Sample records for fluorescent dye staining

  1. Simultaneous staining with three fluorescent dyes of minute plankters on an agarose gel filter

    NASA Astrophysics Data System (ADS)

    Hara, Shigemitsu; Tanoue, Eiichiro

    1989-11-01

    A new method, employing an agarose gel filter and triple staining with fluorescent dyes, was developed for observation and enumeration of planktonic microorganisms (0.2-20 ?m in size range) from a variety of niches in the marine ecosystem. Dansyl chloride was used to stain the cell-surface proteins, Calcofluor white was used to stain cellulose and chitin, and DAPI was used to stain DNA. The stained specimens also could be examined by transmission light microscopy.

  2. Heterogeneous staining: a tool for studies of how fluorescent dyes affect the physical properties of DNA

    PubMed Central

    Nyberg, Lena; Persson, Fredrik; Ĺkerman, Björn; Westerlund, Fredrik

    2013-01-01

    The commonly used fluorescent dye YOYO-1 (YOYO) has, using bulk techniques, been demonstrated to stain DNA heterogeneously at substoichiometric concentrations. We here, using nanofluidic channels and fluorescence microscopy, investigate the heterogeneous staining on the single DNA molecule level and demonstrate that the dye distribution is continuous. The equilibration of YOYO on DNA is extremely slow but can be accelerated by increasing the ionic strength and/or the temperature. Furthermore, we demonstrate how to use the heterogeneous staining as a tool for detailed and time-efficient studies of how fluorescent dyes affect the physical properties of DNA. We show that the relative increase in extension of DNA with increasing amount of YOYO bound is higher at low ionic strengths and also extrapolate the extension of native DNA. Our study reveals important information on how YOYO affects the physical properties of DNA, but it also has broader applications. First, it reveals how cationic intercalators, such as potential DNA drugs, affect DNA under strong confinement. Second, the strategy of using heterogeneous staining is of general use for single molecule studies of DNA interacting with proteins or ligands. PMID:23975199

  3. Fluorescent staining of gels.

    PubMed

    Buxbaum, Engelbert

    2012-01-01

    Certain transition metal complexes show intensive fluorescence when bound to proteins. They can be used to stain gels after electrophoresis with a sensitivity approaching that of silver staining, but in a much simpler and more reproducible procedure. Stains can be prepared easily and at a fraction of the cost of commercially available reagents.Hydrophobic dyes can be used to stain gels without fixing; they do not interfere with later blotting or electro-elution. PMID:22585519

  4. Development of Pathological Diagnostics of Human Kidney Cancer by Multiple Staining Using New Fluorescent Fluolid Dyes

    PubMed Central

    Wuxiuer, Dilibaier; Zhu, Yun; Ogaeri, Takunori; Mizuki, Keiji; Kashiwa, Yuki; Nishi, Kentaro; Isobe, Shin-ichiro; Aoyagi, Tei-ichiro; Kiyama, Ryoiti

    2014-01-01

    New fluorescent Fluolid dyes have advantages over others such as stability against heat, dryness, and excess light. Here, we performed simultaneous immunostaining of renal tumors, clear cell renal cell carcinoma (RCC), papillary RCC, chromophobe RCC, acquired cystic disease-associated RCC (ACD-RCC), and renal angiomyolipoma (AML), with primary antibodies against Kank1, cytokeratin 7 (CK7), and CD10, which were detected with secondary antibodies labeled with Fluolid-Orange, Fluolid-Green, and Alexa Fluor 647, respectively. Kank1 was stained in normal renal tubules, papillary RCC, and ACD-RCC, and weakly or negatively in all other tumors. CK7 was positive in normal renal tubules, papillary RCC, and ACD-RCC. In contrast, CD10 was expressed in renal tubules and clear cell RCC, papillary RCC, AML, and AC-RCC, and weakly in chromophobe RCC. These results may contribute to differentiating renal tumors and subtypes of RCCs. We also examined the stability of fluorescence and found that fluorescent images of Fluolid dyes were identical between a tissue section and the same section after it was stored for almost three years at room temperature. This indicates that tissue sections can be stored at room temperature for a relatively long time after they are stained with multiple fluorescent markers, which could open a door for pathological diagnostics. PMID:24995295

  5. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and chemical solution stains for...purposes are mixtures of synthetic or natural dyes or nondye chemicals in...

  6. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

  7. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

  8. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

  9. 21 CFR 864.1850 - Dye and chemical solution stains.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

  10. Nile red: a selective fluorescent stain for intracellular lipid droplets

    Microsoft Academic Search

    PHILLIP GREENSPAN; EUGENE P. MAYER; STANLEY D. FOWLER

    1985-01-01

    We report that the dye nile red, 9-diethylamino-5H-benzo(a)phenoxazine-5-one, is an excellent vital stain for the detection of intracellular lipid droplets by fluorescence microscopy and flow cytofluorometry. The specificity of the dye for lipid droplets was assessed on cultured aortic smooth muscle cells and on cultured peritoneal macrophages that were incubated with acetylated low density lipoprotein to induce cytoplasmic lipid overloading.

  11. Fiberized fluorescent dye microtubes

    NASA Astrophysics Data System (ADS)

    Vladev, Veselin; Eftimov, Tinko

    2013-03-01

    In the present work we study the effect of the length of fluorescent dye-filled micro-capillaries on the fluorescence spectra. Two types of micro-capillaries have been studied: a 100 ?m inner diameter fused silica capillary with a transparent coating and one of the holes of a fiber optic glass ferrule with 125 ?m inner diameter. The tubes were filled with solutions of Rhodamine 6G dissolved in ethanol and then in glycerin. Experimental data show that the maximum fluorescence and the largest spectral widths are observed for a sample length of about 0.25 mm for the used concentration. This results show that miniature tunable fiberized dye lasers can be developed using available standard micro-and fibre-optic components.

  12. SYPRO Orange and SYPRO Red Protein Gel Stains: One-Step Fluorescent Staining of Denaturing Gels for Detection of Nanogram Levels of Protein

    Microsoft Academic Search

    Thomas H. Steinberg; Laurie J. Jones; Richard P. Haugland; Victoria L. Singer

    1996-01-01

    We have developed two new fluorescent dyes, SYPRO Orange protein gel stain and SYPRO Red protein gel stain, to detect proteins in electrophoretic gels. Stained protein bands can be excited by ultraviolet light at ?300 nm, or at visible wavelengths, with excitation maxima of 472 nm for the Orange stain and 547 nm for the Red stain. Detection can be

  13. Storable, thermally activated, near-infrared chemiluminescent dyes and dye-stained microparticles for optical imaging

    PubMed Central

    Baumes, Jeffrey M.; Gassensmith, Jeremiah J.; Giblin, Jay; Lee, Jung-Jae; White, Alexander G.; Culligan, William J.; Leevy, W. Matthew; Kuno, Masaru; Smith, Bradley D.

    2011-01-01

    Optical molecular imaging employs relatively harmless, low-energy light and technically straightforward instrumentation. Self-illuminating, chemiluminescent systems are especially attractive since they have inherently high signal contrast due to the lack of background emission. Currently, chemiluminescence imaging involves short-lived molecular species that are not stored but instead generated in situ, and they typically emit visible light, which does not penetrate far through heterogeneous biological media. Here, we describe a new paradigm for optical molecular imaging using squaraine rotaxane endoperoxides (SREPs), interlocked fluorescent and chemiluminescent dye molecules that have a squaraine chromophore encapsulated inside a macrocycle endoperoxide. SREPs can be stored indefinitely at temperatures below ?20 °C, but upon warming to body temperature they undergo a unimolecular chemical reaction and emit near infrared light that can pass through a living mouse. Dye-stained microparticles are easily prepared for in vivo near-infrared optical imaging using commercial imaging stations. PMID:21107365

  14. Nuclear stains with soluble metachrome metal mordant dye lakes

    Microsoft Academic Search

    R. D. Lillie; P. Pizzolato; P. T. Donaldson

    1976-01-01

    Following our study on the effect of deoxyribonucleic acid (DNA) extraction on nuclear staining with soluble metal mordant dye lakes covering 29 dye lakes we chose a series of lakes representing the three groups: (1) readily prevented by DNA removal, (2) weakened by DNA extraction but not prevented, (3) unaffected by DNA removal, for application of other endgroup blockade reactions.

  15. Development of an affordable dye-stained microalbuminuria screening test

    Microsoft Academic Search

    Pierrot Lundimu Tugirimana; Joris R. Delanghe

    2008-01-01

    Background. A simple spot test was developed, which al- lows quantification of microalbuminuria. Evaluation was carried out according to the ISO 15189 guidelines. Methods. Urine was spotted on cellulose acetate strips and stained using different sensitive protein binding dyes (ni- grosin, Coomassie Blue R-250, amido black). The colour intensity of the stained spots was quantified using a Kodak Image 450

  16. Simple and Specific Dual-Wavelength Excitable Dye Staining for Glycoprotein Detection in Polyacrylamide Gels and Its Application in Glycoproteomics

    PubMed Central

    Chiang, Yu-Hsuan; Wu, Yu-Jen; Lu, Ya-Ting; Chen, Kuan-Hung; Lin, Tzu-Chun; Chen, Yu-Kuang H.; Li, Ding-Tzai; Shi, Fong-Ku; Chen, Ching-Chuan; Hsu, Jue-Liang

    2011-01-01

    In this study, a commercially available fluorescent dye, Lissamine rhodamine B sulfonyl hydrazine (LRSH), was designed to specifically stain the glycoproteins in polyacrylamide gels. Through the periodate/Schiff base mechanism, the fluorescent dye readily attaches to glycoproteins and the fluorescence can be simultaneously observed under either 305?nm or 532?nm excitation therefore, the dye-stained glycoproteins can be detected under a regular UV transilluminator or a more elegant laser-based gel scanner. The specificity and detection limit were examined using a standard protein mixture in polyacrylamide gels in this study. The application of this glycoprotein stain dye was further demonstrated using pregnancy urine samples. The fluorescent spots were further digested in gel and their identities confirmed through LC-MS/MS analysis and database searching. In addition, the N-glycosylation sites of LRSH-labeled uromodulin were readily mapped via in-gel PNGaseF deglycosylation and LC-MS/MS analysis, which indicated that this fluorescent dye labeling does not interfere with enzymatic deglycosylation. Hence, the application of this simple and specific dual-wavelength excitable dye staining in current glycoproteome research is promising. PMID:21976968

  17. Dimeric fluorescent energy transfer dyes comprising asymmetric cyanine azole-indolenine chromophores

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Albany, CA)

    1996-01-01

    Novel fluorescent DNA-staining dyes are provided combining asymmetric cyanine azole-indolenine dyes, which provide for strong DNA affinity, large Stokes shifts and emission in the red region of the spectrum. The dyes find particular application in gel electrophoresis and for labels which may be bound to a variety of compositions in a variety of contexts.

  18. The development of a nucleus staining fluorescent probe for dynamic mitosis imaging in live cells.

    PubMed

    Ghosh, Krishna Kanta; Jeong, Yun-Mi; Kang, Nam-Young; Lee, JungYeol; Si Yan Diana, Wan; Kim, Jun-Young; Yoo, Jaeduk; Kim, Dohee; Kim, Yun Kyung; Chang, Young-Tae

    2015-05-21

    A low-toxicity nucleus staining fluorescent probe, , was developed for real time mitosis imaging in live cells. was identified by unbiased high-throughput imaging-based screening of a new xanthone library (AX). Unlike the conventional Hoechst dye, the low toxicity of allows long term monitoring of cell division over more than one cell cycle. PMID:25960154

  19. Changes in absorption, fluorescence, dichroism, and birefringence in stained giant axons: Optical measurement of membrane potential

    Microsoft Academic Search

    W. N. Ross; B. M. Salzberg; L. B. Cohen; A. Grinvald; H. V. Davila; A. S. Waggoner; C. H. Wang

    1977-01-01

    Summary The absorption, fluorescence, dichroism, and birefringence of stained squid axons were measured during action potentials and voltage clamp steps in an effort to find large optical signals that could be used to monitor membrane potential. Changes in all four optical properties were found that were linearly related to membrane potential and, with several new dyes, the signal-to-noise ratios were

  20. Evaluation of optimal DNA staining for triggering by scanning fluorescence microscopy (SFM)

    NASA Astrophysics Data System (ADS)

    Mittag, Anja; Marecka, Monika; Pierzchalski, Arkadiusz; Malkusch, Wolf; Bocsi, József; Tárnok, Attila

    2009-02-01

    In imaging and flow cytometry, DNA staining is a common trigger signal for cell identification. Selection of the proper DNA dye is restricted by the hardware configuration of the instrument. The Zeiss Imaging Solutions GmbH (München, Germany) introduced a new automated scanning fluorescence microscope - SFM (Axio Imager.Z1) which combines fluorescence imaging with cytometric parameters measurement. The aim of the study was to select optimal DNA dyes as trigger signal in leukocyte detection and subsequent cytometric analysis of double-labeled leukocytes by SFM. Seven DNA dyes (DAPI, Hoechst 33258, Hoechst 33342, POPO-3, PI, 7-AAD, and TOPRO-3) were tested and found to be suitable for the implemented filtersets (fs) of the SFM (fs: 49, fs: 44, fs: 20). EDTA blood was stained after erythrocyte lysis with DNA dye. Cells were transferred on microscopic slides and embedded in fluorescent mounting medium. Quality of DNA fluorescence signal as well as spillover signals were analyzed by SFM. CD45-APC and CD3-PE as well as CD4-FITC and CD8-APC were selected for immunophenotyping and used in combination with Hoechst. Within the tested DNA dyes DAPI showed relatively low spillover and the best CV value. Due to the low spillover of UV DNA dyes a triple staining of Hoechst and APC and PE (or APC and FITC, respectively) could be analyzed without difficulty. These results were confirmed by FCM measurements. DNA fluorescence is applicable for identifying and triggering leukocytes in SFM analyses. Although some DNA dyes exhibit strong spillover in other fluorescence channels, it was possible to immunophenotype leukocytes. DAPI seems to be best suitable for use in the SFM system and will be used in protocol setups as primary parameter.

  1. Specific In Vivo Staining of Astrocytes in the Whole Brain after Intravenous Injection of Sulforhodamine Dyes

    PubMed Central

    Appaix, Florence; Girod, Sabine; Boisseau, Sylvie; Römer, Johannes; Vial, Jean-Claude; Albrieux, Mireille; Maurin, Mathieu; Depaulis, Antoine; Guillemain, Isabelle; van der Sanden, Boudewijn

    2012-01-01

    Fluorescent staining of astrocytes without damaging or interfering with normal brain functions is essential for intravital microscopy studies. Current methods involved either transgenic mice or local intracerebral injection of sulforhodamine 101. Transgenic rat models rarely exist, and in mice, a backcross with GFAP transgenic mice may be difficult. Local injections of fluorescent dyes are invasive. Here, we propose a non-invasive, specific and ubiquitous method to stain astrocytes in vivo. This method is based on iv injection of sulforhodamine dyes and is applicable on rats and mice from postnatal age to adulthood. The astrocytes staining obtained after iv injection was maintained for nearly half a day and showed no adverse reaction on astrocytic calcium signals or electroencephalographic recordings in vivo. The high contrast of the staining facilitates the image processing and allows to quantify 3D morphological parameters of the astrocytes and to characterize their network. Our method may become a reference for in vivo staining of the whole astrocytes population in animal models of neurological disorders. PMID:22509398

  2. Usefulness of visible dyes for the staining of protein or DNA in electrophoresis.

    PubMed

    Jin, Li-Tai; Choi, Jung-Kap

    2004-08-01

    Since 1993, we have studied visible organic dye stains for protein or DNA to improve methodologies and developed the counterion dye staining method. The method employs two oppositely charged dyes that form an ion-pair complex in the staining solution. The selective binding of free dye to protein or DNA in the staining solution improves detection sensitivity and speed. It is a rapid and sensitive procedure, involving fixing/staining or staining/quick destaining steps that are completed in 1-1.5 h. The lowest detection limits achieved are 4-8 ng of protein on polyacrylamide gels and approximately 10 ng of DNA on agarose gels. The focus of this review is to chronicle the development and current status of the counterion dye staining method for detection of protein or DNA. As an extended application of visible dyes, we also discuss the visible dye staining method for detecting protein on blotting membranes developed in our laboratory. PMID:15300759

  3. Fluorescent staining for leukocyte chemotaxis. Eosinophil-specific fluorescence with aniline blue.

    PubMed

    McCrone, E L; Lucey, D R; Weller, P F

    1988-11-10

    To overcome problems associated with the quantitation of human eosinophil chemotaxis in micropore filters, we have developed a fluorescent method of specifically staining eosinophils in chemotactic filters. A neutral solution of aniline blue yielded bright green fluorescent staining of the cytoplasmic granules of eosinophils. Other leukocytes and contaminating neutrophils potentially present with eosinophils did not fluoresce with aniline blue. The fluorescent staining eosinophils within filters provided bright, non-fading images that facilitated visual microscopic counting and were of sufficiently high contrast, unlike those with conventional eosinophil stains, to allow image analyzer based enumeration of eosinophil chemotactic responses at levels through the filters. Although not cell type-specific, congo red and ethidium bromide also provided high contrast, fluorescent images of all leukocyte types within chemotactic filters. Fluorescent staining with aniline blue constitutes a rapid, stable and eosinophil-specific stain that facilitates the visual or image analyzer-based quantitation of eosinophil chemotaxis. PMID:2460564

  4. Rapid and easy protein staining for SDS-PAGE using an intramolecular charge transfer-based fluorescent reagent.

    PubMed

    Suzuki, Yoshio; Yokoyama, Kenji; Namatame, Ichiji

    2006-09-01

    High-performance staining for 1-D and 2-D SDS-PAGE was carried out using a novel protein-binding fluorophore (Dye 1), which noncovalently interacts with proteins and provides a fluorescence emission response to proteins by intramolecular charge transfer. In order to achieve the high-throughput analysis of proteins for SDS-PAGE, the general protocols for in-gel protein staining (SDS-PAGE, fixation, staining, washing, and detection) were simplified to produce an easy and rapid protocol (SDS-PAGE together with staining, washing, and detection). This method was performed by preparation of an electrophoresis buffer containing Dye 1 under optimum conditions, and by the binding of Dye 1 to proteins in the gel during the SDS-PAGE. As a result, this study required only 15 min for protein staining as a minimum time. On the other hand, it takes several hours for the general protein staining method, such as SYPRO Ruby staining (18 h) and CBB staining (105 min). Moreover, the protein-to-protein variation was low, and the detection limit was 7.0 ng/band of BSA (S/N = 3.0) in this method, which was as sensitive as the short-protocol silver staining methods. On the basis of these results, this rapid and easy protocol for SDS-PAGE using Dye 1 may be widely applicable and convenient for users in the various scientific and medical fields. PMID:16944465

  5. The Relative Location of the Dye Staining Endpoint Indicated With Polypropylene Glycol-Based Caries Dye versus Conventional Propylene Glycol-Based Caries Dye

    PubMed Central

    Boston, Daniel W; Jefferies, Steven R; Gaughan, John P

    2008-01-01

    Objectives This study determined the difference in the location of the caries dye staining endpoint of 1% Acid Red dye in propylene glycol versus that of 1% Acid Red dye in polypropylene glycol. Methods Freshly extracted permanent molar crowns with primary occlusal carious lesions were chisel-split axially to expose the lesion in cross-section on both halves. One half was stained with propylene glycol-based dye and the other with polypropylene glycol-based dye. For the control group, both halves were stained with propylene glycol-based dye. The dye staining front was marked on digital images of the stained split surfaces, and the images were aligned using reference notches. The distance between the marked staining front lines was measured in five locations, and the measurement protocol was repeated. Weighted averages and a 95% confidence interval for the distance between marked staining front lines were calculated for the control and experimental groups. Results The weighted average distance for the experimental group (0.298 mm, 95% confidence interval 0.240 mm – 0.357 mm) was about four times that of the control group (0.070 mm, 95% confidence interval 0.051 mm – 0.089 mm). Generally, the marked staining line for the polypropylene glycol-based dye specimens was located shallow (occlusal) to the propylene glycol-based staining line (range ?0.12 mm to 0.66 mm). Conclusions The staining endpoint of 1% Acid Red dye in polypropylene glycol is shallower than that of 1% Acid Red dye in propylene glycol. The method is useful for comparing staining endpoints of caries dye formulations. (Eur J Dent 2008;2:29–36) PMID:19212506

  6. Fluorescent indicator dyes for calcium ions

    NASA Technical Reports Server (NTRS)

    Tsien, Roger Y. (Inventor); Grynkiewicz, Grzegorz (Inventor)

    1986-01-01

    The present invention discloses a new class of highly fluorescent indicator dyes that are specific for calcium ions. The new fluorescent indicator dyes combine a stilbene-type fluorophore with a tetracarboxylate parent Ca.sup.2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of EGTA and BAPTA. Preferred forms contain extra heterocyclic bridges to reinforce the ethylenic bond of the stilbene and to reduce hydrophobicity. Compared to their widely used predecessor, quin2, the new dyes offer up to thirty-fold brighter fluorescence, major changes in wavelength (not just intensity) upon Ca.sup.2+ binding, slightly lower affinities for Ca.sup.2+, slightly longer wavelengths of excitation, and considerably improved selectivity for Ca.sup.2+ over other divalent cations. These properties, particularly the wavelength sensitivity to Ca.sup.2+, make the dyes useful indicators for many intracellular applications, especially in single cells, adherent cell layers, or bulk tissues. The present invention also discloses an improved method for synthesizing alpha-acyloxyalkyl bromides wherein the bromides so synthesized are free of contaminating bis(1-bromoalkyl)ether. The improved method is exemplified herein in the synthesis of acetoxymethyl bromide, a compound useful in preparing the acetoxymethyl esters disclosed herein as novel Ca.sup.2+ specific fluorescent indicators.

  7. Vital staining from dye-coated microprobes identifies new olfactory interneurons for optical and electrical recording.

    PubMed

    Gelperin, A; Flores, J

    1997-03-01

    A versatile technique for dye application in living tissue is described, which results in labeling of viable cells from which electrophysiological or optical recordings can be obtained. The dye-coated surface of a glass microelectrode tip is used to apply anatomical tracers or calcium sensitive probes with spatial precision. A total of three types of dyes have been applied in this way to find and record from olfactory interneurons in the terrestrial mollusc Limax maximus. Crystals of 1,1'-didodecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) formed on the tips of glass microelectrodes were placed in the procerebral lobe, the major olfactory processing center of Limax. Somata in buccal and pedal ganglia with processes extending several 100 microm to the procerebral lobe were stained within 4-6 h. Intracellular recordings from DiI stained buccal (B(PC)) and pedal (P(PC)) cells were obtained. Cross correlograms of the oscillatory field potential in the procerebral lobe and spontaneous action potentials in P(PC) or B(PC) show that P(PC) activity is weakly coupled to the oscillation in the procerebral lobe, while B(PC) activity is clearly coupled to the oscillation. Stimulation of the procerebral lobe with nitric oxide activated P(PC) cells but suppressed activity in B(PC) cells. Calcium green-10Kdextran coated electrodes were used to place calcium green in the cell body layer of the procerebral lobe. Bursting and nonbursting procerebral neurons incorporated and transported the calcium green-dextran. Optical recordings of changes in fluorescence signals from several bursting cells recorded simultaneously were used to test alternative mechanisms of bursting cell coupling. Application of biotin 3Kdextran to the midline of the cerebral ganglion revealed a group of cells in each procerebral lobe with processes crossing the midline of the cerebral ganglion. These cells may couple right and left procerebral lobe activity during odor processing. PMID:9128173

  8. Energy transfer and binding competition between dyes used to enhance staining differentiation in metaphase chromosomes

    Microsoft Academic Search

    Elhanan Sahar; Samuel A. Latt

    1980-01-01

    The ability of electronic energy transfer and direct binding competition between pairs of dyes to enhance contrast in human or bovine metaphase chromosome staining patterns is illustrated, and the relative effectiveness of these two mechanisms compared. The existence of energy transfer between quinacrine or 33258 Hoechst and 7-amino-actinomycin D in doubly stained chromosomes is demonstrated directly by microfluorometry. The ability

  9. Specific In Vivo Staining of Astrocytes in the Whole Brain after Intravenous Injection of Sulforhodamine Dyes

    E-print Network

    Paris-Sud XI, Université de

    Specific In Vivo Staining of Astrocytes in the Whole Brain after Intravenous Injection In Vivo Staining of Astrocytes in the Whole Brain after Intravenous Injection of Sulforhodamine Dyes. PLo brain [10,11,12] and has opened a new field of dynamic and functional studies on neuron-astrocytes

  10. Identification of active fluorescence stained bacteria by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Krause, Mario; Beyer, Beatrice; Pietsch, Christian; Radt, Benno; Harz, Michaela; Rösch, Petra; Popp, Jürgen

    2008-04-01

    Microorganisms can be found everywhere e.g. in food both as useful ingredients or harmful contaminations causing food spoilage. Therefore, a fast and easy to handle analysis method is needed to detect bacteria in different kinds of samples like meat, juice or air to decide if the sample is contaminated by harmful microorganisms. Conventional identification methods in microbiology require always cultivation and therefore are time consuming. In this contribution we present an analysis approach to identify fluorescence stained bacteria on strain level by means of Raman spectroscopy. The stained bacteria are highlighted and can be localized easier against a complex sample environment e.g. in food. The use of Raman spectroscopy in combination with chemometrical methods allows the identification of single bacteria within minutes.

  11. DAPI staining and fluorescence microscopy techniques for phytoplasmas.

    PubMed

    Andrade, Nancy M; Arismendi, Nolberto L

    2013-01-01

    The 4',6-diamidino-2-phenylindole (DAPI) stain technique is a simple method that was developed for confirming the presence of phytoplasmas in hand-cut or freezing microtome sections of infected tissues. DAPI binds AT-rich DNA preferentially, so that phytoplasmas, localized among phloem cells, can be visualized in a fluorescence microscope. The procedure is quick, easy to use, inexpensive, and can be used as a preliminary or quantitative method to detect or quantify phytoplasma-like bodies in infected plants. PMID:22987410

  12. An easy method for cutting and fluorescent staining of thin roots

    PubMed Central

    Zelko, Ivan; Lux, Alexander; Sterckeman, Thibault; Martinka, Michal; Kollárová, Karin; Lišková, Desana

    2012-01-01

    Background and Aims Cutting plant material is essential for observing internal structures and may be difficult for various reasons. Most fixation agents such as aldehydes, as well as embedding resins, do not allow subsequent use of fluorescent staining and make material too soft to make good-quality hand-sections. Moreover, cutting thin roots can be very difficult and time consuming. A new, fast and effective method to provide good-quality sections and fluorescent staining of fresh or fixed root samples, including those of very thin roots (such as Arabidopsis or Noccaea), is described here. Methods To overcome the above-mentioned difficulties the following procedure is proposed: fixation in methanol (when fresh material cannot be used) followed by en bloc staining with toluidine blue, embedding in 6 % agarose, preparation of free-hand sections of embedded material, staining with fluorescent dye, and observation in a microscope under UV light. Key Results Despite eventual slight deformation of primary cell walls (depending on the species and root developmental stage), this method allows effective observation of different structures such as ontogenetic changes of cells along the root axis, e.g. development of xylem elements, deposition of Casparian bands and suberin lamellae in endodermis or exodermis or peri-endodermal thickenings in Noccaea roots. Conclusions This method provides good-quality sections and allows relatively rapid detection of cell-wall modifications. Also important is the possibility of using this method for free-hand cutting of extremely thin roots such as those of Arabidopsis. PMID:22419758

  13. Efficacy of Dye-Stained Enteral Formula in Detecting Pulmonary Aspiration

    PubMed Central

    Metheny, Norma A.; Dahms, Thomas E.; Stewart, Barbara J.; Stone, Kathleen S.; Edwards, Sharon J.; Defer, Julie E.; Clouse, Ray E.

    2008-01-01

    Study objective To determine the extent to which a mixture of human gastric juice and enteral formula stained with two concentrations of FD&C Blue No. 1 food dye (0.8 and 1.5 mL/L) is visible in suctioned tracheobronchial secretions following three forced small-volume pulmonary aspirations over a 6-h period in an animal model. Design Experimental 2 × 3 repeated measures. Setting Animal laboratory and an acute care hospital. Participants Ninety New Zealand white rabbits weighing approximately 3 kg each, and 90 acutely ill adults who furnished gastric juice. Interventions A mixture of human gastric juice and enteral formula stained with 0.8 or 1.5 mL of dye per liter was instilled intratracheally over a 30-min period into anesthetized intubated animals at baseline, 2 h, and 4 h. A total of 0.4 mL/kg of the mixture was instilled at each session. Ninety minutes after each instillation, suctioned secretions were examined for visible dye and blood. Measurements and results Dye was visible in 46.3% of the secretions (125 of 270). The concentration of dye had no significant effect on dye visibility. Blood that was present in 114 of 270 of the secretions (42.2%) interfered with dye visibility in all but two secretions. For reasons unknown, even in the absence of blood, dye visibility decreased from 90.2% (55 of 61 secretions) after the first aspiration event to only 61% (25 of 41 secretions) after the third aspiration event. Conclusions Findings from this animal model study do not support the use of the dye method to detect repeated small-volume aspirations. For clinicians who choose to use the dye method in selected situations, it appears that a dye concentration of 0.8 mL/L may be as effective in detecting aspiration as a 1.5 mL/L concentration. PMID:12114370

  14. Investigation of Förster Resonance Energy Transfer (FRET) and Competition of Fluorescent Dyes on DNA Microparticles

    PubMed Central

    Kim, Jieun; Lee, Jae Sung; Lee, Jong Bum

    2015-01-01

    Fluorescent labeling is widely used to investigate the structural stability and changes to DNA nano- and microstructures. Despite this, the conventional method for observing DNA structures has several limitations in terms of cost-efficiency. This paper introduces a DNA spherical particle stained with DNA intercalating dyes (SYBR Green and SYTOX Orange) as tracers and reports the interaction between multiple dyes. The interference between the dyes was analyzed in terms of Förster resonance energy transfer (FRET) and competition. The changes in the fluorescence intensity by FRET were uniform, regardless of the sequence. The competition effect could occur when several dyes were added simultaneously. These properties are expected to help in the design of multicolor tracers in bioimaging and environmental applications. PMID:25856674

  15. Brazilwood, sappanwood, brazilin and the red dye brazilein: from textile dyeing and folk medicine to biological staining and musical instruments.

    PubMed

    Dapson, R W; Bain, C L

    2015-08-01

    Brazilin is a nearly colorless dye precursor obtained from the heartwood of several species of trees including brazilwood from Brazil, sappanwood from Asia and the Pacific islands, and to a minor extent from two other species in Central America, northern South America and the Caribbean islands. Its use as a dyeing agent and medicinal in Asia was recorded in the 2(nd) century BC, but was little known in Europe until the 12(th) century AD. Asian supplies were replaced in the 16(th) century AD after the Portuguese discovered vast quantities of trees in what is now Brazil. Overexploitation decimated the brazilwood population to the extent that it never fully recovered. Extensive environmental efforts currently are underway to re-create a viable, sustainable population. Brazilin is structurally similar to the better known hematoxylin, thus is readily oxidized to a colored dye, brazilein, which behaves like hematein. Attachment of the dye to fabric is by hydrogen bonding or in conjunction with certain metallic mordants by coordinative bonding. For histology, most staining procedures involve aluminum (brazalum) for staining nuclei. In addition to textile dyeing and histological staining, brazilin and brazilein have been and still are used extensively in Asian folk medicine to treat a wide variety of disorders. Recent pharmacological studies for the most part have established a scientific basis for these uses and in many cases have elucidated the biochemical pathways involved. The principal use of brazilwood today is for the manufacture of bows for violins and other stringed musical instruments. The dye and other physical properties of the wood combine to produce bows of unsurpassed tonal quality. PMID:25893688

  16. Staining correction in digital pathology by utilizing a dye amount table.

    PubMed

    Bautista, Pinky A; Yagi, Yukako

    2015-06-01

    The stained colors of the tissue components are popularly used as features for image analysis. However, variations in the staining condition of the histology slides prompt variations to the color distribution of the stained tissue samples which could impact the accuracy of the analysis. In this paper, we present a method to correct the staining condition of a histology image. In the method, a look-up table (LUT) based on the dye amounts absorbed by the sample is built. The LUT can be built when either (i) the source and reference staining conditions are specified or (ii) when the user simply wants to recreate his/her preferred staining condition without specifying any reference slide. The effectiveness of the present method was evaluated in two aspects: (i) CIELAB color difference of nuclei, cytoplasm, and red blood cells, between the ten different slides of liver tissue, and (ii) classification of the different tissue components. Application of the present staining correction method reduced the color difference between the slides by an average factor of 9.8 and the classification performance of a linear discriminant classifier improved by 16.5 % on the average. Results of the paired t test statistical analysis further showed that the reduction in the CIELAB color difference between the slides and the improvement in the classifier's performance when staining correction was implemented is significant at p?

  17. Extrinsic Fluorescent Dyes as Tools for Protein Characterization

    PubMed Central

    Hawe, Andrea; Sutter, Marc

    2008-01-01

    Noncovalent, extrinsic fluorescent dyes are applied in various fields of protein analysis, e.g. to characterize folding intermediates, measure surface hydrophobicity, and detect aggregation or fibrillation. The main underlying mechanisms, which explain the fluorescence properties of many extrinsic dyes, are solvent relaxation processes and (twisted) intramolecular charge transfer reactions, which are affected by the environment and by interactions of the dyes with proteins. In recent time, the use of extrinsic fluorescent dyes such as ANS, Bis-ANS, Nile Red, Thioflavin T and others has increased, because of their versatility, sensitivity and suitability for high-throughput screening. The intention of this review is to give an overview of available extrinsic dyes, explain their spectral properties, and show illustrative examples of their various applications in protein characterization. PMID:18172579

  18. Spectroscopic and fluorescence properties of silver-dye composite nanoparticles

    NASA Astrophysics Data System (ADS)

    Laban, B. B.; Vodnik, V.; Vuja?i?, A.; Sovilj, S. P.; Joki?, A. B.; Vasi?, V.

    2013-12-01

    The aim of this work was to investigate the formation of J-aggregates of thiacyanine dye (TC, 5,5'-disulfopropyl-3,3'-dichlorothiacyanine sodium salt) in the presence of 6 nm spherical silver nanoparticles (Ag NPs) using spectrophotometric and fluorescence methods. The formation of J-aggregates was concentration dependent and characterized by the appearance of the new absorption band with the maximum at 481 nm. Spectrophotometric study of J-aggregate formation and time stability suggested that they were formed on the account of monomer form of TC. Moreover, the stability of J-aggregates increased with the lowering AgNPs concentration. The measurements of fluorescence of the NPs—dye assembly clearly indicated that the fluorescence of TC was quenched by Ag NPs on the concentration dependent manner. The spectrophotometric and fluorescence properties of NPs—dye assembly were found to be quantitatively related to the surface coverage of the dye on the Ag NPs.

  19. Evaluation of a Fluorescent Lectin-Based Staining Technique for Some Acidophilic Mining Bacteria

    PubMed Central

    Fife, Dee Jay; Bruhn, Debby F.; Miller, Karen S.; Stoner, Daphne L.

    2000-01-01

    A fluorescence-labeled wheat germ agglutinin staining technique (R. K. Sizemore et al., Appl. Environ. Microbiol. 56:2245–2247, 1990) was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite and soil particles in the samples did not interfere with the staining procedure. PMID:10788401

  20. Specific DNA duplex formation at an artificial lipid bilayer: fluorescence microscopy after Sybr Green I staining

    PubMed Central

    Werz, Emma

    2014-01-01

    Summary The article describes the immobilization of different probe oligonucleotides (4, 7, 10) carrying each a racemic mixture of 2,3-bis(hexadecyloxy)propan-1-ol (1a) at the 5’-terminus on a stable artificial lipid bilayer composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The bilayer separates two compartments (cis/trans channel) of an optical transparent microfluidic sample carrier with perfusion capabilities. Injection of unlabeled target DNA sequences (6, 8, or 9), differing in sequence and length, leads in the case of complementarity to the formation of stable DNA duplexes at the bilayer surface. This could be verified by Sybr Green I double strand staining, followed by incubation periods and thorough perfusions, and was visualized by single molecule fluorescence spectroscopy and microscopy. The different bilayer-immobilized complexes consisting of various DNA duplexes and the fluorescent dye were studied with respect to the kinetics of their formation as well as to their stability against perfusion. PMID:25298798

  1. High efficiency dye laser with low fluorescence yield pyrromethene dyes: experimental and theoretical studies

    NASA Astrophysics Data System (ADS)

    Jagtap, K. K.; Maity, D. K.; Ray, A. K.; Dasgupta, K.; Ghosh, S. K.

    2011-06-01

    A combined experimental and theoretical study of the photo-physical, laser properties and molecular structures of three relatively recent Pyrromethene (PM) class dyes, PM597, PM580 and PM567, have been carried out. Laser characteristics of these three PM dyes were compared with three other widely used Rhodamine (RH) class dyes, RH6G, RHB and KRS, using a narrow-band dye laser setup, transversely pumped by the second harmonic (532 nm) of a Q-switched Nd-YAG laser. In addition to generating comparative data of these dyes for optimal use in dye lasers, we observed that unlike the RH dyes, the PM dyes show high efficiencies and wide tunability, despite the low fluorescence yield and high rate of non-radiative decay. Particularly, PM597 dye, in spite of a very low quantum yield of fluorescence (?=0.42), high non-radiative decay rate, and a large distortion from planarity in its excited state, when used in a laser cavity it exhibited similar laser efficiency and a beneficially wider tuning curve in comparison to other two PM dyes. Theoretical studies were carried out applying density functional theory and time-dependent density functional theory (DFT/TDDFT) to obtain new information on ground and the first excited state geometrical parameters of the PM dyes. Good correlation between calculated molecular properties and experimental results was observed for the evolution of the longest wavelength absorption maximum.

  2. Noninvasive tissue fluorescence study of a fluorescent dye (calcein) on intraperitoneal glucose administration

    NASA Astrophysics Data System (ADS)

    Devoisselle, Jean-Marie; Mordon, Serge R.; Soulie-Begu, Sylvie

    1995-01-01

    The diagnostic exploitation of fluorescence spectroscopy and imaging has been largely used in experimental and clinical oncology. Only a few studies concern the ability of these techniques to study the in vivo behavior of fluorescent drugs or dyes. We have proposed recently a spectroscopic and imaging method to monitor pH in living tissues using pH-sensitive dyes. The tumor pH was depressed by previous glucose injection. We describe in this study the effect of glucose injection on the pharmacokinetic behavior of a fluorescent dye (calcein) by noninvasive fluorescence spectroscopy.

  3. Visualizing Endocytotic Pathways at Transmission Electron Microscopy via Diaminobenzidine Photo-Oxidation by a Fluorescent Cell-Membrane Dye

    PubMed Central

    Grecchi, S.; Malatesta, M.

    2014-01-01

    The endocytotic pathway involves a complex, dynamic and interacting system of intracellular compartments. PKH26 is a fluorescent dye specific for long-lasting cell membrane labelling which has been successfully used for investigating cell internalization processes, at either flow cytometry or fluorescence microscopy. In the present work, diaminobenzidine photo-oxidation was tested as a procedure to detect PKH26 dye at transmission electron microscopy. Our results demonstrated that DAB photo-oxidation is a suitable technique to specifically visualise this fluorescent dye at the ultrastructural level: the distribution of the granular dark reaction product perfectly matches the pattern of the fluorescence staining, and the electron density of the fine precipitates makes the signal evident and precisely detectable on the different subcellular compartments involved in the plasma membrane internalization routes. PMID:25578976

  4. Dimeric fluorescent energy transfer dyes comprising asymmetric cyanine azole-indolenine chromophores

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Oakland, CA)

    1998-01-01

    Novel fluorescent heterodimeric DNA-staining energy transfer dyes are provided combining asymmetric cyanine azole-indolenine dyes, which provide for strong DNA affinity, large Stokes shifts and emission in the red region of the spectrum. The dyes find particular application in gel electrophoresis and for labels which may be bound to a variety of compositions in a variety of contexts. Kits and individual compounds are provided, where the kits find use for simultaneous detection of a variety of moieties, particularly using a single narrow wavelength irradiation source. The individual compounds are characterized by high donor quenching and high affinity to dsDNA as a result of optimizing the length of the linking group separating the two chromophores.

  5. Histochemical fluorescent staining of Sendai virus-infected cells with a novel sialidase substrate.

    PubMed

    Takano, Maiko; Takahashi, Tadanobu; Agarikuchi, Takashi; Kurebayashi, Yuuki; Minami, Akira; Otsubo, Tadamune; Ikeda, Kiyoshi; Kanazawa, Hiroaki; Suzuki, Takashi

    2014-09-01

    Sialidases, enzymes that remove terminal sialic acid residues, are pivotal in various biological processes such as malignancy and infection with pathogens. For histochemical staining of sialidase activity, we have developed a new synthetic sialidase substrate, sialic acid-conjugated fluorescent benzothiazolylphenol derivative (BTP3-Neu5Ac), for rapid, sensitive, and specific fluorescent staining of sialidase activity. Here, we showed the usefulness of BTP3-Neu5Ac for histochemical fluorescent staining of cells infected with Sendai virus (SV), which possesses sialidase activity. BTP3-Neu5Ac also visualised SV-infected regions of lung sections from SV-infected mice. We succeeded in histochemical fluorescent staining of SV both in vitro and in vivo. SV has been utilised in many virological and biotechnological studies such as developments of an oncolytic virus, a gene therapy vector, and a vaccine candidate. BTP3-Neu5Ac should contribute to rapid progress of such studies and researches on viral sialidase. PMID:25090482

  6. Stain Reagent Reversible Stain Kits

    E-print Network

    Lebendiker, Mario

    the protein is stained, not the gel, allowing protein bands to be viewed directly within the staining reagent during the staining process. 1 Water Wash-Enhanced Protein Staining With GelCode ® Blue Stain Reagent Introduction Coomassie® Brilliant Blue is the most common dye used to stain proteins on polyacrylamide gels

  7. Evaluation of voltage-sensitive fluorescence dyes for monitoring neuronal activity in the embryonic central nervous system

    PubMed Central

    Mullah, Saad Habib-E-Rasul; Komuro, Ryo; Yan, Ping; Hayashi, Shihori; Inaji, Motoki; Momose-Sato, Yoko; Loew, Leslie M.; Sato, Katsushige

    2014-01-01

    Using an optical imaging technique with voltage-sensitive dyes (VSDs), we have been investigating the functional organization and architecture of the central nervous system (CNS) during embryogenesis. In the embryonic nervous system, a merocyanine-rhodanine dye, NK2761, has proved to be the most useful absorption dye for detecting neuronal activity because of its high signal-to-noise ratio (S/N), low toxicity, and small dye bleaching. In the present study, we evaluated the suitability of voltage-sensitive fluorescence dyes for optical recording in the embryonic CNS. We screened eight styryl (hemicyanine) dyes in isolated brainstem-spinal cord preparations from 7-day old chick embryos. Measurements of voltage-related optical signals were made using a multiple-site optical recording system. The signal size, S/N, photobleaching, effects of perfusion, and recovery of neural responses after staining were compared. We also evaluated optical responses with various magnifications. Although the S/N was lower than with the absorption dye, clear optical responses were detected with several fluorescence dyes, including di-2-ANEPEQ, di-4-ANEPPS, di-3-ANEPPDHQ, di-4-AN(F)EPPTEA, di-2-AN(F)EPPTEA, and di-2-ANEPPTEA. Di-2-ANEPEQ showed the largest S/N, whereas its photobleaching was faster and the recovery of neural responses after staining was slower. Di-4-ANEPPS and di-3-ANEPPDHQ also exhibited a large S/N, but required a relatively long time for recovery of neural activity. Di-4-AN(F)EPPTEA, di-2-AN(F)EPPTEA, and di-2-ANEPPTEA showed smaller S/Ns than di-2-ANEPEQ, di-4-ANEPPS, and di-3-ANEPPDHQ, but the recovery of neural responses after staining was faster. This study demonstrates the potential utility of these styryl dyes in optical monitoring of voltage changes in the embryonic CNS. PMID:23975337

  8. Early detection of breast cancer: a molecular optical imaging approach using novel estrogen conjugate fluorescent dye

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Shubhadeep; Jose, Iven

    2011-02-01

    Estrogen induced proliferation of mutant cells is widely understood to be the one of major risk determining factor in the development of breast cancer. Hence determination of the Estrogen Receptor[ER] status is of paramount importance if cancer pathogenesis is to be detected and rectified at an early stage. Near Infrared Fluorescence [NIRf] Molecular Optical Imaging is emerging as a powerful tool to monitor bio-molecular changes in living subjects. We discuss pre-clinical results in our efforts to develop an optical imaging diagnostic modality for the early detection of breast cancer. We have successfully carried out the synthesis and characterization of a novel target-specific NIRf dye conjugate aimed at measuring Estrogen Receptor[ER] status. The conjugate was synthesized by ester formation between 17-? estradiol and a hydrophilic derivative of Indocyanine Green (ICG) cyanine dye, bis-1,1-(4-sulfobutyl) indotricarbocyanine-5-carboxylic acid, sodium salt. In-vitro studies regarding specific binding and endocytocis of the dye performed on ER+ve [MCF-7] and control [MDA-MB-231] adenocarcinoma breast cancer cell lines clearly indicated nuclear localization of the dye for MCF-7 as compared to plasma level staining for MDA-MB-231. Furthermore, MCF-7 cells showed ~4.5-fold increase in fluorescence signal intensity compared to MDA-MB-231. A 3-D mesh model mimicking the human breast placed in a parallel-plate DOT Scanner is created to examine the in-vivo efficacy of the dye before proceeding with clinical trials. Photon migration and florescence flux intensity is modeled using the finite-element method with the coefficients (quantum yield, molar extinction co-efficient etc.) pertaining to the dye as obtained from photo-physical and in-vitro studies. We conclude by stating that this lipophilic dye can be potentially used as a target specific exogenous contrast agent in molecular optical imaging for early detection of breast cancer.

  9. Estimation of Fluorescent Dye Amount in Tracer Dye Test

    NASA Astrophysics Data System (ADS)

    Pekkan, Emrah; Balkan, Erman; Balkan, Emir

    2015-04-01

    Karstic groundwater is more influenced by human than the groundwater that disperse in pores. On the other hand karstic groundwater resources, in addition to providing agricultural needs, livestock breeding, drinking and domestic water in most of the months of the year, they also supply drinking water to the wild life at high altitudes. Therefore sustainability and hydrogeological investigation of karstic resources is critical. Tracing techniques are widely used in hydrologic and hydrogeologic studies to determine water storage, flow rate, direction and protection area of groundwater resources. Karanfil Mountain (2800 m), located in Adana, Turkey, is one of the karstic recharge areas of the natural springs spread around its periphery. During explorations of the caves of Karanfil mountain, a 600 m deep cave was found by the Turkish and Polish cavers. At the bottom of the cave there is an underground river with a flow rate of approximately 0.5 m3/s during August 2014. The main spring is located 8 km far from the cave's entrance and its mean flow rate changes between 3.4 m3/s and 0.21 m3/s in March and September respectively according to a flowrate observation station of Directorate of Water Works of Turkey. As such frequent storms, snowmelt and normal seasonal variations in rainfall have a significant and rapid effect on the volume of this main spring resource. The objective of our research is to determine and estimate dye amount before its application on the field inspired from the previously literature on the subject. This estimation is intended to provide a preliminary application of a tracer test of a karstic system. In this study dye injection, inlet point will be an underground river located inside the cave and the observation station will be the spring that is approximately 8 km far from the cave entrance. On the other hand there is 600 meter elevation difference between cave entrance and outlet spring. In this test Rodamin-WT will be used as tracer and the appropriate amount of tracers was found according to the flowrate of the spring. The amount of dye is very important for the consistency of the results and the applicability of the tests. For example if the amount of tracer that is estimated is found to be inadequate, any field readings and data could be lost. Most importantly tracer dye is costly and hard to prepare, transport and will follow a torturous path through the cave to the underground river.

  10. Fluorescence imaging of dendritic spines of Golgi-Cox-stained neurons using brightening background

    NASA Astrophysics Data System (ADS)

    Ai, Min; Xiong, Hanqing; Yang, Tao; Shang, Zhenhua; Chen, Muqing; Liu, Xiuli; Zeng, Shaoqun

    2015-01-01

    We report a novel fluorescence imaging approach to imaging nonfluorescence-labeled biological tissue samples. The method was demonstrated by imaging neurons in Golgi-Cox-stained and epoxy-resin-embedded samples through the excitation of the background fluorescence of the specimens. The dark neurons stood out clearly against background fluorescence in the images, enabling the tracing of a single dendritic spine using both confocal and wide-field fluorescence microscopy. The results suggest that the reported fluorescence imaging method would provide an effective alternative solution to image nonfluorescence-labeled samples, and it allows tracing the dendritic spine structure of neurons.

  11. The effect of graded 60°C 1N nitric acid extraction and of deoxyribonuclease digestion on nuclear staining by metachrome mordant dye metal salt mixtures

    Microsoft Academic Search

    R. D. Lillie; P. T. Donaldson; P. Pizzolato

    1976-01-01

    Summary  We can divide metachrome mordant staining of nuclei after graded 60C 1N nitric acid extraction into three groups. The feulgen\\u000a nucleal reaction and dilute cationic dye staining of nuclei are abolished in about 30 minutes. With one group of metachrome\\u000a dyes nuclear staining is lost with acid exposures of one hour or less. In a second group nuclear staining is

  12. Inhibition of beta-amyloid aggregation by fluorescent dye labels

    SciTech Connect

    Amaro, Mariana; Wellbrock, Thorben; Birch, David J. S.; Rolinski, Olaf J., E-mail: o.j.rolinski@strath.ac.uk [Photophysics group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

    2014-02-10

    The fluorescence decay of beta-amyloid's (A?) intrinsic fluorophore tyrosine has been used for sensing the oligomer formation of dye-labelled A? monomers and the results compared with previously studied oligomerization of the non-labelled A? peptides. It has been demonstrated that two different sized, covalently bound probes 7-diethylaminocoumarin-3-carbonyl and Hilyte Fluor 488 (HLF), alter the rate and character of oligomerization to different extents. The ability of HLF to inhibit formation of highly ordered structures containing beta-sheets was also shown. The implications of our findings for using fluorescence methods in amyloidosis research are discussed and the advantages of this auto-fluorescence approach highlighted.

  13. Neoplasm diagnostics based on fluorescence of polymethine dyes

    NASA Astrophysics Data System (ADS)

    Samtsov, Michael P.; Voropay, Eugene S.; Chalov, Vadim N.; Zhavrid, Edvard A.

    2002-05-01

    Investigated polymethine dye TICS has near IR bands of fluorescence and absorption within the transparency region of biological tissues. It can be detected up to 1.5 cm from the surface of the skin. The intensity of a fluorescence signal of TICS is linear for doses up to 2 mg/kg in both tumor and muscle tissue. The ratio of an intensity of light induced fluorescence in tumor tissue to one in muscle tissue is up to 3.6 for rapidly growing tumors. The retention time of TICS is 7 days in all tissues. TICS can be used in the detection of tumor boundaries and tumor internal structure.

