug administration. A straightforward strategy utilizing liquid chromatography-mass spectrometry (LC-MS) to characterize high-molecular weight PEG in biologic matrices without a need for complex sample preparation is presented. The method is capable of determining whether high-MW PEG is cleaved in vivo to lower-molecular weight PEG species. Reversed-phase chromatographic separation is used to take advantage of the retention principles of polymeric materials whereby elution order correlates with PEG molecular weight. In-source collision-induced dissociation (CID) combined with selected reaction monitoring (SRM) or selected ion monitoring (SIM) mass spectrometry (MS) is then used to monitor characteristic PEG fragment ions in biological samples. MS provides high sensitivity and specificity for PEG and the observed retention times in reversed-phase LC enable estimation of molecular weight. This method was successfully used to characterize PEG molecular weight in mouse serum samples. No change in molecular weight was observed for 48 h after dosing.

  5. 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.

  6. Systematic approach to optimize a pretreatment method for ultrasensitive liquid chromatography with tandem mass spectrometry analysis of multiple target compounds in biological samples.

    PubMed

    Togashi, Kazutaka; Mutaguchi, Kuninori; Komuro, Setsuko; Kataoka, Makoto; Yamazaki, Hiroshi; Yamashita, Shinji

    2016-08-01

    In current approaches for new drug development, highly sensitive and robust analytical methods for the determination of test compounds in biological samples are essential. These analytical methods should be optimized for every target compound. However, for biological samples that contain multiple compounds as new drug candidates obtained by cassette dosing tests, it would be preferable to develop a single method that allows the determination of all compounds at once. This study aims to establish a systematic approach that enables a selection of the most appropriate pretreatment method for multiple target compounds without the use of their chemical information. We investigated the retention times of 27 known compounds under different mobile phase conditions and determined the required pretreatment of human plasma samples using several solid-phase and liquid-liquid extractions. From the relationship between retention time and recovery in a principal component analysis, appropriate pretreatments were categorized into several types. Based on the category, we have optimized a pretreatment method for the identification of three calcium channel blockers in human plasma. Plasma concentrations of these drugs in a cassette-dose clinical study at microdose level were successfully determined with a lower limit of quantitation of 0.2 pg/mL for diltiazem, 1 pg/mL for nicardipine, and 2 pg/mL for nifedipine.

  7. 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

  8. Rapid ionic liquid-based ultrasound assisted dual magnetic microextraction to preconcentrate and separate cadmium-4-(2-thiazolylazo)-resorcinol complex from environmental and biological samples.

    PubMed

    Khan, Sumaira; Kazi, Tasneem Gul; Soylak, Mustafa

    2014-04-05

    A rapid and innovative microextraction technique named as, ionic liquid-based ultrasound-assisted dual magnetic microextraction (IL-UA-DMME) was developed for the preconcentration and extraction of trace cadmium from environmental and biological samples, prior to analyzed by flame atomic absorption spectrometry (FAAS). The proposed method has many obvious advantages, including evading the use of organic solvents and achieved high extraction yields by the combination of dispersive liquid-liquid microextraction (DLLME) and magnetic mediated-solid phase extraction (MM-SPE). In this approach ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] play an important role to extract the cadmium-4-(2-thiazolylazo)-resorcinol (Cd-TAR) complex from acid digested sample solutions and ultrasonic irradiation was applied to assist emulsification. After then, dispersed small amount of Fe3O4 magnetic nanoparticles (MNPs) in sample solutions to salvaged the IL and complete phase separation was attained. Some analytical parameters that influencing the efficiency of proposed (IL-UA-DMME) method, such as pH, volume of IL, ligand concentration, ultra-sonication time, amount of Fe3O4 MNPs, sample volume and matrix effect were optimized. Limit of detection (LOD) and enrichment factor (EF) of the method under optimal experimental conditions were found to be 0.40μgL(-1) and 100, respectively. The relative standard deviation (RSD) of 50μgL(-1) Cd was 4.29%. The validity and accuracy of proposed method, was assessed to analyzed certified reference materials of fortified lake water TMDA-54.4, SPS-WW2 waste water, spinach leaves 1570a and also checked by standard addition method. The obtained values showed good agreement with the certified values and sufficiently high recovery were found in the range of 98.1-101% for Cd. The proposed method was facile, rapid and successfully applied for the determination of Cd in environmental and different biological samples.

  9. 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

  10. 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.

  11. Analysis of 11-nor-9-carboxy-delta(9)-tetrahydrocannabinol in biological samples by gas chromatography tandem mass spectrometry (GC/MS-MS).

    PubMed

    Chiarotti, M; Costamagna, L

    2000-10-09

    Gas chromatography tandem mass spectrometry (GC/MS-MS) analysis of 11-nor-carboxy-delta(9)-tetrahydrocannabinol (delta(9)-THC-COOH), the major metabolite of delta(9)-tetrahydrocannabinol, in biological samples is reported. The proposed method, using deuterated delta(9)-THC-COOH as an internal standard, is able to detect the major metabolite of cannabis derivatives at very low levels (picograms/millilitre) with high specificity. These characteristics render the proposed analytical procedure suitable for confirmatory analysis in drug testing for cannabis use.

  12. Computer-aided analysis of signals from a low-coherence Fabry-Perot interferometer used for measurements of biological samples

    NASA Astrophysics Data System (ADS)

    Mrotek, Marcin; Pluciński, Jerzy; Jedrzejewska-Szczerska, Małgorzata

    2016-09-01

    The aim of the study was to develop an automated computer-aided system for analysis of spectrograms obtained from measurements of biological samples performed with a low-coherence Fabry-Pérot interferometer. Information necessary to determine dispersion characteristics of measured materials can be calculated from the positions of the maxima and minima that are present in their spectra. The main challenge faced during the development of the system was reliable detection of these maxima and minima in the presence of noise, without requiring substantial user interaction, and with an acceptable computational complexity.

  13. 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.

  14. Dual-column cation-exchange chromatographic method for beta-aminoisobutyric acid and beta-alanine in biological samples.

    PubMed

    Kuo, K C; Cole, T F; Gehrke, C W; Waalkes, T P; Borek, E

    1978-08-01

    A rapid, automated chromatographic method has been developed for the quantitation of the nucleic acid catabolites beta-aminoisobutyric acid and beta-alanine in urine, serum, and other physiological fluids. The analyses were performed on a modified Beckman 121M amino acid analyzer with dual ion-exchange columns and the use of a single sodium citrate buffer (pH 4.38, 0.20 mol/liter). By carefully matching the elution pattern for the two ion-exchange columns and alternating use of these columns, analyses are completed every 40 min. The chromatography, regeneration, and equilibration of the two columns are precisely programmed, thus the detector sees only the elution of beta-aminoisobutyric acid and beta-alanine alternately from each column. Long-term precision and analytical recovery for the two metabolites in urine were 1.9 and 102%, and 3.3 and 101%, respectively. Their normal physiological values were determined in human serum and urine. Their excretion in the urine was also studied as a function of collection time, to validate a more convenient, less costly method of sampling. This study shows that randomly collected samples are acceptable when the concentration of the two metabolites are expressed in terms of creatinine excretion. In addition, the distribution of the free and conjugated forms of the two metabolites in urine and serum was studied. A preparative method was also developed for the quantitative isolation of beta-amino-isobutyric acid from urine samples. The alternating dual-column technique may be applied to any ion-exchange chromatographic method where many analyses must be performed. This method is currently used in our laboratories for measuring these beta-amino acids in urine and serum of patients with various types of cancers.

  15. Microwave-assisted digestion followed by parallel electromembrane extraction for trace le