  14. Uptake of fluorescent dyes associated with the functional expression of the cystic fibrosis transmembrane conductance regulator in epithelial cells.

    PubMed Central

    Wersto, R P; Rosenthal, E R; Crystal, R G; Spring, K R

    1996-01-01

    Specific mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), the most common autosomal recessive fatal genetic disease of Caucasians, result in the loss of epithelial cell adenosine 3',5'-cyclic-monophosphate (cAMP)-stimulated Cl- conductance. We show that the influx of a fluorescent dye, dihydrorhodamine 6G (dR6G), is increased in cells expressing human CFTR after retrovirus- and adenovirus-mediated gene transfer. dR6G influx is stimulated by cAMP and is inhibited by antagonists of cAMP action. Dye uptake is ATP-dependent and inhibited by Cl- removal or the addition of 10 mM SCN-. Increased staining is associated with functional activation of CFTR Cl- permeability. dR6G staining enables both the fluorescent assessment of CFTR function and the identification of successfully corrected cells after gene therapy. Images Fig. 5 PMID:8577734

  15. Fluorescence of Alexa Fluor Dye Tracks Protein Folding

    PubMed Central

    Lindhoud, Simon; Westphal, Adrie H.; Visser, Antonie J. W. G.; Borst, Jan Willem; van Mierlo, Carlo P. M.

    2012-01-01

    Fluorescence spectroscopy is an important tool for the characterization of protein folding. Often, a protein is labeled with appropriate fluorescent donor and acceptor probes and folding-induced changes in Förster Resonance Energy Transfer (FRET) are monitored. However, conformational changes of the protein potentially affect fluorescence properties of both probes, thereby profoundly complicating interpretation of FRET data. In this study, we assess the effects protein folding has on fluorescence properties of Alexa Fluor 488 (A488), which is commonly used as FRET donor. Here, A488 is covalently attached to Cys69 of apoflavodoxin from Azotobacter vinelandii. Although coupling of A488 slightly destabilizes apoflavodoxin, the three-state folding of this protein, which involves a molten globule intermediate, is unaffected. Upon folding of apoflavodoxin, fluorescence emission intensity of A488 changes significantly. To illuminate the molecular sources of this alteration, we applied steady state and time-resolved fluorescence techniques. The results obtained show that tryptophans cause folding-induced changes in quenching of Alexa dye. Compared to unfolded protein, static quenching of A488 is increased in the molten globule. Upon populating the native state both static and dynamic quenching of A488 decrease considerably. We show that fluorescence quenching of Alexa Fluor dyes is a sensitive reporter of conformational changes during protein folding. PMID:23056480

  16. Update on flashlamp pumped pulsed dye laser treatment for port wine stains (capillary malformation) patients

    PubMed Central

    Hsiao, Yen-Chang; Chang, Cheng-Jen

    2011-01-01

    Background and Aims: Currently, the method of choice for the treatment of port-wine stains is laser photocoagulation. Because of evolving treatment options, it is no longer enough for port-wine stains merely to be lightened through laser treatment. The best course of management consists of the most appropriate laser that will produce the most complete clearing of a lesion in the fewest treatment sessions with the least morbidity. The goal is generally accomplished with the use of yellow-light lasers. Materials (Subjects) and Methods: Absorption of laser energy by melanin causes localized heating in the epidermis, which may, if not controlled, produce permanent complications such as hypertrophic scarring or dyspigmentation. Refinements of the results can be achieved by using the flashlamp-pumped pulsed dye laser (FLPDL) in conjunction with the cryogen spray cooling (CSC) system. In our related studies, the infrared thermal image instrument is used for doctors in determining the optimum laser light dosage and preventing the side effects caused by FLPDL. Topic application of angiogenesis inhibitor (Imiquimod) in conjunction with pulsed dye laser treatment for the PWS patients has been assessed for improvement of FLPDL treatment. Results: We present the clinical effect of FLPDL, and the efficacy and safety of cooled laser treatment of PWS birthmarks. Our clinical outcome in the laser treatment of patients with PWS has been achieved to maximize thermal impact on targeted vessels, while minimizing adverse complications. Conclusions: CSC in conjunction with FLPDL can improve the treatment of PWS. The infrared image instrument is helpful for doctors in determining the optimum laser light dosage. Topic application of angiogenesis inhibitor (Imiquimod) in conjunction with laser treatment for the PWS patients is promising in the near future. PMID:24155536

  17. Ultrasensitive staining-free protein detection after PAA gel electrophoresis using deep UV fluorescence.

    PubMed

    Riaplov, Eugene; Li, Qiang; Seeger, Stefan

    2007-01-01

    We present the observation of separated protein bands after polyacrylamide (PAA) gel electrophoresis based on the staining-free detection of their ultra violet (UV)-induced fluorescence employing deep UV confocal fluorescence microscopy. Mixtures of the three biological compounds beta-Galactosidase (from Escherichia coli), apo-Transferrin (bovine) and bovine serum albumin (BSA) have been separated and a staining free detection limit below 80 pg (7.0 x 10(8) molecules) per band has been achieved. This corresponds to approximately 270 molecules in the detection volume for confocal microscopy. PMID:17897099

  18. Ethidium bromide: a fast fluorescent staining procedure for the detection of symbiotic partnership of flagellates and prokaryotes.

    PubMed

    Fröhlich, J; König, H

    1999-03-01

    The hindgut of 'lower' termites harbors a dense population of flagellates and bacteria. The flagellates possess ecto- and endosymbiotic prokaryotes. Most of them are hardly visible in the phase contrast microscope. Staining with the DNA-intercalating agent ethidium bromide visualizes the nuclei of the flagellates as well as the ecto- and endosymbiotic bacteria as red objects. Furthermore, it is possible to distinguish between endosymbiotic methanogens and other bacteria. Following UV excitation, the blue-green autofluorescence of the methanogenic bacteria eclipses the red fluorescence light of the intercalated ethidium bromide. The dye facilitates the observation of symbiotic bacteria and helps identify the number, shape, localization, and dividing status of the nuclei. Thus, it is a powerful tool for the examination of microorganisms in complex habitats, which are rich in strongly autofluorescent material, like wood. PMID:10192044

  19. Simultaneous Fluorescent Gram Staining and Activity Assessment of Activated Sludge Bacteria

    Microsoft Academic Search

    Scott Forster; Jason R. Snape; Hilary M. Lappin-Scott; Jonathan Porter

    2002-01-01

    Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that

  20. Assessment of gamete quality for the eastern oyster (Crassostrea virginica) by use of fluorescent dyes

    USGS Publications Warehouse

    Paniagua-Chavez, C. G.; Jenkins, J.; Segovia, M.; Tiersch, T.R.

    2006-01-01

    Evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. While a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. Techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. The eastern oyster Crassostrea virginica is an important mollusk in the United States, and cryopreservation protocols have been developed to preserve sperm and larvae to assist research and hatchery production. In this study, protocols were developed to assess sperm cell membrane integrity and mitochondrial function by flow cytometry and to assess viability of eggs by fluorescence microscopy. The fluorescent dyes SYBR 14 and propidium iodide (PI) (to assess membrane integrity) and rhodamine 123 (R123) (to assess mitochondrial membrane potential) were used to evaluate the quality of thawed oyster sperm previously cryopreserved with different cryoprotectant and thawing treatments. Membrane integrity results were correlated with motility of thawed sperm and mitochondrial membrane potential with fertilizing ability. Fluorescein diacetate (FDA) was used to assess cytotoxicity of cryoprotectant solutions and post-thaw damage to oyster eggs. The results indicated that membrane integrity (P = 0.004) and thawing treatments (P = 0.04), and mitochondrial membrane potential (P = 0.0015) were correlated with motility. Fertilizing ability was correlated with cryoprotectant treatments (P = 0.0258) and with mitochondrial membrane potential (P = 0.001). The dye FDA was useful in indicating structural integrity of fresh and thawed eggs. Exposure of eggs, without freezing, to dimethyl sulfoxide yielded higher percentages of stained eggs and fertilization rate than did exposure to propylene glycol (P = 0.002). Thawed eggs were not stained with FDA (<1%) and larvae were not produced. ?? 2006 Elsevier Inc. All rights reserved.

  1. Aerial Imaging of Fluorescent Dye in the Near Shore DAVID B. CLARK

    E-print Network

    Boss, Emmanuel S.

    relative to many natural tracers. Fluorescent dyes are accurately measured in situ with opticalAerial Imaging of Fluorescent Dye in the Near Shore DAVID B. CLARK Woods Hole Oceanographic) dye in turbid and optically deep water. Tracer releases near the shoreline of an ocean beach and near

  2. Particle Image Velocimetry Applications Using Fluorescent Dye-Doped Particles

    NASA Technical Reports Server (NTRS)

    Petrosky, Brian J.; Maisto, Pietro; Lowe, K. Todd; Andre, Matthieu A.; Bardet, Philippe M.; Tiemsin, Patsy I.; Wohl, Christopher J.; Danehy, Paul M.

    2015-01-01

    Polystyrene latex sphere particles are widely used to seed flows for velocimetry techniques such as Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV). These particles may be doped with fluorescent dyes such that signals spectrally shifted from the incident laser wavelength may be detected via Laser Induced Fluorescence (LIF). An attractive application of the LIF signal is achieving velocimetry in the presence of strong interference from laser scatter, opening up new research possibilities very near solid surfaces or at liquid/gas interfaces. Additionally, LIF signals can be used to tag different fluid streams to study mixing. While fluorescence-based PIV has been performed by many researchers for particles dispersed in water flows, the current work is among the first in applying the technique to micron-scale particles dispersed in a gas. A key requirement for such an application is addressing potential health hazards from fluorescent dyes; successful doping of Kiton Red 620 (KR620) has enabled the use of this relatively safe dye for fluorescence PIV for the first time. In this paper, basic applications proving the concept of PIV using the LIF signal from KR620-doped particles are exhibited for a free jet and a twophase flow apparatus. Results indicate that while the fluorescence PIV techniques are roughly 2 orders of magnitude weaker than Mie scattering, they provide a viable method for obtaining data in flow regions previously inaccessible via standard PIV. These techniques have the potential to also complement Mie scattering signals, for example in multi-stream and/or multi-phase experiments.

  3. Detection of firearm discharge residues in blood-stained articles by fluorescence.

    PubMed

    Nag, N K; Mazumdar, M

    1975-02-01

    A quick and sensitive method has been developed for the chemical detection of nitrous derivatives discharged from a firearm. Detection by fluorescence is especially suitable for blood-stained articles such as clothing, which often give confusing results when the conventional methods are used. PMID:1132864

  4. Application of the DNA-Specific Stain Methyl Green in the Fluorescent Labeling of Embryos.

    PubMed

    Prieto, Daniel; Aparicio, Gonzalo; Machado, Matías; Zolessi, Flavio R

    2015-01-01

    Methyl green has long been known as a histological stain with a specific affinity for DNA, although its fluorescent properties have remained unexplored until recently. In this article, we illustrate the method for preparing a methyl green aqueous stock solution, that when diluted can be used as a very convenient fluorescent nuclear label for fixed cells and tissues. Easy procedures to label whole zebrafish and chick embryos are detailed, and examples of images obtained shown. Methyl green is maximally excited by red light, at 633 nm, and emits with a relatively sharp spectrum that peaks at 677 nm. It is very inexpensive, non-toxic, highly stable in solution and very resistant to photobleaching when bound to DNA. Its red emission allows for unaltered high resolution scanning confocal imaging of nuclei in thick specimens. Finally, this methyl green staining protocol is compatible with other cell staining procedures, such as antibody labeling, or actin filaments labeling with fluorophore-conjugated phalloidin. PMID:25993383

  5. Detection of Candida albicans in oral squamous cell carcinoma by fluorescence staining technique

    PubMed Central

    Jahanshahi, Gholamreza; Shirani, Samaneh

    2015-01-01

    Background: One of the probable etiologic risk factors of oral squamous cell carcinoma (OSCC) is Candidal infection, especially by Candida albicans, whose role has not definitely been confirmed. Some have assigned a primary role to Candida, whereas others consider it as a transient inhabitant. The debate may be due to lack of an accurate and sensitive revealing technique. By identifying the presence of Candida, especially in deeper parts of OSCC, the etiologic role may be verified. The present study was conducted to detect the presence of Candida in OSCC by fluorescence staining technique. Materials and Methods: This study was descriptive experimental. Calcofluor-white, which is applied in fluorescence staining, is a specific staining substance for Candida and has a higher accuracy compared with other common methods. 100 specimens of well-differentiated OSCC with adequate amount of tissue were retrieved from the archive and two serial sections were obtained from each one. The first section was stained using the popular histochemical (periodic acid-Schiff [PAS]) method and then evaluated under a light microscope to detect the presence of Candida. The second section was stained using fluorescence staining technique. The sum of counted Candida in each technique was fed into SPSS software and analyzed by McNamara test. P < 0.001 was considered as significant. Results: The amount of Candida present in OSCCs was 74% measured by fluorescence technique. The sensitivity and specificity of the two staining techniques were significantly different. These parameters in the fluorescence technique were higher than those of the histochemical (PAS) method, confirmed by McNamara test showing significantly different results for them (P < 0.001). The results obtained from the fluorescence technique had higher accuracy compared with the histochemical (PAS) method. Conclusion: Some researchers couldn’t find a considerable number of fungi in OSCC, while our results revealed more presence of Candida, especially in deeper parts of tissue samples and probably a more important role for Candida as an etiologic risk factor for OSCC. However, since the fluorescence technique had a higher accuracy in the identification of Candida and it was nearly evident in two-third of the samples, the role of fungi as a primary cause is suggested to be studied in future investigations. PMID:25878675

  6. Fluorescent performance of electrospun polyimide web mixed with hemicyanine dye

    Microsoft Academic Search

    Chuanxiang Qin; Jianjun Wang; Si Cheng; Xiaomei Wang; Lixing Dai; Guoqiang Chen

    2009-01-01

    Polyamic acid (PAA) solution in N, N-dimethylacetamide was mixed with one hemicyanine dye, DHEASPI-C1, to prepare the fluorescent polyimide (PI) web by electrospinning process (ESP). Firstly, dark orange-red PAA\\/DHEASPI-C1 web consisted of nanofibers about 10–100 nm, could be achieved using ESP at room temperature. Then thermal imidization for 4 h in vacuum oven (200 °C, 133 Pa) led to the cycloimidization of PAA into

  7. Development of a Vital Fluorescent Staining Method for Monitoring Bacterial Transport in Subsurface Environments

    PubMed Central

    Fuller, Mark E.; Streger, Sheryl H.; Rothmel, Randi K.; Mailloux, Brian J.; Hall, James A.; Onstott, Tullis C.; Fredrickson, James K.; Balkwill, David L.; DeFlaun, Mary F.

    2000-01-01

    Previous bacterial transport studies have utilized fluorophores which have been shown to adversely affect the physiology of stained cells. This research was undertaken to identify alternative fluorescent stains that do not adversely affect the transport or viability of bacteria. Initial work was performed with a groundwater isolate, Comamonas sp. strain DA001. Potential compounds were first screened to determine staining efficiencies and adverse side effects. 5-(And 6-)-carboxyfluorescein diacetate, succinimidyl ester (CFDA/SE) efficiently stained DA001 without causing undesirable effects on cell adhesion or viability. Members of many other gram-negative and gram-positive bacterial genera were also effectively stained with CFDA/SE. More than 95% of CFDA/SE-stained Comamonas sp. strain DA001 cells incubated in artificial groundwater (under no-growth conditions) remained fluorescent for at least 28 days as determined by epifluorescent microscopy and flow cytometry. No differences in the survival and culturability of CFDA/SE-stained and unstained DA001 cells in groundwater or saturated sediment microcosms were detected. The bright, yellow-green cells were readily distinguished from autofluorescing sediment particles by epifluorescence microscopy. A high throughput method using microplate spectrofluorometry was developed, which had a detection limit of mid-105 CFDA-stained cells/ml; the detection limit for flow cytometry was on the order of 1,000 cells/ml. The results of laboratory-scale bacterial transport experiments performed with intact sediment cores and nondividing DA001 cells revealed good agreement between the aqueous cell concentrations determined by the microplate assay and those determined by other enumeration methods. This research indicates that CFDA/SE is very efficient for labeling cells for bacterial transport experiments and that it may be useful for other microbial ecology research as well. PMID:11010903

  8. Cell-death assessment by fluorescent and nonfluorescent cytosolic and nuclear staining techniques.

    PubMed

    Atale, N; Gupta, S; Yadav, U C S; Rani, V

    2014-07-01

    Apoptosis, a genetically programmed cellular event leads to biochemical and morphological changes in cells. Alterations in DNA caused by several factors affect nucleus and ultimately the entire cell leading to compromised function of the organ and organism. DNA, a master regulator of the cellular events, is an important biomolecule with regards to cell growth, cell death, cell migration and cell differentiation. It is therefore imperative to develop the staining techniques that may lead to visualize the changes in nucleus where DNA is housed, to comprehend the cellular pathophysiology. Over the years a number of nuclear staining techniques such as propidium iodide, Hoechst-33342, 4', 6-diamidino-2-phenylindole (DAPI), Acridine orange-Ethidium bromide staining, among others have been developed to assess the changes in DNA. Some nonnuclear staining techniques such as Annexin-V staining, which although does not stain DNA, but helps to identify the events that result from DNA alteration and leads to initiation of apoptotic cell death. In this review, we have briefly discussed some of the most commonly used fluorescent and nonfluorescent staining techniques that identify apoptotic changes in cell, DNA and the nucleus. These techniques help in differentiating several cellular and nuclear phenotypes that result from DNA damage and have been identified as specific to necrosis or early and late apoptosis as well as scores of other nuclear deformities occurring inside the cells. PMID:24831993

  9. Determination of collagen content within picrosirius red stained paraffin-embedded tissue sections using fluorescence microscopy

    PubMed Central

    Vogel, Benjamin; Siebert, Hanna; Hofmann, Ulrich; Frantz, Stefan

    2015-01-01

    Picrosirius red (PSR) staining is a commonly used histological technique to visualize collagen in paraffin-embedded tissue sections. PSR stained collagen appears red in light microscopy. However it is largely unknown that PSR stained collagen also shows a red fluorescence, whereas live cells have a distinct green autofluorescence. Both emission patterns can be detected using standard filter sets as found in conventional fluorescence microscopes. Here we used digital image addition and subtraction to determine the relative area of the pure collagen and live cell content in heart tissue in a semi-automated process using standard software. This procedure, which considers empty spaces (holes) within the section, can be easily adapted to quantify the collagen and live cell areas in healthy or fibrotic tissues as aorta, lung, kidney or liver by semi-automated planimetry exemplified herein for infarcted heart tissue obtained from the mouse myocardial infarction model. • Use of conventional PSR stained paraffin-embedded tissue sections for fluorescence analysis. • PSR and autofluorescence images are used to calculate area of collagen and area of live cells in the tissue; empty spaces (holes) in tissue are considered. • High throughput analysis of collagen and live cell content in tissue for statistical purposes.

  10. Fluorescent identification of biological and other stains on skin by the use of alternative light sources.

    PubMed

    Wawryk, Jacob; Odell, Morris

    2005-12-01

    The detection of body fluids in cases of sexual assault or abuse is important for purposes of evidence collection and DNA testing. In cases where semen is deposited on skin, a method for detection of semen may be a valuable aid to evidence collection [Gabby T, Winkleby M, Boyce T, Fisher D, Lancaster A, Sensabaugh G. Sexual abuse of children. The detection of semen on skin. AJCD 1992; 146:700-703]. Semen is known to fluoresce when exposed to light of certain wavelengths. For this study, we placed various body fluids, as well as lubricants and moisturizers on the forearms of volunteers. The areas were illuminated using Alternative Light Sources (ALS) with peak wavelengths of between 370 and 500 nm for examination soon after deposition, and again after 24 h. No fluorescence was visible from any of the substances in the majority of volunteers examined. In a few subjects, semen and urine were found to fluoresce faintly under the more powerful lights. In these cases, the quality of fluorescence provided by urine and semen was noticeably different. For comparison, semen was applied to cloth, and fluoresced well at the expected wavelengths. While ALS is useful for identification of stains on clothing, its use in detecting stains on skin is currently very limited. PMID:15925535

  11. Laser velocimetry with fluorescent dye-doped polystyrene microspheres.

    PubMed

    Lowe, K Todd; Maisto, Pietro; Byun, Gwibo; Simpson, Roger L; Verkamp, Max; Danehy, Paul M; Tiemsin, Pacita I; Wohl, Christopher J

    2013-04-15

    Simultaneous Mie scattering and laser-induced fluorescence (LIF) signals are obtained from individual polystyrene latex microspheres dispersed in an air flow. Microspheres less than 1 ?m mean diameter were doped with two organic fluorescent dyes, Rhodamine B (RhB) and dichlorofluorescein (DCF), intended either to provide improved particle-based flow velocimetry in the vicinity of surfaces or to provide scalar flow information (e.g., marking one of two fluid streams). Both dyes exhibit measureable fluorescence signals that are on the order of 10(-3) to 10(-4) times weaker than the simultaneously measured Mie signals. It is determined that at the conditions measured, 95.5% of RhB LIF signals and 32.2% of DCF signals provide valid laser-Doppler velocimetry measurements compared with the Mie scattering validation rate with 6.5 W of 532 nm excitation, while RhB excited with 1.0 W incident laser power still exhibits 95.4% valid velocimetry signals from the LIF channel. The results suggest that the method is applicable to wind tunnel measurements near walls where laser flare can be a limiting factor and monodisperse particles are essential. PMID:23595429

  12. Treatment of Port-Wine Stains with Flash Lamp Pumped Pulsed Dye Laser on Indian Skin: A Six Year Study

    PubMed Central

    Thajudheen, Chandroth Ponnambath; Jyothy, Kannangath; Priyadarshini, Arul

    2014-01-01

    Context: Port-wine stain (PWS) is one of the commonly encountered congenital cutaneous vascular lesions, with an equal sex distribution. Pulsed dye lasers (PDL) have revolutionized the treatment of both congential and acquired cutaneous vascular lesions. The pulsed dye lasers owing to its superior efficacy and safety profile have become the gold standard for the management of port-wine stains. Aims: To evaluate the efficacy and side effects of pulsed dye laser for the management of Port-wine stain on Indian skin. Materials and Methods: Seventy five patients of Fitzpatrick skin types IV&V with PWS underwent multiple treatments with PDL (V beam-Candela) over a period of six years at monthly intervals. Laser parameters were wavelength 595nm, spot sizes 7-10mm, fluence 6-12 j/cm2, pulse duration 0.45-10ms, along with cryogen cooling. Serial photographs were taken before and after every session. Clinical improvement scores of comparable photographs using a quartile grading (o=<20%, 1=21-40%, 2=41-60%, 3=61-80%, 4=>80%) were judged independently by two dermatologists after the series of treatment. Minimum number of treatments was 6 and maximum 17. They were followed up at six monthly intervals to observe re darkening of PWS. Results: No patient showed total clearance.Grade3 improvement was observed in 70 % of children and 50% of adults after 8-10 sessions. Children showed better and faster response than adults. Thirty percent of patients developed post inflammatory hyper pigmentation which resolved over a period of six to eight weeks. Two patients had superficial scarring due to stacking of pulses. None of the patients showed re darkening of PWS till now. Conclusion: Pulsed dye laser is an effective and safe treatment for port-wine stain in Indian skin. PMID:24761097

  13. Vital staining from dye-coated microprobes identifies new olfactory interneurons for optical and electrical recording

    Microsoft Academic Search

    A Gelperin; J Flores

    1997-01-01

    A versatile technique for dye application in living tissue is described, which results in labeling of viable cells from which electrophysiological or optical recordings can be obtained. The dye-coated surface of a glass microelectrode tip is used to apply anatomical tracers or calcium sensitive probes with spatial precision. A total of three types of dyes have been applied in this

  14. Engineering metal-nanoantennae/dye complexes for maximum fluorescence enhancement.

    PubMed

    Meng, Xiang; Grote, Richard R; Dadap, Jerry I; Panoiu, Nicolae C; Osgood, Richard M

    2014-09-01

    We theoretically investigate the fluorescence enhancement of a molecule placed in a variable (4 - 20 nm) gap of a plasmonic dimer, with different dye molecules as well as different nanoparticle geometries, using a fully vectorial three-dimensional finite-difference time-domain (3D FDTD) method. This work extends previous studies on molecular fluorescence in the vicinity of metal interfaces and single nanoparticles and shows how the radiative emission of a molecule can be further enhanced by engineering the geometry of a plasmonic structure. Through the use of rigorous 3D FDTD calculations, in conjunction with analytic guidance based on temporal coupled-mode (TCM) theory, we develop a design procedure for antennae assemblies that is useful both for general understanding of molecule-metal structure interaction and experimental efforts in plasmon-enhanced molecular spectroscopy. PMID:25321576

  15. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    Microsoft Academic Search

    O. Abdel-Kareem; A. Eltokhy; M. A. Harith

    2011-01-01

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as

  16. The use of fluorescent dyes as tracers in highly saline groundwater

    E-print Network

    Weisbrod, Noam

    groundwater was evaluated by a series of batch experiments on pure miner- als and natural sediments. Dye. Sorption of the dyes on four natural sediments was measured and values were found to be in accordThe use of fluorescent dyes as tracers in highly saline groundwater Einat Magal a,b,*, Noam

  17. Interpretation of the Raman absorptionn lines within the stimulated fluorescence spectrum of some laser dyes

    Microsoft Academic Search

    M. Pfeiffer; A. Lau; H.-J. Weigmann; K. Lenz

    1972-01-01

    The emission spectrum of some laser dyes shows the appearance of Raman abssorption lines within the generation continuum. The absorption line can be interpreted as a gap in the fluorescence profile of the dye molecule. Here we show theoretically with a simple model for the dye molecule, that such gap really exists, lying just at the Raman frequency. The characteristics

  18. Differential fluorescent staining of porcine heterochromatin by chromomycin A3\\/distamycin A\\/DAPI and D 287\\/170

    Microsoft Academic Search

    W. Schnedl; R. Abraham; M. Förster; D. Schweizer

    1981-01-01

    R banding of porcine chromosomes by chromomycin A3 plus distamycin A and DAPI (DA-DAPI) revealed two distinct types of heterochromatin: The GC-rich centromeric heterochromatin of the biarmed autosomes (Nos. 1–12) and of the X chromosome exhibited bright chromomycin A3 fluorescence, while the heterochromatin of the acrocentric chromosomes (Nos. 13–18) stained brightly by DA-DAPI. The latter also fluoresced brightly when stained

  19. Rates of Benthic Protozoan Grazing on Free and Attached Sediment Bacteria Measured with Fluorescently Stained Sediment

    PubMed Central

    Starink, Mathieu; Krylova, Irina N.; Bär-Gilissen, Marie-José; Bak, Rolf P. M.; Cappenberg, Thomas E.

    1994-01-01

    In order to determine the importance of benthic protozoa as consumers of bacteria, grazing rates have been measured by using monodispersed fluorescently labeled bacteria (FLB). However, high percentages of nongrazing benthic protists are reported in the literature. These are related to serious problems of the monodispersed FLB method. We describe a new method using 5-(4,6-dichlorotriazin-2-yl)-aminofluorescein (DTAF)-stained sediment to measure in situ bacterivory by benthic protists. This method is compared with the monodispersed FLB technique. Our estimates of benthic bacterivory range from 61 to 73 bacteria protist-1 h-1 and are about twofold higher than the results of the monodispersed FLB method. The number of nongrazing protists after incubation for 15 min with DTAF-stained sediment is in agreement with theoretical expectation. We also tested the relative affinity for FLB of protists and discuss the results with respect to a grazing model. PMID:16349315

  20. Identification Of Natural Dyes On Archaeological Textile Objects Using Laser Induced Fluorescent Technique

    NASA Astrophysics Data System (ADS)

    Abdel-Kareem, O.; Eltokhy, A.; Harith, M. A.

    2011-09-01

    This study aims to evaluate the use of Laser Fluorescent as a non-destructive technique for identification of natural dyes on archaeological textile objects. In this study wool textile samples were dyed with 10 natural dyes such as cochineal, cutch, henna, indigo, Lac, madder, safflower, saffron, sumac and turmeric. These dyes common present on archaeological textile objects to be used as standard dyed textile samples. These selected natural dyes will be used as known references that can be used a guide to identify unknown archaeological dyes. The dyed textile samples were investigated with laser radiation in different wavelengths to detect the best wavelengths for identification each dye. This study confirms that Laser Florescent is very useful and a rapid technique can be used as a non-destructive technique for identification of natural dyes on archaeological textile objects. The results obtained with this study can be a guide for all conservators in identification of natural organic dyes on archaeological textile objects.

  1. Method and apparatus for staining immobilized nucleic acids

    DOEpatents

    Ramsey, J. Michael (Knoxville, TN); Foote, Robert S. (Oak Ridge, TN); Jacobson, Stephen C. (Knoxville, TN)

    2000-01-01

    A method for staining immobilized nucleic acids includes the steps of affixing DNA probes to a solid substrate, moving target DNA material into proximity with the DNA probes, whereby the target DNA hybridized with specific ones of the DNA probes, and moving a fluorescent dye into proximity with the hybridized target DNA, whereby the fluorescent dye binds to the hybridized DNA to enable subsequent detection of fluorescence.

  2. Enhancement of the fluorescence of triphenylmethane dyes caused by their interaction with nanoparticles from ?-diketonate complexes

    NASA Astrophysics Data System (ADS)

    Sveshnikova, E. B.; Ermolaev, V. L.

    2014-08-01

    We have studied the absorption and fluorescence spectra of Malachite Green and Crystal Violet in aqueous and alcoholic-aqueous solutions in which nanoparticles from Ln(III) and Sc(III) diketonates are formed at concentrations of complexes in a solution of 5-30 ?M. We have shown that, if the concentrations of the dyes in the solution are lower than 0.5 ?M, dye molecules are incorporated completely into nanoparticles or are precipitated onto their surface. The fluorescence intensity of these incorporated and adsorbed Malachite Green and Crystal Violet molecules increases by several orders of magnitude compared to the solution, which takes place because of a sharp increase in the fluorescence quantum yields of these dyes and at the expense of the sensitization of their fluorescence upon energy transfer from ?-diketonate complexes entering into the composition of nanoparticles. We have shown that, if there is no concentration quenching, the values of the fluorescence quantum yield of the Crystal Violet dye incorporated into nanoparticles and adsorbed on their surface vary from 0.06 to 0.13, i.e., are close to the fluorescence quantum yield of this dye in solid solutions of sucrose acetate at room temperature. The independence of the fluorescence quantum yield of Crystal Violet on the morphology of nanoparticles testifies to a high binding constant of complexes and the dye. The considerable fluorescence quantum yields of triphenylmethane dyes in nanoparticles and sensitization of their fluorescence by nanoparticle-forming complexes make it possible to determine the concentration of these dyes in aqueous solutions by the luminescent method in the range of up to 1 nM.

  3. Molecular design and synthesis of a pH independent and cell permeant fluorescent dye and its applications.

    PubMed

    Jiao, Xiaojie; Liu, Chang; Huang, Kun; Zhang, Siwen; He, Song; Zhao, Liancheng; Zeng, Xianshun

    2015-06-21

    Fluorescent dyes have played crucial roles in the field of molecular imaging as fluorescent fluorophores. In this work, a novel water-soluble and pH-independent fluorescent xanthene dye, a hydroxyl regioisomeric 3',4'-benzorhodol, has been designed and synthesized. Compared with those of rhodol dyes, the absorption (ca. 570 nm) and maximum emission (ca. 620 nm) of the dye are largely red-shifted. Due to its ring-opened zwitterion structure in water media, the dye showed good membrane permeability and distributed in the whole cell cytoplasm upon incubation with live cells. Meanwhile, the dye could be easily modified to probes. The hydrazide derivative of the dye exhibited an excellent Hg(2+) selectivity over other relevant metal ions with a detection limit down to 3 nM. Thus, the excellent fluorescence properties and chemical properties of the dye allow it to be designed as a fluorescent chemosensor and biomarker for biological applications. PMID:25990913

  4. Fluorescent DNA Nanotags Featuring Covalently Attached Intercalating Dyes: Synthesis, Antibody Conjugation and Intracellular Imaging

    PubMed Central

    Stadler, Andrea L.; Santos, Junriz Delos; Stensrud, Elizabeth S.; Dembska, Anna; Silva, Gloria L.; Liu, Shengpeng; Shank, Nathaniel I.; Kunttas-Tatli, Ezgi; Sobers, Courtney J.; Gramlich, Philipp M. E.; Carell, Thomas; Peteanu, Linda A.; McCartney, Brooke M.; Armitage, Bruce A.

    2011-01-01

    We have synthesized fluorescent DNA duplexes featuring multiple thiazole orange (TO) intercalating dyes covalently attached to the DNA via a triazole linkage. The intercalating dyes stabilize the duplex against thermal denaturation and show bright fluorescence in the green. The emission color can be changed to orange or red by addition of energy-accepting Cy3 or Cy5 dyes attached covalently to the DNA duplex. The dye-modified DNA duplexes were then attached to a secondary antibody for intracellular fluorescence imaging of centrosomes in Drosophila embryos. Bright fluorescent foci were observed at the centrosomes in both the donor (TO) and acceptor (Cy5) channels, due to the fact that the energy transfer efficiency is moderate. Monitoring the Cy5 emission channel significantly minimized the background signal due to the large shift in emission wavelength allowed by energy transfer. PMID:21755981

  5. The use of fluorescent dyes as tracers in highly saline groundwater

    Microsoft Academic Search

    Einat Magal; Noam Weisbrod; Alex Yakirevich; Yoseph Yechieli

    2008-01-01

    Summary The capability of five fluorescent dyes to serve as conservative tracers in highly saline groundwater was evaluated by a series of batch experiments on pure miner- als and natural sediments. Dye sorption was tested in four different salinities (from fresh rainwater to Dead Sea water) on five pure minerals and four natural sediments taken from boreholes drilled along the

  6. Propidium iodide staining: a new application in fluorescence microscopy for analysis of cytoarchitecture in adult and developing rodent brain.

    PubMed

    Hezel, Marcus; Ebrahimi, Fahim; Koch, Marco; Dehghani, Faramarz

    2012-10-01

    Immunohistochemical visualization of antigens in specimen has evolved to an indispensable technique in biomedical research for investigations of cell morphology and pathology both in bright field and fluorescence microscopy. While there are couple of staining methods that reveal entire cytoarchitecture in bright field microscopy such as Nissl or hemalaun-eosin, there are still limitations in visualizations of cytoarchitecture in fluorescence microscopy. The present study reports a simple staining method that provides the required illustration of cell allocations and cellular composition in fluorescence microscopy in adult and in developing rodent central nervous system using the fluorophore propidium iodide (PI, 5?g/mL). PI is a well-accepted marker for degenerating cells when applied prior to fixation (pre-fixation PI staining). Here, PI was added to the sections after the fixation (post-fixation PI staining). This revised labeling procedure led to similar cytoarchitectural staining patterns in fluorescence microscopy as observed with hemalaun in bright field microscopy. This finding was proven in organotypic hippocampal slice cultures (OHSC) and brain sections obtained from different postnatal developmental stages. Excitotoxically lesioned OHSC subjected to pre-fixation PI staining merely showed brightly labeled condensed nuclei of degenerating neurons. In contrast, post-fixation PI staining additionally revealed extensive labeling of neuronal cell bodies and glial cells within the OHSC, thus allowing visualization of stratification of neuronal layers and cell morphology. Furthermore, post-fixation PI staining was combined with NeuN, calbindin, calretinin, glial fibrillary acidic protein or Griffonia simplicifolia isolectin B4 (IB(4)) in post natal (p1 and p9) and adult rats. In early post-natal brain sections almost all mentioned cellular markers led to an incomplete staining of the native cell organization and resulted in an inaccurate estimation of cell morphology when compared to adult brains. In contrast, post-fixation PI staining allowed investigation of the whole cytoarchitecture independent of the developmental stage. Taken together, post-fixation PI staining provides a detailed insight in the morphology of both developing and adult brain tissues in fluorescence microscopy. PMID:22579654

  7. Trimethine cyanine dyes as fluorescent probes for amyloid fibrils: The effect of N,N'-substituents.

    PubMed

    Kuperman, Marina V; Chernii, Svitlana V; Losytskyy, Mykhaylo Yu; Kryvorotenko, Dmytro V; Derevyanko, Nadiya O; Slominskii, Yurii L; Kovalska, Vladyslava B; Yarmoluk, Sergiy M

    2015-09-01

    The effect of various N,N'-substituents in the molecule of benzothiazole trimethine cyanine dye on its ability to sense the amyloid aggregates of protein was studied. The dyes are low fluorescent when free and in the presence of monomeric proteins, but their emission intensity sharply increases in complexes with aggregated insulin and lysozyme, with the fluorescence quantum yield reaching up to 0.42. The dyes carrying butyl, hydroxyalkyl, and phenylalkyl groups as N,N'-substituents possess the increased fluorescent sensitivity to fibrillar lysozyme, whereas the ones carrying quaternary amino groups are preferably sensitive to fibrillar insulin. This fluorescent sensitivity preference provided by the N,N'-functional groups could be explained by the interaction between these groups and protein side chains. The strongest fluorescent response (up to 70times) and the same sensitivity to aggregates of both proteins were exhibited by the dye D-51 carrying N-sulfoalkyl group. The studied cyanines allow the detection of fibrillar aggregates in the wide range up to 0.8 to 300?g/ml and permit monitoring the protein aggregation kinetics with high reproducibility. The modification of trimethine cyanine dyes by functional substituents in N,N'-positions is suggested as a tool for the design of fluorescent molecules with the enhanced fluorescent sensitivity to the fibrillar aggregates of proteins. PMID:25963892

  8. Fluorescence Quenching of Tris(2,2?-bipyridine)Ruthenium(II) Dichloride by Certain Organic Dyes

    Microsoft Academic Search

    M. Asha Jhonsi; A. Kathiravan; G. Paramaguru; C. Manivannan; R. Renganathan

    2010-01-01

    Fluorescence quenching of [Ru(bpy)3]2+ by a series of organic dyes has been investigated by using the steady state fluorescence technique in aqueous medium. The\\u000a dyes used are anthraquinone dyes: uniblue, acid blue 129, alizarin, alizarin red S and the azo dyes: congo red, sunset yellow,\\u000a methyl orange, tartrazine, acid orange 63, methyl red and erichrome black T. The quenching of

  9. Fluorescent voltage-sensitive dyes: applications for neurophysiology.

    PubMed

    Dasheiff, R M

    1988-07-01

    Voltage-sensitive dyes are a means to optically monitor changes in membrane potential. Their application in research has grown steadily over the last two decades as better dyes have been developed. The techniques presently in use are providing unique information about biologic systems from bacteria to the functional organization of primate occipital cortex. This review provides a history of the dyes, the data supporting their voltage sensitivity, and the techniques required for their use. The limitations in using and interpreting the voltage-sensitive dyes, as well as their diverse applications in all areas of research, especially neurophysiology, are comprehensively presented. PMID:3049666

  10. Fluorescence of dyes in solutions with high absorbance. Inner filter effect correction.

    PubMed

    Fonin, Alexander V; Sulatskaya, Anna I; Kuznetsova, Irina M; Turoverov, Konstantin K

    2014-01-01

    Fluorescence is a proven tool in all fields of knowledge, including biology and medicine. A significant obstacle in its use is the nonlinearity of the dependence of the fluorescence intensity on fluorophore concentration that is caused by the so-called primary inner filter effect. The existing methods for correcting the fluorescence intensity are hard to implement in practice; thus, it is generally considered best to use dilute solutions. We showed that correction must be performed always. Furthermore, high-concentration solutions (high absorbance) are inherent condition in studying of the photophysical properties of fluorescent dyes and the functionally significant interactions of biological macromolecules. We proposed an easy to use method to correct the experimentally recorded total fluorescence intensity and showed that informative component of fluorescence intensity numerically equals to the product of the absorbance and the fluorescence quantum yield of the object. It is shown that if dye molecules do not interact with each other and there is no reabsorption (as for NATA) and spectrofluorimeter provides the proportionality of the detected fluorescence intensity to the part of the absorbed light (that is possible for spectrofluorimeter with horizontal slits) then the dependence of experimentally detected total fluorescence intensity of the dye on its absorbance coincides with the calculated dependence and the correction factor for eliminating the primary inner filter effect can be calculated on the basis of solution absorbance. It was experimentally shown for NATA fluorescence in the wide range of absorbance (at least up to 60). For ATTO-425, which fluorescence and absorption spectra overlap, the elimination of the primary and secondary filter effects and additional spectral analysis allow to conclude that the most probable reason of the deviation of experimentally detected fluorescence intensity dependence on solution absorbance from the calculated dependence is the dye molecules self-quenching, which accompanies resonance radiationless excitation energy transfer. PMID:25072376

  11. Mechanism of response of potential-sensitive dyes studied by time-resolved fluorescence

    PubMed Central

    Das, Tapan K.; Periasamy, N.; Krishnamoorthy, G.

    1993-01-01

    The mechanism of response of two potential-sensitive dyes, diOC2(5) (3,3?-diethyloxadicarbocyanine iodide) and oxonol V (bis-[3-phenyl-5-oxoisoxazol-4-yl]pentamethine oxonol), were studied by using steady-state and time-resolved fluorescence techniques. The lipid concentration dependence of the ?? (membrane potential)-induced change in total fluorescence intensity was quite different for these two dyes. Time-resolved fluorescence measurements showed that the fluorescence decay of these dyes in membranes could be resolved into at least three exponentials. ??-induced changes in the levels of these three populations were also measured under a variety of conditions. In the case of diOC2(5) an inside negative ?? increased the levels of the bound forms. This shows that diOC2(5) responds to ?? mainly by an “on-off” mechanism whereby ?? perturbs the membrane-water partition coefficient of the dye. The ??-induced changes approached zero when the dye was totally membrane bound. In contrast, the ??-induced response of oxonol V increased with increased membrane binding. An inside negative ?? decreased the level of the bound form with a longer lifetime. This shows that the mechanism of response of oxonol V is a ??-induced shift in the equilibrium between bound forms of the dye. PMID:19431883

  12. Evaluation of Polymethine Dyes as Potential Probes for Near Infrared Fluorescence Imaging of Tumors: Part - 1

    PubMed Central

    James, Nadine S.; Chen, Yihui; Joshi, Penny; Ohulchanskyy, Tymish Y.; Ethirajan, Manivannan; Henary, Maged; Strekowsk, Lucjan; Pandey, Ravindra K

    2013-01-01

    Near-infrared (NIR) organic dyes have become important for many biomedical applications, including in vivo optical imaging. Conjugation of NIR fluorescent dyes to photosensitizing molecules (photosensitizers) holds strong potential for NIR fluorescence image guided photodynamic therapy (PDT) of cancer. Therefore, we were interested in investigating the photophysical properties, in vivo tumor-affinity and fluorescence imaging potential of a series of heterocyclic polymethine dyes, which could then be conjugated to certain PDT agents. For our present study, we selected a series of symmetrical polymethine dyes containing a variety of bis-N-substituted indole or benzindole moieties linked by linear conjugation with and without a fused substituted cyclohexene ring. The N-alkyl side chain at the C-terminal position was functionalized with sulfonic, carboxylic acid, methyl ester or hydroxyl groups. Although, among the parent cyanine dyes investigated, the commercially available, cyanine dye IR783 (3) (bis-indole-N-butylsulfonate)-polymethine dye with a cyclic chloro-cyclohexene moiety showed best fluorescence-imaging ability, based on its spectral properties (?Abs=782 nm, ?Fl=810 nm, ? = 261,000 M-1cm-1, ?Fl?0.08) and tumor affinity. In addition to 3, parent dyes IR820 and Cypate (6) were also selected and subjected to further modifications by introducing desired functional groups, which could enable further conjugation of the cyanine dyes to an effective photosensitizer HPPH developed in our laboratory. The synthesis and biological studies (tumor-imaging and PDT) of the resulting bifunctional conjugates are discussed in succeeding paper (Part-2 of this study). PMID:24019854

  13. Characterizing the Interaction Between DNA and GelRed Fluorescent Stain

    E-print Network

    F. A. P. Crisafuli; E. B. Ramos; M. S. Rocha

    2014-08-13

    We have performed single molecule stretching experiments and dynamic light scattering (DLS) in order to characterize the interaction between the DNA molecule and the fluorescent stain GelRed. The results from single molecule stretching show that the persistence length of the DNA-GelRed complexes increases as the ligand concentration increases up to some critical concentration, then decreasing for higher concentrations. The contour length of the complexes, on the other hand, increases monotonically as a function of GelRed concentration, suggesting that intercalation is the main binding mechanism. In order to characterize the phys- ical chemistry of the interaction, we use the McGhee-von Hippel binding isotherm to extract the physicochemical parameters of the interaction from the contour length data. The DLS experiments were performed to study the changes of the effective size of the DNA-GelRed complexes, measured by the hydrodynamic radius, as a function of ligand concentration. We found a qualitative agreement between the results obtained from the two techniques by com- paring the behaviors of the hydrodynamics radius and the radius of gyration, since this last quantity can be expressed as a function of mechanical parameters determined from the stretching experiments.

  14. A sensitive method for confocal fluorescence microscopic visualization of starch granules in iodine stained samples

    PubMed Central

    Ovecka, Miroslav; Bahaji, Abdellatif; Muńoz, Francisco José; Almagro, Goizeder; Ezquer, Ignacio; Baroja-Fernández, Edurne; Li, Jun; Pozueta-Romero, Javier

    2012-01-01

    Synthesized by glycogen synthase and starch synthases (SS) using ADP-glucose as the sugar donor molecule, glycogen and starch accumulate as predominant storage carbohydrates in most bacteria and plants, respectively. We have recently shown that the so-called “starch-less” Arabidopsis thaliana adg1–1 and aps1 mutants impaired in ADP-glucose pyrophosphorylase do indeed accumulate low starch content in normal growth conditions, and relatively high starch content when plants were cultured in the presence of microbial volatiles. Our results were strongly supported by data obtained using a highly sensitive method for confocal fluorescence microscopic visualization of iodine stained starch granules. Using Arabidopsis leaves from WT plants, aps1 plants, ss3/ss4 plants lacking both class III and class IV SS, gbss plants lacking the granule-bound SS, and sus1/sus2/sus3/sus4 plants lacking four genes that code for proteins with sucrose synthase activity, in this work we precisely describe the method for preparation of plant samples for starch microscopic examination. Furthermore, we show that this method can be used to visualize glycogen in bacteria, and pure starch granules, amylose and amylopectin. PMID:22899048

  15. Comparative analysis of heterochromatin distribution in wild and cultivated Abelmoschus species based on fluorescent staining methods.

    PubMed

    Merita, Keisham; Kattukunnel, Joseph John; Yadav, Shrirang Ramchandra; Bhat, Kangila Venkataramana; Rao, Satyawada Rama

    2015-03-01

    A comparative analysis of fluorochrome-binding pattern in nine taxa of Abelmoschus had shown that the type, amount and distribution pattern of heterochromatin were characteristic for each taxa. The fluorescent chromosome-binding sites obtained by chromomycin A3 (CMA) and 4',6-diamidino-2-phenylindole (DAPI) staining in all the nine species showed constitutive heterochromatin CMA(+), DAPI(+) and CMA(+)/DAPI(+). Large amount of heterozygosity was observed with regard to heterochromatin distribution pattern in all the taxa studied. The CMA(+)-binding sites are comparatively less than DAPI(+)-binding sites which is clearly evident as AT-rich regions are more than GC-rich regions in all the nine taxa analysed in Abelmoschus. These CMA(+) and DAPI(+)-binding sites apparently rise with the increased in chromosome numbers of the different species. This pattern of heterochromatin heterogeneity seems to be a general characteristic feature. Therefore, the differential pattern of distribution of GC- and AT-rich sequences might have played an important role in diversification of the genus Abelmoschus. Polyploidy is an important factor in the evolution of Abelmoschus and the sole reason for range in chromosome numbers in this genus. It may be noted that, though often, but not always, the increase of DNA is caused by an increase in the amount of heterochromatin, i.e. increase of non-coding sections indicating restructuring of the heterochromatin. Thus, cumulative small and direct numerical changes might have played a role in the speciation of Abelmoschus. PMID:25300590

  16. Green Tea Catechins Quench the Fluorescence of Bacteria-Conjugated Alexa Fluor Dyes

    PubMed Central

    Zhao, Lin; Li, Wei; Zhu, Shu; Tsai, Sheena; Li, Jianhua; Tracey, Kevin J.; Wang, Ping; Fan, Saijun; Sama, Andrew E.; Wang, Haichao

    2013-01-01

    Accumulating evidence suggests that Green tea polyphenolic catechins, especially the (-)-epigallocatechin gallate (EGCG), can be cross-linked to many proteins, and confer a wide range of anti-bacterial activities possibly by damaging microbial cytoplasmic lipids and proteins. At the doses that conferred protection against lethal polymicrobial infection (induced by cecal ligation and puncture), EGCG significantly reduced bacterial loads particularly in the liver and lung. To elucidate its bactericidal mechanisms, we determined whether EGCG affected the fluorescence intensities of bacteria-conjugated Alexa Fluor 488 or 594 dyes. When mixed with unconjugated Alexa Fluor 488 or 594 dyes, EGCG or analogs did not affect the fluorescence intensity of these dyes. In a sharp contrast, EGCG and some analogs (e.g., Catechin Gallate, CG), markedly reduced the fluorescence intensity of Gram-positive Staphylococcus aureus-conjugated Alexa 594 and Gram-negative Escherichia coli-conjugated Alexa 488. Interestingly, co-treatment with ethanol impaired the EGCG-mediated fluorescence quenching of the G+ S. aureus, but not of the G- E. coli-conjugated Alexa Flour dyes. In light of the notion that Alexa Fluor dyes can be quenched by aromatic amino acids, it is plausible that EGCG exerts anti-microbial activities possibly by altering microbial protein conformations and functions. This possibility can now be explored by screening other fluorescence-quenching agents for possible antimicrobial activities. PMID:24011199

  17. Applicability of different fluorescent dyes for isoform quantification on linear IPG gels.

    PubMed

    Schriebl, Kornelia; Trummer, Evelyn; Weik, Robert; Lattenmayer, Christine; Müller, Dethardt; Kunert, Renate; Katinger, Hermann; Vorauer-Uhl, Karola

    2007-06-01

    For biotechnological research, development, and production various analytical methods are required to determine the quality of the target product. In this context, the determination of isoforms is state-of-the-art; however, the majority of applied techniques are more qualitative than quantitative. To address this fact, we evaluated different post- and pre-electrophoretic staining dyes for their applicability on linear IPG gels using recombinant human erythropoietin as a model protein. Each evaluated dyes was able to detect all isoforms reproducibly, but CyDyes were found to be the most promising. Using CyDyes, up to three samples can be focused on the same lane under identical electrophoretic conditions, thus, a fast, reproducible, sensitive and quantitative isoform determination can be performed. To illustrate the practical relevance, quantitative CyDye technique was used for the characterization of our model protein, recombinant human Epo-Fc. This method makes it possible to determine the isoform pattern of nonpurified supernatants as well as purified proteins. We conclude that quantitative pre-electrophoretic staining IEF using CyDyes is a fast, simple, accurate method to determine isoforms, which can be used in research, development, and manufacturing for product quality analysis, e.g., clone screening, process optimization, and purification monitoring. PMID:17523139

  18. The Nature of the J-band in the Absorption and Fluorescence Spectra of Cyanine Dyes

    NASA Astrophysics Data System (ADS)

    Struganova, Irina; Hazell, Mesha; Gaitor, Jacinta; McNally-Carr, Debra; Zivanovic, Sanya

    2003-05-01

    Some cyanine dyes in solutions in specific conditions show a very narrow and intense absorption band spectra and fluorescence nearly resonance with the absorption. This phenomenon was discovered by J.E. Jelley and A. Scheibe in 1936 and was later explained by formation of an excitonic state among tightly packed molecules in dye aggregates. We discovered that the addition of inorganic anions to water solutions of several cyanine dyes leads to the appearance of the J-bands in the absorption and fluorescence spectra when concentration of the dyes is extremely low (up to 10-8 mol/l). The position of the maximum and the shape of the J-band depended on the inorganic anion. Temperature dependences of the absorption spectra and other data obtained indicated on a possibility of a monomolecular, not excitonic nature of the J-band.

  19. Photophysics of Laser Dye-Doped Polymer Membranes for Laser-Induced Fluorescence Photogrammetry

    NASA Technical Reports Server (NTRS)

    Dorrington, Adrian A.; Jones, Thomas W.; Danehy, Paul M.

    2004-01-01

    Laser-induced fluorescence target generation in dye-doped polymer films has recently been introduced as a promising alternative to more traditional photogrammetric targeting techniques for surface profiling of highly transparent or reflective membrane structures. We investigate the photophysics of these dye-doped polymers to help determine their long-term durability and suitability for laser-induced fluorescence photogrammetric targeting. These investigations included experimental analysis of the fluorescence emission pattern, spectral content, temporal lifetime, linearity, and half-life. Results are presented that reveal an emission pattern wider than normal Lambertian diffuse surface scatter, a fluorescence time constant of 6.6 ns, a pump saturation level of approximately 20 micro J/mm(exp 2), and a useful lifetime of more than 300,000 measurements. Furthermore, two demonstrations of photogrammetric measurements by laser-induced fluorescence targeting are presented, showing agreement between photogrammetric and physically measured dimensions within the measurement scatter of 100 micron.

  20. Application of potential-sensitive fluorescent dyes in anion and cation-sensitive polymer membranes

    Microsoft Academic Search

    Gerhard J. Mohr; Ivana Murkovic; Frank Lehmann; Christian Haider; Otto S. Wolfbeis

    1997-01-01

    The applicability of two potential-sensitive dyes (PSDs) for optical sensing of ions is reported. In particular, nitrate and nitrite-responsive as well as potassium and mercury-sensitive polymer membranes have been developed. In general, membranes are composed of a plasticized polymer, an ion carrier and a fluorescent dye which optically transduces the extraction of the analyte ion in the polymer matrix. The

  1. FLUORESCENCE GAS SENSOR USING TiO2 NANOPARTICLES COATED WITH PORPHYRIN DYE THIN FILMS

    Microsoft Academic Search

    Nurul Huda Yusoff; Muhamad Mat Salleh; Muhammad Yahaya

    This paper explores the possibility of using fluorescence technique to detect the presence of volatile organic compounds based on TiO2 nanoparticles coated with porphyrin dye thin films. Porphyrin dye used was Iron (III) meso-tetraphenylporphine chloride. The thin films were prepared with the variation of TiO2 and porphyrin ratio, i.e. 1:2, 1:3, 1:4 and 1:5 by volume. The purpose of this

  2. Dye distance mapping using waveguide evanescent field fluorescence microscopy and its application to cell biology.

    PubMed

    Fleissner, Frederik; Morawitz, Michael; Dixon, S Jeffrey; Langbein, Uwe; Mittler, Silvia

    2014-11-17

    Previous studies have measured the distance between cells and the substratum at sites of adhesion via the emission of a fluorescent dye and waveguide methods. Here, we demonstrate a novel approach to measure the position of fluorescent dyes above a waveguide surface in the 10-200 nm distance range throughout an entire area, yielding a 2D dye distance map or a 3D contour plot. The dye is located in a multilayered Langmuir Blodgett (LB) film or in the plasma membrane of a cell. Waveguide evanescent field fluorescence (WEFF) images obtained using two different waveguide modes are employed allowing, with a simple mathematical approach, the calculation of dye distance maps. Ultra-thin steps made using LB technology, adhesion distances and the bending of the plasma membrane between focal adhesions of osteoblastic cells are shown as examples. The errors are discussed. False color representation of a dye distance map with four osteoblasts. The inset represents an overexposed WEFF image of the same field of view. PMID:25401699

  3. Differential fluorescent staining of Listeria monocytogenes and a whey food soil for quantitative analysis of surface hygiene.

    PubMed

    Whitehead, Kathryn A; Benson, Paul; Verran, Joanna

    2009-09-30

    The accurate monitoring of surface cleanliness in terms of bacterial contamination is usually carried out using methods such as plate counts or replica plating. However these methods take at least eighteen hours to obtain results and do not determine the presence or amount of residual organic material on a surface, which may interfere with cleaning and disinfection. This work describes the application of fluorescent stains to cells (Listeria monocytogenes) and food soil (solubilized whey) to optimize a dual staining method that can be used in the quantitative analysis of surface cleanability. Seven different stains were tested at a range of concentrations (0.3%-0.001 mg/ml) and application methods. The best stain combination for differential staining of L. monocytogenes and whey food soil was 0.1 mg/ml rhodamine B with 0.1 g/ml DAPI. Differential staining of the cells and soil occurred regardless of the application method. This method has been successfully used to demonstrate the hygienic status of surfaces in an industrial situation. This novel work enables quantitative assessment of soils and cells on surfaces. PMID:19654071

  4. Port-Wine Stains

    MedlinePLUS

    ... port-wine stains called a "pulsed-dye" laser . Laser treatment is often started in infancy when the stain ... easier to treat. But that doesn't mean laser treatments can't help older kids or teens, too — ...

  5. Improved conditions for periodate/Schiff's base-based fluorescent staining of glycoproteins with dansylhydrazine in SDS-PAGE.

    PubMed

    Zhou, Xuan; Hong, Guo-Ying; Huang, Bin-Bin; Duan, Yuan-Meng; Shen, Jia-Yi; Ni, Mao-Wei; Cong, Wei-Tao; Jin, Li-Tai

    2014-05-01

    An improved periodate/Schiff's base based fluorescent stain with dansylhydrazine (DH) for glycoproteins in 1D and 2D SDS-PAGE was described. Down to 4-8 ng of glycoproteins can be selectively detected within 2 h, which is approximately 16-fold higher than that of original protocol, but similar to that of Pro-Q Emerald 488 stain (Invitrogen, Carlsbad, USA). Furthermore, subsequent study of deglycosylation, glycoprotein affinity isolation, and LC-MS/MS analysis were performed to confirm the specificity of the improved method. As a result, improved DH stain may provide a new choice for selective, economic, MS compatible, and convenient visualization of gel-separated glycoproteins. PMID:24591039

  6. Photosensitive Fluorescent Dye Contributes to Phototoxicity and Inflammatory Responses of Dye-doped Silica NPs in Cells and Mice

    PubMed Central

    Zhao, Yang; Ye, Yan; Zhou, Xikun; Chen, Jiao; Jin, Yuihui; Hanson, Aaron; Zhao, Julia Xiaojun; Wu, Min

    2014-01-01

    Dye-doped fluorescent silica nanoparticles provide highly intense and photostable fluorescence signals. However, some dopant dye molecules are photosensitive. A widely-used photosensitive fluorescent dopant, RuBpy, was chosen to systematically investigate the phototoxicity of the dye-doped silica nanoparticles (NPs). We investigated cell viability, DNA damage, and Reactive Oxygen Species (ROS) levels in alveolar macrophages using the dye-doped NPs with or without irradiation. Our results showed that the RuBpy-doped silica NPs could induce significant amount of ROS, DNA damage, apoptosis and impaired proliferation in MH-S cells. In vivo studies in mice showed that RuBpy-doped silica NPs induced significant inflammatory cytokine production and lowered expression in signaling proteins such as ERK1/2 and NF-?B as well as increased lung injury determined by myeloperoxidase and lipid peroxidation. Strikingly, we also found that both RuBpy alone and NPs induced systemic signaling activation in the kidney compared to the liver and lung where showed highly selective signaling patterns, which is more pronounced than RuBpy-doped silica NPs. Moreover, we discovered a critical biomarker (e.g., HMGB1) for silica NPs-induced stress and toxicity and demonstrated differentially-regulated response patterns in various organs. Our results indicate for the first time that the RuBpy-doped silica NPs may impose less inflammatory responses but stronger thermotherapeutic effects on target cells in animals than naked NPs in a time- and dose-dependent manner. PMID:24578727

  7. Ecophysiological Analysis of Microorganisms in Complex Microbial Systems by Combination of Fluorescence In Situ Hybridization with Extracellular Staining Techniques

    NASA Astrophysics Data System (ADS)

    Nielsen, Jeppe Lund; Kragelund, Caroline; Nielsen, Per Halkjćr

    Ecophysiological analysis and functions of single cells in complex microbial systems can be examined by simple combinations of Fluorescence in situ hybridization (FISH) for identification with various staining techniques targeting functional phenotypes. In this chapter, we describe methods and protocols optimized for the study of extracellular enzymes, surface hydrophobicity and specific surface structures. Although primarily applied to the study of microbes in wastewater treatment (activated sludge and biofilms), the methods may also be used with minor modifications in several other ecosystems.

  8. Multifunctional Particles: Magnetic Nanocrystals and Gold Nanorods Coated with Fluorescent Dye-Doped Silica Shells

    PubMed Central

    Heitsch, Andrew T.; Smith, Danielle K.; Patel, Reken E.; Ress, David; Korgel, Brian A.

    2008-01-01

    Multifunctional colloidal core-shell nanoparticles of magnetic nanocrystals (of iron oxide or FePt) or gold nanorods encapsulated in silica shells doped with the fluorescent dye, Tris(2,2?-bipyridyl)dichlororuthenium(II) hexahydrate (Rubpy) were synthesized. The as-prepared magnetic nanocrystals are initially hydrophobic and were coated with silica using a microemulsion approach, while the as-prepared gold nanorods are hydrophilic and were coated with silica using a Stöber-type of process. Each approach yielded monodisperse nanoparticles with uniform fluorescent dye-doped silica shells. These colloidal heterostructures have the potential to be used as dual-purpose tags—exhibiting a fluorescent signal that could be combined with either dark-field optical contrast (in the case of the gold nanorods), or enhanced contrast in magnetic resonance images (in the case of magnetic nanocrystal cores). The optical and magnetic properties of the fluorescent silica-coated gold nanorods and magnetic nanocrystals are reported. PMID:19578476

  9. Polarization and Symmetry of Electronic Transitions in Long Fluorescence Lifetime Triangulenium Dyes

    PubMed Central

    Thyrhaug, Erling; Sřrensen, Thomas Just; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.

    2013-01-01

    To fully exploit the capabilities of fluorescence probes in modern experiments, where advanced instrumentation is used to probe complex environments, other photophysical properties than emission color and emission intensity are monitored. Each dye property can be addressed individually as well as collectively to provide in-depth information unavailable from the standard intensity measurements. Dyes with long emission lifetimes and strongly polarized transitions enable the monitoring of lifetime changes as well as emission polarization (or anisotropy). Thus experiments can be designed to follow slow dynamics. In this article the UV and visible electronic transitions of a series of red emitting dyes based on the triangulenium motif are investigated. We resolve overlapping features in the spectra and assign transition moment of the molecular axes. The result is the complete Jablonski diagram for the UV and visible spectral region. The symmetries of the studied dyes are shown to have a large influence on the optical response and they are clearly separated into two groups of symmetry by their photophysical properties. The C2v symmetric dyes: azadioxatriangulenium (ADOTA+) and diazaoxatriangulenium (DAOTA+) have high emission anisotropies, fluorescence lifetimes around 20 ns, and fluorescence quantum yields of ~50%. The trioxatriangulenium (TOTA+) and triazatriangulenium (TATA+) dyes—nominally of D3h symmetry—have fluorescence lifetimes around 10 ns lifetimes and fluorescence quantum yields of 10-15%. However, the D3h-symmetry is shown to be lowered to a point group, where the axes transform uniquely such that the degeneracy of the E’-states is lifted. PMID:23391292

  10. Testing the Fraunhofer line discriminator by sensing fluorescent dye

    NASA Technical Reports Server (NTRS)

    Stoertz, G. E.

    1969-01-01

    The experimental Fraunhofer Line Discriminator (FLD) has detected increments of Rhodamine WT dye as small as 1 ppb in 1/2 meter depths. It can be inferred that increments considerably smaller than 1 ppb will be detectable in depths considerably greater than 1/2 meter. Turbidity of the water drastically reduces luminescence or even completely blocks the transmission of detectable luminescence to the FLD. Attenuation of light within the water by turbidity and by the dye itself are the major factors to be considered in interpreting FLD records and in relating luminescence coefficient to dye concentration. An airborne test in an H-19 helicopter established feasibility of operating the FLD from the aircraft power supply, and established that the rotor blades do not visibly affect the monitoring of incident solar radiation.

  11. The Excitation Spectra of Two-Photon Induced Fluorescence in Xanthene Dyes

    Microsoft Academic Search

    Takanori Wakebe; Edward Van Keuren

    1999-01-01

    Two-photon excitation spectra of xanthene dyes in ethanol weremeasured by observing fluorescence emission after excitation by lightwith wavelengths from 780 to 1260 nm. The normalized spectra showedlarge two-photon induced fluorescence at higher energies and twomoderate peaks near the one-photon absorption band. These featuresagreed well with the two-photon excitation spectra reported by otherauthors. The peaks near the one-photon absorption band may

  12. Dye-enhanced laser fluorescence detection of caries lesions around brackets

    Microsoft Academic Search

    Cássio José Fornazari Alencar; Mariana Minatel Braga; Elisabeth de Oliveira; José Nicolau; Fausto Medeiros Mendes

    2009-01-01

    The aim was to evaluate the performance of DIAGNOdent [laser fluorescence(LF) and LFpen] devices enhanced by fluorescent dye\\u000a in detecting mineral loss around brackets and comparing the inhibitory effect of bonding material on artificial demineralization,\\u000a and to verify whether LF methods show the same trends of mineral loss. Brackets were bonded to premolar halves with Fuji Ortho\\u000a LC, Transbond XT,

  13. Lasing and fluorescence properties of dye-doped xerogel

    NASA Astrophysics Data System (ADS)

    Weissbeck, A.; Langhoff, H.; Beck, A.

    1995-09-01

    Dye-doped SiO2-xerogels are prepared for application as laser active medium. An optical surface and a sealing of the samples are achieved by covering them with silicon oil and an optical glass window. All optical properties were compatible with the assumption that the active chromophores are dissolved in the liquid which fills the pores of the xerogel. A replacement of the dye molecules destroyed by the pumping radiation via diffusion was observed. For stilbene 3 a diffusion coefficient of D = 0.35 × 10-9 m2/s was determined. Thus a durable operation of the laser with low repetition rates is possible.

  14. A comparison of fluorescent stains for the assessment of viability and metabolic activity of lactic acid bacteria.

    PubMed

    Zotta, T; Guidone, A; Tremonte, P; Parente, E; Ricciardi, A

    2012-03-01

    Lactic acid bacteria (LAB) are used as starter or probiotic cultures in the food and pharmaceutical industries and, therefore, rapid and accurate methods for the detection of their viability are of practical relevance. In this study 10 LAB strains, belonging to the genera Enterococcus, Lactococcus, Leuconostoc, Lactobacillus, Streptococcus and Weissella, were subjected to heat and oxidative stresses and cell injury or death was assessed comparing different fluorescent probes (Syto 9; Propidium Iodide, PI; 4,6-diamidino-2-phenylindole, DAPI; 5,(6)-carboxyfluorescein diacetate, cFDA) to identify the stain combination which most reliably allowed the detection of live/metabolically active and dead cells. Protocols for specimen preparation and staining were optimized and a simple procedure for automated cell counts was developed using NIH ImageJ macros. Cysteine and semi-solid agar solution were efficiently used as anti-fading agent and mounting medium, respectively. The double staining cFDA-PI apparently offered the best and most versatile indication of both cell metabolic activity and membrane integrity. An excellent correlation between manual and automated cell counts for the majority of strain/stain combinations was found. This work provides a simple protocol for specimen preparation and staining based on the use of safe, easy to prepare and inexpensive reagents as compared to other methods. Additionally, the automated cell count procedure developed can be applied to several bacterial species and allows an increase in the number of experimental trials and the reproducibility and sensitivity of the analysis. PMID:22805812

  15. Dual appearance of fluorescein staining in vivo of diseased human corneal epithelium. A non-contact photomicrographic study.

    PubMed Central

    Tabery, H M

    1992-01-01

    Adherence of fluorescein sodium dye to diseased epithelial cells, a hitherto unreported phenomenon, was captured in photomicrographs in severe herpes zoster and keratoconjunctivitis sicca keratopathies. It is notable that this phenomenon differs completely from the well known fluorescent property of the dye penetrating into defective corneal epithelium, and that the staining pattern shown by adherent fluorescein correlates well with the staining pattern shown by rose bengal dye. Images PMID:1371224

  16. Fingerprint visualization enhancement by deposition of columnar thin films and fluorescent dye treatment.

    PubMed

    Dutta, Jhuma; Ramakrishna, S A; Mekkaoui Alaoui, I

    2013-05-10

    Enhanced visualization of latent fingerprints on two non-porous surfaces, smooth glass slides and highly reflecting rough aluminum sheets, is obtained by depositing columnar thin films (CTFs) of calcium fluoride (CaF2) and silica (SiO2) by physical vapor deposition at large oblique angles. Due to the vapor flux getting shadowed by the physical residues in the fingerprints, the CTFs are deposited only on the upraised ridges, resulting in highly enhancing the visibility of the fingerprint. The visualization of these fingerprints with deposited CTFs is further enhanced by subsequently treating them with a fluorescent dye and fluorescence imaging. A specific amino-acid reagent (1,2-indanedione) and non-specific laser dye (Rhodamine 6G), both allowed enhanced visualization of the CTFs grown on the fingerprints, due to the localization and entrenchment of the dye within the CTF regions. PMID:23597736

  17. Fluorescence enhancement monitoring of pyrromethene laser dyes by metallic Ag nanoparticles.

    PubMed

    Sakr, Mahmoud E M; Abou Kana, Maram T H; Abdel Fattah, Gamal

    2014-11-01

    Fluorescence enhancement monitoring of pyrromethene laser dyes using their complexation with Ag nanoparticles (Ag NPs) was studied. The size of the prepared Ag NPs was determined by transmission electron spectroscopy and UV/Vis absorption spectroscopy. Mie theory was also used to confirm the size of NPs theoretically. The effect of different nanoparticle concentrations on the optical properties of 1 × 10(-4) M PM dyes shows that 40%of Ag NPs concentration (40%C Ag NPs) in complex is the optimum concentration. Also, the effects of different concentrations of PM dyes in a complex was measured. Emission enhancement factors were calculated for all samples. Fluorescence enhancement efficiencies depended on the input pumping energy of a Nd-YAG laser (wavelength 532 nm and 8 ns pulse duration) were reported and showed the lowest energy (28 and 32 mJ) in the case of PM567 and PM597, respectively. PMID:24652745

  18. Highly sensitive turn-on biosensors by regulating fluorescent dye assembly on liposome surfaces.

    PubMed

    Seo, Sungbaek; Kwon, Min Sang; Phillips, Andrew W; Seo, Deokwon; Kim, Jinsang

    2015-06-01

    We developed a new self-signaling sensory system built on phospholipid liposomes having H-aggregated R6G dyes on their surface. Selective molecular recognition of a target by the phospholipid displaces R6G from the liposome surface to turn on fluorescence signal. Selective and sensitive detection of neomycin down to 2.3 nM is demonstrated. PMID:26022090

  19. Fabrication of dual dye-doped silica nanotube as a fluorescent ratiometric pH sensor.

    PubMed

    Nguyen, Phuong-Diem; Nguyen, Dung Thi Xuan; Son, Sang Jun; Min, Junhong

    2014-11-01

    This study described a novel fabrication of fluorescence co-encapsulating silica nanotubes (F@SNT) and the further application of the as-synthesized nanostructure as a ratiometric pH sensor in buffer solution. Silica nanotubes (SNTs) embedded anodic alumina oxide (AAO) template was fabricated by sol-gel technique, tetramethyl rhodamine (TMR-the reference dye) was incorporated directly onto silica layer via hydrophobic interaction. Subsequently, fluorescent isothiocyanate (FITC-pH sensitive dye) was encapsulated inside poly-dimethylsiloxane (PDMS) matrix and the FITC-PDMS nanocomposite was doped into the hollow structure of SNT using nano-molding lithography. On removing AAO, free-standing SNTs were obtained and were subsequently applied as a ratiometric pH sensor in phosphate buffer solution. The dual dye-doped SNTs showed excellent fluorescence and a good pH sensing performance from pH 5.2-8.0. The results were distinguishable by the emission spectra and by fluorescent visualization. High photostability, sensitivity, biocompatibility with adjustable sizes make dual dye doped-SNT a promising nanostructure for bioapplications. PMID:25958591

  20. Computational and Experimental Characterization of a Fluorescent Dye for Detection of Potassium Ion Concentration

    E-print Network

    Yaron, David

    1 Computational and Experimental Characterization of a Fluorescent Dye for Detection of Potassium that binds the potassium ion, and a chromophore that signals the presence of the ion. We use quantum chemical. The potassium ion preferentially destabilizes the charge-transfer state, thereby altering the quantum yield

  1. Use of Tunable, Pulsed Dye Laser for Quantitative Fluorescence in Syphilis Serology (FTA-ABS Test)

    PubMed Central

    Kasatiya, S. S.; Lambert, N. G.; Laurence, R. A.

    1974-01-01

    A pulsed dye laser was used as an excitation source in a fluorescent treponemal antibody absorption (FTA-ABS) test. A high precision in quantitative fluorescence was obtained with this high-power excitation source coupled to an electronic detection system and a storage oscilloscope by standardization of fluorescence evaluation and through elimination of human error. One 0.4-?s pulse exposure was sufficient to record fluorescence intensity data on the oscilloscope. Absence of fading of fluorescence after repeated excitation permitted multiple readings of the same microscope field. Almost 100% reproducible results were obtained for the FTA-ABS test with 40 samples. Electronic detection of fluorescence and the high sensitivity obtained with laser excitation raise doubts about the relative value of quantitative immunofluorescence in the FTA-ABS test. PMID:4598221

  2. Influence of the temperature on the detection of fluorescent Y-bodies in blood stains.

    PubMed

    Thomsen, J L

    1978-01-01

    An investigation on the significance of the temperature when examining the presence of Y-bodies in cells from blood stains was performed. Stains on cotton cloth were placed at 53 degrees C and 5 degrees C respectively, and the results were compared with those of an earlier report on stains stored at room temperature. There proved to be a much more rapid decline of the male count, and false negative results appeared earlier. This was most pronounced for the "cold" stains. No false positives were found. Twenty-five fresh blood smears from one male were examined in order to get an impression of the accidental variation. It was found that even in the case of a male with a rather low count (mean: 28%) the chance of accidentally getting a false negative result (less than 10%) was less than 2%. PMID:658857

  3. Development of Thermally Stable and Highly Fluorescent IR Dyes

    NASA Technical Reports Server (NTRS)

    Bu, Xiu R.

    2004-01-01

    Fluorophores are the core component in various optical applications such as sensors and probes. Fluorphores with low-energy or long wavelength emission, in particular, in NIR region, possess advantages of low interference and high sensitivity. In this study, we has explored several classes of imidazole-based compounds for NIR fluorescent properties and concluded: (1) thiazole-based imidazole compounds are fluorescent; (2) emission energy is tunable by additional donor groups; (3) they also possess impressive two- photon absorption properties; and (4) fluorescence emission can be induced by two- photon input. This report summarizes (1) synthesis of new series of fluorophore; (2) impact of electron-withdrawing groups on fluorescent property; (3) unique property of two-photon absorption; and (4) on-going development.

  4. FITC-conjugated cyclic RGD peptides as fluorescent probes for staining integrin ?v?3/?v?5 in tumor tissues.

    PubMed

    Zheng, Yumin; Ji, Shundong; Czerwinski, Andrzej; Valenzuela, Francisco; Pennington, Michael; Liu, Shuang

    2014-11-19

    This study sought to evaluate FITC-conjugated cyclic RGD peptides (FITC-RGD2, FITC-3P-RGD2, and FITC-Galacto-RGD2) as fluorescent probes for in vitro assays of integrin ?v?3/?v?5 expression in tumor tissues. FITC-RGD2, FITC-3P-RGD2, and FITC-Galacto-RGD2 were prepared, and their integrin ?v?3/?v?5 binding affinity was determined using the displacement assay against (125)I-echistatin bound to U87MG glioma cells. IC50 values of FITC-Galacto-RGD2, FITC-3P-RGD2, and FITC-RGD2 were calculated to be 28 ± 8, 32 ± 7, and 89 ± 17 nM, respectively. The integrin ?v?3/?v?5 binding affinity followed a general trend: FITC-Galacto-RGD2 ? FITC-3P-RGD2 > FITC-RGD2. The xenografted tumor-bearing models were established by subcutaneous injection of 5 × 10(6) tumor cells into shoulder flank (U87MG, A549, HT29, and PC-3) or mammary fat pad (MDA-MB-435) of each athymic nude mouse. Three to six weeks after inoculation, the tumor size was 0.1-0.3 g. Tumors were harvested for integrin ?v?3/?v?5 staining, as well as hematoxylin and eosin (H&E) staining. Six human carcinoma tissues (colon cancer, pancreatic cancer, lung adenocarcinoma, squamous cell lung cancer, gastric cancer, and esophageal cancer) were obtained from recently diagnosed cancer patients. Human carcinoma slides were deparaffinized in xylene, rehydrated with ethanol, and then used for integrin ?v?3/?v?5 staining, as well as H&E staining. It was found that the tumor staining procedures with FITC-conjugated cyclic RGD peptides were much simpler than those with the fluorescence-labeled integrin ?v?3 antibodies. Since FITC-RGD2, FITC-3P-RGD2, and FITC-Galacto-RGD2 were able to co-localize with the fluorescence-labeled integrin ?3 antibody, their tumor localization and tumor cell binding are integrin ?v?3-specific. Quantification of the fluorescent intensity in five xenografted tumors (U87MG, MDA-MB-435, A549, HT29, and PC-3) and six human carcinoma tissues revealed an excellent linear relationship between the relative integrin ?v?3/?v?5 expression levels determined with FITC-Galacto-RGD2 and those obtained with the fluorescence-labeled anti-human integrin ?3 antibody. There was also an excellent linear relationship between the tumor uptake (%ID/g) of (99m)Tc-3P-RGD2 (an integrin ?v?3/?v?5-targeted radiotracer) and the relative integrin ?v?3/?v?5 expression levels from the quantification of fluorescent intensity in the tumor tissues stained with FITC-Galacto-RGD2. These results suggest that FITC-conjugated cyclic RGD peptides might be useful to correlate the in vitro findings with the in vivo imaging data from an integrin ?v?3/?v?5-targeted radiotracer. The results from this study clearly showed that the FITC-conjugated cyclic RGD peptides (particularly FITC-3P-RGD2 and FITC-Galacto-RGD2) are useful fluorescent probes for assaying relative integrin ?v?3/?v?5 expression levels in tumor tissues. PMID:25312799

  5. Estimation of the electric plasma membrane potential difference in yeast with fluorescent dyes: comparative study of methods.

    PubMed

    Peńa, Antonio; Sánchez, Norma Silvia; Calahorra, Martha

    2010-10-01

    Different methods to estimate the plasma membrane potential difference (PMP) of yeast cells with fluorescent monitors were compared. The validity of the methods was tested by the fluorescence difference with or without glucose, and its decrease by the addition of 10 mM KCl. Low CaCl? concentrations avoid binding of the dye to the cell surface, and low CCCP concentrations avoid its accumulation by mitochondria. Lower concentrations of Ba˛+ produce a similar effect as Ca˛+, without producing the fluorescence changes derived from its transport. Fluorescence changes without considering binding of the dyes to the cells and accumulation by mitochondria are overshadowed by their distribution between this organelle and the cytoplasm. Other factors, such as yeast starvation, dye used, parameters of the fluorescence changes, as well as buffers and incubation times were analyzed. An additional approach to measure the actual or relative values of PMP, determining the accumulation of the dye, is presented. PMID:21063758

  6. Effect of fluorescent dyes on in vitro-differentiated, late-stage Plasmodium falciparum gametocytes.

    PubMed

    Gebru, Tamirat; Mordmüller, Benjamin; Held, Jana

    2014-12-01

    Plasmodium falciparum gametocytes are not associated with clinical symptoms, but they are responsible for transmitting the pathogen to mosquitoes. Therefore, gametocytocidal interventions are important for malaria control and resistance containment. Currently available drugs and vaccines are not well suited for that purpose. Several dyes have potent antimicrobial activity, but their use against gametocytes has not been investigated systematically. The gametocytocidal activity of nine synthetic dyes and four control compounds was tested against stage V gametocytes of the laboratory strain 3D7 and three clinical isolates of P. falciparum with a bioluminescence assay. Five of the fluorescent dyes had submicromolar 50% inhibitory concentration (IC50) values against mature gametocytes. Three mitochondrial dyes, MitoRed, dihexyloxacarbocyanine iodide (DiOC6), and rhodamine B, were highly active (IC(50)s < 200 nM). MitoRed showed the highest activity against gametocytes, with IC(50)s of 70 nM against 3D7 and 120 to 210 nM against clinical isolates. All compounds were more active against the laboratory strain 3D7 than against clinical isolates. In particular, the endoperoxides artesunate and dihydroartemisinin showed a 10-fold higher activity against 3D7 than against clinical isolates. In contrast to all clinically used antimalarials, several fluorescent dyes had surprisingly high in vitro activity against late-stage gametocytes. Since they also act against asexual blood stages, they shall be considered starting points for the development of new antimalarial lead compounds. PMID:25267675

  7. Synchronous fluorescence spectroscopic study of solvatochromic curcumin dye

    NASA Astrophysics Data System (ADS)

    Patra, Digambara; Barakat, Christelle

    2011-09-01

    Curcumin, the main yellow bioactive component of turmeric, has recently acquired attention by chemists due its wide range of potential biological applications as an antioxidant, an anti-inflammatory, and an anti-carcinogenic agent. This molecule fluoresces weakly and poorly soluble in water. In this detailed study of curcumin in thirteen different solvents, both the absorption and fluorescence spectra of curcumin was found to be broad, however, a narrower and simple synchronous fluorescence spectrum of curcumin was obtained at ? ? = 10-20 nm. Lippert-Mataga plot of curcumin in different solvents illustrated two sets of linearity which is consistent with the plot of Stokes' shift vs. the ET30. When Stokes's shift in wavenumber scale was replaced by synchronous fluorescence maximum in nanometer scale, the solvent polarity dependency measured by ?SFSmax vs. Lippert-Mataga plot or ET30 values offered similar trends as measured via Stokes' shift for protic and aprotic solvents for curcumin. Better linear correlation of ?SFSmax vs. ?* scale of solvent polarity was found compared to ?absmax or ?emmax or Stokes' shift measurements. In Stokes' shift measurement both absorption/excitation as well as emission (fluorescence) spectra are required to compute the Stokes' shift in wavenumber scale, but measurement could be done in a very fast and simple way by taking a single scan of SFS avoiding calculation and obtain information about polarity of the solvent. Curcumin decay properties in all the solvents could be fitted well to a double-exponential decay function.

  8. Identification and quantification of cooling water biofilms using fluorescent staining and ATP monitoring techniques

    SciTech Connect

    Chalut, J.; Cairns, J.; Korkorian, N. [Grace Dearborn Inc., Mississauga, Ontario (Canada)

    1994-12-31

    Biofilm formation can create corrosion problems in industrial water systems. Control of biofilms is achieved most effectively when the mechanism of formation is understood. The use of traditional microbiological analyses such as plate counts and dipslides to analyze deposits provides insufficient information about viable cell content and their role in deposit formation. The ATP assay, a newer technology, is more useful but only measures total living biomass. In order to assess the potential for biofouling in cooling water systems, novel staining and monitoring techniques have been developed. Staining technology allows characterization and assessment of biofilm composition. This staining methodology is used to complement ATP analysis of field samples. Case histories are used to illustrate the benefits of this approach. Case histories included a textile manufacturing plant, an oil refinery, and a pulp and paper mill.

  9. Modulation of quantum dot photoemission based on fluorescence resonance energy transfer to a photochromic dye acceptor

    NASA Astrophysics Data System (ADS)

    Medintz, Igor L.; Clapp, Aaron R.; Trammel, Scott A.; Mattoussi, Hedi M.

    2004-12-01

    We demonstrate the use of a photochromic dye to achieve fluorescence resonance energy transfer (FRET) modulation between a QD donor and the dye acceptor brought in close proximity in a selfassembled QD-protein-dye conjugate. The E. coli maltose binding protein (MBP) appended on its C-terminal with an oligohistidine attachment domain, immobilized onto CdSe-ZnS core-shell QDs was labeled with a sulfo-N-hydroxysuccinimide activated photochromic BIPS molecule (1',3-dihydro-1'-(2-carboxyethyl)-3,3-dimethyl-6-nitrospiro[2H-1-benzopyran-2,2'-(2H)-indoline]). Two different dye-to-MBP-protein ratios of 1:1 and 5:1 were used. The ability of MBP-BIPS to modulate QD photoluminescence was tested by switching BIPS from the colorless spiropyran (SP) to the colored merocyanine (MC) using irradiation with white light (>500 nm) or with UV light (~365 nm), respectively. QDs surrounded by ~20 MBP-BIPS with a dye to protein ratio of 1 showed ~25% loss in their photoemission with consecutive repeated switches, while QDs surrounded by ~20 MBP-BIPS with BIPS to MBP ratio of 5 produced a substantially more pronounced rate of FRET where the QD emission was quenched by ~60%. This result suggests the possibility of using QD-protein conjugates to assemble reversible FRET nanoassemblies where the QD emission can be controlled by changing the properties of the acceptors dyes bound to the protein.

  10. Synthesis and Characterization of Far-Red/NIR-Fluorescent BODIPY Dyes, Solid-State Fluorescence, and Application as Fluorescent Tags Attached to Carbon Nano-onions.

    PubMed

    Bartelmess, Juergen; Baldrighi, Michele; Nardone, Valentina; Parisini, Emilio; Buck, David; Echegoyen, Luis; Giordani, Silvia

    2015-06-26

    A series of ?-extended distyryl-substituted boron dipyrromethene (BODIPY) derivatives with intense far-red/near-infrared (NIR) fluorescence was synthesized and characterized, with a view to enhance the dye's performance for fluorescence labeling. An enhanced brightness was achieved by the introduction of two methyl substituents in the meso positions on the phenyl group of the BODIPY molecule; these substituents resulted in increased structural rigidity. Solid-state fluorescence was observed for one of the distyryl-substituted BODIPY derivatives. The introduction of a terminal bromo substituent allows for the subsequent immobilization of the BODIPY fluorophore on the surface of carbon nano-onions (CNOs), which leads to potential imaging agents for biological and biomedical applications. The far-red/NIR-fluorescent CNO nanoparticles were characterized by absorption, fluorescence, and Raman spectroscopies, as well as by thermogravimetric analysis, dynamic light scattering, high-resolution transmission electron microscopy, and confocal microscopy. PMID:26015289

  11. Sentinel lymph nodes detection with an imaging system using Patent Blue V dye as fluorescent tracer

    NASA Astrophysics Data System (ADS)

    Tellier, F.; Steibel, J.; Chabrier, R.; Rodier, J. F.; Pourroy, G.; Poulet, P.

    2013-03-01

    Sentinel lymph node biopsy is the gold standard to detect metastatic invasion from primary breast cancer. This method can help patients avoid full axillary chain dissection, thereby decreasing the risk of morbidity. We propose an alternative to the traditional isotopic method, to detect and map the sentinel lymph nodes. Indeed, Patent Blue V is the most widely used dye in clinical routine for the visual detection of sentinel lymph nodes. A Recent study has shown the possibility of increasing the fluorescence quantum yield of Patent Blue V, when it is bound to human serum albumin. In this study we present a preclinical fluorescence imaging system to detect sentinel lymph nodes labeled with this fluorescent tracer. The setup is composed of a black and white CCD camera and two laser sources. One excitation source with a laser emitting at 635 nm and a second laser at 785 nm to illuminate the region of interest. The prototype is operated via a laptop. Preliminary experiments permitted to determine the device sensitivity in the ?mol.L-1 range as regards the detection of PBV fluorescence signals. We also present a preclinical evaluation performed on Lewis rats, during which the fluorescence imaging setup detected the accumulation and fixation of the fluorescent dye on different nodes through the skin.

  12. Vital staining of specific monoamine-containing cells in the leech nervous system

    Microsoft Academic Search

    Ann E. Stuart; A. J. Hudspeth; Zach W. Hall

    1974-01-01

    Neutral red and several related dyes selectively stain certain cells in the ventral nerve cord of the leech. These cells are identical with those that can be shown by the FalckHillarp fluorescence technique to contain serotonin or a catecholamine; evidence suggests that the catecholamine is dopamine. Although the mechanism of staining remains unknown, it does not depend on active uptake

  13. Confocal laser scanning microscopy of mitochondria within microspore tetrads of plants using rhodamine 123 as a fluorescent vital stain.

    PubMed

    Gambier, R M; Mulcahy, D L

    1994-11-01

    The present study demonstrates that rhodamine 123 penetrates the callose walls surrounding plant microspores before they are released from tetrads. The stain accumulates in active mitochondria due to the electrical potential across the mitochondrial membrane. Accumulation of dye does not occur in mitochondria of fixed cells and fades quickly when mitochondrial activity is inhibited by exposure to carbonyl cyanide m-chlorophenyl hydrazone. Rhodamine can be used as a viability test for microspores still within tetrads, thus making it possible to determine when during development genes leading to pollen sterility are expressed. Rhodamine 123 is excited by blue (550 nm) light and can thus be used with confocal laser scanning microscopy. Anthers of Nicotiana tabacum, Oenothera villaricae, Silene dioica and Lycopersicum esculentum were studied here. PMID:7703302

  14. Reduction of Nonspecific Background Staining in the Fluorescent Treponemal Antibody-Absorption Test

    PubMed Central

    Roberts, Merritt E.; Miller, James N.; Binnings, Gerald F.

    1968-01-01

    The nonspecific background fluorescence which occurs with the fluorescent treponemal antibody-absorption test for syphilis was found to result from a reaction between serum-treated Treponema pallidum organisms and the conjugated antihuman ?-globulin. It was also shown that ?-lipoprotein and albumin were the important contributing factors in human serum. Various dilutions of 2.5% trypsin in phosphate-buffered saline specifically reduced background fluorescence under proper test conditions. By employing a trypsin digestion method, a semiautomated procedure utilizing a visual readout has been postulated as feasible. PMID:4177869

  15. Polar diketopyrrolopyrrole-imidazolium salts as selective probes for staining mitochondria in two-photon fluorescence microscopy.

    PubMed

    Grzybowski, Marek; Glodkowska-Mrowka, Eliza; Hugues, Vincent; Brutkowski, Wojciech; Blanchard-Desce, Mireille; Gryko, Daniel T

    2015-06-15

    Three rationally designed polar derivatives of diketopyrrolopyrrole consisting of 1,3-dimethylimidazolium cationic units and benzene, thiophene, or furan rings as ? spacers were synthesized and thoroughly studied. The obtained salts are soluble in polar organic solvents and show satisfactory solubility in water, which makes them suitable for the applications in bioimaging. Photophysical measurements revealed that the obtained derivatives are characterized by strong absorption and good fluorescence quantum yields. The corresponding two-photon properties were also examined and showed that the synthesized salts exhibit large two-photon absorption cross-sections reaching 4000?GM (GM=Goeppert-Mayer unit, 1?GM=10(-50) ?cm(4) ?s?photon(-1) ) and very high two-photon brightness values exceeding 2000?GM. It was demonstrated that these salts can be safely applied in two-photon fluorescence microscopy for selective staining of mitochondria in living cells. PMID:25966282

  16. Benchtop Antigen Detection Technique using Nanofiltration and Fluorescent Dyes

    NASA Technical Reports Server (NTRS)

    Scardelletti, Maximilian C.; Varaljay, Vanessa

    2009-01-01

    The designed benchtop technique is primed to detect bacteria and viruses from antigenic surface marker proteins in solutions, initially water. This inclusive bio-immunoassay uniquely combines nanofiltration and near infrared (NIR) dyes conjugated to antibodies to isolate and distinguish microbial antigens, using laser excitation and spectrometric analysis. The project goals include detecting microorganisms aboard the International Space Station, space shuttle, Crew Exploration Vehicle (CEV), and human habitats on future Moon and Mars missions, ensuring astronaut safety. The technique is intended to improve and advance water contamination testing both commercially and environmentally as well. Lastly, this streamlined technique poses to greatly simplify and expedite testing of pathogens in complex matrices, such as blood, in hospital and laboratory clinics.

  17. Hierarchical growth of fluorescent dye aggregates in water by fusion of segmented nanostructures.

    PubMed

    Zhang, Xin; Görl, Daniel; Stepanenko, Vladimir; Würthner, Frank

    2014-01-27

    Dye aggregates are becoming increasingly attractive for diverse applications, in particular as organic electronic and sensor materials. However, the growth processes of such aggregates from molecular to small assemblies up to nanostructures is still not properly understood, limiting the design of materials' functional properties. Here we elucidate the supramolecular growth process for an outstanding class of functional dyes, perylene bisimides (PBIs), by transmission electron microscopy (TEM), cryogenic scanning electron microscopy (cryo-SEM), and atomic force microscopy (AFM). Our studies reveal a sequential growth of amphiphilic PBI dyes from nanorods into nanoribbons in water by fusion and fission processes. More intriguingly, the fluorescence observed for higher hierarchical order nanoribbons was enhanced relative to that of nanorods. Our results provide insight into the relationship between molecular, morphological, and functional properties of self-assembled organic materials. PMID:24352910

  18. Expedient placement of two fluorescent dyes for investigating dynamic DNA protein interactions in real time

    PubMed Central

    Leuba, Sanford H.; Anand, Syam P.; Harp, Joel M.; Khan, Saleem A.

    2008-01-01

    Many questions in molecular and cellular biology can be reduced to questions about ‘who talks to whom, when and how frequently’. Here, we review approaches we have used with single-pair fluorescence resonance energy transfer (spFRET) to follow the motions between two well-placed fluorescent probes to ask similar questions. We describe two systems. We have used a nucleosomal system in which the naked DNA molecule has the acceptor and donor dyes too far apart for FRET to occur whereas the dyes are close enough in the reconstituted nucleosome for FRET. As these individual nucleosomes were tethered on a surface, we could follow dynamics in the repositioning of these two dyes, inferring that nucleosomes stochastically and reversibly open and close. These results imply that most of the DNA on the nucleosome can be sporadically accessible to regulatory proteins and proteins that track the DNA double helix. In the case of following the binding of recombination protein RecA to double-stranded DNA (dsDNA) and the RecA filament displacement by DNA helicase motor PcrA, the dsDNA template is prepared with the two dyes close enough to each other to generate high FRET. Binding of the RecA molecules to form a filament lengthens the dsDNA molecule 1.5-fold and reduces the FRET accordingly. Once added, DNA motor protein helicase PcrA can displace the RecA filament with concomitant return of the DNA molecule to its original B-form and high FRET state. Thus, appropriately placed fluorescent dyes can be used to monitor conformational changes occurring in DNA and or proteins and provide increased sensitivity for investigating dynamic DNA–protein interactions in real time. PMID:18461484

  19. Measurement of atmospheric OH by titration of near-IR fluorescent dyes

    NASA Technical Reports Server (NTRS)

    Betterton, Eric A.; Gast, Karl

    1994-01-01

    Recent research has shown that certain polymethine dyes can be detected at ultratrace levels (greater than or equal to 6x10(exp -14) M) in solution by fluorimetry. These detection limits are possible because of the inherent sensitivity of fluorescence techniques, because the dyes fluoresce in the near infrared region where background interference is negligible, and because powerful infrared diode lasers are now available to improve the signal to noise ratio. Other work has shown that the hydroxyl radical destroys the ability of polymethine dyes to fluoresce. These observations form the basis for a new hydroxyl radical detector that is essentially a fluorometric titrator. Theoretically, the detector should show an acceptable sensitivity and response time. Assuming that the atmospheric HO concentration is about 10(exp -11) moles m(exp -3) (i.e. 10(exp 6) molecules cm(exp -3)), then 10 L of air 'titrated' with 20 mL of 10(exp -11) M dye solution (an easily detected concentration) should result in a drop in the fluorescent signal of 50 percent - a readily detectable change. At a flow rate of 3 L min(exp -1) the sampling time would be 3 minutes. The biggest potential problem is selectivity: other oxidants may also cause the fluorescence signal to be lost. The chemistry of polymethine dyes has not been studied in detail and so no quantitative data are available. However, a survey of the literature suggests that in general HO should react up to six orders of magnitude faster than HO2 and other radicals such as RO2 and RO. It should also react much more rapidly than H2O2 and O3. Thus it may be possible to discriminate kinetically against potential interfering substances. It was shown in the laboratory that 10(exp -4) M H2O2 has little effect on the absorption spectrum of the dye IR125 over a period of hours but that the band at 780 nm is slowly lost in water over a period of days even under argon in the dark. By contrast, DMSO solutions of IR125 are stable.

  20. Phosphorescence and delayed fluorescence properties of fluorone dyes in bio-related films

    NASA Astrophysics Data System (ADS)

    Penzkofer, ?.; Tyagi, A.; Slyusareva, E.; Sizykh, A.

    2010-12-01

    The phosphorescence and delayed fluorescence behaviour of the fluorone dyes disodium fluorescein (FL, uranine), 4,5-dibromofluorescein (DBF), eosin Y (EO), erythrosine B (ER), and rose bengal (RB) in bio-films of gelatine, starch, and chitosan at room temperature is studied. Phosphorescence and delayed fluorescence quantum yields and lifetimes were measured. The singlet-triplet dynamics is described and applied to the fluorone dyes for parameter extraction. For uranine films at room temperature no phosphorescence could be resolved. The efficiency of singlet-triplet intersystem crossing increased in the order ? ISC(DBF) < ? ISC(EO) < ? ISC(ER) < ? ISC(RB) due to the heavy atom effect on spin-orbit coupling. The phosphorescence quantum yields increased in the order ? P(DBF) < ? P(EO) < ? P(RB) < ? P(ER). The phosphorescence lifetimes followed the order ? P(DBF) > ? P(EO) > ? P(ER) > ? P(RB).

  1. Macrocyclic host-dye reporter for sensitive sandwich-type fluorescent aptamer sensor.

    PubMed

    Yang, Cheng; Spinelli, Nicolas; Perrier, Sandrine; Defrancq, Eric; Peyrin, Eric

    2015-03-17

    We describe herein a novel approach for the fluorescent detection of small molecules using a sandwich-type aptamer strategy based on a signaling macrocyclic host-dye system. One split adenosine aptamer fragment was 5'-conjugated to a ?-cylodextrin (CD) molecule while the other nucleic acid fragment was labeled at the 3'-end by a dansyl molecule prone to be included into the macrocycle. The presence of the small target analyte governed the assembly of the two fragments, bringing the dye molecule and its specific receptor in close proximity and promoting the inclusion interaction. Upon the inclusion complex formation, the microenvironment of dansyl was modified in such a way that the fluorescent intensity increased. Concomitantly, this supplementary interaction at the aptamer extremities induced stabilizing effects on the ternary complex. We next proposed a bivalent signaling design where the two extremities of one split aptamer fragment were conjugated to the ?-CD molecule while those of the other fragment were tagged by the dansyl dye. The dual reporting dye inclusion promoted an improvement of both the signal-to-background change and the assay sensitivity. Owing to the vast diversity of responsive host-macrocycle systems available, this aptasensor strategy has potential to be extended to the multiplexed analysis and to other kinds of transducers (such as electrochemical). PMID:25738735

  2. Organic dye penetration quantification into a dental composite resin cured by LED system using fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Lizarelli, Rosane de Fátima Zanirato; Silva, Maciel E., Jr.; Lins, Emery C. C. C.; Costa, Mardoqueu M.; Pelino, José Eduardo P.; Bagnato, Vanderlei S.

    2007-02-01

    A major characteristic of LEDs systems is the lower heat emission related with the kind of light generation and spectral emission band. Material temperature during photoactivation can promote different photocuring performance. Organic dye penetration could be a trace to identify the efficacy of photocured composite resin. A new method using fluorescent spectroscopy through digital image evaluation was developed in this study. In order to understand if there is a real influence of material temperature during the photoactivation procedure of a dental restorative material, a hybrid composite resin (Z250, 3M-Espe, USA) and 3 light sources, halogen lamp (510 mW/cm2) and two LED systems 470+/-10nm (345 and 1000 mW/cm2) under different temperatures and intensities were used. One thousand and five hundred samples under different associations between light sources and temperatures (0, 25, 50, 75 and 100 °C were tested and immediately kept in 6G rodamin dye solution. Dye penetration was evaluated through fluorescent spectroscopy recorded by digital image data. Pixels in gray scale showed the percentage penetration of organic dye into the composite resin mass. Time and temperature were statistically significant (p<0.05) through the ANOVA statistical test. The lowest penetration value was with 60 seconds and 25 °C. Time and temperature are important factors to promote a homogeneous structure polymerized composite resin more than the light source type, halogen or LEDs system.

  3. Rapid Macrocycle Threading by a Fluorescent Dye-Polymer Conjugate in Water with Nanomolar Affinity.

    PubMed

    Peck, Evan M; Liu, Wenqi; Spence, Graeme T; Shaw, Scott K; Davis, Anthony P; Destecroix, Harry; Smith, Bradley D

    2015-07-15

    A macrocyclic tetralactam host is threaded by a highly fluorescent squaraine dye that is flanked by two polyethylene glycol (PEG) chains with nanomolar dissociation constants in water. Furthermore, the rates of bimolecular association are very fast with kon ? 10(6)-10(7) M(-1) s(-1). The association is effective under cell culture conditions and produces large changes in dye optical properties including turn-on near-infrared fluorescence that can be imaged using cell microscopy. Association constants in water are ?1000 times higher than those in organic solvents and strongly enthalpically favored at 27 °C. The threading rate is hardly affected by the length of the PEG chains that flank the squaraine dye. For example, macrocycle threading by a dye conjugate with two appended PEG2000 chains is only three times slower than threading by a conjugate with triethylene glycol chains that are 20 times shorter. The results are a promising advance toward synthetic mimics of streptavidin/biotin. PMID:26106948

  4. Optical quantification of caries-like lesions in vitro by use of a fluorescent dye

    SciTech Connect

    Van de Rijke, J.W.; Ten Bosch, J.J. (Univ. of Groningen (Netherlands))

    1990-05-01

    An experimental method was developed for measurement of the fluorescence intensity of a dye that was introduced into caries-like lesions in vitro. A distinct pattern of change of fluorescence intensity with time appeared, displaying a plateau value and a peak value for each measurement. Both plateau and peak values showed a linear correlation with calcium loss, as measured with longitudinal microradiography. The correlation coefficients were r = 0.87 for plateau values and r = 0.89 for peak values. The difference in scattering by dry and wet caries lesions was also measured with the same equipment, which showed a linear correlation with calcium loss of r = -0.53.

  5. Fluorescence energy transfer in quantum dot/azo dye complexes in polymer track membranes

    PubMed Central

    2013-01-01

    Fluorescence resonance energy transfer in complexes of semiconductor CdSe/ZnS quantum dots with molecules of heterocyclic azo dyes, 1-(2-pyridylazo)-2-naphthol and 4-(2-pyridylazo) resorcinol, formed at high quantum dot concentration in the polymer pore track membranes were studied by steady-state and transient PL spectroscopy. The effect of interaction between the complexes and free quantum dots on the efficiency of the fluorescence energy transfer and quantum dot luminescence quenching was found and discussed. PMID:24172215

  6. Design and Synthesis of Efficient Fluorescent Dyes for Incorporation into DNA Backbone and Biomolecule Detection

    PubMed Central

    Wang, Wei; Li, Alexander D. Q.

    2008-01-01

    We report here the design and synthesis of a series of ?-conjugated fluorescent dyes with D-A-D (D: donor; A: Acceptor), D-?-D, A-?-A, and D-?-A for applications as the signaling motif in biological-synthetic hybrid foldamers for DNA detection. Horner-Wadsworth-Emmons (HWE) reaction and Knoevenagel condensation were demonstrated as the optimum ways for construction of long ?-conjugated systems. Such rod-like chromophores have distinct advantages, as their fluorescence properties are not quenched by the presence of DNA. To be incorporated into the backbone of DNA, the chromophores need to be reasonably soluble in organic solvent for solid-phase synthesis, and therefore a strategy of using flexible tetra(ethylene glycol) (TEG) linkers at either end of these rod-like dyes were developed. The presence of TEG facilitates the protection of the chain-growing hydroxyl group with DMTrCl (dimethoxy trityl chloride) as well as the activation of the coupling step with phosphoramidite chemistry on an automated DNA synthesizer. To form fluorescence resonance energy transfer (FRET) pairs, six synthetic chromophores with blue to red fluorescence have been developed and those with orthogonal fluorescent emission were chosen for incorporation into DNA-chromophore hybrid foldamers. PMID:17508711

  7. Nitrate-selective optical sensor applying a lipophilic fluorescent potential-sensitive dye

    Microsoft Academic Search

    Christian Huber; Ingo Klimant; Christian Krause; Tobias Werner; Otto S Wolfbeis

    2001-01-01

    An optical sensor has been developed for continuous determination of nitrate that is based on a polymer-stabilized emulsion system consisting of a hydrogel with entrapped plasticizer droplets. The droplets contain a cationic potential-sensitive fluorescent dye (PSD) located near its surface. The cationic PSD also acts as an anion-exchange catalyst that extracts nitrate out of the aqueous solution to form a

  8. Color-Variable Light-Emitting Diode Utilizing Conducting Polymer Containing Fluorescent Dye

    Microsoft Academic Search

    Masao Uchida; Yutaka Ohmori; Takanobu Noguchi; Toshihiro Ohnishi; Katsumi Yoshino

    1993-01-01

    A color-variable light-emitting diode has been realized utilizing conducting polymer, poly(2,5-dioctyloxy-p-phenylene vinylene) (ROPPV-8), mixed with fluorescent dye, 8-hydroxyquinoline aluminum (Alq3). The electroluminescence of the diode changes from orange to greenish-yellow in color with increasing applied voltage. On the other hand, a light-emitting diode with the two-layer structure of ROPPV-8 and Alq3 shows only light emission from the ROPPV-8 layer. This

  9. Use of fluorescent dyes and spectrofluorometry to observe evidence of vesicant toxicity in human epidermal cells

    Microsoft Academic Search

    M. M. Mershon; L. S. Rhoads; R. G. Van Buskirk

    1993-01-01

    Normal human epidermal keratinocyes (NHEK) show multiple dose-related biochemical ranges at 3 hours after in vitro exposure to a vesicant compound, 2-chloroethyl ethyl sulfide (CEES) CEES in ethanol was diluted to 0.8, 8.0 and 80 mM concentrations in cell culture medium over confluent NHEK on gel-coated membranes of Millipore Millicells or in NHEK suspensions. A site-specific fluorescent dye was incubated

  10. New fluorescent symmetrically substituted perylene-3,4,9,10-dianhydride-azohybrid dyes: synthesis and spectroscopic studies.

    PubMed

    Saeed, Aamer; Shabir, Ghulam

    2014-12-10

    Five phenolic azo-dyes (3a-e) were synthesized by diazo coupling of the suitably substituted anilines (1a-e) with phenol at low temperature in alkaline medium. The resulting dyes have low solubility in aqueous medium due to lack of carboxylic or sulfonic solubilizing functionalities. The hybridization of perylene dianhydride with phenolic azo-dyes was achieved by the nucleophilic aromatic substitution (SNAr) reaction of perylene-3,4,9,10-dianhydride 4 with phenolic azo-dyes 3a-e in basic medium. The hybrid dyes exhibit absorption maxima ?max in the range 440-460nm in aqueous medium due to presence of azo linkage and highly conjugated system of ? bonds. Fluorescence spectra of these dyes in water show sharp emission peaks with small band widths. The structures of perylene-azo dyes were confirmed by FTIR and NMR spectroscopy. PMID:24914994

  11. Pyrazole-substituted Near-infrared Cyanine Dyes Exhibit pH-dependent Fluorescence Lifetime Properties

    PubMed Central

    Lee, Hyeran; Berezin, Mikhail Y.; Tang, Rui; Zhegalova, Natalia; Achilefu, Samuel

    2012-01-01

    Near-infrared heptamethine cyanine dye is functionalized with pyrazole derivatives at the meso-position to induce pH-dependent photophysical properties. The presence of pyrazole unsubstituted at 1-position is essential to induce pH-dependent fluorescence intensity and lifetime changes of these dyes. Replacement of meso-chloro group of cyanine dye IR820 with 1N-unsubstituted pyrazole resulted in the pH-dependent fluorescence lifetime changes from 0.93 ns in neutral media to 1.27 ns in acidic media in DMSO. Time resolved emission spectra (TRES) revealed that at lower pH, the pyrazole consists of fluorophores with two distinct lifetimes, which corresponds to pH sensitive and non-pH sensitive species. In contrast, 1N-substituted pyrazoles do not exhibit pH response, suggesting excited state electron transfer as the mechanism of pH-dependent fluorescence lifetime sensitivity for this class of compounds. PMID:23094959

  12. Boron difluoride complexes of 2?-hydroxychalcones and curcuminoids as fluorescent dyes for photonic applications

    NASA Astrophysics Data System (ADS)

    D’Aléo, Anthony; Felouat, Abdellah; Fages, Frédéric

    2015-03-01

    The field of fluorescent boron complexes has witnessed tremendous developments in recent years. In that context, we have investigated two series of boron difluoride complexes based on 2?-hydroxychalcone and curcuminoid ligands that represent naturally occurring pigment structures. The dyes display significantly large Stokes shift values, indicating that an ICT state is involved as lower-energy state in the singlet manifold. Remarkably they are also fluorescent in the solid-state, with emission wavelengths usually in the visible and mainly in the near infrared (NIR). It is especially intriguing that those dyes experience strong ?-interactions in the crystal phase. We have observed that the formation of those highly stacked structures was not detrimental to solid-state emission and could even be exploited for the generation of efficient NIR emitters. For example, the boron complexes of curcuminoid ligands can be used to generate NIR fluorescent organic nanoparticles with large cross sections for two-photon absorption. The design of organic dyes displaying NIR emission in solution or in the solid-state remains challenging for applications in bioimaging and organic photonics. Invited talk at the 7th International Workshop on Advanced Materials Science and Nanotechnology IWAMSN2014, 2-6 November, 2014, Ha Long, Vietnam.

  13. Sub-diffusion decays in fluorescence correlation spectroscopy: dye photophysics or protein dynamics?

    PubMed

    Mazouchi, Amir; Bahram, Abdullah; Gradinaru, Claudiu C

    2013-09-26

    Transitions between bright and dark fluorescent states of several rhodamine dyes were investigated by fluorescence correlation spectroscopy. We resolved two sub-diffusion exponential decays for free rhodamines in aqueous solutions, of which the slower component scales linearly with the viscosity of the solution. Correlation data for proteins and DNA labeled with tetramethylrhodamine were fitted with three to four exponential decays describing flickering dynamics on a time scale between 0.5 and 100 ?s. We investigated the nature of these processes by performing experiments under different experimental conditions and for different samples. On the basis of how their population and lifetime change with viscosity, the oxygen content of the solution, the laser irradiance, and the detection geometry, we assigned these states, in the order of increasing lifetimes, to a triplet state, a hybrid between twisted-intramolecular-charge-transfer state and a ground state lactonic state, a lactonic state, and a photoionized state, respectively. Our data suggests that none of the observed sub-diffusion correlation decays can be directly assigned to the intramolecular dynamics of the labeled biomolecules. However, we found evidence that the intrinsic conformational dynamics of the biomolecule appears in the correlation curves as a modulation of the photophysics of the dye label. This shows the importance of accurate control measurements and appropriate modeling of the dye photophysics in fluorescence correlation studies, and it cautions against direct assignments of dark-state relaxation times to folding kinetics in proteins and nucleic acids. PMID:23675915

  14. Cyclopenta[b]naphthalene cyanoacrylate dyes: synthesis and evaluation as fluorescent molecular rotors.

    PubMed

    Kocsis, Laura S; Elbel, Kristyna M; Hardigree, Billie A; Brummond, Kay M; Haidekker, Mark A; Theodorakis, Emmanuel A

    2015-03-14

    We describe the design, synthesis and fluorescent profile of a family of environment-sensitive dyes in which a dimethylamino (donor) group is conjugated to a cyanoacrylate (acceptor) unit via a cyclopenta[b]naphthalene ring system. This assembly satisfies the typical D-?-A motif of a fluorescent molecular rotor and exhibits solvatochromic and viscosity-sensitive fluorescence emission. The central naphthalene ring system of these dyes was synthesized via a novel intramolecular dehydrogenative dehydro-Diels-Alder (IDDDA) reaction that permits incorporation of the donor and acceptor groups in variable positions around the aromatic core. A bathochromic shift of excitation and emission peaks was observed with increasing solvent polarity but the dyes exhibited a complex emission pattern with a second red emission band when dissolved in nonpolar solvents. Consistent with other known molecular rotors, the emission intensity increased with increasing viscosity. Interestingly, closer spatial proximity between the donor and the acceptor groups led to decreased viscosity sensitivity combined with an increased quantum yield. This observation indicates that structural hindrance of intramolecular rotation dominates when the donor and acceptor groups are in close proximity. The examined compounds give insight into how excited state intramolecular rotation can be influenced by both the solvent and the chemical structure. PMID:25614187

  15. Amine-Reactive Dyes for Dead Cell Discrimination in Fixed Samples

    PubMed Central

    Perfetto, Stephen P.; Chattopadhyay, Pratip K.; Lamoreaux, Laurie; Nguyen, Richard; Ambrozak, David; Koup, Richard A.; Roederer, Mario

    2010-01-01

    Amine-reactive dyes, also known as LIVE/DEAD® fixable dead cell stains, are a class of viability dyes suitable for identifying dead cells in samples that will be fixed. These dyes cross the cell membranes of dead cells, and react with free amines in the cytoplasm. Live cells exclude these dyes because their cell membranes are intact, and free dye is washed away after staining. Notably, the reaction is irreversible; therefore, when cells are fixed and permeabilized (as with intracellular staining procedures), the bound dye remains associated with the dead cells (unlike other viability dyes). Since amine-reactive dyes are fluorescent when excited by lasers, dead cells can be identified by flow cytometry. This unit describes procedures, troubleshooting, and outcomes for using the two most commonly used amine-reactive dyes, ViViD and Aqua Blue. PMID:20578108

  16. Using microencapsulated fluorescent dyes for simultaneous measurement of temperature and velocity fields

    NASA Astrophysics Data System (ADS)

    Vogt, J.; Stephan, P.

    2012-10-01

    In this paper, a novel particle image thermometry method based on microcapsules filled with a fluorescent dye solution is described. The microcapsules consist of a liquid core of hexadecane in which the dye is dissolved and a solid polymer shell. The combination of a temperature-sensitive dye (Pyrromethene 597-8C9) and a dye showing a relatively smaller temperature sensitivity (Pyrromethene 567) in hexadecane makes application of the ratiometric LIF possible. This is necessary to compensate for fluctuations of the illuminating pulsed Nd:YAG laser (532 nm) as well as the different particle sizes. The applicability of this measurement technique is demonstrated for a cubic test cell (10 × 10 × 10 mm3) with flow and temperature fields driven by natural convection and a capillary tube (1.16 mm inner diameter) inducing a temperature gradient and a Hagen-Poiseuille velocity profile. For the first case, a light sheet illumination is used making two optical accesses necessary. In the second case an inverted microscope is used, so only one optical access is needed and a volume illumination is applied. The technique facilitates high-resolution measurements (first case: 79 × 79 ?m2 second case: 8 × 8 ?m2). Although the measurement uncertainty is high compared to LIF measurements with dissolved dyes, temperature fields can be reproduced very well, and the experimental results are in good agreement with numerical computations.

  17. Development of an image processing support system based on fluorescent dye to prevent elderly people with dementia from wandering.

    PubMed

    Nishigaki, Yutaka; Tanaka, Kentaro; Kim, Juhyon; Nakajima, Kazuki

    2013-01-01

    The wandering of elderly people with dementia is a significant behavioral problem and is a heavy burden on caregivers in residential and nursing homes. Thus, warning systems have been developed to prevent elderly people with dementia from leaving the premises. Some of these systems use radio waves. However, systems based on radio waves present several practical problems. For instance, the transmitter must be carried and may become lost; in addition, the battery of the transmitter must be changed. To solve these problems, we developed a support system that prevents elderly people with dementia from wandering. The system employs image processing technology based on fluorescent dye. The composition of the support system can be described as follows: fluorescent dye is painted in a simple shape on the clothes of an elderly person. The fluorescent color becomes visible by irradiation with a long wavelength of ultraviolet light. In the present paper, the relationship between the color of the dye and the cloth was investigated. A 3D video camera was used to acquire a 3D image and detect the simple shape. As a preliminary experiment, 3 colors (red, green and blue) of fluorescent dye were applied to cloths of 9 different colors. All fluorescent colors were detected on 6 of the cloths, but red and blue dye could not be detected on the other 3 cloths. In contrast, green dye was detectable on all 9 of the cloths. Additionally, we determined whether green dye could be detected in an actual environment. A rectangular shaped patch of green fluorescent dye was painted on the shoulder area of a subject, from the scapula to the clavicle. As a result, the green dye was detected on all 9 different colored cloths. PMID:24111431

  18. Gram stain

    MedlinePLUS

    A Gram stain is a test used to identify bacteria. It is one of the most common ways to ... Urethral discharge Gram stain; Feces Gram stain; Stool Gram stain; Joint fluid Gram stain; Pericardial fluid Gram stain; Gram stain of ...

  19. Staining paraffin extracted, alcohol rinsed and air dried plant tissue with an aqueous mixture of three dyes.

    PubMed

    Graham, E T; Trentham, W R

    1998-07-01

    A staining solution containing alcian blue 8GX, Bismarck brown Y and safranin O was prepared with 0.1 M sodium acetate buffer, pH 5.0. Paraffin was extracted with MicroClear solvent from 10 microm tissue sections mounted on slides. Paraffin solvent was removed by rinsing with isopropanol, and tissues were air dried. Slides with bare dry tissue sections were immersed in the triple stain and structures could be distinguished within 30 min as follows: nonlignified cell walls, blue; lignified cell walls, nuclei and chloroplasts, red; and cuticle, brown or yellow-brown. Excess staining solution was removed by rinsing with tap water, and the tissues were air dried again. Coverslips were affixed with resin over the stained dry tissues. This novel procedure was tested with immature tomato fruit, mature apple fruit, and various leaf and stem specimens of dogwood, laurel, pawpaw, poinsettia and zonal geranium. PMID:9735876

  20. The use of fluorescence enhancement to improve the microscopic diagnosis of falciparum malaria

    PubMed Central

    Guy, Rebecca; Liu, Paul; Pennefather, Peter; Crandall, Ian

    2007-01-01

    Background Giemsa staining of thick blood smears remains the "gold standard" for detecting malaria. However, this method is not very good for diagnosing low-level infections. A method for the simultaneous staining of Plasmodium-parasitized culture and blood smears for both bright field and fluorescence was developed and its ability to improve detection efficiency tested. Methods A total of 22 nucleic acid-specific fluorescent dyes were tested for their ability to provide easily observable staining of Plasmodium falciparum-parasitized red blood cells following Giemsa staining. Results Of the 14 dyes that demonstrated intense fluorescence staining, only SYBR Green 1, YOYO-1 and ethidum homodimer-2 could be detected using fluorescent microscopy, when cells were first stained with Giemsa. Giemsa staining was not effective when applied after the fluorescent dyes. SYBR Green 1 provided the best staining in the presence of Giemsa, as a very high percentage of the parasitized cells were simultaneously stained. When blood films were screened using fluorescence microscopy the parasites were more readily detectable due to the sharp contrast between the dark background and the specific, bright fluorescence produced by the parasites. Conclusion The dual staining method reported here allows fluorescence staining, which enhances the reader's ability to detect parasites under low parasitaemia conditions, coupled with the ability to examine the same cell under bright field conditions to detect the characteristic morphology of Plasmodium species that is observed with Giemsa staining. PMID:17617912

  1. New highly efficient two-photon fluorescent dyes

    NASA Astrophysics Data System (ADS)

    Belfield, Kevin D.; Morales, Alma R.; Yao, Sheng; Brice, Allyn; Hales, Joel M.; Hagan, David J.; Van Stryland, Eric W.

    2004-06-01

    Organic compounds that undergo strong nonlinear, multiphoton absorption have been gaining greater interest, mainly in the developing fields of multiphoton fluorescence imaging, optical data storage, 3-D microfabrication, and photodynamic therapy. Systematic studies have shown that conjugated organic molecules with large delocalized ? electron systems show very large nonlinear optical effects. Two-photon absorbing chromophores have also been incorporated into dendrimers to increase two-photon absorptivity. A cooperative enhancement of two-photon absorption (2PA) has been observed, such as in the linkage of branched chromophores through a common amine group and chromophore-metal complexes. This enhancement may be related to extensive two-dimensional ?-delocalization in these molecules. Herein, we describe the synthesis, structural characterization and photophysical study of a series of compounds (model, oligomer, and polymer) with symmetric molecular structure of the D-?-D motif and branched D-?-D dendrimeric structures based on substituted fluorene derivatives. Femtosecond 2PA cross sections were very large for some derivatives (over 10,000 GM) and often exhibited substantial solvent effects.

  2. Ability of laser fluorescence device associated with fluorescent dyes in detecting and quantifying early smooth surface caries lesions

    NASA Astrophysics Data System (ADS)

    Mendes, Fausto M.; de Oliveira, Elisabeth; de Faria, Dalva L. A.; Nicolau, José

    2006-03-01

    A laser fluorescence (LF) device is a portable tool, but it does not measure minor mineral changes. Our in vitro study aim is to propose the association of an LF with two fluorescent dyes and to evaluate the performance in detecting and quantifying early demineralization. Artificial caries lesions are created in 40 primary canine teeth using a demineralizing solution (pH=4.8) for 12, 24, 48, and 96 h. LF measurements are performed with DIAGNOdent after demineralization in these samples and in 20 sound primary teeth. Measurements with LF with 0.2-mM tetrakis(N-methylpyridyl)porphyrin (LF TMPyP) and with 4-mM protoporphyrin IX (LF PPIX) are made. The amount of calcium loss is determined by atomic emission spectrometry. A correlation between LF and LF with dyes and mineral loss and receiver operating characteristics analysis are performed, as well as comparisons of sensitivity, specificity, and accuracy values. Significant correlation is obtained with LF TMPyP and mineral loss of lesions demineralized for 24, 48, and 96 h. Better performance is achieved with LF TMPyP for all parameters than with LF alone. LF PPIX does not present good results. In conclusion, LF TMPyP provides good performance in detecting and quantifying very early enamel caries lesions.

  3. Apparatus for eliminating background interference in fluorescence measurements

    DOEpatents

    Martin, John C. (Los Alamos, NM); Jett, James H. (Los Alamos, NM)

    1986-01-01

    The disclosure is directed to an apparatus for eliminating background interference during fluorescence measurements in a multiple laser flow cytometer. A biological particle stained with fluorescent dyes is excited by a laser. A fluorescence detector detects the fluorescence. The particle scatters light and a gate signal is generated and delayed until the biological particle reaches the next laser. The delayed signal turns on this next laser, which excites a different stained component of the same biological particle.

  4. The evaluation of a novel method comparing quantitative light-induced fluorescence (QLF) with spectrophotometry to assess staining and bleaching of teeth

    Microsoft Academic Search

    A. A. Adeyemi; F. D. Jarad; E. de Josselin de Jong; N. Pender; S. M. Higham

    2010-01-01

    This study reports the development and evaluation of a novel method using quantitative light-induced fluorescence (QLF), which\\u000a enables its use for quantifying and assessing whole tooth surface staining and tooth whitening. The method was compared with\\u000a a spectrophotometer to assess reliability. Two experimental phases, intrinsic stain formation and tooth whitening, were conducted\\u000a in vitro on 16 extracted bovine teeth. Intrinsic

  5. Diffusion of organic dyes in a niosome immobilized on a glass surface using fluorescence correlation spectroscopy.

    PubMed

    Ghosh, Shirsendu; Mandal, Amit Kumar; Das, Atanu Kumar; Mondal, Tridib; Bhattacharyya, Kankan

    2012-07-21

    Giant multilameller niosomes containing cholesterol and triton X-100 are studied using fluorescence correlation spectroscopy (FCS). Dynamic light scattering (DLS) data indicates formation of niosomes of broadly two different sizes (diameter)--~150 nm and ~1300 nm. This is confirmed by field emission scanning electron microscopy (FE-SEM) and confocal microscopy. The diffusion coefficient (D(t)) of three organic dyes in the niosome immobilized on a glass surface is studied using fluorescence correlation spectroscopy. On addition of the room temperature ionic liquids (RTIL) (1-methyl-3-pentylimidazolium bromide, [pmim][Br] and 1-methyl- 3-pentylimidazolium tetra-fluoroborate, [pmim][BF(4)]) the size of the niosome particles increases. The D(t) of all the organic dyes (DCM, C343 and C480) increases on addition of RTILs, indicating faster diffusion. The viscosity calculated from the D(t) of the three dyes exhibits weak probe dependence. Unlike lipid or catanionic vesicle, the D(t) values in a niosome exhibit very narrow distribution. This indicates that the niosomes are fairly homogeneous with small variation of viscosity. PMID:22692627

  6. Use of fluorescent dyes and spectrofluorometry to observe evidence of vesicant toxicity in human epidermal cells

    SciTech Connect

    Mershon, M.M.; Rhoads, L.S.; Van Buskirk, R.G.

    1993-05-13

    Normal human epidermal keratinocyes (NHEK) show multiple dose-related biochemical ranges at 3 hours after in vitro exposure to a vesicant compound, 2-chloroethyl ethyl sulfide (CEES) CEES in ethanol was diluted to 0.8, 8.0 and 80 mM concentrations in cell culture medium over confluent NHEK on gel-coated membranes of Millipore Millicells or in NHEK suspensions. A site-specific fluorescent dye was incubated with each NHEK layer for 1 hr prior to comparisons of normal and challenged NHEK within a Cytofluor 2300 spectrofluorometer. Reduced fluorescence from loss of all dye probes indicated severe membrane damage with 80 mM CEES in medium. Intracellular increases in Ca++, evidence of altered mitochondrial activity, and decreases in pH, glutathione levels and lysosomal integrity, were observed with 0.8 and 8.0 mM CEES in the culture medium. Control studies performed with Testskin and another human epidermal model suggest that dermal substitutes and transportation stresses can influence results with the dye probe/Cytofluor 2300 method. However, the feasibility of using the described methods to observe vesicant biochemical effects, screen antivesicants and perform other toxicological studies with NHEK models is supported by the results of the preliminary studies.

  7. Procion Yellow Fluorescent Microscopy: A New Method of Studying Arterial and Venous Pathology

    Microsoft Academic Search

    Richard B. Berlin; Patricia Farnsworth; Barbara Groth-Vasselli; June Azu Kuo

    1992-01-01

    A new means of studying vessel wall pathology is presented. This technique utilizes Procion yellow, a vital fluorescent dye, to stain and delineate the connective elements, matrix, and elastic tissue within the arterial wall. In addition, penetration of the dye into cells provides evidence of membrane pathology. A canine model was used, and clamped segments of femoral artery were stained

  8. Magneto-fluorescent hybrid of dye and SPION with ordered and radially distributed porous structures

    NASA Astrophysics Data System (ADS)

    Gogoi, Madhulekha; Deb, Pritam

    2014-04-01

    We have reported the development of a silica based magneto-fluorescent hybrid of a newly synthesized dye and superparamagnetic iron oxide nanoparticles with ordered and radially distributed porous structure. The dye is synthesized by a novel yet simple synthetic approach based on Michael addition between dimer of glutaraldehyde and oleylamine molecule. The surfactant used for phase transformation of the dye from organic to aqueous phase, also acts as a structure directing agent for the porous structure evolution of the hybrid with radial distribution. The evolution of the radially distributed pores in the hybrids can be attributed to the formation of rod-like micelles containing nanoparticles, for concentration of micelles greater than critical micelle concentration. A novel water extraction method is applied to remove the surfactants resulting in the characteristic porous structure of the hybrid. Adsorption isotherm analysis confirms the porous nature of the hybrids with pore diameter ?2.4 nm. A distinct modification in optical and magnetic property is observed due to interaction of the dye and SPION within the silica matrix. The integration of multiple structural components in the so developed hybrid nanosystem results into a potential agent for multifunctional biomedical application.

  9. Evaluation of the Salmonellae Fluoro-Kit for Fluorescent-Antibody Staining

    PubMed Central

    Insalata, N. F.; Dunlap, W. G.; Mahnke, C. W.

    1973-01-01

    An evaluation of the newly developed Clinical Sciences, Inc. Salmonellae Fluoro-Kit, which attempts to standardize the various aspects of the fluorescent-antibody (FA) procedure, was performed with 120 naturally contaminated human food, animal feed, and raw material samples. The Association of Official Analytical Chemists (AOAC) method for the detection of salmonellae was used as the control method. The Fluoro-Kit was found to be simple and conveniento to use. The results of this preliminary study show an industrially acceptable rate of recovery of salmonellae by using the Fluoro-Kit in comparison with the A.O.A.C. method. The Fluoro-Kit shows promise as a rapid, salmonellae FA screening method. Problems originally encountered in the application of the Fluoro-Kit are discussed. According to the manufacturer, strict adherence to the now revised procedures included in the Fluoro-Kit will control these problems. PMID:4571655

  10. The use of fluorescent dyes as tracers in highly saline groundwater

    NASA Astrophysics Data System (ADS)

    Magal, Einat; Weisbrod, Noam; Yakirevich, Alex; Yechieli, Yoseph

    2008-08-01

    SummaryThe capability of five fluorescent dyes to serve as conservative tracers in highly saline groundwater was evaluated by a series of batch experiments on pure minerals and natural sediments. Dye sorption was tested in four different salinities (from fresh rainwater to Dead Sea water) on five pure minerals and four natural sediments taken from boreholes drilled along the Dead Sea shore. It was found that the dyes Sulfo-Rhodamine B and Eosin are strongly adsorbed on pure minerals and sediments and therefore cannot be used as conservative tracers in saline groundwater. Uranine and Pyranine sorption is increased at higher salinities, therefore they can be used as tracers in moderately saline groundwater only. Na Naphthionate was found to be the best tracer for fresh and saline water, with minimal sorption in all cases. Sorption of the dyes on four natural sediments was measured and values were found to be in accord with those of previous sorption on pure minerals. Sorption on natural sediments was also estimated based on the mineral composition of the sediment and the known sorption on the pure minerals. The estimated sorption values were usually 25% lower than those of the sorption directly measured. Nevertheless, sorption on pure minerals can be used as a first approximation for sorption on natural sediments. The impact of sediment to solution ratio was tested for Uranine as a model dye. The distribution coefficient ( Kd) of Uranine in highly saline Dead Sea water was found to be dependent on the sediment to solution ratio (mass/volume), where low ratios resulted in higher values of Kd. Also, higher Kd values were calculated for fine grain size due to higher sorption capacity on larger surface areas. The difference in Kd, however, is not directly related to the specific surface size of the grains and should be examined separately.

  11. Detailed analysis of ultrathin fluorescent red dye interlayer for organic photovoltaic cells

    Microsoft Academic Search

    Yue Zang; Jun-Sheng Yu; Na-Na Wang; Ya-Dong Jiang

    2011-01-01

    The influence of an ultrathin 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) fluorescent dye layer at donor\\/acceptor heterojunction on the performance of small-molecule organic photovoltaic (OPV) cell is studied. The structure of OPV cell is of indium-tin oxide (ITO)\\/copper phthalocyanine (CuPc)\\/DCJTB\\/fullerene (C60)\\/bathophenanthroline (Bphen)\\/Ag. The results show that open circuit voltage (VOC) increases to 0.57 V as the film thickness of DCJTB layer increases from 0.2

  12. Switching properties of fluorescent photochromic poly(methyl methacrylate) with spironaphthoxazine and D-?-A type pyran-based fluorescent dye

    NASA Astrophysics Data System (ADS)

    Lee, Eun-Mi; Gwon, Seon-Young; Son, Young-A.; Kim, Sung-Hoon

    2012-02-01

    Fluorescent photochromic poly(methyl methacrylate) (PMMA) with spironaphthoxazine (SPO) and D-?-A type pyran-base fluorescent dye as a fluorophore was synthesized by typical free radical copolymerization. The poly(MMA- co-SPO- co-fluorophore) in both solution and solid film exhibited excellent photoregulated fluorescence switching behavior and reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. The poly(MMA- co-SPO- co-fluorophore) also showed viscosity and conductivity switching behaviors along with photoresponse.

  13. Comparison of sieving matrices for on-the-fly fluorescence lifetime detection of dye-labeled DNA fragments

    Microsoft Academic Search

    Lijuan Li; Linda B. McGown

    2001-01-01

    Commercially available, replaceable sieving matrices and their solvent modulated forms were evaluated for use in on-the-fly\\u000a fluorescence lifetime detection of dye-labeled DNA fragments in capillary electrophoresis. The fragments were labeled with\\u000a dyes that can be excited by the 488 nm line of an argon ion laser and have lifetimes in the range of 0.8 ns to 3.8 ns. The\\u000a sieving

  14. Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

    PubMed Central

    Popenko, Oleksandr

    2014-01-01

    Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects. PMID:25435859

  15. Synthesis of New Styrylquinoline Cellular Dyes, Fluorescent Properties, Cellular Localization and Cytotoxic Behavior

    PubMed Central

    Dulski, Mateusz; Mrozek-Wilczkiewicz, Anna; Cieslik, Wioleta; Spaczy?ska, Ewelina; Bartczak, Piotr; Ratuszna, Alicja; Polanski, Jaroslaw; Musiol, Robert

    2015-01-01

    New styrylquinoline derivatives with their photophysical constants are described. The synthesis was achieved via Sonogashira coupling using the newly developed heterogeneous nano-Pd/Cu catalyst system, which provides an efficient synthesis of high purity products. The compounds were tested in preliminary fluorescent microscopy studies to in order to identify their preferable cellular localization, which appeared to be in the lipid cellular organelles. The spectroscopic properties of the compounds were measured and theoretical TD-DFT calculations were performed. A biological analysis of the quinolines that were tested consisted of cytotoxicity assays against normal human fibroblasts and colon adenocarcinoma cells. All of the compounds that were studied appeared to be safe and indifferent to cells in a high concentration range. The presented results suggest that the quinoline compounds that were investigated in this study may be valuable structures for development as fluorescent dyes that could have biological applications. PMID:26114446

  16. Flow cytometric enumeration of bacteria using TO-PRO®-3 iodide as a single-stain viability dye.

    PubMed

    Kerstens, Monique; Boulet, Gaëlle; Tritsmans, Christian; Horemans, Tessa; Hellings, Mario; Delputte, Peter; Maes, Louis; Cos, Paul

    2014-12-01

    Quantification of bacteria using conventional viable plate counting (VPC) is labor-intensive and time-consuming. Flow cytometry (FCM) can be proposed as a faster alternative. This study aimed to develop a flow cytometric, single-stain approach using TO-PRO®-3 iodide (TP3) for the quantification of Staphylococcus aureus, Escherichia coli, and Bacillus subtilis cells. Live or dead bacterial suspensions were stained with TP3 and analyzed using a FACSCalibur flow cytometer. After optimization of staining parameters and instrument settings, an excellent separation of viable and dead cells was achieved for all species. The quantitative performance of the technique was assessed by analyzing serial dilutions of bacterial suspensions using FCM and VPC. A highly linear correlation (r2 > 0.99) was observed between the colony forming units (CFU)/mL as determined by FCM and by VPC over a concentration range of about 104 to 108 CFU/mL. As such, FCM quantification of viable bacteria using TP3 can be considered as an accurate and reliable alternative for VPC. The monostain procedure is easy to apply and cost-effective, and it allows bacterial enumeration in a broad variety of samples. PMID:25124156

  17. On the incorporation of Rhodamine B and 2?,7?-dichlorofluorescein dyes in silica: Synthesis of fluorescent nanoparticles

    NASA Astrophysics Data System (ADS)

    Gomes, Elis C. C.; de Carvalho, Idalina M. M.; Diógenes, Izaura C. N.; de Sousa, Eduardo H. S.; Longhinotti, Elisane

    2014-05-01

    The present paper reports the incorporation of 2?,7?-dichlorofluorescein (DCF) and Rhodamine B (RhB) dyes in silica nanoparticles by using the Stöber's method with some modifications. Based on infrared and electronic spectroscopies, these dyes were successfully incorporated resulting in fluorescent nanomaterials of an average size of 80 nm. A composite fluorescent nanomaterial containing both dyes was also synthesized and showed the occurrence of Förster resonant energy transfer process (FRET) with the average distance between the donor (DCF) and acceptor (RhB) of 3.6 nm. Furthermore, these fluorescent nanoparticles were modified with folic acid producing nanomaterials whose Zeta potential values were in the range of -2 to -13 mV. These values are consistent with the low dispersivity observed by TEM micrographs. Altogether, these suitable properties can lead to the development of nanomaterials for cancer bioimaging and drug release.

  18. Study of foxing stains on paper by chemical methods, infrared spectroscopy, micro-X-ray fluorescence spectrometry and laser induced breakdown spectroscopy

    Microsoft Academic Search

    M. Bicchieri; S Ronconi; F. P Romano; L Pappalardo; M Corsi; G Cristoforetti; S Legnaioli; V Palleschi; A Salvetti; E Tognoni

    2002-01-01

    Foxing spots appear on the paper as stains of reddish-brown, brown or yellowish color, generally of small dimensions, with sharp or irregular edges, most of which, if excited with UV light, show fluorescence. The formation mechanisms of foxed areas have been studied since 1935, however, despite more recent intensive research there are still no conclusive results. Some authors found evidence

  19. Dye analysis of Shosoin textiles using excitation-emission matrix fluorescence and ultraviolet-visible reflectance spectroscopic techniques.

    PubMed

    Nakamura, Rikiya; Tanaka, Yoko; Ogata, Atsuhiko; Naruse, Masakazu

    2009-07-15

    The dyes of 8th century textiles, treasured for more than 1250 years in the Shosoin treasure repository in Japan, were analyzed by nondestructive methods, i.e., excitation-emission matrix (EEM) fluorescence and ultraviolet-visible (UV-vis) reflectance spectrometry, in combination with natural dye references extracted from plants, which have been widely used from ancient times. In this analysis, five dyes were found in the following objects: embroidered shoes dedicated to Great Buddha of the Todaiji temple by the empress of that time, the cloth lining for a case holding a mirror belonging to the emperor of that time, two rolls of yellow and light green plain-weave silks, and a sleeveless coat used for a musical in a Buddhist ceremony in 752 A.D. EEM fluorescence spectrometry distinguished kihada yellow (Amur cork tree), kariyasu yellow (eulalia), and akane red (Japanese madder). UV-vis spectrometry also distinguished kariyasu yellow, ai blue (knotweed), akane red, and shikon purple (murasaki); the characteristic peaks of these dyes were detected by a second derivatization. The results show that although the dyes used easily degrade with age, EEM fluorescence and UV-vis reflectance spectrometry are useful for distinguishing dyes used in the Shosoin textiles, which had been stored for more than 1250 years. PMID:19507884

  20. Efficient plasmonic dye-sensitized solar cells with fluorescent Au-encapsulated C-dots.

    PubMed

    Narayanan, Remya; Deepa, Melepurath; Srivastava, Avanish Kumar; Shivaprasad, Sonnada Math

    2014-04-14

    A simple strategy to improve the efficiency of a ZnO-nanorod-based dye-sensitized solar cell (DSSC) by use of Au-encapsulated carbon dots (Au@C-dots) in the photoanode is presented. The localized surface plasmonic resonance of Au in the 500-550 nm range coupled with the ability of C-dots to undergo charge separation increase the energy-harvesting efficiency of the DSSC with ZnO/N719/Au@C-dots photoanodes. Charge transfer from N719 dye to Au@C-dots is confirmed by fluorescence and lifetime enhancements of Au@C-dots. Forster resonance energy transfer (FRET) from the gap states of ZnO nanorods to N719 dye is also ratified and the energy transfer rate is 4.4×10(8) s(-1) and the Forster radius is 1.89 nm. The overall power conversion efficiency of the plasmonic and FRET-enabled DSSC with ZnO/N719/Au@C-dots as the photoanode, I2/I(-) as the electrolyte and multiwalled carbon nanotubes as the counter electrode is 4.1%, greater by 29% compared to a traditional ZnO/N719 cell. PMID:24677662

  1. Detection of microlesions induced by heavy ions using liposomes filled with fluorescent dye

    NASA Technical Reports Server (NTRS)

    Koniarek, J. P.; Thomas, J. L.; Vazquez, M.

    2004-01-01

    In cells irradiation by heavy ions has been hypothesized to produce microlesions, regions of local damage. In cell membranes this damage is thought to manifest itself in the form of holes. The primary evidence for microlesions comes from morphological studies of cell membranes, but this evidence is still controversial, especially since holes also have been observed in membranes of normal, nonirradiated, cells. However, it is possible that damage not associated with histologically discernable disruptions may still occur. In order to resolve this issue, we developed a system for detecting microlesions based on liposomes filled with fluorescent dye. We hypothesized that if microlesions form in these liposomes as the result of irradiation, then the entrapped dye will leak out into the surrounding medium in a measurable way. Polypropylene vials containing suspensions of vesicles composed of either dipalmitoyl phosphatidylcholine, or a combination of egg phosphatidylcholine and cholesterol were irradiated at the Brookhaven National Laboratory using 56Fe ions at 1 GeV/amu. In several cases we obtained a significant loss of the entrapped dye above the background level. Our results suggest that holes may form in liposomes as the result of heavy ion irradiation, and that these holes are large enough to allow leakage of cell internal contents that are at least as large as a 1 nm diameter calcein molecule. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  2. UV laser interaction with a fluorescent dye solution studied using pulsed digital holography.

    PubMed

    Amer, Eynas; Gren, Per; Sjödahl, Mikael

    2013-10-21

    A frequency tripled Q-switched Nd-YAG laser (wavelength 355 nm, pulse duration 12 ns) has been used to pump Coumarin 153 dye solved in ethanol. Simultaneously, a frequency doubled pulse (532 nm) from the same laser is used to probe the solvent perpendicularly resulting in a gain through stimulated laser induced fluorescence (LIF) emission. The resulting gain of the probe beam is recorded using digital holography by blending it with a reference beam on the detector. Two digital holograms without and with the pump beam were recorded. Intensity maps were calculated from the recorded digital holograms and used to calculate the gain of the probe beam due to the stimulated LIF. In addition numerical data of the local temperature rise was calculated from the corresponding phase maps using Radon inversion. It was concluded that about 15% of the pump beam energy is transferred to the dye solution as heat while the rest is consumed in the radiative process. The results show that pulsed digital holography is a promising technique for quantitative study of fluorescent species. PMID:24150372

  3. Fluorescence microscopy is superior to polarized microscopy for detecting amyloid deposits in Congo red-stained trephine bone marrow biopsy specimens.

    PubMed

    Marcus, Alan; Sadimin, Evita; Richardson, Maurice; Goodell, Lauri; Fyfe, Billie

    2012-10-01

    The classic gold standard for detecting amyloid deposits is Congo red-stained bright field and polarized microscopy (CRPM). A prior study showed that Congo red fluorescence (CRF) microscopy had increased sensitivity compared with traditional CRPM when analyzing fat pad specimens. The purpose of the current study was to determine the sensitivity of CRF for evaluating Congo red-stained bone marrow biopsy specimens, and to compare these results with those of CRPM. We compared the CRPM and the CRF analyses of 33 trephine bone marrow biopsy specimens with clinical or morphologic suspicion of amyloid deposits. These results were verified against immunohistochemical staining with anti-amyloid P antibody. CRF achieved 100% sensitivity, and CRPM achieved 75% sensitivity. Both groups showed 100% specificity compared with amyloid P immunohistochemical staining. The results show that CRF is a sensitive method to analyze trephine bone marrow biopsy specimens for amyloid deposits. PMID:23010714

  4. MnO2 nanosheets based fluorescent sensing platform with organic dyes as a probe with excellent analytical properties.

    PubMed

    Wang, Chunxia; Zhai, Wanying; Wang, Yuexiang; Yu, Ping; Mao, Lanqun

    2015-06-21

    Manganese dioxide (MnO2) nanosheets have recently been demonstrated to be particularly attractive for fluorescent sensing and imaging; however, almost all MnO2 nanosheets-based fluorescent assays have been developed with emissive nanoparticles as the probes. In this study, we developed a novel strategy to use organic dyes, instead of emissive nanoparticles, as the probe to construct a platform for biosensing with excellent analytical properties. With 5-carboxyfluorescein (FAM) as a model organic dye, we firstly investigate the effect of MnO2 nanosheets on the fluorescence of FAM and find that the fluorescence intensity of FAM is considerably suppressed by MnO2 nanosheets based on the inner filter effect (IFE). To demonstrate that the MnO2 nanosheets-based fluorescence sensing platform can easily achieve a high selectivity with organic dyes as the probe, we use single-stranded DNA (ssDNA) oligonucleotide as a typical biorecognition unit, which is labeled with the FAM probe to form FAM-ssDNA. The fluorescent intensity of FAM-ssDNA is first suppressed by MnO2 nanosheets through the combination of IFE and Förster resonant energy transfer (FRET), and then recovered with subsequent hybridization with the complementary DNA oligonucleotide. To demonstrate the potential applications of the MnO2 nanosheets-based fluorescence sensing platform with organic dyes as the probes, we developed methods for simple but effective microRNA and thrombin assays. With the platform demonstrated here, the limits of detection for miR124a and thrombin are 0.8 nM and 11 nM, respectively. Moreover, the fluorescent sensing assay for thrombin exhibits high selectivity. This study essentially demonstrates a new 2D nanostructure-based fluorescent sensing platform that is robust, technically simple, and easily manipulated to achieve high selectivity and sensitivity for practical applications. PMID:25919222

  5. Rapid detection of total and viable Legionella pneumophila in tap water by immunomagnetic separation, double fluorescent staining and flow cytometry

    PubMed Central

    Keserue, Hans?Anton; Baumgartner, Andreas; Felleisen, Richard; Egli, Thomas

    2012-01-01

    Summary We developed a rapid detection method for Legionella pneumophila (Lp) by filtration, immunomagnetic separation, double fluorescent staining, and flow cytometry (IMS?FCM method). The method requires 120?min and can discriminate ‘viable’ and ‘membrane?damaged’ cells. The recovery is over 85% of spiked Lp SG 1 cells in 1?l of tap water and detection limits are around 50 and 15 cells per litre for total and viable Lp, respectively. The method was compared using water samples from house installations in a blind study with three environmental laboratories performing the ISO 11731 plating method. In 53% of the water samples from different taps and showers significantly higher concentrations of Lp were detected by flow cytometry. No correlation to the plate culture method was found. Since also ‘viable but not culturable’ (VNBC) cells are detected by our method, this result was expected. The IMS?FCM method is limited by the specificity of the used antibodies; in the presented case they target Lp serogroups 1–12. This and the fact that no Lp?containing amoebae are detected may explain why in 21% of all samples higher counts were observed using the plate culture method. Though the IMS?FCM method is not yet fit to completely displace the established plating method (ISO 11731) for routine Lp monitoring, it has major advantages to plating and can quickly provide important insights into the ecology of this pathogen in water distribution systems. PMID:23062200

  6. The evaluation of a novel method comparing quantitative light-induced fluorescence (QLF) with spectrophotometry to assess staining and bleaching of teeth.

    PubMed

    Adeyemi, A A; Jarad, F D; de Josselin de Jong, E; Pender, N; Higham, S M

    2010-02-01

    This study reports the development and evaluation of a novel method using quantitative light-induced fluorescence (QLF), which enables its use for quantifying and assessing whole tooth surface staining and tooth whitening. The method was compared with a spectrophotometer to assess reliability. Two experimental phases, intrinsic stain formation and tooth whitening, were conducted in vitro on 16 extracted bovine teeth. Intrinsic stains were developed via access through lingual surfaces and root canals of these teeth using tea solution (2 g/100 ml, Marks and Spencer Extra Strong Tea, Marks and Spencer, London, UK) for 6 days. Stains were removed using 33% hydrogen peroxide (VWR Prolab, Leicestershire, UK) in cycles over 150 min. Stain development/whitening was monitored with QLF (Inspektor Research systems, Amsterdam, Netherlands) and spectrophotometry (Easy shade, Vita Zahnfabrik, Bad Säckingen, Germany). Parameters Delta F for QLF and Delta E for the spectrophotometer were obtained. The progression of stain intensity and removal observed by the methods were tested for correlation using Pearson's correlation coefficient. Intra-examiner reliability for each method was tested. QLF showed a high correlation with spectrophotometry for detecting and monitoring intrinsic tooth stain progression (Pearson coefficient r was -0.987 with correlation significant p < 0.0001). For stain removal, the Pearson coefficient (r) between both methods was -0.906 with no significance p = 0.094. The use of an external reference material in combination with the inner patch QLF analysis technique had the ability to detect and measure whole tooth surface staining and its removal longitudinally. The reliability of the method shows a potential clinical application. PMID:19306025

  7. Characterization of the vitreous body of the human eye using a cyanine dye as a spectral and fluorescent probe

    NASA Astrophysics Data System (ADS)

    Panova, Ina G.; Tatikolov, Alexander S.

    2009-02-01

    We used one of cyanine dyes as a spectral and fluorescent probe in the study of the composition of the extracellular matrix of the human eye (its vitreous body). Owing to the unique ability of the dye to bind to collagens and human serum albumin, we revealed the simultaneous presence of both types of biomacromolecules in the vitreous body. The formation of the dye complex with human serum albumin leads to appearance of a long-wavelength absorption band (~612 nm) and a steep rise of fluorescence, whereas in the presence of collagens the dye forms J-aggregates with a longer-wavelength absorption band (640-660 nm) and moderate fluorescence. In this work we studied the composition of the human fetus vitreous body and its dynamics from 9 to 31 gestation weeks. On the basis of the data obtained by this method, we may assume that albumin, being a carrier protein, probably provides the vitreous body and surrounding tissues with necessary growth factors, hormones, lipids, vitamins, and some other biomolecules. The data show that the dye is promising not only for study of albumin functions in eye development, but also for characterization of some eye diseases and for analysis of other extracellular media.

  8. Rational Approach to Select Small Peptide Molecular Probes Labeled with Fluorescent Cyanine Dyes for in vivo Optical Imaging

    PubMed Central

    Berezin, Mikhail Y.; Guo, Kevin; Akers, Walter; Livingston, Joseph; Solomon, Metasebya; Lee, Hyeran; Liang, Kexian; Agee, Anthony; Achilefu, Samuel

    2011-01-01

    We demonstrate that the structure of carbocyanine dyes, which are commonly used to label small peptides for molecular imaging, and not the bound peptide, controls the rate of extravasation from blood vessels to tissue. By examining several near-infrared (NIR) carbocyanine fluorophores, we demonstrate a quantitative correlation between the binding of a dye to albumin, a model plasma protein, and the rate of extravasation of the probe into tissue. Binding of the dyes was measured by fluorescence quenching of the tryptophans in albumin and was found to be inversely proportional to the rate of extravasation. The rate of extravasation, determined by kurtosis from longitudinal imaging studies using rodent ear models, provided a basis for quantitative measurements. Structure-activity studies aimed at evaluating a representative library of NIR fluorescent cyanine probes showed that hydrophilic dyes with binding constants several orders of magnitude lower than their hydrophobic counterparts have much faster extravasation rate, establishing a foundation for rational probe design. The correlation provides a guideline for dye selection in optical imaging and a method to verify if a certain dye is optimal for a specific molecular imaging application PMID:21329363

  9. Optical tweezers and non-ratiometric fluorescent-dye-based studies of respiration in sperm mitochondria

    NASA Astrophysics Data System (ADS)

    Chen, Timothy; Shi, Linda Z.; Zhu, Qingyuan; Chandsawangbhuwana, Charlie; Berns, Michael W.

    2011-04-01

    The purpose of this study is to investigate how the mitochondrial membrane potential affects sperm motility using laser tweezers and a non-ratiometric fluorescent probe, DiOC6(3). A 1064 nm Nd:YVO4 continuous wave laser was used to trap motile sperm at a power of 450 mW in the trap spot. Using customized tracking software, the curvilinear velocity (VCL) and the escape force from the laser tweezers were measured. Human (Homo sapiens), dog (Canis lupis familiaris) and drill (Mandrillus leucophaeus) sperm were treated with DiOC6(3) to measure the membrane potential in the mitochondria-rich sperm midpieces. Sperm from all three species exhibited an increase in fluorescence when treated with the DiOC6(3). When a cyanide inhibitor (CCCP) of aerobic respiration was applied, sperm of all three species exhibited a reduction in fluorescence to pre-dye levels. With respect to VCL and escape force, the CCCP had no effect on dog or human sperm, suggesting a major reliance upon anaerobic respiration (glycolysis) for ATP in these two species. Based on the preliminary study on drill sperm, CCCP caused a drop in the VCL, suggesting potential reliance on both glycolysis and aerobic respiration for motility. The results demonstrate that optical trapping in combination with DiOC6(3) is an effective way to study sperm motility and energetics.

  10. Signal decomposition of transmembrane voltage-sensitive dye fluorescence using a multiresolution wavelet analysis.

    PubMed

    Asfour, Huda; Swift, Luther M; Sarvazyan, Narine; Doroslova?ki, Miloš; Kay, Matthew W

    2011-07-01

    Fluorescence imaging of transmembrane voltage-sensitive dyes is used to study electrical activation in cardiac tissue. However, the fluorescence signals, typically, have low SNRs and may be contaminated with motion artifact. In this report, we introduce a new processing approach for fluoresced transmembrane potentials (fTmps) that is based upon a discrete wavelet transform. We show how fTmp signals can be decomposed and reconstructed to form three subsignals that contain signal noise (noise signal), the early depolarization phase of the action potential (rTmp signal), and motion artifact (rMA signal). A coiflet4 wavelet is used for fTmp decomposition and reconstruction of these subsignals. Results using fTmp signals that are contaminated with motion artifact indicate that the approach is a useful processing step to remove baseline drift, reduce noise, and reveal wavefronts. It streamlines the preprocessing of fTmps for the subsequent measurement of activation times and conduction velocities. It is a promising approach for studying wavefronts without aggressive mechanical tissue constraint or electromechanical uncoupling agents and is, useful for single-camera systems that do not provide for ratiometric imaging. PMID:21511560

  11. Auxin conjugated to fluorescent dyes--a tool for the analysis of auxin transport pathways.

    PubMed

    Soko?owska, K; Kizi?ska, J; Szewczuk, Z; Banasiak, A

    2014-09-01

    Auxin is a small molecule involved in most processes related to plant growth and development. Its effect usually depends on the distribution in tissues and the formation of concentration gradients. Until now there has been no tool for the direct tracking of auxin transport at the cellular and tissue level; therefore the majority of studies have been based on various indirect methods. However, due to their various restrictions, relatively little is known about the relationship between various pathways of auxin transport and specific developmental processes. We present a new research tool: fluorescently labelled auxin in the form of a conjugate with two different fluorescent tracers, FITC and RITC, which allows direct observation of auxin transport in plant tissues. Chemical analysis and biological tests have shown that our conjugates have auxin-like biological activity and transport; therefore they can be used in all experimental systems as an alternative to IAA. In addition, the conjugates are a universal tool that can be applied in studies of all plant groups and species. The conjugation procedure presented in this paper can be adapted to other fluorescent dyes, which are constantly being improved. In our opinion, the conjugates greatly expand the possibilities of research concerning the role of auxin and its transport in different developmental processes in plants. PMID:24397706

  12. Fluorescence-based sensing of glucose using engineered glucose/galactose-binding protein: A comparison of fluorescence resonance energy transfer and environmentally sensitive dye labelling strategies

    SciTech Connect

    Khan, Faaizah; Gnudi, Luigi [Metabolic Unit, King's College London School of Medicine, Guy's Hospital, London SE1 9RT (United Kingdom); Pickup, John C. [Metabolic Unit, King's College London School of Medicine, Guy's Hospital, London SE1 9RT (United Kingdom)], E-mail: john.pickup@kcl.ac.uk

    2008-01-04

    Fluorescence-based glucose sensors using glucose-binding protein (GBP) as the receptor have employed fluorescence resonance energy transfer (FRET) and environmentally sensitive dyes, but with widely varying sensitivity. We therefore compared signal changes in (a) a FRET system constructed by transglutaminase-mediated N-terminal attachment of Alexa Fluor 488/555 as donor and QSY 7 as acceptor at Cys 152 or 182 mutations with (b) GBP labelled with the environmentally sensitive dye badan at C152 or 182. Both FRET systems had a small maximal fluorescence change at saturating glucose (7% and 16%), badan attached at C152 was associated with a 300% maximal fluorescence increase with glucose, though with badan at C182 there was no change. We conclude that glucose sensing based on GBP and FRET does not produce a larger enough signal change for clinical use; both the nature of the environmentally sensitive dye and its site of conjugation seem important for maximum signal change; badan-GBP152C has a large glucose-induced fluorescence change, suitable for development as a glucose sensor.

  13. AIRBORNE LIDAR MONITORING OF FLUORESCENT DYE PARTICLES AS A TRACER TO CHARACTERIZE TRANSPORT AND DISPERSION: A FEASIBILITY STUDY

    EPA Science Inventory

    The feasibility of using airborne lidar to observe the three-dimensional distribution of fluorescent dye particle (FDP) tracers in long-range atmospheric transport and dispersion studies has been successfully demonstrated in field experiments conducted in the North East U.S. duri...

  14. Differential Effects of Deuterium Oxide on the Fluorescence Lifetimes and Intensities of Dyes with Different Modes of Binding to DNA

    Microsoft Academic Search

    Brian L. Sailer; Anthony J. Nastasi; Joseph G. Valdez; John A. Steinkamp; Harry A. Crissman

    1997-01-01

    SUMMARY Deuterium oxide (D 2 O) increases both the fluorescence lifetime and the fluo- rescence intensity of the intercalating dyes propidium iodide (PI) and ethidium bromide (EB) when bound to nucleic acid structures. We have used spectroscopic analysis coupled with conventional and phase-sensitive flow cytometry to compare the alterations in inten- sity and lifetime of various DNA-binding fluorochromes bound to

  15. DOI: 10.1002/chem.200501541 Squaraine-Derived Rotaxanes: Highly Stable, Fluorescent Near-IR Dyes

    E-print Network

    Smith, Bradley D.

    DOI: 10.1002/chem.200501541 Squaraine-Derived Rotaxanes: Highly Stable, Fluorescent Near-IR Dyes) radiation can pass through 10­20 cm of tissue.[2] Major advances in tomograph- ic three-dimensional, molecular beacons with dendritic structures consisting of a core chromophore that emits in the NIR region

  16. Protein labeling with red squarylium dyes for analysis by capillary electrophoresis with laser-induced fluorescence detection.

    PubMed

    Yan, Weiying; Sloat, Amy L; Yagi, Shigeyuki; Nakazumi, Hiroyuki; Colyer, Christa L

    2006-04-01

    Two new red luminescent asymmetric squarylium dyes (designated "Red-1c and Red-3") have been shown to exhibit absorbance shifts to longer wavelengths upon the addition of protein, along with a concomitant increase in fluorescence emission. Specifically, the absorbance maxima for Red-1c and Red-3 dyes are 607 and 622 nm, respectively, in the absence of HSA, and 642 and 640 nm in the presence of HSA, making the excitation of their protein complexes feasible with inexpensive and robust diode lasers. Fluorescence emission maxima, in the presence of HSA, are 656 and 644 nm for Red-1c and Red-3, respectively. Because of the inherently low fluorescence of the dyes in their free state, Red-1c and Red-3 were used as on-column labels (that is, with the dye incorporated into the separation buffer), thus eliminating the need for sample derivatization prior to injection and separation. A comparison of precolumn and on-column labeling of proteins with these squarylium dyes revealed higher efficiencies and greater sensitivities for on-column labeling, which, when conducted with a basic, high-salt content buffer, permitted baseline resolution of a mixture of five model proteins. LOD for model proteins, such as transferrin, alpha-lactalbumin, BSA, and beta-lactoglobulin A and B, labeled with these dyes and analyzed by CE with LIF detection (CE-LIF) were found to be dependent upon dye concentration and solution pH, and are as low as 5 nM for BSA. Satisfactory linear relationships between peak height (or peak area) and protein concentration were obtained by CE-LIF for this on-column labeling method with Red-3 and Red-1c. PMID:16568403

  17. Fluorescence dye-based detection of mAb aggregates in CHO culture supernatants.

    PubMed

    Paul, Albert Jesuran; Schwab, Karen; Prokoph, Nina; Haas, Elena; Handrick, René; Hesse, Friedemann

    2015-06-01

    Product yields, efficacy, and safety of monoclonal antibodies (mAbs) are reduced by the formation of higher molecular weight aggregates during upstream processing. In-process characterization of mAb aggregate formation is a challenge since there is a lack of a fast detection method to identify mAb aggregates in cell culture. In this work, we present a rapid method to characterize mAb aggregate-containing Chinese hamster ovary (CHO) cell culture supernatants. The fluorescence dyes thioflavin T (ThT) and 4-4-bis-1-phenylamino-8-naphthalene sulfonate (Bis-ANS) enabled the detection of soluble as well as large mAb aggregates. Partial least square (PLS) regression models were used to evaluate the linearity of the dye-based mAb aggregate detection in buffer down to a mAb aggregate concentration of 2.4 ?g mL(-1). Furthermore, mAb aggregates were detected in bioprocess medium using Bis-ANS and ThT. Dye binding to aggregates was stable for 60 min, making the method robust and reliable. Finally, the developed method using 10 ?mol L(-1) Bis-ANS enabled discrimination between CHO cell culture supernatants containing different levels of mAb aggregates. The method can be adapted for high-throughput screening, e.g., to screen for cell culture conditions influencing mAb product quality, and hence can contribute to the improvement of production processes of biopharmaceuticals in mammalian cell culture. PMID:25869484

  18. Fluorescence spectra of organic dyes in solution: a time dependent multilevel approach.

    PubMed

    Barone, Vincenzo; Bloino, Julien; Monti, Susanna; Pedone, Alfonso; Prampolini, Giacomo

    2011-02-14

    Classical all-atom molecular dynamics (MD) simulations and quantum mechanical (QM) time-dependent density functional theory (TD-DFT) calculations are employed to study the conformational and photophysical properties of the first emitter excited state of tetramethyl-rhodamine iso-thiocyanate fluorophore in aqueous solution. For this purpose, a specific and accurate force field has been parameterised from QM data to model the fluorophore's first bright excited state. During the MD simulations, the consequences of the ???* electronic transition on the structure and microsolvation sphere of the dye has been analysed in some detail and compared to the ground state behaviour. Thereafter, fluorescence has been calculated at the TD-DFT level on configurations sampled from the simulated MD trajectories, allowing us to include time dependent solvent effects in the computed emission spectrum. The latter, when compared with the absorption spectrum, reproduces well the experimental Stokes shift, further validating the proposed multilevel computational procedure. PMID:21127788

  19. Bright red organic light-emitting diodes doped with a fluorescent dye

    Microsoft Academic Search

    Masayuki Mitsuya; Takayuki Suzuki; Toshiki Koyama; Hirofusa Shirai; Yoshio Taniguchi; Makoto Satsuki; Sadaharu Suga

    2000-01-01

    We have evaluated a synthetic red fluorescent dye, 6-methyl-3-[3-(1,1,6,6-tetramethyl-10-oxo2,3,5,6-tetrahydro-1H,4H,10H-11 -oxa-3a-aza-benzo[de]anthracen-9-yl)-acryloyl]-pyran-2,4-dione (AAAP), as a dopant for an organic light-emitting diode (LED). Bright emission of a good red (maximum luminance: 5600 cd\\/m2, chromaticity coordinates: x=0.63, y=0.36) was obtained. The device consisted of ITO\\/TPD(50 nm)\\/Alq3 doped with AAAP(1.5 mol %,15 nm)\\/bOXDF(20 nm)\\/Alq3(25 nm)\\/Mg:Ag (ITO: indium tin oxide, TPD: N, N'-diphenyl- N,N'-di(3-methylphenyl)-1, 1'biphenyl-4,4'-diamine, Alq3:

  20. Fluorescence enhancement of dyes embedded in nanoparticles of Lu, Eu, Al, and Sc diketonates of different composition and concentration

    NASA Astrophysics Data System (ADS)

    Mironov, L. Yu.; Sveshnikova, E. B.; Ermolaev, V. L.

    2014-12-01

    We have studied the effect of central ions (Lu(III), Eu(III), Sc(III), and Al(III)), organic ligands (2-naphthoyltrifluoroacetone (NTA) and p-phenylbenzoyltrifluoroacetone (PhBTA)), and their concentration in a water-alcohol solution on the fluorescence of ?-diketonate complexes formed and nanoparticles (NPs) generated by the self-assembly of these complexes. The fluorescence quenching of ligands of the complexes of nanoparticles because of the introduction of molecules of dyes, such as Nile Blue (NB), Lissamine Rhodamine RB-200 (RB), and Crystal Violet (CV), in these nanoparticles is investigated, and the NP-sensitization of the fluorescence of these dyes is explored. The dependence of the intensity of the NP-sensitized fluorescence of NB on its concentration in nanoparticles consisting of complexes that differ in composition and concentration is studied. By analyzing this dependence for the nanoparticles consisting of Sc(NTA)3, the size of the studied nanoparticles is evaluated. It is shown that the nature of this dependence is determined by a competition of two processes: the migration of the excitation energy over complexes to dyes and the migration of the excitation energy of dyes to impurities or dimer of dyes. The size of nanoparticles is compared to the estimated values of the exciton diffusion length and the critical radius of energy transfer from complexes to NB. An energy transfer of close to 100% from the nanoparticles formed of 10 ?M of Sc(NTA)3 to 50 nM of NB molecules embedded therein is observed. The introduction of NB molecules into nanoparticles leads to a 200-fold increase in fluorescence intensity compared to their direct excitation in solution.

  1. Measurement of DNA Polymerase Incorporation Kinetics of Dye-Labeled Nucleotides Using Total Internal Reflection Fluorescence Microscopy.

    PubMed

    Walsh, Matthew T; Roller, Eric E; Ko, Kwang-Seuk; Huang, Xiaohua

    2015-07-01

    We report a method for the rapid and automated measurements of the incorporation kinetics of fluorescent dye-labeled nucleotides by DNA polymerases without using stopped-flow and quench-flow methods. Total internal reflection fluorescence microscopy is used to monitor the incorporation of fluorescently labeled nucleotides by DNA polymerase into surface-bound primed DNA templates, and a microfluidic system is used to perform the reactions. We successfully demonstrated the method using Bst DNA polymerase and a set of coumarin-labeled nucleotides. Our method allows the rapid acquisition of polymerase kinetics for implementing and improving DNA sequencing technologies that rely on labeled nucleotides and DNA polymerases. PMID:26096371

  2. Carboxylate-modified squaraine dye doped silica fluorescent pH nanosensors

    NASA Astrophysics Data System (ADS)

    Xue, Lina; Li, Baiyan; Fei, Qiang; Feng, Guodong; Huan, Yanfu; Shi, Zhan

    2010-05-01

    Novel carboxylate-modified fluorescent silica pH nanosensors were synthesized using a reverse microemulsion method with a pH sensitive squaraine dye used as pH indicator. This pH sensitive squaraine dye was simply doped inside SiNPs without any complicated procedures. To avoid aggregation among the particles and to increase the water solubility of the pH nanosensors, the SiNPs were surface modified with a carboxyl group. This pH probe exhibits a good linear dynamic response between pH 3.01 and 5.72. Many alkali, alkaline earth, and transitional metal ions including Li + , Na + , K + , Rb + , Cs + , Mg2 + , Ca2 + , Sr2 + , Al3 + , V5 + , Cr3 + , Cr6 + , Mn2 + , Fe2 + , Fe3 + , Co2 + , Ni3 + , Cu2 + , Zn2 + , As3 + , Se4 + , Mo6 + , Ag + , Cd2 + , La3 + , Er3 + , Ir3 + , Hg + , Hg2 + , and Pb2 + had no significant interference on pH value determination. Artificial sample determination showed that the pH nanosensors developed in this work possess a very promising applicability in biological and biomedical fields.

  3. Fluorescence imaging of the desorption of dye from fused silica versus silica gel.

    PubMed

    Ludes, Melody D; Anthony, Shyroine R; Wirth, Mary J

    2003-07-01

    The desorption rate constants for a cationic dye from strong adsorption sites are compared for the same chromatographic interface but for two different substrates, fused silica and chromatographic silica gel. The dye is 1,1'-didodecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI). The interface consists of acetonitrile and a hydrocarbon monolayer (C8) covalently bound to the silica substrate. To measure slow desorption from fused silica, fluorescence imaging combined with correlation spectroscopy is used. To measure slow desorption from silica gel, fluorescence movies of silica gel particles are used. In both cases, the results show that there are two types of slow desorption processes on time scales exceeding 1 s. The desorption time from one type of site is within an experimental error of 7 s for both silica substrates. The adsorption kinetics for this type of site are slow, and the equilibrium population of DiI on these sites is comparable to that for DiI weakly adsorbed to the hydrocarbon monolayer. For the second type of site, for fused silica, the population of DiI is even higher than that of weakly adsorbed DiI, and the desorption time constant is approximately 2 min, although this is likely shortened by photobleaching. For silica gel, the relative population of DiI on this ultrastrong site is more than an order of magnitude lower, and the desorption time constant is 4.0 +/- 0.1 min. Both silica substrates thus show two types of sites whose time constants agree within experimental error, suggesting that the strong adsorption sites on fused silica are chemically the same as those on chromatographic silica gel. PMID:12964753

  4. Substituent and Solvent Effects on Excited State Charge Transfer Behavior of Highly Fluorescent Dyes Containing Thiophenylimidazole-Based Aldehydes

    NASA Technical Reports Server (NTRS)

    Santos, Javier; Bu, Xiu R.; Mintz, Eric A.

    2001-01-01

    The excited state charge transfer for a series of highly fluorescent dyes containing thiophenylimidazole moiety was investigated. These systems follow the Twisted Intramolecular Charge Transfer (TICT) model. Dual fluorescence was observed for each substituted dye. X-ray structures analysis reveals a twisted ground state geometry for the donor substituted aryl on the 4 and 5 position at the imidazole ring. The excited state charge transfer was modeled by a linear solvation energy relationship using Taft's pi and Dimroth's E(sub T)(30) as solvent parameters. There is linear relation between the energy of the fluorescence transition and solvent polarity. The degree of stabilization of the excited state charge transfer was found to be consistent with the intramolecular molecular charge transfer. Excited dipole moment was studied by utilizing the solvatochromic shift method.

  5. Targeting G-quadruplex structures with extrinsic fluorogenic dyes: promising fluorescence sensors.

    PubMed

    Bhasikuttan, Achikanath C; Mohanty, Jyotirmayee

    2015-05-01

    The research on the G-quadruplex DNAs has received much attention in recent years and numerous reports appeared probing their detection, structure, stability, reactivity, selectivity, etc. for the chemical intervention of their biological activity or sensor applications. This feature article provides an account of the recent reports from different research groups on the intriguing fluorescence properties showcased by certain fluorogenic dyes upon their binding to the G-quadruplex DNAs. Aptly, these selective and sensitive emission features demonstrated with structure specific G-quadruplex DNAs have been turned into label-free fluorescence-based detection methods for various metal ions and small biomolecules, down to the pico molar range, having promising bio-analytical applications. While the in vivo formation of G-quadruplexes is dynamically sensitive to the cell cycle, in tandem with the in vitro applications, it is essential to understand the factors that affect chemical, biological and genetic roles of the G-quadruplex structures plausible along the human genome. Towards this, the recent findings on the quantitative visualization of the quadruplex structures in the human cells using immunofluorescent probes open up avenues to explore highly specific quadruplex responsive agents for diagnostic and therapeutic applications, especially to develop a clinically viable method for cancer treatment. PMID:25716687

  6. An Oxygen Scavenging System for Improvement of Dye Stability in Single-Molecule Fluorescence Experiments?

    PubMed Central

    Aitken, Colin Echeverría; Marshall, R. Andrew; Puglisi, Joseph D.

    2008-01-01

    The application of single-molecule fluorescence techniques to complex biological systems places demands on the performance of single fluorophores. We present an enzymatic oxygen scavenging system for improved dye stability in single-molecule experiments. We compared the previously described protocatechuic acid/protocatechuate-3,4-dioxygenase system to the currently employed glucose oxidase/catalase system. Under standardized conditions, we observed lower dissolved oxygen concentrations with the protocatechuic acid/protocatechuate-3,4-dioxygenase system. Furthermore, we observed increased initial lifetimes of single Cy3, Cy5, and Alexa488 fluorophores. We further tested the effects of chemical additives in this system. We found that biological reducing agents increase both the frequency and duration of blinking events of Cy5, an effect that scales with reducing potential. We observed increased stability of Cy3 and Alexa488 in the presence of the antioxidants ascorbic acid and n-propyl gallate. This new O2-scavenging system should have wide application for single-molecule fluorescence experiments. PMID:17921203

  7. Ultra Q-bodies: quench-based antibody probes that utilize dye-dye interactions with enhanced antigen-dependent fluorescence

    PubMed Central

    Abe, Ryoji; Jeong, Hee-Jin; Arakawa, Dai; Dong, Jinhua; Ohashi, Hiroyuki; Kaigome, Rena; Saiki, Fujio; Yamane, Kyosuke; Takagi, Hiroaki; Ueda, Hiroshi

    2014-01-01

    Recently, we described a novel reagentless fluorescent biosensor strategy named Quenchbody, which functions via the antigen-dependent removal of the quenching effect on a fluorophore that is attached to a single-chain antibody variable region. To explore the practical utility of Quenchbodies, we prepared antibody Fab fragments that were fluorolabeled at either one or two of the N-terminal regions, using a cell-free translation-mediated position-specific protein labeling system. Unexpectedly, the Fab fragment labeled at the heavy chain N-terminal region demonstrated a deeper quenching and antigen-dependent release compared to that observed using scFv. Moreover, when the Fab was fluorolabeled at the two N-termini with either the same dye or with two different dyes, an improved response due to enhanced quenching via dye-dye interactions was observed. On the basis of this approach, several targets, including peptides, proteins, and haptens, as well as narcotics, were quantified with a higher response up to 50-fold. In addition, differentiation of osteosarcoma to osteoblasts was successfully imaged using a similarly fluorolabeled recombinant Fab protein prepared from E. coli. Due to its versatility, this “Ultra-Quenchbody” is expected to exhibit a range of applications from in vitro diagnostics to the live imaging of various targets in situ. PMID:24721819

  8. Influence of energy transfer on fluorescence and lasing properties of various laser dyes co-doped in ORMOSILs

    NASA Astrophysics Data System (ADS)

    Su, Deliang; Yang, Yu; Qian, Guodong; Wang, Zhiyu; Wang, Minquan

    2004-10-01

    Laser dye perylene red (p-red) was co-doped with coumarin 440 (C440) and/or pyrromethene 567 (p567) into MTES-derived organically modified silicates (ORMOSILs) by sol-gel process. Energy transfer among C440, p567 and p-red has been observed. The fluorescence and lasing properties of such energy transfer dye lasers have been investigated. Improved laser efficiency of p-red and broad tunable range as wide as 60 nm were obtained. The effect of dye concentration on energy transfer, laser efficiency and tunable range were also discussed. With the presence of C440 and/or p567, the laser lifetime of p-red exceeded 45 000 pulses at pump intensity beyond 0.5 J/cm 2.

  9. Studies of the photophysics of highly fluorescent Red Mega 480 laser dye in solutions: Steady state spectroscopy.

    PubMed

    Tangod, V B; Mastiholi, B M; Raikar, Prasad; Kulkarni, S G; Raikar, U S

    2015-09-01

    The absorption and fluorescence spectra of highly fluorescent industrially useful medium sized Red Mega 480 dye have been studied in various solvents at 298K. The solute photophysical behavior depends strongly on the solute-solvent interactions. In order to understand the effect of inter molecular interactions on spectral behaviors of the dye in different solvents extent of this behavior can be analyzed by linear solvation energy relationships. In addition, ground and excited state dipole moments were evaluated by various methods. It is observed that excited state dipole moment (?e) is larger than the ground state (?g), absorption spectra show a bathochromic shift with increasing polarity indicating that transition involved is ???(?) and Onsager cavity radius is determined by atomic increment method. PMID:25875032

  10. Interaction of fluorescence dyes with 5-fluorouracil: A photoinduced electron transfer study in bulk and biologically relevant water

    NASA Astrophysics Data System (ADS)

    Kuchlyan, Jagannath; Banik, Debasis; Kundu, Niloy; Roy, Arpita; Sarkar, Nilmoni

    2014-10-01

    The interactions of widely used chemotherapeutic drug, 5-fluorouracil (5FU) with coumarin dyes have been investigated for the first time using steady-state and time-resolved fluorescence spectroscopic measurements. The fluorescence quenching along with the decrease in lifetimes of excited state of coumarin derivatives with gradual addition of 5FU is explained by photoinduced electron transfer (PET) mechanism. Our studies were performed in bulk water and confined water of AOT (aerosol OT) reverse micelle to investigate the effect of confinement on PET dynamics. The feasibility of PET reaction for coumarin-5FU systems is investigated calculating the standard free energy changes using the Rehm-Weller equation.

  11. Fluorescence quenching of (dimethylamino)naphthalene dyes Badan and Prodan by tryptophan in cytochromes P450 and micelles.

    PubMed

    Pospíšil, Petr; Luxem, Katja E; Ener, Maraia; Sýkora, Jan; Kocábová, Jana; Gray, Harry B; Vl?ek, Antonín; Hof, Martin

    2014-08-28

    Fluorescence of 2-(N,N-dimethylamino)-6-propionylnaphthalene dyes Badan and Prodan is quenched by tryptophan in Brij 58 micelles as well as in two cytochrome P450 proteins (CYP102, CYP119) with Badan covalently attached to a cysteine residue. Formation of nonemissive complexes between a dye molecule and tryptophan accounts for about 76% of the fluorescence intensity quenching in micelles, the rest is due to diffusive encounters. In the absence of tryptophan, fluorescence of Badan-labeled cytochromes decays with triexponential kinetics characterized by lifetimes of about 100 ps, 700-800 ps, and 3 ns. Site mutation of a histidine residue in the vicinity of the Badan label by tryptophan results in shortening of all three decay lifetimes. The relative amplitude of the fastest component increases at the expense of the two slower ones. The average quenching rate constants are 4.5 × 10(8) s(-1) (CYP102) and 3.7 × 10(8) s(-1) (CYP119), at 288 K. Cyclic voltammetry of Prodan in MeCN shows a reversible reduction peak at -1.85 V vs NHE that becomes chemically irreversible and shifts positively upon addition of water. A quasireversible reduction at -0.88 V was observed in an aqueous buffer (pH 7.3). The excited-state reduction potential of Prodan (and Badan) is estimated to vary from about +0.6 V (vs NHE) in polar aprotic media (MeCN) to approximately +1.6 V in water. Tryptophan quenching of Badan/Prodan fluorescence in CYPs and Brij 58 micelles is exergonic by ?0.5 V and involves tryptophan oxidation by excited Badan/Prodan, coupled with a fast reaction between the reduced dye and water. Photoreduction is a new quenching mechanism for 2-(N,N-dimethylamino)-6-propionylnaphthalene dyes that are often used as solvatochromic polarity probes, FRET donors and acceptors, as well as reporters of solvation dynamics. PMID:25079965

  12. Applicability of radiocolloids, blue dyes and fluorescent indocyanine green to sentinel node biopsy in melanoma.

    PubMed

    Uhara, Hisashi; Yamazaki, Naoya; Takata, Minoru; Inoue, Yuji; Sakakibara, Akihiro; Nakamura, Yasuhiro; Suehiro, Keisuke; Yamamoto, Akifumi; Kamo, Riei; Mochida, Kosuke; Takenaka, Hideya; Yamashita, Toshiharu; Takenouchi, Tatsuya; Yoshikawa, Shusuke; Takahashi, Akira; Uehara, Jiro; Kawai, Mikio; Iwata, Hiroaki; Kadono, Takafumi; Kai, Yoshitaka; Watanabe, Shoichi; Murata, Satoru; Ikeda, Tetsuya; Fukamizu, Hidekazu; Tanaka, Toshihiro; Hatta, Naohito; Saida, Toshiaki

    2012-04-01

    Patients with primary cutaneous melanoma underwent sentinel node (SN) mapping and biopsy at 25 facilities in Japan by the combination of radiocolloid with gamma probe and dye. Technetium-99m ((99m)Tc)-tin colloid, (99m)Tc-phytate, 2% patent blue violet (PBV) and 0.4% indigo carmine were used as tracers. In some hospitals, 0.5% fluorescent indocyanine green, which allows visualization of the SN with an infrared camera, was concomitantly used and examined. A total of 673 patients were enrolled, and 562 cases were eligible. The detection rates of SN were 95.5% (147/154) with the combination of tin colloid and PBV, 98.9% (368/372) with the combination of phytate and PBV, and 97.2% (35/36) with the combination of tin colloid or phytate and indigo carmine. SN was not detected in 12 cases by the combination method, and the primary tumor was in the head and neck in six of those 12 cases. In eight of 526 cases (1.5%), SN was detected by PBV but not by radiocolloid. There were 13 cases (2.5%) in which SN was detected by radiocolloid but not by PBV. In 18 of 36 cases (50%), SN was detected by radiocolloid but not by indigo carmine. Concomitantly used fluorescent indocyanine green detected SN in all of 67 cases. Interference with transcutaneous oximetry by PVB was observed in some cases, although it caused no clinical trouble. Allergic reactions were not reported with any of the tracers. (99m)Tc-tin colloid, (99m)Tc-phytate, PBV and indocyanine green are useful tracers for SN mapping. PMID:21933261

  13. Removal of dyes using immobilized titanium dioxide illuminated by fluorescent lamps

    Microsoft Academic Search

    Zulkarnain Zainal; Lee Kong Hui; Mohd Zobir Hussein; Yun Hin Taufiq-Yap; Abdul Halim Abdullah; Irmawati Ramli

    2005-01-01

    The photodegradation of various dyes in aqueous solution was studied. Experiments were carried out using glass coated titanium dioxide thin film as photocatalyst. Photodegradation processes of methylene blue (MB), methyl orange (MO), indigo carmine (IC), chicago sky blue 6B (CSB), and mixed dye (MD, mixture of the four mentioned single dye) were reported. As each photodegradation system is pH dependent,

  14. Fluorescent porous film modified polymer optical fiber via "click" chemistry: stable dye dispersion and trace explosive detection.

    PubMed

    Ma, Jiajun; Lv, Ling; Zou, Gang; Zhang, Qijin

    2015-01-14

    In this paper, we report a facile strategy to fabricate fluorescent porous thin film on the surface of U-bent poly(methyl methacrylate) optical fiber (U-bent POF) in situ via "click" polymerization for vapor phase sensing of explosives. Upon irradiation of evanescent UV light transmitting within the fiber under ambient condition, a porous film (POSS-thiol cross-linking film, PTCF) is synthesized on the side surface of the fiber by a thiol-ene "click" reaction of vinyl-functionalized polyhedral oligomeric silsesquioxanes (POSS-V8) and alkane dithiols. When vinyl-functionalized porphyrin, containing four allyl substituents at the periphery, is added into precursors for the polymerization, fluorescence porphyrin can be covalently bonded into the cross-linked network of PTCF. This "fastened" way reduces the aggregation-induced fluorescence self-quenching of porphyrin and enhances the physicochemical stability of the porous film on the surface of U-bent POF. Fluorescent signals of the PTCF/U-bent POF probe made by this method exhibit high fluorescence quenching toward trace TNT and DNT vapor and the highest fluorescence quenching efficiency is observed for 1, 6-hexanedimercaptan-based film. In addition, because of the presence of POSS-V8 with multi cross-linkable groups, PTCF exhibits well-organized pore network and stable dye dispersion, which not only causes fast and sensitive fluorescence quenching against vapors of nitroaromatic compounds, but also provides a repeatability of the probing performance. PMID:25487515

  15. Application of highly sensitive fluorescent dyes (CyDye DIGE Fluor saturation dyes) to laser microdissection and two-dimensional difference gel electrophoresis (2D-DIGE) for cancer proteomics.

    PubMed

    Kondo, Tadashi; Hirohashi, Setsuo

    2006-01-01

    Proteome data combined with histopathological information provides important, novel clues for understanding cancer biology and reveals candidates for tumor markers and therapeutic targets. We have established an application of a highly sensitive fluorescent dye (CyDye DIGE Fluor saturation dye), developed for two-dimensional difference gel electrophoresis (2D-DIGE), to the labeling of proteins extracted from laser microdissected tissues. The use of the dye dramatically decreases the protein amount and, in turn, the number of cells required for 2D-DIGE; the cells obtained from a 1 mm2 area of an 8-12 microm thick tissue section generate up to 5,000 protein spots in a large-format 2D gel. This protocol allows the execution of large-scale proteomics in a more efficient, accurate and reproducible way. The protocol can be used to examine a single sample in 5 d or to examine hundreds of samples in large-scale proteomics. PMID:17406554

  16. Resolution of fluorescence signals from cells labeled with fluorochromes having different lifetimes by phase-sensitive flow cytometry

    Microsoft Academic Search

    John A. Steinkamp; Harry A. Crissman

    1993-01-01

    A flow cytometric method has been developed that uses phase-sensitive detection to separate signals from simultaneous fluorescence emissions in cells labeled with fluorochromes having different fluorescence decay lifetimes. CHO cells were stained with propidium iodide (PI) and fluorescein isothiocyanate (FITC). These dyes bind to DNA and protein and the fluorescence lifetimes of the bound dyes are 15.0 and 3.6 ns,

  17. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes

    PubMed Central

    Samigullin, Dmitry; Fatikhov, Nijaz; Khaziev, Eduard; Skorinkin, Andrey; Nikolsky, Eugeny; Bukharaeva, Ellya

    2015-01-01

    At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers—which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal—has hitherto been technically impossible. With the aim of quantifying both Ca2+ currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 pA and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 ?M and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity. PMID:25709579

  18. Sensitive Spectroscopic Detection of Large and Denatured Protein Aggregates in Solution by Use of the Fluorescent Dye Nile Red

    PubMed Central

    Oliveira, Sabrina; Sanders, Niek N.; Lucas, Bart; van Hoek, Arie; Hink, Mark A.; Visser, Antonie J. W. G.; De Smedt, Stefaan C.; Hennink, Wim E.; Jiskoot, Wim

    2007-01-01

    The fluorescent dye Nile red was used as a probe for the sensitive detection of large, denatured aggregates of the model protein ?-galactosidase (E. coli) in solution. Aggregates were formed by irreversible heat denaturation of ?-galactosidase below and above the protein’s unfolding temperature of 57.4°C, and the presence of aggregates in heated solutions was confirmed by static light scattering. Interaction of Nile red with ?-galactosidase aggregates led to a shift of the emission maximum (?max) from 660 to 611 nm, and to an increase of fluorescence intensity. Time-resolved fluorescence and fluorescence correlation spectroscopy (FCS) measurements showed that Nile red detected large aggregates with hydrodynamic radii around 130 nm. By steady-state fluorescence measurements, it was possible to detect 1 nM of denatured and aggregated ?-galactosidase in solution. The comparison with size exclusion chromatography (SEC) showed that native ?-galactosidase and small aggregates thereof had no substantial effect on the fluorescence of Nile red. Large aggregates were not detected by SEC, because they were excluded from the column. The results with ?-galactosidase demonstrate the potential of Nile red for developing complementary analytical methods that overcome the size limitations of SEC, and can detect the formation of large protein aggregates at early stages. PMID:17294134

  19. Comparison of sieving matrices for on-the-fly fluorescence lifetime detection of dye-labeled DNA fragments.

    PubMed

    Li, L; McGown, L B

    2001-02-01

    Commercially available, replaceable sieving matrices and their solvent modulated forms were evaluated for use in on-the-fly fluorescence lifetime detection of dye-labeled DNA fragments in capillary electrophoresis. The fragments were labeled with dyes that can be excited by the 488 nm line of an argon ion laser and have lifetimes in the range of 0.8 ns to 3.8 ns. The sieving matrices and buffer systems included poly(vinylpyrrolidone) (PVP), poly(ethyleneoxide) (PEO), hydroxyethylcellulose (HEC), Tris-borate-EDTA (TBE) and Tris-TAPS-EDTA buffers modified with DMSO and formamide. Selection of the optimal sieving matrix is based on the separation efficiency and the enhancement of lifetime resolution of DNA fragments. Best results for both electrophoretic resolution and lifetime detection were obtained using a poly(ethyleneoxide)/TBE gel buffer in the presence of 10% formamide. PMID:11293703

  20. One- and two-photon time-resolved fluorescence of visible and near-infrared dyes in scattering media

    NASA Astrophysics Data System (ADS)

    Esposito, R.; Altucci, C.; Velotta, R.; Gaeta, G. M.; Lepore, M.

    2009-02-01

    Visible and near-infrared dyes are largely used in diagnostics and sensing. For this reason, it is very important to study their time-resolved fluorescence in presence or in absence of proper scattering medium in order to simulate the optical characteristics of biological tissues. Moreover, if one- or two-photon excitation processes are available also visible dyes will be employed taking advantages from using exciting sources in the diagnostic window (red and near IR) of the electromagnetic spectrum, where the photons are rarely absorbed and more often scattered. Visible and near IR fluorescent samples (Indocyanine Green and Rhodamine 6G) in absence and in presence of scattering agents (different Intralipid concentrations) and one- and two- photon time-resolved experiments have been performed. As expected, the presence of scattering agents modified time-resolved spectra and the related lifetime components. The experimental results have been used to preliminarly test different theoretical approaches describing the propagation of fluorescence signals in scattering media.

  1. Laboratory investigation of triple marking the parasitoid Gonatocerus ashmeadi with a fluorescent dye and

    E-print Network

    Hoddle, Mark S.

    dye and two animal proteins N. A. Irvin1 *, J. R. Hagler2 & M. S. Hoddle1,3 1 Department of Entomology: ELISA, protein marking, dye marking, mark­capture, survival, Hymenoptera, Mymari- dae, glassy for monitoring dispersal patterns of natural enemies in the field. The triple mark contained egg albumin

  2. Removal of dyes using immobilized titanium dioxide illuminated by fluorescent lamps.

    PubMed

    Zainal, Zulkarnain; Hui, Lee Kong; Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin; Abdullah, Abdul Halim; Ramli, Irmawati

    2005-10-17

    The photodegradation of various dyes in aqueous solution was studied. Experiments were carried out using glass coated titanium dioxide thin film as photocatalyst. Photodegradation processes of methylene blue (MB), methyl orange (MO), indigo carmine (IC), chicago sky blue 6B (CSB), and mixed dye (MD, mixture of the four mentioned single dye) were reported. As each photodegradation system is pH dependent, the photodegradation experiment was carried out in each dye photodegradation reactive pH range at approximately 28 degrees C. The dyes removal efficiency was studied and compared using UV-vis spectrophotometer analysis. The total removal of each dye was: methylene blue (90.3%), methyl orange (98.5%), indigo carmine (92.4%), chicago sky blue 6B (60.3%), and mixed dyes (70.1%), respectively. The characteristic of the photocatalyst was investigated using X-ray diffractometer (XRD). The amount of each dye intermediate produced in the photodegradation process was also determined with the help of total organic carbon (TOC) analysis. PMID:15996813

  3. Tryptophan-to-dye fluorescence energy transfer applied to oxygen sensing by using type-3 copper proteins.

    PubMed

    Zauner, Gerhild; Lonardi, Emanuela; Bubacco, Luigi; Aartsma, Thijs J; Canters, Gerard W; Tepper, Armand W J W

    2007-01-01

    A fluorescence-based system to sense oxygen in solution is described. The method exploits the sensitivity of the endogenous fluorescence of type-3 copper proteins towards the presence of oxygen by translating the near-UV emission of the protein to label fluorescence in the visible range through a FRET mechanism. The main protein in this study, a recombinant tyrosinase from the soil bacterium Streptomyces antibioticus, has been covalently labeled with a variety of fluorescent dye molecules with emission maxima spanning the whole visible wavelength range. In all cases, the emission of the label varied considerably between O2-bound and O2-free protein with a contrast exceeding that of the Trp emission for some labels. It is shown that different constructs may be simultaneously observed using a single excitation wavelength. Next to the described application in oxygen sensing, the method may be applicable to any protein showing variations in tryptophan fluorescence, for example as a function of ligand binding or catalysis. PMID:17577913

  4. A new fluorescent imaging procedure in vivo for evaluation of the retinal microcirculation in rats.

    PubMed

    Kimura, H; Kiryu, J; Nishiwaki, H; Ogura, Y

    1995-03-01

    We investigated a new method for in vivo evaluation of the retinal microcirculation in rats using a cell-permeant fluorescent dye, acridine orange (AO), which stains cell nuclei and cytoplasm, and a scanning laser ophthalmoscope (SLO). AO, which binds and interacts with DNA and RNA, and thus stains cell nuclei and cytoplasm, was administered intravenously to rats. Fluorescein angiography was performed after administration of the AO, and fundus images were recorded on S-VHS videotape by means of an SLO. Argon laser was used as an exciter of the dye. The retinal vessels were stained with the dye, rendering the retinal microvasculature clearly visible. Cell nuclei and vessel walls were observed as greater fluorescence and lesser fluorescence, respectively. Leukocytes were also observed as highly fluorescent dots moving through the vessels. The results suggest that SLO visualization of AO uptake by cells may be a useful procedure for the evaluation of retinal microcirculation in vivo in rats. PMID:7796605

  5. A Long-Wavelength Fluorescent Squarylium Cyanine Dye Possessing Boronic Acid for Sensing Monosaccharides and Glycoproteins with High Enhancement in Aqueous Solution

    PubMed Central

    Saito, Shingo; Massie, Tara L.; Maeda, Takeshi; Nakazumi, Hiroyuki; Colyer, Christa L.

    2012-01-01

    Fluorescence sensing of saccharides and glycoproteins using a boronic acid functionalized squarylium cyanine dye (“SQ-BA”) is characterized in terms of synthetic, fluorometric, thermodynamic and kinetic parameters. In our previous work, this newly synthesized dye was successfully applied to the separation and quantification of Gram-positive bacteria by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF); however, the fundamental properties of the dye and its saccharide complexes still required elucidation, as presented in this paper. The dye itself forms nonemissive, soluble aggregates in aqueous solution. With the addition of a monosaccharide, the dye aggregate dissociates to form an emissive monomer accompanied by the formation of a cyclic cis-diol ester with long-wavelength emission (?ex = 630 nm, ?em = 660 nm). A very large fluorescence enhancement factor of 18× was observed for the sensing dye as a fructose complex at pH 10, yielding a limit of detection of 10 ?M fructose. The relative order of fluorescence enhancement of SQ-BA with other monosaccharides was found to be: fructose > ribose > arabinose ? galactose > xylose > mannose > rhamnose > fucose ? glucose; and apparent affinity constants of 102.80, 102.08 and 100.86 M?1 were determined for fructose, ribose and glucose, respectively. Formation of the emissive complexes occurred within minutes, proving the kinetics of the sugar-dye interactions to be suitable for on-column labeling methods in CE-LIF. Furthermore, the sensing dye was successfully applied to glycoproteins, mucin type I–S and type III, which were detected with high sensitivity in batch aqueous solution as a result of the sugar-selective boronic acid-diol esterification as well as hydrophobic interactions. PMID:22778592

  6. Fluorescence Resonance Energy Transfer and Complex Formation Between Thiazole Orange and Various Dye-DNA Conjugates: Implications in Signaling Nucleic Acid Hybridization

    Microsoft Academic Search

    W. Russ Algar; Melissa Massey; Ulrich J. Krull

    2006-01-01

    Fluorescence resonance energy transfer (FRET) was investigated between the intercalating dye thiazole orange (TO), and the dyes Cyanine 3 (Cy3), Cyanine 5 (Cy5), Carboxytetramethyl Rhodamine (TAMRA), Iowa Black FQ (IabFQ), and Iowa Black RQ (IabRQ), which were covalently immobilized at the end of dsDNA oligonucleotides. In addition to determining that TO was an effective energy donor, FRET efficiency data obtained

  7. Two-step cycle sequencing improves base ambiguities and signal dropouts in DNA sequencing reactions using energy-transfer-based fluorescent Dye terminators

    Microsoft Academic Search

    Long Wen

    2001-01-01

    The use of automated fluorescent DNA sequencer systems and PCR-based DNA sequencing methods plays an important role in the\\u000a actual effort to improve the efficiency of large-scale DNA analysis. While dideoxy-terminators labeled with energy-transfer\\u000a dyes (BigDyes) provide the most versatile method of automated DNA sequencing, premature terminations result in a substantially\\u000a reduced reading length of the DNA sequence. Premature terminations

  8. Fluorescence in situ hybridization using an old world monkey Y chromosome specific probe combined with immunofluorescence staining on rhesus monkey tissues.

    PubMed

    Xia, Xiujin; Rasmussen, Terri; Alvarez, Xavier; Taguchi, Takahiro; Li, Marilyn; La Russa, Vincent F

    2007-11-01

    To date, there is no commercially available Y chromosome probe that can be used for fluorescence in situ hybridization (FISH) for the male rhesus monkey. We have recently generated a probe for FISH with high specificity to the short arm of the rhesus monkey Y chromosome. In this study, we further describe a method that keeps the integrity of tissue-specific antigenic structures for immunofluorescence staining subsequent to FISH on paraffin-embedded rhesus monkey tissues. We have examined this technique in combination with an epithelial cell-specific marker, cytokeratin 8/18 (CK8/18), on various tissues, including jejunum, liver, kidney, and pancreas. CK8/18 and Y chromosome signals were distinctly seen simultaneously on epithelial cells from the same tissue section from male but not female monkeys. These studies indicate that our FISH immunofluorescence technique can be reliably used to identify and phenotype male cells in paraffin-embedded rhesus monkey tissues. PMID:17595337

  9. Near Infrared Voltage Sensitive Fluorescent Dyes Optimized for Optical Mapping in Blood-Perfused Myocardium

    PubMed Central

    Matiukas, Arvydas; Mitrea, Bogdan G.; Qin, Maochun; Pertsov, Arkady M.; Shvedko, Alexander G.; Warren, Mark D.; Zaitsev, Alexey V.; Wuskell, Joseph P.; Wei, Mei-de; Watras, James; Loew, Leslie M.

    2007-01-01

    Background Styryl voltage-sensitive dyes (e.g. di-4-ANEPPS) have been successfully used for optical mapping in cardiac cells and tissues. However, their utility for probing electrical activity deep inside the myocardial wall and in blood-perfused myocardium has been limited because of light scattering and high absorption by endogenous chromophores and hemoglobin at blue-green excitation wavelengths. Objectives The purpose of this study was to characterize two new styryl dyes Di-4-ANBDQPQ (JPW-6003) and Di-4-ANBDQBS (JPW-6033) optimized for blood-perfused tissue and intramural optical mapping. Methods Voltage-dependent spectra were recorded in a model lipid bilayer. Optical mapping experiments were conducted in 4 species (mouse, rat, guinea pig, and pig). Hearts were Langendorff-perfused using Tyrode’s solution and blood (pig). Dyes were loaded via bolus injection into perfusate. Transillumination experiments were conducted in isolated coronary-perfused pig right ventricular wall preparations. Results The optimal excitation wavelength in cardiac tissues (650nm) was >70nm beyond the absorption maximum of hemoglobin. Voltage-sensitivity of both dyes was ~10–20%. Signal decay half-life due to dye internalization was 80–210 minutes, which is 5–7 times slower than for di-4-ANEPPS. In transillumination mode, ?F/F was as high as 20%. In blood-perfused tissues, ?F/F reached 5.5% (1.8 times higher than for di-4-ANEPPS). Conclusion We have synthesized and characterized two new NIR dyes with excitation/emission wavelengths shifted >100nm to the red. They provide both high voltage-sensitivity, and 5–7 times slower internalization rate compared to conventional dyes. The dyes are optimized for deeper tissue probing and optical mapping of blood-perfused tissue, and can also be used for conventional applications. PMID:17954405

  10. Diffusion of organic dyes in ionic liquid and giant micron sized ionic liquid mixed micelle: fluorescence correlation spectroscopy.

    PubMed

    Sasmal, Dibyendu Kumar; Mandal, Amit Kumar; Mondal, Tridib; Bhattacharyya, Kankan

    2011-06-23

    Diffusion of organic dyes in neat room temperature ionic liquid (RTIL) and RTIL-mixed micelle has been studied by fluorescence correlation spectroscopy (FCS). We have selected two RTILs, 3-pentyl-1-methyl imidazolium bromide ([C5C1Im][Br]) and the corresponding tetra-fluoroborate ([C5C1Im][BF(4)]). Diffusion coefficients (D(t)) of three organic dyes--DCM (neutral), C480 (neutral), and C343 (anionic)--in these RTILs are ?100 times slower compared to water. This indicates very high viscosity of the RTILs. In contrast to water, the D(t) in RTIL exhibits a wide distribution which suggests the presence of heterogeneity (nanoscale organization). The presence of ions in the RTILs markedly affects diffusion in the RTILs. D(t)'s of C480 (neutral) and C343 (anionic) are very similar in water but in RTILs the ionic dye C343 diffuses 1.7 times slower than neutral C480. This is attributed to the electrostatic force exerted by the ions in the RTILs. In the giant (?2-4 ?m) [C5C1Im][Br]-triblock copolymer (P123) mixed micelle D(t) of DCM, C480, and C343 are found to be 7, 15, and 7 ?m(2) s(-1), respectively. The results are compared with those in P123 micelle and gel. PMID:21619001

  11. A highly sensitive fluorescent indicator dye for calcium imaging of neural activity in vitro and in vivo

    PubMed Central

    Tada, Mayumi; Takeuchi, Atsuya; Hashizume, Miki; Kitamura, Kazuo; Kano, Masanobu

    2014-01-01

    Calcium imaging of individual neurons is widely used for monitoring their activity in vitro and in vivo. Synthetic fluorescent calcium indicator dyes are commonly used, but the resulting calcium signals sometimes suffer from a low signal-to-noise ratio (SNR). Therefore, it is difficult to detect signals caused by single action potentials (APs) particularly from neurons in vivo. Here we showed that a recently developed calcium indicator dye, Cal-520, is sufficiently sensitive to reliably detect single APs both in vitro and in vivo. In neocortical neurons, calcium signals were linearly correlated with the number of APs, and the SNR was > 6 for in vitro slice preparations and > 1.6 for in vivo anesthetised mice. In cerebellar Purkinje cells, dendritic calcium transients evoked by climbing fiber inputs were clearly observed in anesthetised mice with a high SNR and fast decay time. These characteristics of Cal-520 are a great advantage over those of Oregon Green BAPTA-1, the most commonly used calcium indicator dye, for monitoring the activity of individual neurons both in vitro and in vivo. PMID:24405482

  12. Consideration of fluorescence properties for the direct determination of erythrosine in saffron in the presence of other synthetic dyes.

    PubMed

    Ordoudi, S A; Tsimidou, M Z

    2011-04-01

    Direct selective detection of erythrosine in saffron in the presence of other synthetic dyes considers its fluorescence at 532 nm excitation/548 nm emission. Saffron pre-treatment was according to the ISO 3632-2 trade standard test methods. On account of calculated quantum yield values, none of the yellow dyes is expected to interfere. Among red ones, reservations about allura red AC, azorubine and red 2G were not verified by experimentation, signifying excellent method specificity. Detection and quantification limits (0.56 and 1.70 nM) were of the same magnitude as those reported in the literature after chromatographic separation of erythrosine. The percentage recovery from spiked saffron samples ranging from 63 to 141 was acceptable for residue levels in foods. The matrix effect from crocins (saffron pigments) was evidenced only at a lower spiking level (0.02 mg kg(-1)). The minimum required performance limit (MRPL) was 0.04 mg kg(-1), indicating that the method is appropriate for determining traces of erythrosine in saffron. The approach offers improved sensitivity (by three orders of magnitude) and specificity than the direct spectrophotometric detection of certain synthetic dyes in saffron and deserves attention by the ISO Technical Committee for 'Herbs, culinary spices and condiments'. PMID:21337237

  13. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Albany, CA)

    1995-01-01

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated.

  14. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, A.N.; Benson, S.C.

    1997-07-08

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated. 4 figs.

  15. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Albany, CA)

    1997-01-01

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated.

  16. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, Alexander M. (Orinda, CA); Benson, Scott C. (Albany, CA)

    1999-01-01

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated.

  17. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, A.N.; Benson, S.C.

    1995-03-28

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated. 4 figures.

  18. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, Alexander M. (Orinde, CA); Benson, Scott C. (Albany, CA)

    1998-01-01

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated.

  19. DNA complexes with dyes designed for energy transfer as fluorescent markers

    DOEpatents

    Glazer, A.M.; Benson, S.C.

    1998-06-16

    Heteromultimeric fluorophores are provided for binding to DNA, which allow for the detection of DNA in electrical separations and preparation of probes having high-fluorescent efficiencies and large Stokes shifts. In addition, by appropriate choice of fluorescent molecules, one can use a single narrow wavelength band excitation light source, while obtaining fluorescent emissions having sufficient separation to be readily discriminated. 4 figs.

  20. Fluorescent Dye Encapsulated ZnO Particles with Cell-specific Toxicity for Potential use in Biomedical Applications

    SciTech Connect

    Wang, Hua; Wingett, Denise; Engelhard, Mark H.; Feris, Kevin; Reddy, K. M.; Turner, Paul; Layne, Janet; Hanley, Cory; Bell, Jason; Tenne, Dmitri; Wang, Chong M.; Punnoose, Alex

    2009-01-01

    Fluorescein isothiocyanate (FITC)-encapsulated core-shell particles with a nanoscale ZnO finishing layer have been synthesized for the first time as multifunctional “smart” nanostructures for particle tracking and cell imaging using the visible fluorescence emission of the dye or UV fluorescence emission of ZnO, and anti-cancer/antibacterial treatments using the selective toxicity of the nanoscale ZnO outer surface. The chemical phase composition, morphology, size, and the layered core-shell architecture of the particles were characterized using detailed transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis-NIR spectrophotometry. Systematic XPS studies after removing nanometer thick layers confirmed the expected layered structure in the order ZnO-SiO2-APTMS-FITC proceeding from the surface to the core of the ~200 nm sized particles. Detailed investigation of the fluorescence properties of these hydrophilic particles in bio-compatible media using fluorescence spectroscopy, flow cytometry and fluorescence confocal microscopy demonstrated that the silica/ZnO outer layer offers considerable protection to the encapsulated dye molecules from photobleaching and quenching due to reactive species such as oxygen in the solvent. These particles showed promise toward cell imaging, for example when the bacterium Escherichia coli was used as a test system, the green fluorescence of the particles allowed confocal microscopy to image the cells. The FITC encapsulated ZnO (FITC-ZnO) particles demonstrated excellent selectivity in preferentially killing Jurkat cancer cells (18% cell viability) without any significant toxicity to normal primary immune cells (75% cell viability) at 60 ?g/mL concentrations and inhibited the growth of both gram-positive and gram negative bacteria at concentrations ? 250-500 ?g/mL (for Staphylococcus aureus and Escherichia coli, respectively). These results indicate that the novel FITC encapsulated multifunctional particles with nanoscale ZnO surface layer are smart nanostructures for particle tracking, cell imaging, antibacterial treatments and cancer therapy.

  1. Fully automated fluorescent in situ hybridization (FISH) staining and digital analysis of HER2 in breast cancer: a validation study.

    PubMed

    van der Logt, Elise M J; Kuperus, Deborah A J; van Setten, Jan W; van den Heuvel, Marius C; Boers, James E; Schuuring, Ed; Kibbelaar, Robby E

    2015-01-01

    HER2 assessment is routinely used to select patients with invasive breast cancer that might benefit from HER2-targeted therapy. The aim of this study was to validate a fully automated in situ hybridization (ISH) procedure that combines the automated Leica HER2 fluorescent ISH system for Bond with supervised automated analysis with the Visia imaging D-Sight digital imaging platform. HER2 assessment was performed on 328 formalin-fixed/paraffin-embedded invasive breast cancer tumors on tissue microarrays (TMA) and 100 (50 selected IHC 2+ and 50 random IHC scores) full-sized slides of resections/biopsies obtained for diagnostic purposes previously. For digital analysis slides were pre-screened at 20x and 100x magnification for all fluorescent signals and supervised-automated scoring was performed on at least two pictures (in total at least 20 nuclei were counted) with the D-Sight HER2 FISH analysis module by two observers independently. Results were compared to data obtained previously with the manual Abbott FISH test. The overall agreement with Abbott FISH data among TMA samples and 50 selected IHC 2+ cases was 98.8% (? = 0.94) and 93.8% (? = 0.88), respectively. The results of 50 additionally tested unselected IHC cases were concordant with previously obtained IHC and/or FISH data. The combination of the Leica FISH system with the D-Sight digital imaging platform is a feasible method for HER2 assessment in routine clinical practice for patients with invasive breast cancer. PMID:25844540

  2. A sensitive, viable-colony staining method using Nile red for direct screening of bacteria that accumulate polyhydroxyalkanoic acids and other lipid storage compounds

    Microsoft Academic Search

    Patricia Spiekermann; Bernd H. A. Rehm; Rainer Kalscheuer; Dirk Baumeister; Alexander Steinbüchel

    1999-01-01

    The oxazine dye Nile blue A and its fluorescent oxazone form, Nile red, were used to develop a simple and highly sensitive\\u000a staining method to detect poly(3-hydroxybutyric acid) and other polyhydroxyalkanoic acids (PHAs) directly in growing bacterial\\u000a colonies. In contrast to previously described methods, these dyes were directly included in the medium at concentrations of\\u000a only 0.5 ?g\\/ml, and growth

  3. Cell wall staining with Trypan blue enables quantitative analysis of morphological changes in yeast cells

    PubMed Central

    Liesche, Johannes; Marek, Magdalena; Günther-Pomorski, Thomas

    2015-01-01

    Yeast cells are protected by a cell wall that plays an important role in the exchange of substances with the environment. The cell wall structure is dynamic and can adapt to different physiological states or environmental conditions. For the investigation of morphological changes, selective staining with fluorescent dyes is a valuable tool. Furthermore, cell wall staining is used to facilitate sub-cellular localization experiments with fluorescently-labeled proteins and the detection of yeast cells in non-fungal host tissues. Here, we report staining of Saccharomyces cerevisiae cell wall with Trypan Blue, which emits strong red fluorescence upon binding to chitin and yeast glucan; thereby, it facilitates cell wall analysis by confocal and super-resolution microscopy. The staining pattern of Trypan Blue was similar to that of the widely used UV-excitable, blue fluorescent cell wall stain Calcofluor White. Trypan Blue staining facilitated quantification of cell size and cell wall volume when utilizing the optical sectioning capacity of a confocal microscope. This enabled the quantification of morphological changes during growth under anaerobic conditions and in the presence of chemicals, demonstrating the potential of this approach for morphological investigations or screening assays. PMID:25717323

  4. Genetically encoded fluorescent sensors of membrane potential

    PubMed Central

    Baker, B. J.; Mutoh, H.; Dimitrov, D.; Akemann, W.; Perron, A.; Iwamoto, Y.; Jin, L.; Cohen, L. B.; Isacoff, E. Y.; Pieribone, V. A.; Hughes, T.; Knöpfel, T.

    2009-01-01

    Imaging activity of neurons in intact brain tissue was conceived several decades ago and, after many years of development, voltage-sensitive dyes now offer the highest spatial and temporal resolution for imaging neuronal functions in the living brain. Further progress in this field is expected from the emergent development of genetically encoded fluorescent sensors of membrane potential. These fluorescent protein (FP) voltage sensors overcome the drawbacks of organic voltage sensitive dyes such as non-specificity of cell staining and the low accessibility of the dye to some cell types. In a transgenic animal, a genetically encoded sensor could in principle be expressed specifically in any cell type and would have the advantage of staining only the cell population determined by the specificity of the promoter used to drive expression. Here we critically review the current status of these developments. PMID:18679801

  5. Structural, dynamic and photophysical properties of a fluorescent dye incorporated in an amorphous hydrophobic polymer bundle.

    PubMed

    De Mitri, N; Prampolini, G; Monti, S; Barone, V

    2014-08-21

    The properties of a low molecular weight organic dye, namely 4-naphthyloxy-1-methoxy-2,2,6,6-tetramethylpiperidine, covalently bound to an apolar polyolefin were investigated by means of a multi-level approach, combining classical molecular dynamics simulations, based on purposely parameterized force fields, and quantum mechanical calculations based on density functional theory (DFT) and its time-dependent extension (TD-DFT). The structure and dynamics of the dye in its embedding medium were analyzed and discussed taking the entangling effect of the surrounding polymer into account, and also by comparing the results to those obtained for a different environment, i.e. toluene solution. Finally, the influence was investigated of long lived cages found in the polymeric embedding on photophysical properties, in terms of the slow and fast dye's internal dynamics, by comparing computed IR and UV spectra with their experimental counterparts. PMID:24988373

  6. Visualization of Phospholipid Domains in Escherichia coli by Using the Cardiolipin-Specific Fluorescent Dye 10-N-Nonyl Acridine Orange

    Microsoft Academic Search

    EUGENIA MILEYKOVSKAYA; WILLIAM DOWHAN

    2000-01-01

    Cardiolipin (CL)-specific fluorescent dye 10-N-nonyl-acridine orange (NAO) was used to visualize CL distribution in Escherichia coli cells of different phospholipid compositions. In a filamentous mutant containing only anionic phospholipids, green fluorescent spots were observed along the filaments at approximately regular intervals. Three-dimensional image reconstruction obtained by optical sectioning and a deconvolution algo- rithm revealed NAO-binding domains in the plane of

  7. Dye Like A Natural

    NSDL National Science Digital Library

    Julie Yu

    2010-01-01

    In this activity, learners stain fabrics--on purpose! Learners explore the art of natural dyeing by using dyes and substrates that are both derived from plant or animal sources as well as mordant solutions. Learners compare the color and effectiveness of different mordant/dye combinations on the different substrates.

  8. Pyranine (a fluorescent dye) is a target for oxidation by tert-butylhydroperoxide (TBH)

    Microsoft Academic Search

    J. C. Barreto; M. S. Tornwall; T. A. Miller

    1991-01-01

    The authors' desire was to utilize a vesicle model in order to investigate TBH permeation across membranes and TBH oxidation of membranes themselves. In vesicle experiments it has been demonstrated that pyranine can be encapsulated within vesicles with > 90% of the dye internalized, and that pyranine leak rates are negligible. They have also found that pyranine is a sensitive

  9. Investigation of time-resolved fluorescence lifetime of perylene dye molecules embedded in silicon nanopillars

    NASA Astrophysics Data System (ADS)

    Acikgoz, Sabriye

    2015-02-01

    The radiative decay rate of a perylene dye molecule attached to silicon nanopillar is investigated using a conventional time-correlated single photon counting technique. It is hard to produce a sustainable host with exactly the same dimensions all the time during fabrication to accommodate dye molecules for enhancement of spontaneous emission rate. The laser-induced electrochemical anodization method allows us to have a control over size and shape of the silicon nanostructures. The effect of the silicon nanopillar on the radiative decay rate of the dye molecules is described by the Klimov's prolate nanospheroid model. It is observed that the decay rate is significantly enhanced or inhibited due to plasmon resonance, depending on whether the dipole is embedded closely right at the tip or at equator of the prolate nanospheroid. Both inhibition and enhancement disappear when the distance between the dipole and prolate nanospheroid becomes large. Thus, the decay rate of the dye molecule approaches its natural value in the free space.

  10. Influence of the substrate on the spectroscopic characteristics of the fluorescence of adsorbed dye molecules

    Microsoft Academic Search

    V. A. Bespalov; V. B. Zaitsev; L. V. Levshin; G. S. Plotnikov; A. M. Saletskii

    1992-01-01

    UDC 535.37 It was previously shown that various electronic [i, 2] and even phase [3] transitions in a solid substrate can be sensitized with the aid of dye molecules adsorbed on the surface of the solid. On the other hand, the heterogeneity of the surface and the presence of charges have a strong influence on the spectroscopic characteristics of the

  11. Optical Properties of Fluorescent Mixtures: Comparing Quantum Dots to Organic Dyes

    ERIC Educational Resources Information Center

    Hutchins, Benjamin M.; Morgan, Thomas T.; Ucak-Astarlioglu, Mine G.; Wlilliams, Mary Elizabeth

    2007-01-01

    The study describes and compares the size-dependent optical properties of organic dyes with those of semiconductor nanocrystals or quantum dots (QDs). The analysis shows that mixtures of QDs contain emission colors that are sum of the individual QD components.

  12. Improved Diagnosis of Trichomonas vaginalis Infection by PCR Using Vaginal Swabs and Urine Specimens Compared to Diagnosis by Wet Mount Microscopy, Culture, and Fluorescent Staining

    PubMed Central

    van der Schee, Cindy; van Belkum, Alex; Zwijgers, Lisette; van der Brugge, Esther; O'neill, Errol L.; Luijendijk, Ad; van Rijsoort-Vos, Tineke; van der Meijden, Willem I.; Verbrugh, Henri; Sluiters, Hans J. F.

    1999-01-01

    Four vaginal cotton swab specimens were obtained from each of 804 women visiting the outpatient sexually transmitted disease clinic of the Erasmus University Medical Center Rotterdam, Rotterdam, The Netherlands, for validation of various forms of Trichomonas vaginalis diagnostic procedures. One swab specimen was immediately examined by wet mount microscopy, a second swab was placed in Kupferberg's Trichosel medium for cultivation, and two swabs were placed in phosphate-buffered saline (PBS), pH 7.2. The resulting PBS suspension was used for direct staining with acridine orange and fluorescence microscopy, inoculation of modified Diamond's culture medium, and a PCR specific for T. vaginalis. A total of 70 samples positive in one or more of the tests were identified: 31 (3.8%) infections were detected by wet mount microscopy, and 36 (4.4%) were identified by acridine orange staining, as opposed to 40 (4.9%) and 46 (5.7%) positives in modified Diamond's and Trichosel media, respectively. PCR was positive for 61 (7.5%) samples. Secondly, from each of 200 women were obtained a urine sample and a vaginal cotton swab specimen, and 200 urine samples were obtained from men. For the women, 15 (7.4%) of the samples showed a positive result for either the wet mount (n = 1), Trichosel culture (n = 6), PCR on the vaginal swab sample (n = 10), or PCR on the urine specimen (n = 11). Four men (2%) were diagnosed with a T. vaginalis infection. Thus, PCR appears to be the method of choice for the detection of genital infections with T. vaginalis. PMID:10565943

  13. Synthesis, spectral properties, and detection limits of reactive squaraine dyes, a new class of diode laser compatible fluorescent protein labels.

    PubMed

    Oswald, B; Patsenker, L; Duschl, J; Szmacinski, H; Wolfbeis, O S; Terpetschnig, E

    1999-01-01

    We describe the synthesis and spectral characterization of two reactive long-wavelength fluorescence labels (Sq635-m and Sq635-b), having either one or two N-hydroxysuccinimidyl esters. Both are squaraine derivatives and consist of a cyanine-type chromophore and a central squarate bridge. To improve water solubility, we introduced two sulfonic acid groups into the heterocyclic ring systems, and for covalent attachment to proteins, a reactive N-hydroxy-succinimide ester (NHS ester) was synthesized. The squaraine markers exhibit low quantum yields in water (phi = 0.15) and high quantum yields (phi = 0.6-0.7) when bound to proteins. The absorption maxima at 635 nm in water and at approximately 645 nm when bound to proteins allow excitation with commercially available diode lasers. The detection limit of a representative squaraine dye in blood was estimated to be half that of a commonly used fluorophore. PMID:10563760

  14. Oxygen-dependent photochemistry of fluorescent dyes studied at the single molecule level

    NASA Astrophysics Data System (ADS)

    Renn, Alois; Seelig, Johannes; Sandoghdar, Vahid

    We perform wide-field microscopy to investigate the photobleaching of organic fluorophores embedded in the polymeric host PMMA. Our experimental arrangement facilitates the comparison between the ensemble and single molecule data. We characterize the photostability of dye molecules of various families by measuring the 'bleaching number', defined as the average number of photons a molecule emits until photobleaching occurs. In particular, we have analysed the dependence of the bleaching number on the presence of oxygen. Surprisingly, we find an improvement of photostability in the presence of oxygen for ionic dyes (DiI, TMR, Rh6G, Alexa 546), suggesting that oxygen quenches the photoactive triplet state, but it only indirectly contributes to photochemistry. In contrast, we observe that photobleaching of the aromatic hydrocarbon is strongly enhanced by oxygen.

  15. Expedient placement of two fluorescent dyes for investigating dynamic DNA protein interactions in real time

    Microsoft Academic Search

    Sanford H. Leuba; Syam P. Anand; Joel M. Harp; Saleem A. Khan

    2008-01-01

    Many questions in molecular and cellular biology can be reduced to questions about ‘who talks to whom, when and how frequently’.\\u000a Here, we review approaches we have used with single-pair fluorescence resonance energy transfer (spFRET) to follow the motions\\u000a between two well-placed fluorescent probes to ask similar questions. We describe two systems. We have used a nucleosomal system\\u000a in which

  16. Fluorescence of the natural dye saffron: Selective reaction with eosinophil leucocyte granules

    Microsoft Academic Search

    Clara Isabel Trigoso; Juan Carlos Stockert

    1995-01-01

    Treatment of methanol-fixed chicken, rat, horse and human blood smears with saturated solutions of saffron in borate buffer at pH 10 results in a bright yellow-green fluorescence reaction of the acidophilic cytoplasm granules in mammalian eosinophils and chicken heterophils under violet-blue exciting light. Spectral characteristics of saffron (emission peak at 543 nm under 436 nm excitation) and its selective fluorescence

  17. A femtosecond fluorescence study of vibrational relaxation and cooling dynamics of UV dyes.

    PubMed

    Braem, Olivier; Penfold, Thomas J; Cannizzo, Andrea; Chergui, Majed

    2012-03-14

    We present a femtosecond broad-band fluorescence up-conversion study of the vibrational relaxation dynamics of two UV chromophores, 2,5-diphenyloxazole (PPO) and para-terphenyl (pTP), pumped with a large excess of vibrational energy (>2000 cm(-1)). The band narrowing of the transient fluorescence spectrum reflects a biphasic cooling process in a few hundreds of fs and a few ps. In the sub-ps regime, our data suggest a structural rearrangement in the excited state, followed by thermalization of the excess energy. These dynamics affect the fluorescence spectra of PPO and pTP in different ways. In PPO, the damping of a low frequency vibrational wavepacket and a significant sub-ps narrowing of the band characterize the vibrational relaxation. In pTP, the latter is faster and appears as a red shift with distortion of the band in <200 fs. PMID:22307066

  18. Improved method for combination of immunocytochemistry and Nissl staining

    Microsoft Academic Search

    Andrea Kádár; Gábor Wittmann; Zsolt Liposits; Csaba Fekete

    2009-01-01

    Nissl staining is a widely used method to study morphology and pathology of neural tissue. After standard immunocytochemistry, the Nissl staining labels only the nucleus of neurons and the characteristic staining of the neuronal perikarya is absent or very weak. We hypothesized that the RNA degradation during the immunocytochemical treatment results in the loss of cytoplasmic staining with Nissl-dyes. To

  19. An accurate and efficient method to predict the electronic excitation energies of BODIPY fluorescent dyes.

    PubMed

    Wang, Jia-Nan; Jin, Jun-Ling; Geng, Yun; Sun, Shi-Ling; Xu, Hong-Liang; Lu, Ying-Hua; Su, Zhong-Min

    2013-03-15

    Recently, the extreme learning machine neural network (ELMNN) as a valid computing method has been proposed to predict the nonlinear optical property successfully (Wang et al., J. Comput. Chem. 2012, 33, 231). In this work, first, we follow this line of work to predict the electronic excitation energies using the ELMNN method. Significantly, the root mean square deviation of the predicted electronic excitation energies of 90 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives between the predicted and experimental values has been reduced to 0.13 eV. Second, four groups of molecule descriptors are considered when building the computing models. The results show that the quantum chemical descriptions have the closest intrinsic relation with the electronic excitation energy values. Finally, a user-friendly web server (EEEBPre: Prediction of electronic excitation energies for BODIPY dyes), which is freely accessible to public at the web site: http://202.198.129.218, has been built for prediction. This web server can return the predicted electronic excitation energy values of BODIPY dyes that are high consistent with the experimental values. We hope that this web server would be helpful to theoretical and experimental chemists in related research. PMID:23115129

  20. Crystalline lens capsule staining with trypan blue

    Microsoft Academic Search

    Joseph San Laureano; Minas T. Coroneo

    2004-01-01

    A 1-step method for staining the anterior lens capsule with trypan blue is described. The dye is instilled via a paracentesis port at the start of cataract extraction. As aqueous humor is allowed to exit the anterior chamber (AC), which consequently shallows, the resulting pupil block confines the dye to the AC. An ophthalmic viscosurgical device (OVD) is used to

  1. Diagnostic utility of NCOA2 fluorescence in situ hybridization and Stat6 immunohistochemistry staining for soft tissue angiofibroma and morphologically similar fibrovascular tumors.

    PubMed

    Sugita, Shintaro; Aoyama, Tomoyuki; Kondo, Kei; Keira, Yoshiko; Ogino, Jiro; Nakanishi, Katsuya; Kaya, Mitsunori; Emori, Makoto; Tsukahara, Tomohide; Nakajima, Hisaya; Takagi, Masayuki; Hasegawa, Tadashi

    2014-08-01

    Soft tissue angiofibroma (STA), a recently suggested new histologic entity, is a benign fibrovascular soft tissue tumor composed of bland spindle-shaped tumor cells with abundant collagenous to myxoid stroma and branching small vessels. The lesion has a characteristic AHRR-NCOA2 fusion gene derived from chromosomal translocation of t(5;8)(p15;q13). However, morphologically similar tumors containing abundant fibrovascular and myxoid stroma can complicate diagnosis. We designed an original DNA probe for detecting NCOA2 split signals on fluorescence in situ hybridization (FISH) and estimated its utility with 20 fibrovascular tumors: 4 each of STAs, solitary fibrous tumors (SFTs), and cellular angiofibromas and 3 each of low-grade myxofibrosarcomas, myxoid liposarcomas, and low-grade fibromyxoid sarcomas. We also performed FISH for 13q14 deletion and immunohistochemistry (IHC) staining for estrogen receptor, progesterone receptor, retinoblastoma protein, and MUC-4 expression. Furthermore, IHC for Stat6 was conducted in the 20 cases analyzed by FISH and in an additional 26 SFTs. We found moderate to strong nuclear Stat6 expression in all SFTs but no expression in the other tumors. Both estrogen receptor and progesterone receptor expressions were observed in STAs, SFTs, and cellular angiofibromas. Expression of retinoblastoma protein was found in less than 10% of cells in all tumor types except myxoid liposarcoma. The low-grade fibromyxoid sarcomas were strongly positive for MUC-4. All STAs showed NCOA2 split signals on FISH. All tumors, regardless of histologic type, had 13q14 deletion. The NCOA2 FISH technique is a practical method for confirming STA diagnosis. The combination of NCOA2 FISH and Stat6 IHC proved effective for the differential diagnosis of STA, even when using small biopsy specimens. PMID:24856853

  2. In Situ Measurement of Airway Surface Liquid [K+] Using a Ratioable K+-sensitive Fluorescent Dye*

    PubMed Central

    Namkung, Wan; Song, Yuanlin; Mills, Aaron D.; Padmawar, Prashant; Finkbeiner, Walter E.; Verkman, A. S.

    2009-01-01

    The airway surface liquid (ASL) is the thin fluid layer lining airway surface epithelial cells, whose volume and composition are tightly regulated and may be abnormal in cystic fibrosis (CF). We synthesized a two-color fluorescent dextran to measure ASL [K+], TAC-Lime-dextran-TMR, consisting of a green-fluorescing triazacryptand K+ ionophore-Bodipy conjugate, coupled to dextran, together with a red fluorescing tetramethylrhodamine reference chromophore. TAC-Lime-dextran-TMR fluorescence was K+-selective, increasing >4-fold with increasing [K+] from 0 to 40 mm. In well differentiated human airway epithelial cells, ASL [K+] was 20.8 ± 0.3 mm and decreased by inhibition of the Na+/K+ pump (ouabain), ENaC (amiloride), CF transmembrane conductance regulator (CFTRinh-172), or K+ channels (TEA or XE991). ASL [K+] was increased by forskolin but not affected by Na+/K+/2Cl? cotransporter inhibition (bumetanide). Functional and expression studies indicated the involvement of [K+] channels KCNQ1, KCNQ3, and KCNQ5 as determinants of ASL [K+]. [K+] in CF cultures was similar to that in non-CF cultures, suggesting that abnormal ASL [K+] is not a factor in CF lung disease. In intact airways, ASL [K+] was also well above extracellular [K+]: 22 ± 1 mm in pig trachea ex vivo and 16 ± 1 mm in mouse trachea in vivo. Our results provide the first noninvasive measurements of [K+] in the ASL and indicate the involvement of apical and basolateral membrane ion transporters in maintaining a high ASL [K+]. PMID:19364771

  3. Complexation induced fluorescence and acid-base properties of dapoxyl dye with ?-cyclodextrin: a drug-binding application using displacement assays.

    PubMed

    Pal, Kaushik; Mallick, Suman; Koner, Apurba L

    2015-06-28

    Host-guest complexation of dapoxyl sodium sulphonate (DSS), an intramolecular charge transfer dye with water-soluble and non-toxic macrocycle ?-cyclodextrin (?-CD), has been investigated in a wide pH range. Steady-state absorption, fluorescence and time-resolved fluorescence measurements confirm the positioning of DSS into the hydrophobic cavity of ?-CD. A large fluorescence enhancement ca. 30 times, due to 1?:?2 complex formation and host-assisted guest-protonation have been utilised for developing a method for the utilisation of CD based drug-delivery applications. A simple fluorescence-displacement based approach is implemented at physiological pH for the assessment of binding strength of pharmaceutically useful small drug molecules (ibuprofen, paracetamol, methyl salicylate, salicylic acid, aspirin, and piroxicam) and six important antibiotic drugs (resazurin, thiamphenicol, chloramphenicol, ampicillin, kanamycin, and sorbic acid) with ?-CD. PMID:26028009

  4. A simple system for the identification of fluorescent dyes capable of reporting differences in secondary structure and hydrophobicity among amyloidogenic protein oligomers

    NASA Astrophysics Data System (ADS)

    Yates, Emma

    2012-02-01

    Thioflavin T and Congo Red are fluorescent dyes that are commonly used to identify the presence of amyloid structures, ordered protein aggregates. Despite the ubiquity of their use, little is known about their mechanism of interaction with amyloid fibrils, or whether other dyes, whose photophysics indicate that they may be more responsive to differences in macromolecular secondary structure and hydrophobicity, would be better suited to the identification of pathologically relevant oligomeric species in amyloid diseases. In order to systematically address this question, we have designed a strategy that discretely introduces differences in secondary structure and hydrophobicity amidst otherwise identical polyamino acids. This strategy will enable us to quantify and compare the affinities of Thioflavin T, Congo Red, and other, incompletely explored, fluorescent dyes for different secondary structural elements and hydrophobic motifs. With this information, we will identify dyes that give the most robust and quantitative information about structural differences among the complex population of oligomeric species present along an aggregation pathway between soluble monomers and amyloid fibrils, and correlate the resulting structural information with differential oligomeric toxicity.

  5. Lewis Acid-Assisted Isotopic 18F-19F Exchange in BODIPY Dyes: Facile Generation of Positron Emission Tomography/Fluorescence Dual Modality Agents for Tumor Imaging

    PubMed Central

    Liu, Shuanglong; Lin, Tzu-Pin; Li, Dan; Leamer, Lauren; Shan, Hong; Li, Zibo; Gabbaď, François P.; Conti, Peter S.

    2013-01-01

    Positron emission tomography (PET) is a powerful technique for imaging biological pathways in vivo, particularly those that are key targets in disease processes. In contrast, fluorescence imaging has demonstrated to be a superior method for image-guided surgery, such as tumor removal. Although the integration of PET and optical imaging could provide an attractive strategy for patient management, there is a significant shortage of established platforms/methods for PET/optical probe construction. In this study, various reaction conditions were explored to develop a simple and fast method allowing for the introduction of [18F]-fluoride into BODIPY dyes. Through a systematic optimization of the reaction conditions, we found that BODIPY dyes, including commercial amine-reactive BODIPY succinimidyl esters, may be converted into their radioactive analogues in the matter of minutes via a 18F-19F isotopic exchange reaction promoted by a Lewis acid such as SnCl4. An integrin-targeting RGD peptide was also conjugated with [18F]BODIPY® R6G , derived from the commercially available BODIPY® R6G fluorescent tag, to provide a [18F]-RGD conjugate in 82% yield. In vivo evaluation of this imaging probe showed a discernible tumor uptake in the U87MG xenograft model. The dual modality imaging properties of the probe was confirmed by ex vivo fluorescence and microPET imaging experiments. In summary, in the matter of minutes, BODIPY dyes were converted into their “hot” radioactive analogues via a 18F-19F isotopic exchange reaction promoted by a Lewis acid. This approach, which can be applied to commercial BODIPY dyes, provides easy access to positron emission tomography/fluorescence dual modality imaging agents. PMID:23471211

  6. Fluorescence Ratiometric Properties Induced by Nanoparticle Plasmonics and Nanoscale Dye Dynamics

    PubMed Central

    2013-01-01

    Nanoscale transport of merocyanine 540 within/near the plasmon field of gold nanoparticles was recognized as an effective inducer of single-excitation dual-emission ratiometric properties. With a high concentration of the signal transducer (ammonium), a 700% increase in fluorescence was observed at the new red-shifted emission maximum, compared to a nanoparticle free sensor membrane. A previously nonrecognized isosbestic point is demonstrated at 581.4 ± 0.1?nm. The mechanism can be utilized for enhanced and simplified ratiometric optical chemical sensors and potentially for thin film engineering to make solar cells more effective and stable by a broader and more regulated absorption. PMID:23781159

  7. Method for measuring the three-dimensional distribution of a fluorescent dye in a cell membrane

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuya; Ishimaru, Ichirou; Fujii, Yoshiki; Yasokawa, Toshiki; Kuriyama, Shigeki; Masaki, Tsutomu; Takegawa, Kaoru; Tanaka, Naotaka

    2007-01-01

    This letter reports on a method for accurately determining the component distribution in a cell membrane over the entire cell surface. This method involves exciting a fluorescent-dyed cell membrane using evanescent light and scanning the entire cell surface by rotating the cell using a noncontact technique, namely, proximal two-beam optical tweezers. To position the cell membrane in the thin evanescent field, the authors designed an optical system capable of precisely positioning the focal position. Using this method, they were able to measure the surface distribution of glycoprotein labeled by lectin in a breast cancer cell membrane.

  8. Fluorescence Reporting Based on FRET Between Conjugated Polyelectrolyte and Organic Dye for Biosensor Applications

    Microsoft Academic Search

    Kan-Yi Pu; Bin Liu

    \\u000a \\u000a Abstract  Conjugated polyelectrolytes (CPEs), with highly delocalized electronic backbones and charged ionic side chains, are naturally\\u000a robust light-harvesting antenna for fluorescence resonance energy transfer (FRET) applications. This chapter describes FRET-based\\u000a biosensors using CPEs as energy donors from the viewpoint of sensing mechanism, donor–acceptor selection and detection targets.\\u000a Important information on how to design CPE structures and assay schemes is elucidated, and

  9. Mitochondrial staining allows robust elimination of apoptotic and damaged cells during cell sorting.

    PubMed

    Barteneva, Natasha S; Ponomarev, Eugeny D; Tsytsykova, Alla; Armant, Myriam; Vorobjev, Ivan A

    2014-04-01

    High-speed fluorescence-activated cell sorting is relevant for a plethora of applications, such as PCR-based techniques, microarrays, cloning, and propagation of selected cell populations. We suggest a simple cell-sorting technique to eliminate early and late apoptotic and necrotic cells, with good signal-to-noise ratio and a high-purity yield. The mitochondrial potential dye, TMRE (tetramethylrhodamine ethyl ester perchlorate), was used to separate viable and non-apoptotic cells from the cell sorting samples. TMRE staining is reversible and does not affect cell proliferation and viability. Sorted TMRE(+) cells contained a negligible percentage of apoptotic and damaged cells and had a higher proliferative potential as compared with their counterpart cells, sorted on the basis of staining with DNA viability dye. This novel sorting technique using TMRE does not interfere with subsequent functional assays and is a method of choice for the enrichment of functionally active, unbiased cell populations. PMID:24394470

  10. Comparison of a chimeric anti-carcinoembryonic antigen antibody conjugated with visible or near-infrared fluorescent dyes for imaging pancreatic cancer in orthotopic nude mouse models

    NASA Astrophysics Data System (ADS)

    Maawy, Ali A.; Hiroshima, Yukihiko; Kaushal, Sharmeela; Luiken, George A.; Hoffman, Robert M.; Bouvet, Michael

    2013-12-01

    The aim of this study was to evaluate a set of visible and near-infrared dyes conjugated to a tumor-specific chimeric antibody for high-resolution tumor imaging in orthotopic models of pancreatic cancer. BxPC-3 human pancreatic cancer was orthotopically implanted into pancreata of nude mice. Mice received a single intravenous injection of a chimeric anti-carcinoembryonic antigen antibody conjugated to one of the following fluorophores: 488-nm group (Alexa Fluor 488 or DyLight 488); 550-nm group (Alexa Fluor 555 or DyLight 550); 650-nm group (Alexa Fluor 660 or DyLight 650), or the 750-nm group (Alexa Fluor 750 or DyLight 755). After 24 h, the Olympus OV100 small-animal imaging system was used for noninvasive and intravital fluorescence imaging of mice. Dyes were compared with respect to depth of imaging, resolution, tumor-to-background ratio (TBR), photobleaching, and hemoglobin quenching. The longer wavelength dyes had increased depth of penetration and ability to detect the smallest tumor deposits and provided the highest TBRs, resistance to hemoglobin quenching, and specificity. The shorter wavelength dyes were more photostable. This study showed unique advantages of each dye for specific cancer imaging in a clinically relevant orthotopic model.

  11. Three-color fluorescence measurements on single cells excited at three laser wavelengths

    SciTech Connect

    Steinkamp, J.A.; Stewart, C.C.; Crissman, H.A.

    1982-01-01

    A three-laser flow cytometer for quantitative analysis and sorting of cells and microscopic particles has been developed and evaluated using argon- and krypton-ion lasers as excitation sources. Cells stained with three fluorescent dyes having different excitation spectra enter a flow chamber where they first pass through an electronic volume sensor and then intersect three spatially separated laser beams for fluorescence excitation of bound dyes and light scatter measurements. Separate pairs of beam-shaping optics independently position and focus each beam onto the cell stream thus permitting cells to be sequentially illuminated. Fluorescence is measured by a detector that employs a single collecting lens for single or multilaser excitation experiments. Fluorescence signals are processed and displayed as frequency distribution histograms using an LSI-11 computer. This instrument is described in detail with illustrative examples using cells stained for DNA content, protein, and cell surface antigens and cells that have phagocytized fluorescent microspheres.

  12. Quantitative evaluation of in vivo vital-dye fluorescence endoscopic imaging for the detection of Barrett's-associated neoplasia.

    PubMed

    Thekkek, Nadhi; Lee, Michelle H; Polydorides, Alexandros D; Rosen, Daniel G; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

    2015-05-01

    Current imaging tools are associated with inconsistent sensitivity and specificity for detection of Barrett's-associated neoplasia. Optical imaging has shown promise in improving the classification of neoplasia in vivo. The goal of this pilot study was to evaluate whether in vivo vital dye fluorescence imaging (VFI) has the potential to improve the accuracy of early-detection of Barrett's-associated neoplasia. In vivo endoscopic VFI images were collected from 65 sites in 14 patients with confirmed Barrett's esophagus (BE), dysplasia, oresophageal adenocarcinoma using a modular video endoscope and a high-resolution microendoscope(HRME). Qualitative image features were compared to histology; VFI and HRME images show changes in glandular structure associated with neoplastic progression. Quantitative image features in VFI images were identified for objective image classification of metaplasia and neoplasia, and a diagnostic algorithm was developed using leave-one-out cross validation. Three image features extracted from VFI images were used to classify tissue as neoplastic or not with a sensitivity of 87.8% and a specificity of 77.6% (AUC = 0.878). A multimodal approach incorporating VFI and HRME imaging can delineate epithelial changes present in Barrett's-associated neoplasia. Quantitative analysis of VFI images may provide a means for objective interpretation of BE during surveillance. PMID:25950645

  13. Fluorescence characterization of the structural heterogeneity of polytene chromosomes.

    PubMed

    Noothi, Sunil K; Kombrabail, Mamata; Rao, Basuthkar J; Krishnamoorthy, G

    2010-01-01

    Studies on the physical nature of the structural heterogeneity of chromatin in their native states are few. The eukaryotic chromatin as observed by dye staining studies is of heterogeneous intensity when observed by fluorescent stains, where less and more bright regions apparently correspond to euchromatin and heterochromatin respectively. These are also associated with differential gene expression where it is believed that euchromatin is transcriptionally more active due to increased flexibility. Unfixed squashed preparations of polytene chromosomes of Drosophila were stained with a dsDNA specific dye PicoGreen and fluorescence lifetimes as well as fluorescence anisotropy decay kinetics were measured. Here we report a positive correlation between fluorescence lifetimes and fluorescence intensities, and show that less bright regions corresponding to euchromatin have shorter lifetimes, whereas more bright regions corresponding to heterochromatin have longer lifetimes. We interpret this as less bright regions being more dynamic, a conclusion also supported by fluorescence anisotropy decay kinetics. We infer that the comparatively higher flexibility associated with euchromatin can be directly measured by fluorescence lifetimes and fluorescence anisotropy decay kinetics. PMID:19629653

  14. New fluorescence reactions in DNA cytochemistry. 2. Microscopic and spectroscopic studies on fluorescent aluminum complexes

    SciTech Connect

    Del Castillo, P.; Llorente, A.R.; Gomez, A.; Gosalvez, J.; Goyanes, V.J.; Stockert, J.C. (Autonomous Univ., Madrid (Spain))

    1990-02-01

    Metal-dye complexes are widely applied in light microscopic techniques for chromatin staining (e.g., hematoxylin and carmine), but fluorescent complexes between phosphate-binding cations and suitable ligands have been little used. Preformed and postformed Al complexes with different anionic dyes induced strong and selective fluorescence reactions in nuclei from chicken blood smears, frozen sections, paraffin-embedded sections and Epon-embedded sections of mouse and rat tissues, mitotic chromosomes, meiotic chromosomes and kinetoplasts of Trypanosoma cruzi epimastigotes. The DNA-dependent fluorescence of these structures showed a very low fading rate. The emission colors were related to the ligand. The most suitable compounds for forming fluorescent Al chelates were 8-hydroxyquinoline, morin, nuclear fast red and purpurin. Staining with diluted carmine solutions and InCl3 mordanting, followed by 8-hydroxyquinoline, also induced chromatin fluorescence. After treating isolated mouse chromosomes with the preformed complex Al-nuclear fast red, x-ray microanalysis indicated a P:Al:dye binding ratio of about 40:15:1. The selectivity, stability and easy formation of these fluorescent Al complexes are obvious advantages for their use as new cytochemical probes in cytologic studies.

  15. Use of CMFDA and CMTMR fluorescent dyes in FACS-based antibody screening.

    PubMed

    Yang, X P; Gallo, M; Ngan, I; Nocerini, M; Chen, M M

    2002-03-01

    Cell-based immunizations are often used when membrane antigens are difficult to purify. To confirm that an antibody binding to the surface of a cell line is, in fact, binding to the desired antigen, FACS can be performed independently on two cell lines, a transfected cell line expressing the antigen of interest and a control cell line not expressing the antigen. Antibodies binding only to the transfected cell line are then selected for further analysis. This approach can be challenging if a large number of antibodies need to be screened and the antibody quantities are limited. Here we describe a novel method that combines the above two steps of FACS screening into a single step, based on the use of two fluorochromes, CMFDA and CMTMR, to stain transfected and control cell lines, respectively. Antibodies conjugated to a thirdfluorochrome are then added to the combined cells, followed by three-color FACS analysis. The newly modified FACS method is simple, sensitive, and high throughput. It can be used for antibody screening in multiple cell lines simultaneously. PMID:11911670

  16. Quantification of dsDNA using the Hitachi F-7000 Fluorescence Spectrophotometer and PicoGreen dye.

    PubMed

    Moreno, Luis A; Cox, Kendra L

    2010-01-01

    Quantification of DNA, especially in small concentrations, is an important task with a wide range of biological applications including standard molecular biology assays such as synthesis and purification of DNA, diagnostic applications such as quantification of DNA amplification products, and detection of DNA molecules in drug preparations. During this video we will demonstrate the capability of the Hitachi F-7000 Fluorescence Spectrophotometer equipped with a Micro Plate Reader accessory to perform dsDNA quantification using Molecular Probes Quant-it PicoGreen dye reagent kit. The F-7000 Fluorescence Spectrophotometer offers high sensitivity and high speed measurements. It is a highly flexible system capable of measuring fluorescence, luminescence, and phosphorescence. Several measuring modes are available, including wavelength scan, time scan, photometry and 3-D scan measurement. The spectrophotometer has sensitivity in the range of 50 picomoles of fluorescein when using a 300 ?L sample volume in the microplate, and is capable of measuring scan speeds of 60,000 nm/minute. It also has a wide dynamic range of up to 5 orders of magnitude which allows for the use of calibration curves over a wide range of concentrations. The optical system uses all reflective optics for maximum energy and sensitivity. The standard wavelength range is 200 to 750 nm, and can be extended to 900 nm when using one of the optional near infrared photomultipliers. The system allows optional temperature control for the plate reader from 5 to 60 degrees Celsius using an optional external temperature controlled liquid circulator. The microplate reader allows for the use of 96 well microplates, and the measuring speed for 96 wells is less than 60 seconds when using the kinetics mode. Software controls for the F-7000 and Microplate Reader are also highly flexible. Samples may be set in either column or row formats, and any combination of wells may be chosen for sample measurements. This allows for optimal utilization of the microplate. Additionally, the software allows importing micro plate sample configurations created in Excel and saved in comma separated values, or "csv" format. Microplate measuring configurations can be saved and recalled by the software for convenience and increased productivity. Data results can be output to a standard report, to Excel, or to an optional Report Generator Program. PMID:21189464

  17. The use of vitamins as tracer dyes for laser-induced fluorescence in liquid flow applications

    NASA Astrophysics Data System (ADS)

    Zähringer, Katharina

    2014-04-01

    Tracers commonly used in experimental flow studies are mostly nocuous to the environment and human health. Particularly, in large flow installations, this can become a problem. In this study, a solution of this problem is presented, based on using water-soluble vitamins. Five of them are examined here for their applicability in flow studies. Vitamins B2 and B6 turned out to be the most promising candidates, and the dependency of their fluorescence intensity on parameters like concentration, laser energy, temperature, and pH are determined for two commonly used laser excitation wavelengths (532, 355 nm). Two examples of application in a static mixer and a spray flow are shown and demonstrate the applicability of the vitamin tracers.

  18. Simultaneous probing of hydration and polarity of lipid bilayers with 3-hydroxyflavone fluorescent dyes.

    PubMed

    Klymchenko, Andrey S; Mély, Yves; Demchenko, Alexander P; Duportail, Guy

    2004-10-11

    The penetration of water into the hydrophobic interior leads to polarity and hydration profiles across lipid membranes which are fundamental in the maintenance of membrane architecture as well as in transport and insertion processes into the membrane. The present paper is an original attempt to evaluate simultaneously polarity and hydration properties of lipid bilayers by a fluorescence approach. We applied two 3-hydroxyflavone probes anchored in lipid bilayers at a relatively precise depth through their attached ammonium groups. They are present in two forms: either in H-bond-free form displaying a two-band emission due to an excited state intramolecular proton transfer reaction (ESIPT), or in H-bonded form displaying a single-band emission with no ESIPT. The individual emission profiles of these forms were obtained by deconvolution of the probes' fluorescence spectra. The polarity of the probe surrounding the bilayer was estimated from the two-band spectra of the H-bond-free form, while the local hydration was estimated from the relative contribution of the two forms. Our results confirm that by increasing the lipid order (phase transition from fluid to gel phase, addition of cholesterol or decrease in the lipid unsaturation), the polarity and to a lesser extent, the hydration of the bilayers decrease simultaneously. In contrast, when fluidity (i.e. lipid order) is kept invariant, increase of temperature and of bilayer curvature leads to a higher bilayer hydration with no effect on the polarity. Furthermore, no correlation was found between dipole potential and the hydration of the bilayers. PMID:15471566

  19. STAINING TOXOPLASMA GONDII WITH FLUORESCEIN-LABELLED ANTIBODY

    PubMed Central

    Goldman, Morris

    1957-01-01

    A new serologic test for antibodies to Toxoplasma is described, which is based upon inhibition of specific staining with fluorescent antibody. In performing the test, a mixture of the test serum and known fluorescein-labelled antiserum is added to a dried smear of toxoplasms for 1 hour at 37°C. The smear is then rinsed and examined with a fluorescence microscope. Reduction in the brightness of fluorescence, as compared to that of a negative control slide, indicates the presence of antibody in the test serum. A comparison of the results of this test with those of the methylene blue dye test showed a strong parallelism between the two sets of results. On the other hand, the complement-fixation test for toxoplasmosis did not yield nearly as many positives as the inhibition test. The specificity of the new test was studied by comparing it with dye test results and clinical histories in human patients, and by testing a group of animals immunized with a variety of non-Toxoplasma antigens. No evidence of cross-reactions was obtained in the latter series. Some advantages and disadvantages of the inhibition test are discussed. PMID:13428924

  20. LumicyanoTM: a new fluorescent cyanoacrylate for a one-step luminescent latent fingermark development.

    E-print Network

    Paris-Sud XI, Université de

    -porous surfaces, semi-porous substrates, dye staining, Lumicyano. 1. INTRODUCTION Among the lot of finger mark, in Japan and slightly later in UK and Canada [2, 3]. Items with potential latent marks are placedLumicyanoTM: a new fluorescent cyanoacrylate for a one-step luminescent latent fingermark

  1. Long-term monitoring of live cell proliferation in presence of PVP-Hypericin: a new strategy using ms pulses of LED and the fluorescent dye CFSE

    PubMed Central

    Penjweini, Rozhin; Loew, Hans G.; Hamblin, Michael R.; Kratky, Karl W.

    2011-01-01

    Summary During fluorescent live cell imaging it is critical to keep excitation light dose as low as possible, especially in the presence of photosensitizer drugs, which generate free radicals upon photobleaching. During fluorescent imaging, stress by excitation and free radicals induces serious cell damages that may arrest the cell cycle. This limits the usefulness of the technique for drug discovery, when prolonged live cell imaging is necessary. This paper presents a strategy to provide gentle experimental conditions for dynamic monitoring of the proliferation of human lung epithelial carcinoma cells (A549) in the presence of the photosensitizer Polyvinylpyrrolidone-Hypericin. The distinctive strategy of this paper is based on the stringent environmental control and optimizing the excitation light dose by (i) using a low-power pulsed blue light-emitting diode with short pulse duration of 1.29 ms and (ii) adding a nontoxic fluorescent dye called carboxyfluorescein-diacetate-succinimidyl-ester (CFSE) to improve the fluorescence signals. To demonstrate the usefulness of the strategy, fluorescence signals and proliferation of dual-marked cells, during 5-h fluorescence imaging under pulsed excitation, were compared with those kept under continuous excitation and nonmarked reference cells. The results demonstrated 3% cell division and 2% apoptosis due to pulsed excitation compared to no division and 85% apoptosis under the continuous irradiation. Therefore, our strategy allows live cell imaging to be performed over longer time scales than with conventional continuous excitation. PMID:21974829

  2. The use of fluorescent Nile red and BODIPY for lipid measurement in microalgae.

    PubMed

    Rumin, Judith; Bonnefond, Hubert; Saint-Jean, Bruno; Rouxel, Catherine; Sciandra, Antoine; Bernard, Olivier; Cadoret, Jean-Paul; Bougaran, Gaël

    2015-01-01

    Microalgae are currently emerging as one of the most promising alternative sources for the next generation of food, feed, cosmetics and renewable energy in the form of biofuel. Microalgae constitute a diverse group of microorganisms with advantages like fast and efficient growth. In addition, they do not compete for arable land and offer very high lipid yield potential. Major challenges for the development of this resource are to select lipid-rich strains using high-throughput staining for neutral lipid content in microalgae species. For this purpose, the fluorescent dyes most commonly used to quantify lipids are Nile red and BODIPY 505/515. Their fluorescent staining for lipids offers a rapid and inexpensive analysis tool to measure neutral lipid content, avoiding time-consuming and costly gravimetric analysis. This review collates and presents recent advances in algal lipid staining and focuses on Nile red and BODIPY 505/515 staining characteristics. The available literature addresses the limitations of fluorescent dyes under certain conditions, such as spectral properties, dye concentrations, cell concentrations, temperature and incubation duration. Moreover, the overall conclusion of the present review study gives limitations on the use of fluorochrome for screening of lipid-rich microalgae species and suggests improved protocols for staining recalcitrant microalgae and recommendations for the staining quantification. PMID:25788982

  3. Direct Blue 71 staining of proteins bound to blotting membranes.

    PubMed

    Hong, H Y; Yoo, G S; Choi, J K

    2000-03-01

    A sensitive staining method for protein blots using Direct Blue 71 is described. It is based on the selective binding of dye molecules to proteins in acidic solution and produces bluish violet colored bands. It is a simple and rapid procedure, involving only staining and rinsing steps that occur within 7 min. The sensitivity of this method is 5-10 ng of protein on nitrocellulose (NC) and 10-20 ng on polyvinylidene difluoride (PVDF), which is tenfold better than that of the commonly used Ponceau S staining. Moreover, the staining is reversible for subsequent immunostaining, without impairing immunoreactivity. To remove the dye from the developed bands, changes in pH and hydrophobicity of the solvent are required. Due to its sensitivity, rapidity, simplicity, and low cost, this stain may be more practical than other dye-based stains or metal-based stains for routine laboratory purposes. PMID:10768767

  4. Seven-color fluorescence imaging of tissue samples based on Fourier spectroscopy and singular value decomposition.

    PubMed

    Tsurui, H; Nishimura, H; Hattori, S; Hirose, S; Okumura, K; Shirai, T

    2000-05-01

    Seven-color analyses of immunofluorescence-stained tissue samples were accomplished using Fourier spectroscopy-based hyperspectral imaging and singular value decomposition. This system consists of a combination of seven fluorescent dyes, three filtersets, an epifluorescence microscope, a spectral imaging system, a computer for data acquisition, and data analysis software. The spectra of all pixels in a multicolor image were taken simultaneously using a Sagnac type interferometer. The spectra were deconvolved to estimate the contribution of each component dye, and individual dye images were constructed based on the intensities of assigned signals. To obtain mixed spectra, three filter sets, i.e., Bl, Gr, and Rd for Alexa488 and Alexa532, for Alexa546, Alexa568, and Alexa594, and for Cy5 and Cy5.5, respectively, were used for simultaneous excitation of two or three dyes. These fluorophores have considerable spectral overlap which precludes their separation by conventional analysis. We resolved their relative contributions to the fluorescent signal by a method involving linear unmixing based on singular value decomposition of the matrices consisting of dye spectra. Analyses of mouse thymic tissues stained with seven different fluorescent dyes provided clear independent images, and any combination of two or three individual dye images could be used for constructing multicolor images. PMID:10769049

  5. Whole mount nuclear fluorescent imaging: convenient documentation of embryo morphology.

    PubMed

    Sandell, Lisa L; Kurosaka, Hiroshi; Trainor, Paul A

    2012-11-01

    Here, we describe a relatively inexpensive and easy method to produce high quality images that reveal fine topological details of vertebrate embryonic structures. The method relies on nuclear staining of whole mount embryos in combination with confocal microscopy or conventional wide field fluorescent microscopy. In cases where confocal microscopy is used in combination with whole mount nuclear staining, the resulting embryo images can rival the clarity and resolution of images produced by scanning electron microscopy (SEM). The fluorescent nuclear staining may be performed with a variety of cell permeable nuclear dyes, enabling the technique to be performed with multiple standard microscope/illumination or confocal/laser systems. The method may be used to document morphology of embryos of a variety of organisms, as well as individual organs and tissues. Nuclear stain imaging imposes minimal impact on embryonic specimens, enabling imaged specimens to be utilized for additional assays. PMID:22930523

  6. DUAL STAINING OF NATURAL BACTERIOPLANKTON WITH 4,6-DIAMINDO-2-PHENYLINDOLE AND FLUORESCENT OLIGONUCLEOTIDE PROBES TARGETING KINGDOM-LEVEL 16S RRNA SEQUENCES

    EPA Science Inventory

    A method for quantifying eubacterial cell densities in dilute communities of small bacterioplankton is presented. ells in water samples were stained with 4',6-diamidino-2-phenylindole (DAPI), transferred to gelatin-coated slides, and hybridized with rhodamine-labeled oligonucleot...

  7. Structurally Rigid 9-Amino-benzo[c]cinnoliniums Make Up a Class of Compact and Large Stokes-Shift Fluorescent Dyes for Cell-Based Imaging Applications.

    PubMed

    Shen, Yanming; Shang, Zhihao; Yang, Yanhong; Zhu, Shaojia; Qian, Xuhong; Shi, Ping; Zheng, Jing; Yang, Youjun

    2015-06-01

    Classic fluorescent dyes, such as coumarin, naphthalimide, fluorescein, BODIPY, rhodamine, and cyanines, are cornerstones of various spectroscopic and microscopic methods, which hold a prominent position in biological studies. We recently found that 9-amino-benzo[c]cinnoliniums make up a novel group of fluorophores that can be used in biological studies. They are featured with a succinct conjugative push-pull backbone, a broad absorption band, and a large Stokes shift. They are potentially useful as a small-molecule alternative to R-phycoerythrin to pair with fluorescein in multiplexing applications. PMID:25951429

  8. Influence of dehydrated nanotubed titanic acid on charge transport and luminescent properties of polymer light-emitting diodes with fluorescent dye

    NASA Astrophysics Data System (ADS)

    Qian, Lei; Bera, Debasis; Jin, Zhen-Sheng; Du, Zu-Liang; Xu, Zheng; Teng, Feng; Liu, Wei

    2007-09-01

    In this paper, we discuss the influence of dehydrated nanotubed titanic acid (DNTA) on charge transport and luminescent properties of polymer light-emitting diodes (PLEDs) doped with fluorescent dye. Photoluminescence results confirm the efficient energy transfer from PVK to 4-(dicyanom-ethylene)-2- t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) and tris-(8-hydroxtquinoline) aluminum (Alq 3) in a DNTA-doped device. The device showed lower turn-on voltages and higher charge current by doping with DNTA, which also caused a shift in the exciton's recombination region.

  9. Stem cell marker upregulation in normal cutaneous vessels following pulsed-dye laser exposure and its abrogation by concurrent rapamycin administration: implications for treatment of port-wine stain birthmarks

    PubMed Central

    Loewe, Robert; Oble, Darryl A.; Valero, Teresa; Zukerberg, Lawrence; Mihm, Martin C.; Nelson, J. Stuart

    2011-01-01

    Port-wine stains (PWS) represent a group of vascular malformations that are usually accompanied by psychological distress for affected patients, often reflected in high treatment demand. Although the pulsed-dye laser (PDL) was established as standard therapy for PWS more than a decade ago, therapeutic outcome may be unsatisfactory. One of the main drawbacks to successful PDL therapy is PWS revascularization shortly after laser exposure. Therefore, inhibition of revascularization should improve therapeutic outcome of PDL therapy. In this study, we first evaluated the effects of various light energies on normal cutaneous vessels over a period of 14 days, particularly the proliferation and stem cell marker expression of dermal endothelial cells, which were found to be highest 8 days following laser exposure. We found that PDL exposure induced dose-dependent damage of dermal vessels up to energy densities of 6 J/cm2, above which no increase in PDL-induced effects were observed with the energies employed in this study. In dermal endothelial cells of PDL-exposed skin, we found strong expression of the proliferation marker Ki-67 as well as the stem cell marker nestin but not other stem cell markers such as CD133 and CD166. The influence of rapamycin (RPM), used as an adjuvant to PDL exposure, was also investigated. RPM administration reduced Ki-67 and nestin expression in dermal endothelial cells and increased PDL-induced destruction of dermal vessels, indicating that the use of RPM after PDL exposure may be an interesting new approach for prolonging and improving PWS laser therapeutic outcome. PMID:20482679

  10. Use of Fluorescently Labeled Algae to Measure the Clearance Rate of the Rotifer Keratella-Cochlearis

    Microsoft Academic Search

    Telesh V. I; Oomswilms L. A; R. D. Gulati

    1995-01-01

    1. Fluorescently labelled algae (FLA) were used to measure clearance rates of the rotifer Keratella cochlearis. The freshwater algae Chlorella vulgaris and Stichococcus bacillaris were labelled with a fluorescent dye, 5-(4,6-dichlorotriazin-2- yl) aminofluorescein (DTAF), following a modified staining procedure. 2. Keratella cochlearis ingested both algal species. Clearance rates on tracer foods varied between 2.4 and 6.9 mu l ind(-1) h(-1),

  11. Fast and Sensitive Colloidal Coomassie G-250 Staining for Proteins in Polyacrylamide Gels

    PubMed Central

    Dyballa, Nadine; Metzger, Sabine

    2009-01-01

    Coomassie Brilliant Blue (CBB) is a dye commonly used for the visualization of proteins separated by SDS-PAGE, offering a simple staining procedure and high quantitation. Furthermore, it is completely compatible with mass spectrometric protein identification. But despite these advantages, CBB is regarded to be less sensitive than silver or fluorescence stainings and therefore rarely used for the detection of proteins in analytical gel-based proteomic approaches. Several improvements of the original Coomassie protocol1 have been made to increase the sensitivity of CBB. Two major modifications were introduced to enhance the detection of low-abundant proteins by converting the dye molecules into colloidal particles: In 1988, Neuhoff and colleagues applied 20% methanol and higher concentrations of ammonium sulfate into the CBB G-250 based staining solution2, and in 2004 Candiano et al. established Blue Silver using CBB G-250 with phosphoric acid in the presence of ammonium sulfate and methanol3. Nevertheless, all these modifications just allow a detection of approximately 10 ng protein. A widely fameless protocol for colloidal Coomassie staining was published by Kang et al. in 2002 where they modified Neuhoff's colloidal CBB staining protocol regarding the complexing substances. Instead of ammonium sulfate they used aluminum sulfate and methanol was replaced by the less toxic ethanol4. The novel aluminum-based staining in Kang's study showed superior sensitivity that detects as low as 1 ng/band (phosphorylase b) with little sensitivity variation depending on proteins. Here, we demonstrate application of Kang's protocol for fast and sensitive colloidal Coomassie staining of proteins in analytical purposes. We will illustrate the quick and easy protocol using two-dimensional gels routinely performed in our working group. PMID:19684561

  12. Fast and sensitive colloidal coomassie G-250 staining for proteins in polyacrylamide gels.

    PubMed

    Dyballa, Nadine; Metzger, Sabine

    2009-01-01

    Coomassie Brilliant Blue (CBB) is a dye commonly used for the visualization of proteins separated by SDS-PAGE, offering a simple staining procedure and high quantitation. Furthermore, it is completely compatible with mass spectrometric protein identification. But despite these advantages, CBB is regarded to be less sensitive than silver or fluorescence stainings and therefore rarely used for the detection of proteins in analytical gel-based proteomic approaches. Several improvements of the original Coomassie protocol(1) have been made to increase the sensitivity of CBB. Two major modifications were introduced to enhance the detection of low-abundant proteins by converting the dye molecules into colloidal particles: In 1988, Neuhoff and colleagues applied 20% methanol and higher concentrations of ammonium sulfate into the CBB G-250 based staining solution(2), and in 2004 Candiano et al. established Blue Silver using CBB G-250 with phosphoric acid in the presence of ammonium sulfate and methanol(3). Nevertheless, all these modifications just allow a detection of approximately 10 ng protein. A widely fameless protocol for colloidal Coomassie staining was published by Kang et al. in 2002 where they modified Neuhoff's colloidal CBB staining protocol regarding the complexing substances. Instead of ammonium sulfate they used aluminum sulfate and methanol was replaced by the less toxic ethanol(4). The novel aluminum-based staining in Kang's study showed superior sensitivity that detects as low as 1 ng/band (phosphorylase b) with little sensitivity variation depending on proteins. Here, we demonstrate application of Kang's protocol for fast and sensitive colloidal Coomassie staining of proteins in analytical purposes. We will illustrate the quick and easy protocol using two-dimensional gels routinely performed in our working group. PMID:19684561

  13. Fluorescent double-labeling with carbocyanine neuronal tracing and immunohistochemistry using a cholesterol-specific detergent digitonin

    Microsoft Academic Search

    Yutaka Matsubayashi; Lena Iwai; Hiroshi Kawasaki

    2008-01-01

    The fluorescent carbocyanine dye DiI (1,1?-dioctadecyl-3,3,3?,3?-tetramethylindocarbocyanine perchlorate) has been widely used for tracing of neuronal pathways. To examine identities of the DiI-labeled neuronal pathways, it is desirable to combine DiI labeling with immunofluorescent staining. However, DiI labeling and immunofluorescent staining are not well compatible, mainly because treatment of DiI-labeled neurons with detergents, which are commonly used for immunohistochemistry, results in

  14. Monitoring the Wet-Heat Inactivation Dynamics of Single Spores of Bacillus Species by Using Raman Tweezers, Differential Interference Contrast Microscopy, and Nucleic Acid Dye Fluorescence Microscopy?

    PubMed Central

    Zhang, Pengfei; Kong, Lingbo; Wang, Guiwen; Setlow, Peter; Li, Yong-qing

    2011-01-01

    Dynamic processes during wet-heat treatment of individual spores of Bacillus cereus, Bacillus megaterium, and Bacillus subtilis at 80 to 90°C were investigated using dual-trap Raman spectroscopy, differential interference contrast (DIC) microscopy, and nucleic acid stain (SYTO 16) fluorescence microscopy. During spore wet-heat treatment, while the spores' 1:1 chelate of Ca2+ with dipicolinic acid (CaDPA) was released rapidly at a highly variable time Tlag, the levels of spore nucleic acids remained nearly unchanged, and the Tlag times for individual spores from the same preparation were increased somewhat as spore levels of CaDPA increased. The brightness of the spores' DIC image decreased by ?50% in parallel with CaDPA release, and there was no spore cortex hydrolysis observed. The lateral diameters of the spores' DIC image and SYTO 16 fluorescence image also decreased in parallel with CaDPA release. The SYTO 16 fluorescence intensity began to increase during wet-heat treatment at a time before Tlag and reached maximum at a time slightly later than Trelease. However, the fluorescence intensities of wet-heat-inactivated spores were ?15-fold lower than those of nutrient-germinated spores, and this low SYTO 16 fluorescence intensity may be due in part to the low permeability of the dormant spores' inner membranes to SYTO 16 and in part to nucleic acid denaturation during the wet-heat treatment. PMID:21602365

  15. A ‘Magnetic’ Gram Stain for Bacterial Detection

    PubMed Central

    Budin, Ghyslain; Chung, Hyun Jung; Lee, Hakho

    2012-01-01

    Magnetic stain. Bacteria are often classified into Gram-positive and Gram-negative strains by their visual staining properties using crystal violet (CV), a triarylmethane dye. Here we show, that bioorthogonal modification of crystal violet with transcyclooctene (TCO) can be used to render Gram-positive bacteria magnetic with magneto-nanoparticles-Tetrazine (MNP-Tz). This allows for class specific automated magnetic detection, magnetic separation or other magnetic manipulations. PMID:22744868

  16. Organic Fluorescent Dyes Supported on Activated Boron Nitride: A Promising Blue Light Excited Phosphors for High-Performance White Light-Emitting Diodes

    PubMed Central

    Li, Jie; Lin, Jing; Huang, Yang; Xu, Xuewen; Liu, Zhenya; Xue, Yanming; Ding, Xiaoxia; Luo, Han; Jin, Peng; Zhang, Jun; Zou, Jin; Tang, Chengchun

    2015-01-01

    We report an effective and rare-earth free light conversion material synthesized via a facile fabrication route, in which organic fluorescent dyes, i.e. Rhodamine B (RhB) and fluorescein isothiocyanate (FITC) are embedded into activated boron nitride (?BN) to form a composite phosphor. The composite phosphor shows highly efficient Förster resonance energy transfer and greatly improved thermal stability, and can emit at broad visible wavelengths of 500–650?nm under the 466?nm blue-light excitation. By packaging of the composite phosphors and a blue light-emitting diode (LED) chip with transparent epoxy resin, white LED with excellent thermal conductivity, current stability and optical performance can be realized, i.e. a thermal conductivity of 0.36?W/mk, a Commission Internationale de 1'Eclairage color coordinates of (0.32, 0.34), and a luminous efficiency of 21.6?lm·W?1. Our research opens the door toward to the practical long-life organic fluorescent dyes-based white LEDs. PMID:25682730

  17. Using Microcontact Printing as a Novel Method for Patterned Dyeing of Surface-adsorbed DNA

    NASA Astrophysics Data System (ADS)

    Shea, Emily; Budassi, Julia; Zhu, Ke; Sokolov, Jonathan

    2012-02-01

    We use microcontact printing (MCP)^1 to stain individual DNA molecules adsorbed and combed onto a polymer-coated silicon surface. Polydimethylsiloxane (PDMS) stamps with micron-sized features have been used to selectively stain lambda DNA molecules with SyBr Gold dye. DNA was deposited out of dilute solution onto polymethylmethacrylate (PMMA) layers, 70nm thick, spun-coated on Si wafers, producing linearly stretched and aligned molecules. The stamps were soaked in dye solutions for one minute, followed by wiping of excess solution with a swap. The stamp was pressed onto the surface, varying the pressure and time of application (typically 5-10 minutes) to control the staining. The DNA molecules were imaged with a fluorescence microscope equipped with a cooled CCD camera. Single molecules of DNA were successfully dyed and imaged with stamps having a grating pattern either parallel to or perpendicular to the DNA orientation. Supported by NSF-DMR MRSEC program.

  18. Anthraquinone dyes as photosensitizers for dye-sensitized solar cells

    Microsoft Academic Search

    Chaoyan Li; Xichuan Yang; Ruikui Chen; Jingxi Pan; Haining Tian; Hongjun Zhu; Xiuna Wang; Anders Hagfeldt; Licheng Sun

    2007-01-01

    Three anthraquinone dyes with carboxylic acid as anchoring group are designed and synthesized as sensitizers for dye-sensitized solar cells (DSSCs). Preliminary photophysical and photoelectrochemical measurements show that these anthraquinone dyes have very low performance on DSSC applications, although they have broad and intense absorption spectra in the visible region (up to 800nm). Transient absorption kinetics, fluorescence lifetime measurements and density

  19. DNA fragment sizing and sorting by laser-induced fluorescence

    DOEpatents

    Hammond, Mark L. (Angier, NC); Jett, James H. (Los Alamos, NM); Keller, Richard A. (Los Alamos, NM); Marrone, Babetta L. (Los Alamos, NM); Martin, John C. (Los Alamos, NM)

    1996-01-01

    A method is provided for sizing DNA fragments using high speed detection systems, such as flow cytometry to determine unique characteristics of DNA pieces from a sample. In one characterization the DNA piece is fragmented at preselected sites to produce a plurality of DNA fragments. The DNA piece or the resulting DNA fragments are treated with a dye effective to stain stoichiometrically the DNA piece or the DNA fragments. The fluorescence from the dye in the stained fragments is then examined to generate an output functionally related to the number of nucleotides in each one of the DNA fragments. In one embodiment, the intensity of the fluorescence emissions from each fragment is linearly related to the fragment length. The distribution of DNA fragment sizes forms a characterization of the DNA piece for use in forensic and research applications.

  20. Joint fluid Gram stain

    MedlinePLUS

    Gram stain of joint fluid ... result means no bacteria are present on the Gram stain. Note: Normal value ranges may vary slightly ... Abnormal results mean bacteria were seen on the Gram stain. This may be a sign of a ...

  1. Fluorescence-based fixative and vital staining of lipid droplets in Caenorhabditis elegans reveal fat stores using microscopy and flow cytometry approaches[S

    PubMed Central

    Klapper, Maja; Ehmke, Madeleine; Palgunow, Daniela; Böhme, Mike; Matthäus, Christian; Bergner, Gero; Dietzek, Benjamin; Popp, Jürgen; Döring, Frank

    2011-01-01

    The proportions of body fat and fat-free mass are determining factors of adiposity-associated diseases. Work in Caenorhabditis elegans has revealed evolutionarily conserved pathways of fat metabolism. Nevertheless, analysis of body composition and fat distribution in the nematodes has only been partially unraveled because of methodological difficulties. We characterized metabolic C. elegans mutants by using novel and feasible BODIPY 493/503-based fat staining and flow cytometry approaches. Fixative as well as vital BODIPY staining procedures visualize major fat stores, preserve native lipid droplet morphology, and allow quantification of fat content per body volume of individual worms. Colocalization studies using coherent anti-Stokes Raman scattering microscopy, Raman microspectroscopy, and imaging of lysosome-related organelles as well as biochemical measurement confirm our approaches. We found that the fat-to-volume ratio of dietary restriction, TGF-?, and germline mutants are specific for each strain. In contrast, the proportion of fat-free mass is constant between the mutants, although their volumes differ by a factor of 3. Our approaches enable sensitive, accurate, and high-throughput assessment of adiposity in large C. elegans populations at a single-worm level. PMID:21421847

  2. A Two-Colour Fluorescence Assay for the Measurement of Syncytial Fusion between Trophoblast-Derived Cell Lines

    Microsoft Academic Search

    M. Borges; P. Bose; H.-G. Frank; P. Kaufmann; A. J. G. Pötgens

    2003-01-01

    Syncytial fusion is a key event in implantation and placentation. Its regulation is only poorly understood. We present a cell–cell fusion assay based on staining of cells in two portions with a green and a red fluorescent cytoplasmic dye that become intracellularly mixed only after syncytial fusion. We quantified cell–cell fusion by fluorescence microscopy in choriocarcinoma cell lines BeWo, JAR

  3. Proflavine Hemisulfate as a Fluorescent Contrast Agent for Point-of-Care Cytology

    PubMed Central

    Prieto, Sandra P.; Powless, Amy J.; Boice, Jackson W.; Sharma, Shree G.; Muldoon, Timothy J.

    2015-01-01

    Proflavine hemisulfate, an acridine-derived fluorescent dye, can be used as a rapid stain for cytologic examination of biological specimens. Proflavine fluorescently stains cell nuclei and cytoplasmic structures, owing to its small amphipathic structure and ability to intercalate DNA. In this manuscript, we demonstrated the use of proflavine as a rapid cytologic dye on a number of specimens, including normal exfoliated oral squamous cells, cultured human oral squamous carcinoma cells, and leukocytes derived from whole blood specimens using a custom-built, portable, LED-illuminated fluorescence microscope. No incubation time was needed after suspending cells in 0.01% (w/v) proflavine diluted in saline. Images of proflavine stained oral cells had clearly visible nuclei as well as granular cytoplasm, while stained leukocytes exhibited bright nuclei, and highlighted the multilobar nature of nuclei in neutrophils. We also demonstrated the utility of quantitative analysis of digital images of proflavine stained cells, which can be used to detect significant morphological differences between different cell types. Proflavine stained oral cells have well-defined nuclei and cell membranes which allowed for quantitative analysis of nuclear to cytoplasmic ratios, as well as image texture analysis to extract quantitative image features. PMID:25962131

  4. R-phycoerythrin-conjugated antibodies are inappropriate for intracellular staining of murine plasma cells.

    PubMed

    Kim, Myun Soo; Kim, Tae Sung

    2013-05-01

    Phycoerythrin (PE) is a type of phycobiliproteins found in cyanobacteria and red algae. PE-conjugated antibodies are broadly used for flow cytometry and immunofluorescence microscopy. Because nonspecific binding of antibodies results in decreased analytic accuracy, numerous efforts have been made to unveil cases and mechanisms of nonspecific bindings. However, nonspecific binding of specific cell types by a fluorescent dye-conjugated form of antibody has been rarely reported. In the present study, we discovered that PE-conjugated antibodies, but not FITC- or APC-antibodies, selectively stained lamina propria plasma cells (LP-PCs) from the murine small intestine after membrane permeabilization. We demonstrated that LP-PC-selective staining with PE-antibodies was not due to interactions of antibody-epitope or antibody-Fc receptor. This unexpected staining by PE-antibody was not dependent on the mouse strain of LP-PCs, experimental methods, or origin species of the antibody, but dependent on PE itself. This phenomenon was also observed in plasma cells isolated from bone marrow, spleen, and mesenteric lymph nodes. Furthermore, in vitro activated B cells and in vivo generated LP-PCs were also selectively stained by PE-conjugated antibodies. Taken together, these results show that PE-conjugated antibodies are inappropriate for intracellular staining of murine plasma cells. PMID:23463627

  5. Automated Slide Staining Machine

    PubMed Central

    Drew, W. Lawrence; Pedersen, Anders N.; Roy, Jacques J.

    1972-01-01

    A machine is described which can perform the Gram stain. Comparison of slides stained by machine versus hand revealed no difference in reproducibility or accuracy. In addition to providing clean, dry, uniformly stained slides, the machine saves 24 sec per slide when compared with a hand staining technique. Images PMID:4110426

  6. Cellular uptake of modified oligonucleotides: fluorescence approach

    NASA Astrophysics Data System (ADS)

    Ko?išová, Eva; Praus, Petr; Rosenberg, Ivan; Seksek, Olivier; Sureau, Franck; Št?pánek, Josef; Turpin, Pierre-Yves

    2005-06-01

    Cellular uptake and intracellular distribution of the synthetic antisense analogue of dT 15 oligonucleotide (homogenously containing 3'-O-P-CH 2-O-5' internucleotide linkages and labeled with tetramethylrhodamine dye) was studied on B16 melanoma cell line by fluorescence micro-imaging and time-resolved microspectrofluorimetry. By using amphotericin B 3-dimethylaminopropyl amide as an enhancer molecule for the uptake process, homogenous staining of the cells with rather distinct nucleoli staining was achieved after 4 h of incubation. Two spectral components of 2.7 and 1.3 ns lifetime, respectively, were resolved in the emission collected from the cell nucleus. The way of staining and the long-lived component differed from our previous experiments demonstrating complexity of the intracellular oligonucleotide distribution and in particular of the binding inside the nucleus.

  7. Single-molecule resolution and fluorescence imaging of mixed-mode sorption of a dye at the interface of C18 and acetonitrile/water.

    PubMed

    Ludes, Melody D; Wirth, Mary J

    2002-01-15

    Single-molecule imaging is used for the first time to study the cationic dye, 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI), at the chromatographic interface consisting of acetonitrile/water and a hydrocarbon monolayer (C18) covalently bound to silica. Autocorrelations of burst data agree with our previous single-molecule counting results, showing that most dye molecules are diffusing and that there is a rare specific adsorption site associated with a 0.07-s desorption time. These autocorrelations go further in detecting an even rarer specific adsorption event associated with a 2.6-s desorption time. The latter desorption time would contribute much more significantly to peak tailing in chromatography. In water, the populations of DiI at these two specific adsorption sites are shown to be 11% and 4%, respectively, for the weaker and stronger sites, relative to the diffusing population of DiI. In 60% acetonitrile/water, the relative populations of the specific adsorption sites are 11% and 17%, showing that acetonitrile enhances the population of the stronger specific adsorption site. Fluorescence movies of single and multiple molecules link the stronger specific adsorption sites to specific locations on the surface. The imaging makes rare observations frequent by pinpointing where the events occur spatially. This ability to observe rare events by imaging reveals the presence of a third type of specific adsorption site, for which DiI has a desorption time in excess of 20 s. PMID:11811413

  8. Immunofluorescence analysis of cytokeratin 8/18 staining is a sensitive assay for the detection of cell apoptosis

    PubMed Central

    DONG, QIAO-MEI; LING, CHUN; ZHAO, LI

    2015-01-01

    Apoptosis is one of the major types of programmed cell death. During this process, cells experience a series of morphological and biochemical changes. Flow cytometric analysis of Annexin V staining of cell surface phosphatidylserine, in combination with a DNA-staining dye to probe the permeability of the cell membrane, is an established method for detecting apoptosis. The present study aimed to show that the immunofluorescence analysis of cytokeratin (CK) 8/18 staining may provide a new and sensitive assay for the detection of apoptotic cells. Tumor cells were treated with 20 ?M cisplatin to induce apoptosis. Following 12 and 24 h of cisplatin treatment, cells were collected and stained with 4?,6-diamidine-2?-phenylindole dihydrochloride (DAPI) and fluorescein-labeled anti-CK8/18 antibody. The apoptotic cells were subsequently examined by fluorescence microscopy. Annexin V-fluorescein isothiocyanate/propidium iodide staining followed by flow cytometric analysis confirmed that cisplatin was able to induce apoptosis in tumor cells. Immunofluorescence analysis demonstrated that apoptotic cells had a distinct CK8/18 staining pattern. In living cells, CK8/18 was uniformly distributed in the cytoplasm and cytosol; however in the apoptotic cells with a condensed and/or fragmented apoptotic nucleus (as identified by DAPI staining), fluorescein-labeled anti-CK8/18 antibody exhibited unusual punctate and/or bubbly staining in the cytosol. In the apoptotic cells that could not be identified by DAPI staining, fluorescein-labeled CK8/18 displayed polarized aggregated staining in the cytosol. These results indicate that fluorescein-conjugated CK8/18 may be a useful and sensitive indicator of cell apoptosis. PMID:25663887

  9. A review of the chemistry and uses of crocins and crocetin, the carotenoid natural dyes in saffron, with particular emphasis on applications as colorants including their use as biological stains.

    PubMed

    Bathaie, S Z; Farajzade, A; Hoshyar, R

    2014-08-01

    The perennial flowering plant, saffron crocus (Crocus sativus L.), is the source of the most expensive spice in the world. The dried stigmas of saffron flowers are the source of a natural dye, saffron, which has been used from ancient times for dyeing silk and fabric rugs, and for painting; it also has been used for cooking and in medicine. The yellow compounds present in the dye include crocins, which are 20-carbon water soluble glycosyl derivatives of the carotenoid, crocetin, and the dicarboxylic acid itself. We review the chemistry of these compounds and discuss various applications of saffron as a natural dye. We review in particular the use of saffron or its constituents in histopathologic techniques. PMID:24665936

  10. Monodansylpentane as a Blue-Fluorescent Lipid-Droplet Marker for Multi-Color Live-Cell Imaging

    PubMed Central

    Yang, Huei-Jiun; Hsu, Chia-Ling; Yang, Jin-Yi; Yang, Wei Yuan

    2012-01-01

    Lipid droplets (LDs) are dynamic cellular organelles responsible for the storage of neutral lipids, and are associated with a multitude of metabolic syndromes. Here we report monodansylpentane (MDH) as a high contrast blue-fluorescent marker for LDs. The unique spectral properties make MDH easily combinable with other green and red fluorescent reporters for multicolor fluorescence imaging. MDH staining does not apparently affect LD trafficking, and the dye is extraordinarily photo-stable. Taken together MDH represents a reliable tool to use for the investigation of dynamic LD regulation within living cells using fluorescence microscopy. PMID:22396789

  11. Nonphotochemical hole-burning study of selectively stained normal and cancerous human ovarian tissues.

    PubMed

    Matsuzaki, S; Hayes, J M; Benbrook, D M; Jankowiak, R

    2006-08-17

    Results are presented of nonphotochemical hole-burning (HB) experiments on cancerous ovarian and analogous normal peritoneal in vitro tissues stained with the mitochondrial-selective dye rhodamine 800. A comparison of fluorescence excitation spectra, hole-growth kinetics data, and external electric field (Stark) effects on the shape of spectral holes burned in cancerous and normal tissues stained with rhodamine 800 revealed significant differences only in the dipole moment change (fDeltamu) measured by a combination of HB and Stark spectroscopies. It is shown that the permanent dipole moment change for the S0--> S1 transition of the rhodamine 800 molecules in cancerous tissue is higher than that of normal tissue by a factor of about 1.4. The finding is similar to the HB results obtained earlier for human ovarian surface epithelial cell lines, i.e., OV167 carcinoma and OSE(tsT)-14 normal cells stained with the same mitochondria-specific dye (Walsh et al. Biophys. J. 2003, 84, 1299). We propose that the observed difference in the permanent dipole moment change in cancerous ovarian tissue is related to a modification in mitochondrial membrane potential. PMID:16898770

  12. Steady-state and time-resolved fluorescence study of some dyes in polymer microspheres showing morphology dependent resonances

    Microsoft Academic Search

    Prem B. Bisht; Kazuhiro Fukuda; Satoshi Hirayama

    1996-01-01

    Fluorescence emission spectra of N,N?-bis(2,5-di-tert-butylphenyl)-3,4:9,10- Perylenebis(dicarboximide) (DBPI), rhodamine 6G (R6G), and cresyl violet (CV) in spherical polymer beads of less than 20 ?m diameter show sharp ripple structures. The observed peak positions and the intervals of the structures are consistent with the calculations of the morphology dependent resonances (MDR). Observed intensities of the MDR in the fluorescence emission spectra are

  13. Short-term transformation and long-term replacement of branchial chloride cells in killifish transferred from seawater to freshwater, revealed by morphofunctional observations and a newly established 'time-differential double fluorescent staining' technique.

    PubMed

    Katoh, Fumi; Kaneko, Toyoji

    2003-11-01

    Short- and long-term responses to direct transfer from seawater to freshwater were examined in gill chloride cells of killifish, which developed distinct freshwater- and seawater-type chloride cells in the respective environments. In a short-term response within 24 h after transfer, seawater-type chloride cells forming a pit structure on the apical surface were transformed into freshwater-type cells equipped with developed microvilli on the flat or projecting apical membrane, via the intermediate type. The transformation process was accompanied by the disappearance of apically located Cl- channel (cystic fibrosis transmembrane conductance regulator) and neighboring accessory cells. Chloride cell replacement was also examined as a long-term adaptation to freshwater transfer, using a newly established 'time-differential double fluorescent staining (TDS)' technique. In the TDS technique, in vivo labeling of chloride cells was performed on two separate days, using two distinguishable mitochondria-specific fluorescent probes. For 3 days after freshwater transfer, 14.7% of seawater-type cells were replaced with newly differentiated freshwater-type cells, whereas these ratios of chloride cell replacement were much lower (1.2% and 1.8%) in seawater- and freshwater-maintained groups, respectively. In consequence, following direct transfer of killifish from seawater to freshwater, seawater-type chloride cells were transformed morphologically and functionally into freshwater-type cells as a short-term response, followed by the promotion of chloride cell replacement as a long-term response. PMID:14555751

  14. Micromanipulation and physiological monitoring of cells using two-photon excited fluorescence in cw laser tweezers

    NASA Astrophysics Data System (ADS)

    Sonek, Gregory J.; Liu, Yagang; Berns, Michael W.; Tromberg, Bruce J.

    1996-05-01

    We report the observation of two-photon fluorescence excitation and cell confinement, simultaneously, in a continuous-wave (cw) single-beam gradient force optical trap, and demonstrate its use as an in-situ probe to study the physiological state of an optically confined cell sample. At the wavelength of 1064 nm, a single focused gaussian laser beam is used to simultaneously confine, and excite visible fluorescence from, a human sperm cell that has been tagged with propidium iodide, a exogenous fluorescent dye that functions as a viability assay of cellular physiological state. The intensity at the dye peak emission wavelength of 620 nm exhibits a near-square-law dependence on incident trapping beam photon laser power, a behavior consistent with a two-photon absorption process. In addition, for a sperm cell held stationary in the optical tweezers for a period of several minutes at a constant trapping power, red fluorescence emission was observed to increase the time, indicating that the cell has gradually transitioned between a live and dead state. Two-photon excited fluorescence was also observed in chinese hamster ovary cells that were confined by cw laser tweezers and stained with either propidium iodide or Snarf, a pH-sensitive dye probe. These results suggest that, for samples suitably tagged with fluorescent probes and vital stains, optical tweezers can be used to generate their own in-situ diagnostic optical probes of cellular viability or induced photodamage, via two-photon processes.

  15. Dye-Enhanced Multimodal Confocal Imaging of Brain Cancers

    NASA Astrophysics Data System (ADS)

    Wirth, Dennis; Snuderl, Matija; Sheth, Sameer; Curry, William; Yaroslavsky, Anna

    2011-04-01

    Background and Significance: Accurate high resolution intraoperative detection of brain tumors may result in improved patient survival and better quality of life. The goal of this study was to evaluate dye enhanced multimodal confocal imaging for discriminating normal and cancerous brain tissue. Materials and Methods: Fresh thick brain specimens were obtained from the surgeries. Normal and cancer tissues were investigated. Samples were stained in methylene blue and imaged. Reflectance and fluorescence signals were excited at 658nm. Fluorescence emission and polarization were registered from 670 nm to 710 nm. The system provided lateral resolution of 0.6 ?m and axial resolution of 7 ?m. Normal and cancer specimens exhibited distinctively different characteristics. H&E histopathology was processed from each imaged sample. Results and Conclusions: The analysis of normal and cancerous tissues indicated clear differences in appearance in both the reflectance and fluorescence responses. These results confirm the feasibility of multimodal confocal imaging for intraoperative detection of small cancer nests and cells.

  16. pH-induced vesicle-to-micelle transition in amphiphilic diblock copolymer: investigation by energy transfer between in situ formed polymer embedded gold nanoparticles and fluorescent dye.

    PubMed

    Maiti, Chiranjit; Banerjee, Rakesh; Maiti, Saikat; Dhara, Dibakar

    2015-01-13

    The ability to regulate the formation of nanostructures through self-assembly of amphiphilic block copolymers is of immense significance in the field of biology and medicine. In this work, a new block copolymer synthesized by using reversible addition-fragmentation chain transfer (RAFT) polymerization technique from poly(ethylene glycol) monomethyl ether acrylate (PEGMA) and Boc-l-tryptophan acryloyloxyethyl ester (Boc-l-trp-HEA) was found to spontaneously form pH-responsive water-soluble nanostructures after removal of the Boc group. While polymer vesicles or polymerosomes were formed at physiological pH, the micelles were formed at acidic pH (< 5.2), and this facilitated a pH-induced reversible vesicle-to-micelle transition. Formation of these nanostructures was confirmed by different characterization techniques, viz. transmission electron microscopy, dynamic light scattering, and steady-state fluorescence measurements. Further, these vesicles were successfully utilized to reduce HAuCl4 and stabilize the resulting gold nanoparticles (AuNPs). These AuNPs, confined within the hydrophobic shell of the vesicles, could participate in energy transfer process with fluorescent dye molecules encapsulated in the core of the vesicles, thus forming a nanometal surface energy transfer (NSET) pair. Subsequently, following the efficiency of energy transfer between this pair, it was possible to monitor the process of transition from vesicles to micelles. Thus, in this work, we have successfully demonstrated that NSET can be used to follow the transition between nanostructures formed by amphiphilic block copolymers. PMID:25494810

  17. Gram stain of urethral discharge

    MedlinePLUS

    Urethral discharge Gram stain ... microscope slide. A series of stains called a Gram stain is applied to the specimen. The stained ... culture ) should be performed in addition to the gram stain. More sophisticated diagnostic tests (such as PCR ...

  18. Port-wine stain

    MedlinePLUS

    A port-wine stain is a birthmark in which swollen blood vessels create a reddish-purplish discoloration of the skin. ... Port-wine stains occur in about 3 out of 1,000 people. In rare cases, port-wine stains are ...

  19. High-speed, random-access fluorescence microscopy: II. Fast quantitative measurements with voltage-sensitive dyes.

    PubMed

    Bullen, A; Saggau, P

    1999-04-01

    An improved method for making fast quantitative determinations of membrane potential with voltage-sensitive dyes is presented. This method incorporates a high-speed, random-access, laser-scanning scheme (Bullen et al., 1997. Biophys. J. 73:477-491) with simultaneous detection at two emission wavelengths. The basis of this ratiometric approach is the voltage-dependent shift in the emission spectrum of the voltage-sensitive dye di-8-butyl-amino-naphthyl-ethylene-pyridinium-propyl-sulfonate (di-8-ANEPPS). Optical measurements are made at two emission wavelengths, using secondary dichroic beamsplitting and dual photodetectors (<570 nm and >570 nm). Calibration of the ratiometric measurements between signals at these wavelengths was achieved using simultaneous optical and patch-clamp measurements from adjacent points. Data demonstrating the linearity, precision, and accuracy of this technique are presented. Records obtained with this method exhibited a voltage resolution of approximately 5 mV, without any need for temporal or spatial averaging. Ratiometric recordings of action potentials from isolated hippocampal neurons are used to illustrate the usefulness of this approach. This method is unique in that it is the first to allow quantitative determination of dynamic membrane potential changes in a manner optimized for both high spatiotemporal resolution (2 micrometers and <0.5 ms) and voltage discrimination. PMID:10096922

  20. Single Fluorescence Channel-based Multiplex Detection of Avian Influenza Virus by Quantitative PCR with Intercalating Dye.

    PubMed

    Ahberg, Christian D; Manz, Andreas; Neuzil, Pavel

    2015-01-01

    Since its invention in 1985 the polymerase chain reaction (PCR) has become a well-established method for amplification and detection of segments of double-stranded DNA. Incorporation of fluorogenic probe or DNA intercalating dyes (such as SYBR Green) into the PCR mixture allowed real-time reaction monitoring and extraction of quantitative information (qPCR). Probes with different excitation spectra enable multiplex qPCR of several DNA segments using multi-channel optical detection systems. Here we show multiplex qPCR using an economical EvaGreen-based system with single optical channel detection. Previously reported non quantitative multiplex real-time PCR techniques based on intercalating dyes were conducted once the PCR is completed by performing melting curve analysis (MCA). The technique presented in this paper is both qualitative and quantitative as it provides information about the presence of multiple DNA strands as well as the number of starting copies in the tested sample. Besides important internal control, multiplex qPCR also allows detecting concentrations of more than one DNA strand within the same sample. Detection of the avian influenza virus H7N9 by PCR is a well established method. Multiplex qPCR greatly enhances its specificity as it is capable of distinguishing both haemagglutinin (HA) and neuraminidase (NA) genes as well as their ratio. PMID:26088868

  1. Measurement of radical-species concentrations and polycyclic aromatic hydrocarbons in flames by fluorescence and absorption using a tunable dye laser. Progress report, March 1, 1981-February 28, 1982

    SciTech Connect

    Lucht, R.P.; Ludington, P.D.; Sweeney, D.W.; Laurendeau, N.M.

    1982-03-01

    A laser saturated fluorescence technique which can be used to measure accurate OH radical concentrations over wide ranges of flame pressure, composition and temperature has been demonstrated. The balanced cross-rate model is used to analyze the fluorescence data. OH number densities calculated from saturated fluorescence agree to within 20% with number densities calculated from independent absorption measurements. In addition, the ratio of number densities calculated from saturated fluorescence and absorption is constant over an order of magnitude range of flame pressure, demonstrating the insensitivity of the saturated fluorescence signal to collisional transfer rates. A two line saturated fluorescence temperature measurement technique has been developed and demonstrated. The flame temperatures measured by the technique exhibit low scatter and show good agreement with OH absorption and corrected thermocouple measurements. The effect of the multi-axial mode structure of the dye laser on saturation of OH resonances has been investigated both theoretically, using a quantum mechanical density matrix analysis, and experimentally, by measuring the OH saturation parameter for two different transitions over a wide range of flame pressure. Preliminary single pulse laser saturated fluorescence measurements have been demonstrated for OH in 350 torr flat flames. Initial PAH fluorescence measurements of naphthalene and anthracene have been performed in a vapor cell. The results suggest that these two species can be distinguished by their characteristic excitation or fluorescence spectra.

  2. Epitaxial growth of two-dimensional cyanine dye single crystals by adsorption at a pre-conditioned fatty acid monolayer

    NASA Astrophysics Data System (ADS)

    Schmitt, Franz-Josef; Knoll, Wolfgang

    1990-01-01

    We have studied the adsorption of water-soluble cyanine dyes (pseudoisocyanine, PIC and "stains all", SA) to monomolecular layers of arachidic acid (AA) at the water-air interface in a Langmuir trough. Upon adsorption the dye molecules organize themselves and form two-dimensional J-aggregates that can easily be observed and characterized in the fluorescence microscope. We show that AA can be "conditioned" by the adsorption of PIC in a lateral order that can be read-out after desorption of this first dye, by the adsorption of another dye, SA in our case. We interpret this memory effect as being caused by a structural and/or orientational modification of the AA monolayer that controls in addition to an electrostatic contribution, details of the crystal morphology and in this sense is a first example of epitaxial growth of two-dimensional organic crystals.

  3. Laser treatment of port-wine stains

    PubMed Central

    Brightman, Lori A; Geronemus, Roy G; Reddy, Kavitha K

    2015-01-01

    Port-wine stains are a type of capillary malformation affecting 0.3% to 0.5% of the population. Port-wine stains present at birth as pink to erythematous patches on the skin and/or mucosa. Without treatment, the patches typically darken with age and may eventually develop nodular thickening or associated pyogenic granuloma. Laser and light treatments provide improvement through selective destruction of vasculature. A variety of vascular-selective lasers may be employed, with the pulsed dye laser being the most common and well studied. Early treatment produces more optimal results. Advances in imaging and laser treatment technologies demonstrate potential to further improve clinical outcomes. PMID:25624768

  4. The chemically synthesized ageladine A-derivative LysoGlow84 stains lysosomes in viable mammalian brain cells and specific structures in the marine flatworm Macrostomum lignano.

    PubMed

    Mordhorst, Thorsten; Awal, Sushil; Jordan, Sebastian; Petters, Charlotte; Sartoris, Linda; Dringen, Ralf; Bickmeyer, Ulf

    2015-02-01

    Based on the chemical structure and the known chemical synthesis of the marine sponge alkaloid ageladine A, we synthesized the ageladine A-derivative 4-(naphthalene-2-yl)-1H-imidazo[4,5-c]pyridine trifluoroacetate (LysoGlow84). The two-step synthesis started with the Pictet-Spengler reaction of histamine and naphthalene-2-carbaldehyde to a tetrahydropyridine intermediate, which was dehydrogenated with activated manganese (IV) oxide to LysoGlow84. Structure and purity of the synthesized LysoGlow84 were confirmed by NMR spectroscopy and mass spectrometry. The fluorescence intensity emitted by LysoGlow84 depended strongly on the pH of the solvent with highest fluorescence intensity recorded at pH 4. The fluorescence maximum (at 315 nm excitation) was observed at 440 nm. Biocompatibility of LysoGlow84 was investigated using cultured rat brain astrocytes and the marine flatworm Macrostomum lignano. Exposure of the astrocytes for up to 6 h to micromolar concentrations of LysoGlow84 did not compromise cell viability, as demonstrated by several viability assays, but revealed a promising property of this compound for staining of cellular vesicles. Conventional fluorescence microscopy as well as confocal scanning microscopy of LysoGlow84-treated astrocytes revealed co-localization of LysoGlow84 fluorescence with that of LysoTracker® Red DND-99. LysoGlow84 stained unclear structures in Macrostomum lignano, which were identified as lysosomes by co-staining with LysoTracker. Strong fluorescence staining by LysoGlow84 was further observed around the worms' anterior gut and the female genital pore which were not counterstained by LysoTracker Red. Thus, LysoGlow84 is a new promising dye that stains lysosomes and other acidic compartments in cultured cells and in worms. PMID:25679913

  5. Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections

    Microsoft Academic Search

    L. C. U. Junqueira; G. Bignolas; R. R. Brentani

    1979-01-01

    Synopsis  Sirius Red, a strong anionic dye, stains collagen by reacting, via its sulphonic acid groups, with basic groups present in the collagen molecule. The elongated dye molecules are attached to the collagen fibre in such a way that their long axes are parallel. This parallel relationship between dye and collagen results in an enhanced birefringency.Examination of tissue sections from 15

  6. Tunneling spectra for single molecules of HEX-fluorescent dye attached to DNA adsorbed on Cu(1 1 1) surfaces

    NASA Astrophysics Data System (ADS)

    Kawahara, Toshio; Takahashi, Takuya; Tanaka, Hiroyuki; Kawai, Tomoji

    2006-05-01

    We used the scanning tunneling microscope (STM) to examine single-stranded deoxyribonucleic acid (DNA) oligomers deposited on a metal surface. Because STM can be used to study the electrical properties of materials via the tunneling spectra, we used it to visualize DNA oligomers at the single molecule resolution. The 5'-hexachloro-fluorescein phosphoramidite (HEX)-labeled oligomers (sequence, AGCTTC) were observed on an atomically flat Cu(1 1 1) surface. At large tip-sample distances at large set-point biases, the lowest unoccupied molecular orbit (LUMO) peak of the empty state can be observed for the dye molecules on the tunneling spectra. When this distance becomes small, similar spectra as for the Cu substrate were observed for the dye molecule on the LUMO-related peak. Cu gave peaks at small bias voltages in the filled state. From comparison of these peaks on each subunit of the molecules, the measured values of d I/d V on HEX were smaller to those on Cu because of the large size of the HEX molecule, but the normalized values of d I/d V/( I/ V) were apparently equal. We believe that the tunneling current is able to pass through the HEX molecules to the Cu substrate, thus reflecting the density of the Cu(1 1 1) surface. Molecular size therefore affects the intensity of d I/d V. LUMO-related peaks sometimes cannot be observed for HEX because of conformational differences, but Cu peaks can almost always be observed for HEX molecules. These peaks for the counter ions are almost the same as those for the Cu substrate. Thus, tunneling spectra can assist in the molecular mapping of DNA.

  7. The performance of fluorescence gas sensor using TiO2 coated dye-porphyrin nanocomposite thin films

    Microsoft Academic Search

    Nurul Huda Yusoff; Muhamad Mat Salleh; Muhammad Yahaya

    2008-01-01

    This paper reports the performance of fluorescence gas sensor to detect the presence of volatile organic compounds. Two thin films were prepared; TiO2 coated with iron (III) meso-tetraphenylporphine chloride (TiO2 coated IMTPPCl) and TiO2 coated with manganase (III) 5,10,15,20 tetra (4-pyridyl)-21 H, 23 H porphine chloride tetrakis (TiO2 coated MnTPCl). All the thin films were deposited on quartz substrate using

  8. Detection of chloroform in water using an azo dye-modified ?-cyclodextrin - Epichlorohydrin copolymer as a fluorescent probe

    NASA Astrophysics Data System (ADS)

    Ncube, Phendukani; Krause, Rui W. M.; Mamba, Bhekie B.

    Chlorination disinfection by-products (DBPs) in water pose a health threat to humans and the aquatic environment. Their detection in water sources is therefore vital. Herein we present the detection of chloroform, a DBP, using a molecular fluorescent probe. The detection was based on the quenching of fluorescence of the probe by chloroform due to host-guest complex formation between ?-cyclodextrin in the probe and the chloroform molecule. The stability constant for the host-guest complex was high at 3.825 × 104 M-1. Chloroform quenched the fluorescence of the copolymer the most compared to the other small chlorinated compounds studied, suggesting that the probe was more sensitive to chloroform, with a sensing factor of 0.35 compared to as low as 0.0073 for dichloromethane. There was no interference from other chloroalkanes on the quenching efficiency of chloroform. The probe was used to detect chloroform in dam water as well as in bottled water. Detection of chloroform in both water samples using the probe was possible without chemically treating the water samples which may introduce other pollutants.

  9. Relationship between laser fluorescence and bacterial invasion in arrested dentinal carious lesions

    Microsoft Academic Search

    Yukiteru Iwami; Hiroko Yamamoto; Mikako Hayashi; Shigeyuki Ebisu

    2011-01-01

    This study investigated the relationship between caries assessment using a laser fluorescence device (DIAGNOdent), and bacterial\\u000a invasion in arrested carious dentin detected by polymerase chain reaction (PCR). The ten extracted human molars used in this\\u000a study had black or dark brown, hard occlusal carious lesions, and were found to be only weakly stained or unstained with a\\u000a caries detector dye

  10. Dye-coated europium monosulfide

    SciTech Connect

    Kar, Srotoswini [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States); Dollahon, Norman R. [Department of Biology, Villanova University, Villanova, PA 19085 (United States); Stoll, Sarah L., E-mail: sls55@georgetown.ed [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States)

    2011-05-15

    Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

  11. Applying fluorescence lifetime imaging microscopy to evaluate the efficacy of anticancer drugs

    NASA Astrophysics Data System (ADS)

    Kawanabe, Satoshi; Araki, Yoshie; Uchimura, Tomohiro; Imasaka, Totaro

    2015-06-01

    Fluorescence lifetime imaging microscopy was applied to evaluate the efficacy of anticancer drugs. A decrease in the fluorescence lifetime of the nucleus in apoptotic cancer cells stained by SYTO 13 dye was detected after treatment with antitumor antibiotics such as doxorubicin or epirubicin. It was confirmed that the change in fluorescence lifetime occurred earlier than morphological changes in the cells. We found that the fluorescence lifetime of the nucleus in the cells treated with epirubicin decreased more rapidly than that of the cells treated with doxorubicin. This implies that epirubicin was more efficacious than doxorubicin in the treatment of cancer cells. The change in fluorescence lifetime was, however, not indicated when the cells were treated with cyclophosphamide. The decrease in fluorescence lifetime was associated with the processes involving caspase activation and chromatin condensation. Therefore, this technique would provide useful information about apoptotic cells, particularly in the early stages.

  12. Fluorescent visualization of germline apoptosis in living Caenorhabditis elegans.

    PubMed

    Lant, Benjamin; Derry, W Brent

    2014-04-01

    Visualization of apoptosis using fluorescent tools is quite straightforward in living Caenorhabditis elegans. Several transgenic lines are available that mark dying cells with fluorescent proteins, making it possible to quantify kinetics at various stages of the apoptotic process. Proteins required for the engulfment of cell corpses are particularly useful for detecting early apoptotic stages using this approach. For example, expression of the engulfment protein CED-1 fused to green fluorescent protein (CED-1::GFP) creates a halo around cells during early apoptosis, before their refractile morphology can be detected by differential interference contrast (DIC) optics. In addition, vital dyes such as acridine orange (AO) and SYTO-12 are selectively retained in apoptotic cells and can be used to visualize apoptosis in the germlines of living animals. It is also possible to use vital dyes in combination with transgenic strains expressing fluorescent markers of cell corpses to examine, in detail, multiple stages of apoptosis in vivo. Because of the high optical contrast of fluorescent reagents, apoptosis can be visualized even at low magnification, facilitating the use of screening platforms to identify apoptosis regulators. This protocol describes multiple uses of fluorescent reagents for visualization of germline apoptosis in living C. elegans, including AO staining, time-course studies using fluorescent proteins, and low-throughput screening of cell death genes using RNA interference (RNAi). PMID:24692492

  13. Nanoparticle Stained Glass

    NSDL National Science Digital Library

    2014-06-18

    In this activity/demo, learners are introduced to the connection between medieval stained glass artisans and nanotechnology. Learners discover that the red and yellow colors in stained glass windows come from nanoparticles of gold and silver embedded in the glass. This activity/demo consists of two hands-on activities: making a collaborative stained glass window with pre-made nanoparticle solutions containing silver or gold and making a take-away card that contains a small piece of nanoparticle stained “glass."

  14. High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

    PubMed Central

    Bullen, A; Patel, S S; Saggau, P

    1997-01-01

    The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging. Images FIGURE 6 PMID:9199810

  15. A Loop-Mediated Isothermal Amplification (LAMP) Assay for Strongyloides stercoralis in Stool That Uses a Visual Detection Method with SYTO-82 Fluorescent Dye

    PubMed Central

    Watts, Matthew R.; James, Gregory; Sultana, Yasmin; Ginn, Andrew N.; Outhred, Alexander C.; Kong, Fanrong; Verweij, Jaco J.; Iredell, Jonathan R.; Chen, Sharon C-A.; Lee, Rogan

    2014-01-01

    An assay to detect Strongyloides stercoralis in stool specimens was developed using the loop-mediated isothermal amplification (LAMP) method. Primers were based on the 28S ribosomal subunit gene. The reaction conditions were optimized and SYTO-82 fluorescent dye was used to allow real-time and visual detection of the product. The product identity was confirmed with restriction enzyme digestion, cloning, and sequence analysis. The assay was specific when tested against DNA from bacteria, fungi and parasites, and 30 normal stool samples. Analytical sensitivity was to < 10 copies of target sequence in a plasmid and up to a 10-2 dilution of DNA extracted from a Strongyloides ratti larva spiked into stool. Sensitivity was increased when further dilutions were made in water, indicative of reduced reaction inhibition. Twenty-seven of 28 stool samples microscopy and polymerase chain reaction positive for S. stercoralis were positive with the LAMP method. On the basis of these findings, the assay warrants further clinical validation. PMID:24323513

  16. Visualization of cytoplasmic diffusion within living myelin sheaths of CNS white matter axons using microinjection of the fluorescent dye Lucifer Yellow.

    PubMed

    Velumian, Alexander A; Samoilova, Marina; Fehlings, Michael G

    2011-05-01

    The compactness of myelin allows for efficient insulation defining rapid propagation of action potentials, but also raises questions about how cytoplasmic access to its membranes is achieved, which is critical for physiological activity. Understanding the organization of cytoplasmic ('water') spaces of myelin is also important for diffusion MRI studies of CNS white matter. Using longitudinal slices of mature rat spinal cord, we monitored the diffusion of the water-soluble fluorescent dye Lucifer Yellow injected into individual oligodendrocytes or internodal myelin. We show that living myelin sheaths on CNS axons are fenestrated by a network of diffusionally interconnected cytoplasmic 'pockets' (1.9 ± 0.2 pockets per 10?m sheath length, n=58) that included Schmidt-Lanterman clefts (SLCs) and numerous smaller compartments. 3-D reconstructions of these cytoplasmic networks show that the outer cytoplasmic layer of CNS myelin is cylindrically 'encuffing', which differs from EM studies using fixed tissue. SLCs were found in different 'open states' and remained stable within a 1-2hour observation period. Unlike the peripheral nervous system, where similarly small (<500Da) molecules diffuse along the whole myelin segment within a few minutes, in mature CNS this takes more than one hour. The slower cytoplasmic diffusion in CNS myelin possibly contributes to its known vulnerability to injury and limited capacity for repair. Our findings point to an elaborate cytoplasmic access to compact CNS myelin. These results could be of relevance to MRI studies of CNS white matter and to CNS repair/regeneration strategies. PMID:21073961

  17. A loop-mediated isothermal amplification (LAMP) assay for Strongyloides stercoralis in stool that uses a visual detection method with SYTO-82 fluorescent dye.

    PubMed

    Watts, Matthew R; James, Gregory; Sultana, Yasmin; Ginn, Andrew N; Outhred, Alexander C; Kong, Fanrong; Verweij, Jaco J; Iredell, Jonathan R; Chen, Sharon C-A; Lee, Rogan

    2014-02-01

    An assay to detect Strongyloides stercoralis in stool specimens was developed using the loop-mediated isothermal amplification (LAMP) method. Primers were based on the 28S ribosomal subunit gene. The reaction conditions were optimized and SYTO-82 fluorescent dye was used to allow real-time and visual detection of the product. The product identity was confirmed with restriction enzyme digestion, cloning, and sequence analysis. The assay was specific when tested against DNA from bacteria, fungi and parasites, and 30 normal stool samples. Analytical sensitivity was to < 10 copies of target sequence in a plasmid and up to a 10(-2) dilution of DNA extracted from a Strongyloides ratti larva spiked into stool. Sensitivity was increased when further dilutions were made in water, indicative of reduced reaction inhibition. Twenty-seven of 28 stool samples microscopy and polymerase chain reaction positive for S. stercoralis were positive with the LAMP method. On the basis of these findings, the assay warrants further clinical validation. PMID:24323513

  18. Theory of pulsed dye lasers including dye-molecule rotational relaxation

    Microsoft Academic Search

    Roger A. Haas; Mark D. Rotter

    1991-01-01

    In this paper a phenomenological semiclassical theory of pulsed-laser-pumped dye-laser light amplifiers is presented. The theory accounts for the broadband radiation absorption and emission characteristics of dye molecules in liquid solvents. Dye-molecule fluorescence, vibrational, rotational, and electric polarization relaxation processes are represented by phenomenological relaxation rates. In general, it is found that due to dye-molecule rotational relaxation the laser-pumped dye

  19. Dye filled security seal

    DOEpatents

    Wilson, Dennis C. W. (Tijeras, NM)

    1982-04-27

    A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member.

  20. Using the vital dye acridine orange to detect dying cells in Drosophila.

    PubMed

    Denton, Donna; Kumar, Sharad

    2015-01-01

    Acridine orange is a cell-permeable fluorescent dye that binds to nucleic acids, resulting in an altered spectral emission. Acridine orange staining has been shown to be highly selective for apoptotic cells in Drosophila; however, the precise mechanism underlying this effect is not known. Advantages of acridine orange staining include the speed and ease of the staining. But there are disadvantages: It should be performed on unfixed tissue that therefore must be examined immediately, and multiple labeling cannot be performed. Slightly different protocols for the uptake of acridine orange are required for different developmental stages. Here, we present protocols for use of acridine orange to detect apoptosis in Drosophila embryos and in larval tissue. Slight modifications might be required for other Drosophila tissues. PMID:26034308

  1. Fluorescent labeling of DNA for genetic analysis

    NASA Astrophysics Data System (ADS)

    Menchen, Steve; Benson, Scott; Upadhya, Krishna; Theisen, Pete; Hauser, Joan; Kenney, Paul

    2000-03-01

    Labeling of DNA with fluorescent reporter is generally accomplished by attaching fluorescent dyes to the 5'-end of primers for PCR based applications, including geno-typing and linkage mapping. Requirements of spectral resolution and chemical stability have guided us toward asymmetric fluorescein dye structures whose chemical and physical properties have been fine-tuned through substituent modification. We have developed dyes that are amenable to 5'-prime labeling on solid support as dye-amidites facilitating automated dye-primer synthesis.

  2. Fluorescein eye stain

    MedlinePLUS

    ... test that uses orange dye (fluorescein) and a blue light to detect foreign bodies in the eye. This ... eye. The health care provider then shines a blue light at your eye. Any problems on the surface ...

  3. Lectin staining of cultured CNS microglia.

    PubMed

    Colton, C A; Abel, C; Patchett, J; Keri, J; Yao, J

    1992-04-01

    Carbohydrate binding proteins, known as lectins, bind to specific sugar groups on most membranes. We used fluorescent and light microscopy to study the interaction of various lectins with the membranes of microglia cultured from neonatal rat or fetal mouse cerebral cortices. Microglia stained intensely with GS-1, RCA, WGA, and ConA and slightly with DBA, UEA, BPA, and SBA. No staining was seen with GS-2, MPA, or PNA. Staining was specific for microglia in the mixed glial cultures and was dose dependent. In addition, microglial lectin binding could be reduced or blocked by competitive inhibition using specific sugars. Treatment of the microglia with agents such as dimethylsulfoxide (DMSO), interleukin-1 (IL-1), interferon (IFN), or lipopolysaccharide (LPS) did not eliminate lectin staining, although the degree of staining was altered. Positive staining of the microglia was also associated with a functional change for at least one lectin, i.e., ConA. Superoxide anion production by microglia was increased in the presence of ConA. Overall, binding of the lectins GS-1, RCA, WGA, and ConA can be used as an identifying tool for microglia in glial cultures, but intensity of staining varies depending on their functional state. PMID:1372634

  4. Reliable Screening of Dye Phototoxicity by Using a Caenorhabditis elegans Fast Bioassay

    PubMed Central

    Bianchi, Javier Ignacio; Stockert, Juan Carlos; Buzz, Lucila Ines; Blázquez-Castro, Alfonso; Simonetta, Sergio Hernán

    2015-01-01

    Phototoxicity consists in the capability of certain innocuous molecules to become toxic when subjected to suitable illumination. In order to discover new photoactive drugs or characterize phototoxic pollutants, it would be advantageous to use simple biological tests of phototoxicy. In this work, we present a pilot screening of 37 dyes to test for phototoxic effects in the roundworm Caenorhabditis elegans. Populations of this nematode were treated with different dyes, and subsequently exposed to 30 min of white light. Behavioral outcomes were quantified by recording the global motility using an infrared tracking device (WMicrotracker). Of the tested compounds, 17 dyes were classified as photoactive, being phloxine B, primuline, eosin Y, acridine orange and rose Bengal the most phototoxic. To assess photoactivity after uptake, compounds were retested after washing them out of the medium before light irradiation. Dye uptake into the worms was also analyzed by staining or fluorescence. All the positive drugs were incorporated by animals and produced phototoxic effects after washing. We also tested the stress response being triggered by the treatments through reporter strains. Endoplasmic reticulum stress response (hsp-4::GFP strain) was activated by 22% of phototoxic dyes, and mitochondrial stress response (hsp-6::GFP strain) was induced by 16% of phototoxic dyes. These results point to a phototoxic perturbation of the protein functionality and an oxidative stress similar to that reported in cell cultures. Our work shows for the first time the feasibility of C. elegans for running phototoxic screenings and underscores its application on photoactive drugs and environmental pollutants assessment. PMID:26039060

  5. Deep in vivo two-photon imaging of blood vessels with a new dye encapsulated in pluronic nanomicelles

    PubMed Central

    Maurin, Mathieu; Stéphan, Olivier; Vial, Jean-Claude; Marder, Seth R.; Van Der Sanden, Boudewijn

    2011-01-01

    The purpose of this work was to validate the use of Pluronic fluorescent nanomicelles for in vivo two-photon imaging of both the normal and the tumor vasculature. The nanomicelles were obtained after encapsulating a hydrophobic two-photon dye: di-stryl benzene derivative, in Pluronic block copolymers. Their performance with respect to imaging depth, blood plasma staining, and diffusion across the tumor vascular endothelium was compared to a classic blood pool dye Rhodamin B dextran (70 kDa) using two-photon microscopy. Pluronic nanomicelles showed, like Rhodamin B dextran, a homogeneous blood plasma staining for at least 1 hour after intravenous injection. Their two-photon imaging depth was similar in normal mouse brain using 10 times less injected mass. In contrast with Rhodamin B dextran, no extravasation is observed in leaky tumor vessels due to their large size: 20–100 nm. In conclusion, Pluronic nanomicelles can be used as a blood pool dye, even in leaky tumor vessels. The use of Pluronic block co-polymers is a valuable approach for encapsulating two-photon fluorescent dyes that are hydrophobic and not suitable for intravenous injection. PMID:21456865

  6. Deep in vivo two-photon imaging of blood vessels with a new dye encapsulated in pluronic nanomicelles

    NASA Astrophysics Data System (ADS)

    Maurin, Mathieu; Stéphan, Olivier; Vial, Jean-Claude; Marder, Seth R.; van der Sanden, Boudewijn

    2011-03-01

    Our purpose is to test if Pluronic® fluorescent nanomicelles can be used for in vivo two-photon imaging of both the normal and the tumor vasculature. The nanomicelles were obtained after encapsulating a hydrophobic two-photon dye: di-stryl benzene derivative, in Pluronic block copolymers. Their performance with respect to imaging depth, blood plasma staining, and diffusion across the tumor vascular endothelium is compared to a classic blood pool dye Rhodamin B dextran (70 kDa) using two-photon microscopy. Pluronic nanomicelles show, like Rhodamin B dextran, a homogeneous blood plasma staining for at least 1 h after intravenous injection. Their two-photon imaging depth is similar in normal mouse brain, using 10 times less injected mass. In contrast with Rhodamin B dextran, no extravasation is observed in leaky tumor vessels due to their large size: 20-100 nm. In conclusion, Pluronic nanomicelles can be used as a blood pool dye, even in leaky tumor vessels. The use of Pluronic block copolymers is a valuable approach for encapsulating two-photon fluorescent dyes that are hydrophobic and not suitable for intravenous injection.

  7. Measurement of radical-species concentrations and polycyclic aromatic hydrocarbons in flames by fluorescence and absorption using a tunable dye laser. Progress report, March 1, 1980-February 28, 1981

    SciTech Connect

    Lucht, R.P.; Sweeney, D.W.; Laurendeau, N.M.

    1981-03-01

    A theoretical and experimental investigation of OH saturated fluorescence is described. The goal of the research is to develop a saturated fluorescence technique which will yield accurate molecular number densities over a wide range of flame pressure, temperature, and composition. Experimentally, OH is excited by a ten nanosecond pulse from a Nd:YAG-pumped dye laser tuned to an isolated rotational transition in the (0,0) band of the A/sup 2/..sigma../sup +/-X/sup 2/ pi electronic system. The resulting fluorescence signal is resolved both spectrally and temporally. Total OH number densities are calculated by collecting fluorescence from the directly excited upper rotational level, and using the balanced cross-rate model to analyze the experimental data. Fluorescence measurements of OH number density agree to within a factor of three with the results of independent OH absorption measurements. Significantly, the ratio of the fluorescence signal to the number density measured by absorption is nearly the same in 30, 100 and 250 torr H/sub 2//O/sub 2//N/sub 2/ flat flames, demonstrating the insensitivity of the saturated fluorescence signal to the quenching environment of the radical. Collisional transfer in excited OH is studied by recording the time development of OH fluorescence spectrum. The experimental spectra are compared with the results of time-dependent computer modeling. By varying rotational transfer rates until the calculated and experimental spectra agree, rotational transfer cross sections can be calculated. The signal processing system was thoroughly checked by comparing the photomultiplier output to that of a fast photodiode, and by comparing single pulse Rayleigh scattering and fluorescence traces with sampling oscilloscope traces.

  8. A near-infrared phthalocyanine dye-labeled agent for integrin ?v?6-targeted theranostics of pancreatic cancer.

    PubMed

    Gao, Duo; Gao, Liquan; Zhang, Chenran; Liu, Hao; Jia, Bing; Zhu, Zhaohui; Wang, Fan; Liu, Zhaofei

    2015-06-01

    Integrin ?v?6 is widely upregulated in variant malignant cancers but is undetectable in normal organs, making it a promising target for cancer diagnostic imaging and therapy. Using streptavidin-biotin chemistry, we synthesized an integrin ?v?6-targeted near-infrared phthalocyanine dye-labeled agent, termed Dye-SA-B-HK, and investigated whether it could be used for cancer imaging, optical imaging-guided surgery, and phototherapy in pancreatic cancer mouse models. Dye-SA-B-HK specifically bound to integrin ?v?6 in vitro and in vivo with high receptor binding affinity. Using small-animal optical imaging, we detected subcutaneous and orthotopic BxPC-3 human pancreatic cancer xenografts in vivo. Upon optical image-guidance, the orthotopically growing pancreatic cancer lesions could be successfully removed by surgery. Using light irradiation, Dye-SA-B-HK manifested remarkable antitumor effects both in vitro and in vivo. (18)F-FDG positron emission tomography (PET) imaging and ex vivo fluorescence staining validated the observed decrease in proliferation of treated tumors by Dye-DA-B-HK phototherapy. Tissue microarray results revealed overexpression of integrin ?v?6 in over 95% cases of human pancreatic cancer, indicating that theranostic application of Dye-DA-B-HK has clear translational potential. Overall, the results of this study demonstrated that integrin ?v?6-specific Dye-SA-B-HK is a promising theranostic agent for the management of pancreatic cancer. PMID:25890722

  9. Loading and release of fluorescent dye from layer-by-layer film-coated magnetic particles in response to hydrogen peroxide.

    PubMed

    Sato, Katsuhiko; Abe, Eiichi; Takahashi, Mao; Anzai, Jun-ichi

    2014-10-15

    Polymer-coated magnetic particles (MPs) were prepared to study the binding of fluorescence dye on the surface and its H2O2-induced release. For this goal, multilayer films were prepared by layer-by-layer deposition of shikimic acid-appended poly(allylamine hydrochloride) (SA-PAH) and poly(styrenesulfonate) (PSS) on the surface of MPs. 3-(Dansylamino)phenylboronic acid (DPBA) was loaded on the MPs through boronate ester bonding between SA-PAH and DPBA. DPBA was released from the MPs in response to H2O2 as a result of breakage of the boronate ester bond by an oxidative reaction with H2O2. DPBA release was dependent on the H2O2 concentration. For example, 65% and 93% of the DPBA was released from (SA-PAH/PSS)4SA-PAH film-coated MPs in 30min after the addition of 0.1 and 0.5mM H2O2, respectively. In addition, the multilayer film-coated MPs were further modified by using glucose oxidase (GOx) to develop glucose-induced release systems. GOx-modified MPs released DPBA in response to 0.1mM d-glucose as a result of H2O2 generation through a GOx-catalyzed oxidation reaction of d-glucose. The results suggest a potential use of the multilayer film-coated MPs in the development of H2O2- and/or glucose-sensitive drug delivery systems. PMID:25084230

  10. The native state of apomyoglobin described by proton NMR spectroscopy: interaction with the paramagnetic probe HyTEMPO and the fluorescent dye ANS.

    PubMed Central

    Cocco, M. J.; Lecomte, J. T.

    1994-01-01

    Proton NMR experiments were carried out on apomyoglobin from sperm whale and horse skeletal muscle. Two small molecules, the paramagnetic relaxation agent 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxy (HyTEMPO) and the fluorescent dye 8-anilino-1-naphthalenesulfonic acid (ANS), were used to alter and simplify the spectrum. Both were shown to bind in the heme pocket by docking onto the hydrophobic residues lining the distal side. Only 1 extensive region of the apoprotein structure, composed of hydrophobic residues, is not affected by HyTEMPO. It includes the 2 tryptophans (located in the A helix), other nonpolar residues of the A helix and side chains from the E, G, and GH helices. The spectral perturbations induced by ANS allowed assignment of the distal histidine (His-64) in horse apomyoglobin. This residue was previously reported to titrate with a pKa below 5 and tentatively labeled as His-82 on the basis of this value (Cocco MJ, Kao YH, Phillips AT, Lecomte JTJ, 1992, Biochemistry 31:6481-6491). The packing of the side chains and the low pKa of His-64 reinforce the idea that the distal side of the binding site is folded in a manner closely related to that in the holoprotein. ANS was found to sharpen the protein signals and the improvement of the spectral resolution facilitated the assignment of backbone amide resonances. Secondary structure, as manifested in characteristic inter-amide proton NOEs, was detected in the A, B, C, E, G, and H helices. The combined information on the hydrophobic cores and the secondary structure composes an improved representation of the native state of apomyoglobin. PMID:8003963

  11. Pleural fluid Gram stain

    MedlinePLUS

    Gram stain of pleural fluid ... lungs fill a person's chest with air. If fluid builds up in the space outside the lungs ... chest, it can cause many problems. Removing the fluid can relieve a person's breathing problems and help ...

  12. Quirks of dye nomenclature. 2. Congo red.

    PubMed

    Cooksey, C J

    2014-07-01

    The history, origin, identity, chemistry and uses of Congo red are described. Originally patented in 1884, Congo red soon found applications in dyeing cotton, as a pH indicator for chemists and as a biological stain. Unlike the majority of the 19th century synthetic dyes, it still is available commercially. PMID:24520883

  13. Automated four color CD4/CD8 analysis of leukocytes by scanning fluorescence microscopy using Quantum dots

    NASA Astrophysics Data System (ADS)

    Bocsi, Jozsef; Mittag, Anja; Varga, Viktor S.; Molnar, Bela; Tulassay, Zsolt; Sack, Ulrich; Lenz, Dominik; Tarnok, Attila

    2006-02-01

    Scanning Fluorescence Microscope (SFM) is a new technique for automated motorized microscopes to measure multiple fluorochrome labeled cells (Bocsi et al. Cytometry 2004, 61A:1). The ratio of CD4+/CD8+ cells is an important in immune diagnostics in immunodeficiency and HIV. Therefor a four-color staining protocol (DNA, CD3, CD4 and CD8) for automated SFM analysis of lymphocytes was developed. EDTA uncoagulated blood was stained with organic and inorganic (Quantum dots) fluorochromes in different combinations. Aliquots of samples were measured by Flow Cytometry (FCM) and SFM. By SFM specimens were scanned and digitized using four fluorescence filter sets. Automated cell detection (based on Hoechst 33342 fluorescence), CD3, CD4 and CD8 detection were performed, CD4/CD8 ratio was calculated. Fluorescence signals were well separable on SFM and FCM. Passing and Bablok regression of all CD4/CD8 ratios obtained by FCM and SFM (F(X)=0.0577+0.9378x) are in the 95% confidence interval. Cusum test did not show significant deviation from linearity (P>0.10). This comparison indicates that there is no systemic bias between the two different methods. In SFM analyses the inorganic Quantum dot staining was very stable in PBS in contrast to the organic fluorescent dyes, but bleached shortly after mounting with antioxidant and free radical scavenger mounting media. This shows the difficulty of combinations of organic dyes and Quantum dots. Slide based multi-fluorescence labeling system and automated SFM are applicable tools for the CD4/CD8 ratio determination in peripheral blood samples. Quantum Dots are stable inorganic fluorescence labels that may be used as reliable high resolution dyes for cell labeling.

  14. Resolution of fluorescence signals from cells labeled with fluorochromes having different lifetimes by phase-sensitive flow cytometry

    SciTech Connect

    Steinkamp, J.A.; Crissman, H.A. (Los Alamos National Lab., NM (United States))

    1993-01-01

    A flow cytometric method has been developed that uses phase-sensitive detection to separate signals from simultaneous fluorescence emissions in cells labeled with fluorochromes having different fluorescence decay lifetimes. CHO cells were stained with propidium iodide (PI) and fluorescein isothiocyanate (FITC). These dyes bind to DNA and protein and the fluorescence lifetimes of the bound dyes are 15.0 and 3.6 ns, respectively. Cells were analyzed as they passed through a modulated (sinusoidal) laser excitation beam. Fluorescence was measured using only a long-pass filter to block scattered laser excitation light and a single photomultiplier tube detector. The fluorescence detector output signals were processed by dual-channel phase-sensitive detection electronics and the phase-resolved PI and FITC signals were displayed as frequency distribution histograms and bivariate plots. By shifting the phase of one detector channel reference signal by [pi]/2 + [phi][sub 1] degrees and the phase of the other detector channel reference signal by -[pi]/2 + [phi][sub 2] degrees, where [phi][sub 1] and [phi][sub 2] are the phase shifts associated with the PI and FITC lifetimes, the PI and FITC signals were separately resolved at their respective phase-sensitive detector outputs. This technology is also applicable to suppressing by cellular autofluorescence, unbound/free dye, nonspecific dye binding, and Raman and Rayleigh scattering. 21 refs., 2 figs.

  15. Preparation of 6-hydroxyindolines and their use for preparation of novel laser dyes

    DOEpatents

    Field, G.F.; Hammond, P.R.

    1993-10-26

    A novel method is described for the synthesis of 6-hydroxyindolines and new fluorescent dyes produced therefrom, which dyes are ring-constrained indoline-based rhodamine class dyes. These dyes have absorption and emission spectra which make them particularly useful in certain dye laser applications.

  16. "Stained Glass" Landscape Windows

    ERIC Educational Resources Information Center

    Vannata, Janine

    2008-01-01

    Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

  17. Rapid, one step staining procedures for analysis of cellular DNA and protein by single and dual laser flow cytometry

    Microsoft Academic Search

    H. A. Crissman; J. A. Steinkamp

    1982-01-01

    Detailed, simplified techniques are described for simultaneous staining and analysis of DNA and protein in a number of mammalian cell types. Cell staining involves the addition of appropriate dye mixtures to unfixed or ethanol-fixed cells and subsequent analysis of cell populations in the staining reagents generally within 10 to 20 minutes. The approach is novel in that no centrifugation steps

  18. Fluorescence imaging of microbe-containing particles shot from a two-stage Light-gas gun into an aerogel.

    PubMed

    Kawaguchi, Yuko; Sugino, Tomohiro; Tabata, Makoto; Okudaira, Kyoko; Imai, Eichi; Yano, Hajime; Hasegawa, Sunao; Hashimoto, Hirofumi; Yabuta, Hikaru; Kobayashi, Kensei; Kawai, Hideyuki; Mita, Hajime; Yokobori, Shin-ichi; Yamagishi, Akihiko

    2014-02-01

    We have proposed an experiment (the Tanpopo mission) to capture microbes on the Japan Experimental Module of the International Space Station. An ultra low-density silica aerogel will be exposed to space for more than 1 year. After retrieving the aerogel, particle tracks and particles found in it will be visualized by fluorescence microscopy after staining it with a DNA-specific fluorescence dye. In preparation for this study, we simulated particle trapping in an aerogel so that methods could be developed to visualize the particles and their tracks. During the Tanpopo mission, particles that have an orbital velocity of ~8 km/s are expected to collide with the aerogel. To simulate these collisions, we shot Deinococcus radiodurans-containing Lucentite particles into the aerogel from a two-stage light-gas gun (acceleration 4.2 km/s). The shapes of the captured particles, and their tracks and entrance holes were recorded with a microscope/camera system for further analysis. The size distribution of the captured particles was smaller than the original distribution, suggesting that the particles had fragmented. We were able to distinguish between microbial DNA and inorganic compounds after staining the aerogel with the DNA-specific fluorescence dye SYBR green I as the fluorescence of the stained DNA and the autofluorescence of the inorganic particles decay at different rates. The developed methods are suitable to determine if microbes exist at the International Space Station altitude. PMID:25086872

  19. Fluorescence imaging of microbe-containing particles shot from a two-stage Light-gas gun into an aerogel

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Yuko; Sugino, Tomohiro; Tabata, Makoto; Okudaira, Kyoko; Imai, Eichi; Yano, Hajime; Hasegawa, Sunao; Hashimoto, Hirofumi; Yabuta, Hikaru; Kobayashi, Kensei; Kawai, Hideyuki; Mita, Hajime; Yokobori, Shin-ichi; Yamagishi, Akihiko

    2014-02-01

    We have proposed an experiment (the Tanpopo mission) to capture microbes on the Japan Experimental Module of the International Space Station. An ultra low-density silica aerogel will be exposed to space for more than 1 year. After retrieving the aerogel, particle tracks and particles found in it will be visualized by fluorescence microscopy after staining it with a DNA-specific fluorescence dye. In preparation for this study, we simulated particle trapping in an aerogel so that methods could be developed to visualize the particles and their tracks. During the Tanpopo mission, particles that have an orbital velocity of ~8 km/s are expected to collide with the aerogel. To simulate these collisions, we shot Deinococcus radiodurans-containing Lucentite particles into the aerogel from a two-stage light-gas gun (acceleration 4.2 km/s). The shapes of the captured particles, and their tracks and entrance holes were recorded with a microscope/camera system for further analysis. The size distribution of the captured particles was smaller than the original distribution, suggesting that the particles had fragmented. We were able to distinguish between microbial DNA and inorganic compounds after staining the aerogel with the DNA-specific fluorescence dye SYBR green I as the fluorescence of the stained DNA and the autofluorescence of the inorganic particles decay at different rates. The developed methods are suitable to determine if microbes exist at the International Space Station altitude.

  20. Are picro-dye reactions for collagens quantitative?

    Microsoft Academic Search

    H. Puchtler; S. N. Meloan; F. S. Waldrop

    1988-01-01

    Previous studies of picro-dye reactions demonstrated wide variations in the binding of different dyes. Picro-Sirius Red F3BA was recommended because it colors all collagens intensely and is suitable for polarization microscopy. Recent publications on quantitative uses of this stain were surprising. To obtain further information on the chemical mechanisms of dye binding by proteins, 94 sulfonated azo dyes were tested

  1. Differential staining of acid glycosaminoglycans (mucopolysaccharides) by Alcian blue in salt solutions

    Microsoft Academic Search

    J. E. Scott; J. Dorling

    1965-01-01

    The application of the “critical electrolyte concentration” (CEC) concept to the differentiation of acidic glycosaminglycans (mucopolysaccharides) is described. Alcian Blue 8GX stains with increasing selectivity as increasing amounts of magnesium chloride are incorporated into the dye solution. Model experiments with pure polyanions, or artifically carboxylated, phosphorylated and sulphated liver sections, showed that binding of dye to carboxylate or phosphate groups

  2. Activity staining method of chitinase on chitin agar plate through polyacrylamide gel electrophoresis

    Microsoft Academic Search

    Vipul Gohel; Pranav Vyas; H. S. Chhatpar

    2005-01-01

    A method for detection of chitinase activity on chitin agar plate after polyacrylamide gel electrophoresis is described. Different staining dyes such as calcofluor white M2R, fluorescein isothiocyanate, rhodamine B, ruthenium red and congo red were separately incorporated in chitin agar plates. After running polyacrylamide gel electrophoresis, the gel was transferred onto chitin agar plate containing different dyes for the activity

  3. Enhancing analysis of cells and proteins by fluorescence imaging on silk-based biomaterials: modulating the autofluorescence of silk.

    PubMed

    Neo, Puay Yong; Tan, Daryl Jian-An; Shi, Pujiang; Toh, Siew Lok; Goh, James Cho-Hong

    2015-02-01

    Silk is a versatile and established biomaterial for various tissue engineering purposes. However, it also exhibits strong autofluorescence signals-thereby hindering fluorescence imaging analysis of cells and proteins on silk-derived biomaterials. Sudan Black B (SB) is a lysochrome dye commonly used to stain lipids in histology. It has also been reported to be able to quench autofluorescence of tissues in histology and has been tested on artificial biomedical polymers in recent years. It was hypothesized that SB would exert similar quenching effects on silk, modulating the autofluorescence signals, and thereby enabling improved imaging analysis of cells and molecules of interests. The quenching effect of SB on the intrinsic fluorescence properties of silk and on commercial fluorescent dyes were first investigated in this study. SB was then incorporated into typical fluorescence-based staining protocols to study its effectiveness in improving fluorescence-based imaging of the cells and proteins residing with the silk-based biomaterials. Silk processed into various forms of biomaterials (e.g., films, sponges, fibers, and electrospun mats) was seeded with cells and cultured in vitro. At sacrificial time points, specimens were harvested, fixed, and prepared for fluorescence staining. SB, available commercially as a powder, was dissolved in 70% ethanol (0.3% [w/v]) to form staining solutions. SB treatment was introduced at the last step of typical immunofluorescence staining protocols for 15-120?min. For actin staining protocols by phalloidin toxin, SB staining solutions were added before and after permeabilization with Triton-X for 15-30?min. Results showed that ideal SB treatment duration is about 15?min. Apart from being able to suppress the autofluorescence of silk, this treatment duration was also not too long to adversely affect the fluorescent labeling probes used. The relative improvement brought about by SB treatment was most evident in the blue and green emission wavelengths compared with the red emission wavelength. This study has showed that the use of SB is a cost and time effective approach to enhance fluorescence-based imaging analyses of cell-seeded silk biomaterials, which otherwise would have been hindered by the unmodulated autofluorescence signals. PMID:25050876

  4. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James E., Jr.; Cobb, E.D.; Kilpatrick, F.A.

    1984-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The outstanding characteristics of dye tracing are: (1) the low detection and measurement limits, and (2) the simplicity and accuracy of measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a general guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section is included on aerial photography because of its possible use to supplement ground-level fluorometry. (USGS)

  5. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James F.; Cobb, Ernest D.; Kilpatrick, F.A.

    1986-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

  6. Fluorometric procedures for dye tracing

    USGS Publications Warehouse

    Wilson, James F.

    1968-01-01

    This manual describes the current fluorometric procedures used by the U.S. Geological Survey in dye tracer studies such as time of travel, dispersion, reaeration, and dilution-type discharge measurements. The advantages of dye tracing are (1) low detection and measurement limits and (2) simplicity and accuracy in measuring dye tracer concentrations using fluorometric techniques. The manual contains necessary background information about fluorescence, dyes, and fluorometers and a description of fluorometric operation and calibration procedures as a guide for laboratory and field use. The background information should be useful to anyone wishing to experiment with dyes, fluorometer components, or procedures different from those described. In addition, a brief section on aerial photography is included because of its possible use to supplement ground-level fluorometry.

  7. Quick Stain Removal Guide 

    E-print Network

    Brown, Pamela J.

    1998-07-29

    . Avoid using a rubbing motion. Launder the whole item after treating. Laundry products Soaps are mild cleansers that come in granules, which are used for lightly soiled and delicate items, or bars, which are good for pretreating heavy soils... and stains before laundering. Avoid harsh rubbing with the bar. L-5199 3-98 *Extension Consumer Science Specialist; The Texas A&M University System Pamela J. Brown* You can prevent many of these problems if you: ? Empty all pockets and close zippers...

  8. Blood stain pattern analysis

    Microsoft Academic Search

    O. Peschel; S. N. Kunz; M. A. Rothschild; E. Mützel

    2011-01-01

    Bloodstain pattern analysis (BPA) refers to the collection, categorization and interpretation of the shape and distribution\\u000a of bloodstains connected with a crime. These kinds of stains occur in a considerable proportion of homicide cases. They offer\\u000a extensive information and are an important part of a functional, medically and scientifically based reconstruction of a crime.\\u000a The following groups of patterns can

  9. Removing Stains from Washable Fabrics. 

    E-print Network

    Beard, Ann Vanderpoorten

    1988-01-01

    , then rinse. If color or texture is affected, do not use this product to treat the stain. ? When treating a spot, place it face down on white paper towels or a soft, clean, white cloth pad. Apply stain remover to the wrong side of the stain so... that the stain will be forced off the surface and not through the fabric. An eyedropper is useful for applying removers. Replace the towels or cloth pad frequently to prevent the stain from transfer ring back onto the fabric. ? Sponge by applying stain...

  10. Detection of carcinoembryonic antigen using single-domain or full-size antibodies stained with quantum dot conjugates.

    PubMed

    Rousserie, Gilles; Grinevich, Regina; Brazhnik, Kristina; Even-Desrumeaux, Klervi; Reveil, Brigitte; Tabary, Thierry; Chames, Patrick; Baty, Daniel; Cohen, Jacques H M; Nabiev, Igor; Sukhanova, Alyona

    2015-06-01

    Compact single-domain antibodies (sdAbs) are nearly 13 times smaller than full-size monoclonal antibodies (mAbs) and have a number of advantages for biotechnological applications, such as small size, high specificity, solubility, stability, and great refolding capacity. Carcinoembryonic antigen (CEA) is a tumor-associated glycoprotein expressed in a variety of cancers. Detection of CEA on the tumor cell surface may be carried out using anti-CEA antibodies and conventional fluorescent dyes. Semiconductor quantum dots (QDs) are brighter and more photostable than organic dyes; they provide the possibility for labeling of different recognition molecules with QDs of different colors but excitable with the same wavelength of excitation. In this study, the abilities for specific detection of CEA expressed by tumor cells with anti-CEA sdAbs biotinylated in vitro and in vivo, as well as with anti-CEA mAbs biotinylated in vitro, were compared using flow cytometry and the conjugates of streptavidin with QDs (SA-QDs). The results demonstrated that either in vitro or in vivo biotinylated anti-CEA sdAbs are more sensitive for cell staining compared to biotinylated anti-CEA mAbs. The data also show that simultaneous use of biotinylated sdAbs with highly fluorescent SA-QDs can considerably improve the sensitivity of detection of CEA on tumor cell surfaces. PMID:25766579

  11. A time differential staining technique coupled with full bilateral gill denervation to study ionocytes in fish.

    PubMed

    Tzaneva, Velislava; Perry, Steve F

    2015-01-01

    Branchial ionocytes (ICs) are the functional units for ionic regulation in fish. In adults, they are found on the filamental and lamellar epithelia of the gill where they transport ions such as Na+, Cl- and Ca2+ via a variety of ion channels, pumps and exchangers. The teleost gill is extrinsically innervated by the facial (VI), glossopharyngeal (IX) and vagus (X) nerves. The IX and X nerves are also the extrinsic source of branchial IC innervation. Here, two techniques used to study the innervation, proliferation and distribution of ICs are described: a time differential staining technique and a full bilateral gill denervation technique. Briefly, goldfish are exposed to a vital mitochondrion-specific dye (e.g., MitoTracker Red) which labels (red fluorescence) pre-existing ICs. Fish were either allowed to recover for 3-5 days or immediately underwent a full bilateral gill denervation. After 3-5 days of recovery, the gills are harvested and fixed for immunohistochemistry. The tissue is then stained with an ?-5 primary antibody (targets Na+/K+ ATPase containing cells) in conjunction with a secondary antibody that labels all (both new and pre-existing) ICs green. Using confocal imaging, it was demonstrated that pre-existing ICs appear yellow (labelled with both a viable mitochondrion-specific dye and ?-5) and new ICs appear green (labelled with ?-5 only). Both techniques used in tandem can be applied to study the innervation, proliferation and distribution of ICs on the gill filament when fish are exposed to environmental challenges. PMID:25868043

  12. 7.G Stained Glass

    NSDL National Science Digital Library

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The students in Mr. Rivera's art class are designing a stained-glass window to hang in the school entryway. The window will be 2 feet tall and 5 feet w...

  13. Hair Dyes

    Microsoft Academic Search

    David Basketter; Jeanne Duus Johansen; John McFadden; Heidi Sřsted

    \\u000a Contact dermatitis to hair dye ingredients have been known since human started dyeing with aromatic amines like p-phenylenediamine\\u000a (PPD). Hair dye allergy may cause severe clinical reactions, with edema of the face, eyelids, and scalp. More moderate reactions\\u000a such as erythema, suppuration, and ulceration, typically at the scalp margin, on the ears, and sometimes with evidence of\\u000a eczema where the

  14. Reduced Fluorescence Quenching of Cyclodextrin-Acetylene Dye Rotaxanes Jong S. Park, James N. Wilson, Kenneth I. Hardcastle, Uwe H. F. Bunz,*, and

    E-print Network

    Srinivasarao, Mohan

    ; the R-CD hovers over one end of the dye molecule, leaving the other end uncovered. Aromatic protons from are observed from the aromatic protons d and c of the dumbbell to protons H3 and H4 of the R-CD, and from b

  15. Length of stain dosimeter

    NASA Technical Reports Server (NTRS)

    Lueck, Dale E. (inventor)

    1994-01-01

    Payload customers for the Space Shuttle have recently expressed concerns about the possibility of their payloads at an adjacent pad being contaminated by plume effluents from a shuttle at an active pad as they await launch on an inactive pad. As part of a study to satisfy such concerns a ring of inexpensive dosimeters was deployed around the active pad at the inter-pad distance. However, following a launch, dosimeters cannot be read for several hours after the exposure. As a consequence factors such as different substrates, solvent systems, and possible volatilization of HCl from the badges were studied. This observation led to the length of stain (LOS) dosimeters of this invention. Commercial passive LOS dosimeters are sensitive only to the extent of being capable of sensing 2 ppm to 20 ppm if the exposure is 8 hours. To map and quantitate the HCl generated by Shuttle launches, and in the atmosphere within a radius of 1.5 miles from the active pad, a sensitivity of 2 ppm HCl in the atmospheric gases on an exposure of 5 minutes is required. A passive length of stain dosimeter has been developed having a sensitivity rendering it capable of detecting a gas in a concentration as low as 2 ppm on an exposure of five minutes.

  16. On the interaction of triarylmethane dye crystal violet with LAPONITE® clay: using mineral nanoparticles to control the dye photophysics.

    PubMed

    Ley, C; Brendlé, J; Walter, A; Jacques, P; Ibrahim, A; Allonas, X

    2015-06-24

    The combination of an organic dye with clays leads to very interesting hybrid materials with original properties. It is found that LAPONITE® nanoparticles have an impact on the photophysical properties of the crystal violet dye inducing a kinetic stabilization of its excited emissive state, turning this nonemissive dye into a fluorescent compound. PMID:26028222

  17. Development of novel fluorescent probe- protein protected gold nanoclusters for biomedical applications

    NASA Astrophysics Data System (ADS)

    Rostamzadeh Renani, Fatemeh

    This dissertation explores photo-physics, fluorescence polarization properties; resonance energy transfer (RET) probes, and cellular imaging applications for novel fluorescent probe BSA Au clusters By Rayleigh scattering subtraction from extinction spectrum, we found that BSA Au clusters shows peak absorption around 360 nm and shoulder near 500 nm. Peak fluorescence emission lies around 650nm. The fluorescence quantum yield was determined to be 0.06%, while it displayed long fluorescence lifetime of 1.8 mus. BSA Au clusters show stable fluorescence properties and resistance to unfolding and quenching with varying pH, temperature, quencher and denaturant concentration. Moreover, BSA Au clusters shows distinct fluorescence polarization behavior as measured in solvents of different viscosity. The BSA Au cluster, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight and developing fluorescence polarization immunoassays. BSA Au clusters suffer from several disadvantages such as low quantum efficiency (typically near 6%) and broad emission spectrum (540nm to 800nm). We describe an approach by developing RET probes to enhance the apparent brightness more than 2 fold of BSA Au clusters by linking it with high extinction donor organic dye pacific blue (PB). Moreover, we prepared another conjugate of BSA Au clusters with the near infra-red (NIR) dye Dylight 750 (Dy750), where BSA Au cluster act as a donor to Dy750, showing 46% transfer efficiency to the NIR dye Dy750 with long lifetime component in acceptor decay through RET. Transferring energy from BSA Au cluster to Dy750 will have a RET probe with narrow emission spectrum and long lifetime component which can be explored in imaging applications. Furthermore, herein I describe the use of these long lived BSA Au clusters in cellular and tissue imaging applications. In first approach, I have shown its utility as FLIM probe as well as a time gated intensity imaging probe. In second approach we have shown the one can increase the intensity of long lived BSA Au cluster in cells without increasing the short lived auto-fluorescence background thereby increasing signal to noise ratio at least by 15 times. Furthermore, by applying gated detection strategy to multipulse excitation imaging experiment we increased the signal to noise ratio to 30, a dramatic improvement in contrast for low fluorescence quantum yield dye. In summary, BSA Au clusters can be used as a fluorescent cellular stain advancing the bioimaging technology via their long fluorescence lifetime.

  18. Near Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    PubMed Central

    Bwambok, David K.; El-Zahab, Bilal; Challa, Santhosh K.; Li, Min; Chandler, Lin; Baker, Gary A.; Warner, Isiah M.

    2009-01-01

    Herein, we report on near infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 °C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS. PMID:19928781

  19. Near-infrared fluorescent nanoGUMBOS for biomedical imaging.

    PubMed

    Bwambok, David K; El-Zahab, Bilal; Challa, Santhosh K; Li, Min; Chandler, Lin; Baker, Gary A; Warner, Isiah M

    2009-12-22

    Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 degrees C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS. PMID:19928781

  20. Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    SciTech Connect

    Bwambok, David [Louisiana State University; El-Zahab, Bilal [Lousianna State University; Challa, Santhosh [Louisiana State University; Li, Min [Lousianna State University; Chandler, Lin [Horiba Jobin Yvon Inc.; Baker, Gary A [ORNL; Warner, Isiah M [ORNL

    2009-01-01

    Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

  1. Labeling TiO2 Nanoparticles with Dyes for Optical Fluorescence Microscopy and Determination of TiO2-DNA Nanoconjugate Stability

    PubMed Central

    Thurn, Kenneth T.; Paunesku, Tatjana; Wu, Aiguo; Brown, Eric M.B.; Lai, Barry; Vogt, Stefan; Maser, Jörg; Aslam, Mohammed; Dravid, Vinayak; Bergan, Raymond; Woloschak, Gayle

    2009-01-01

    Visualization of nanoparticles without intrinsic optical fluorescence properties is a significant problem when performing intracellular studies. Such is the case with titanium dioxide (TiO2) nanoparticles. These nanoparticles, when electronically linked to single stranded DNA oligonucleotides, have been proposed to be used both as gene knockout devices and as possible tumor imaging agents. By interacting with complementary target sequences in living cells, these photo-inducible TiO2-DNA nanoconjugates have the potential to cleave intracellular genomic DNA in a sequence specific and inducible manner. The nanoconjugates also become detectable by magnetic resonance imaging (MRI) with the addition of gadolinium Gd(III) contrast agents. Herein we describe two approaches for labeling TiO2 nanoparticles and TiO2-DNA nanoconjugates with optically fluorescent agents. This permits, for the first time, direct quantification of fluorescently labeled TiO2 nanoparticle uptake in a large population of living cells (>104 cells). X-Ray Fluorescence Microscopy (XFM) was combined with fluorescent microscopy to determine the relative intracellular stability of the nanoconjugates. It was also used to quantify intracellular nanoparticles. Imaging the DNA component of the TiO2-DNA nanoconjugate by fluorescent confocal microscopy within the same cell showed an overlap with the titanium signal as mapped by XFM. This strongly implies the intracellular integrity of the TiO2-DNA nanoconjugates in malignant cells. PMID:19242946

  2. Fluorescence quenching N,N-bis(2,6-dimethylphenyl)-3,4:9,10-perylenetetracarboxylic diimide (BDPD) laser dye by colloidal silver nanoparticles.

    PubMed

    El-Daly, Samy A; Salem, Ibrahim A; Hussein, Mahmoud A; Asiri, Abdullah M

    2015-03-01

    The fluorescence quenching N,N-bis(2,6-dimethylphenyl)-3,4:9,10-perylenetetra-carboxylic diimide (BDPD) by colloidal silver nanoparticles (AgNPs) was studied in methanol and ethylene glycol by steady state fluorescence measurements. The Stern-Volmer quenching rate constant (Ksv) was calculated as 8.1?×?10(8) and 8.22?×?10(8) M(-1) in methanol and ethylene glycol respectively. Taking the fluorescence lifetime of BDPD in the absence of silver nanoparticles as 3.2 ns, the values of the fluorescence quenching rate constants (kq?=?Ksv/?) are calculated as 2.54?×?10(17) and 2.56?×?10(17) M(-1) s(-1) in methanol and ethylene glycol respectively. From the data, fluorescence resonance energy transfer and / or electron transfer processes play a major role in the fluorescence quenching of BDPD by AgNPs in methanol and low concentrations of Ag NPs in ethylene glycol. The static quenching rate constant in ethylene glycol was calculated by modified Stern-Volmer equation as V?=?8.86?×?10(9) M(-1). For dynamic quenching, the radius of quenching sphere volume r values were found to be 68.3 and 70.6 nm in ethanol and ethylene glycol, respectively. For static quenching in ethylene glycol the effective radius of quenching sphere action (kinetic radius) was calculated as r?=?152 nm. PMID:25656068

  3. The fluorescence properties and binding mechanism of SYTOX green, a bright, low photo-damage DNA intercalating agent.

    PubMed

    Thakur, Shreyasi; Cattoni, Diego I; Nöllmann, Marcelo

    2015-07-01

    DNA intercalators are widely used in cancer therapeutics, to probe protein-DNA interactions and to investigate the statistical-mechanical properties of DNA. Here, we employ single-molecule fluorescence microscopy, magnetic tweezers, and ensemble-binding assays to investigate the fluorescence properties and binding mechanism of SYTOX green, a DNA labeling dye previously used for staining dead cells and becoming of common use for single-molecule methodologies. Specifically, we show that SYTOX green presents several advantages with respect to other dyes: (1) binds DNA rapidly and with high affinity; (2) has a good signal-to-noise ratio even at low concentrations; (3) exhibits a low photobleaching rate; and (4) induces lower light-induced DNA degradation. Finally, we show that SYTOX green is a DNA intercalator that binds DNA cooperatively with a binding site of 3.5 bp, increasing the DNA length upon binding by 43 %, while not affecting its mechanical properties. PMID:26024786

  4. Selective gray matter staining of human brain slices: optimized use of cadaver materials.

    PubMed

    Loftspring, M C; Smanik, J; Gardner, C; Pixley, S K

    2008-06-01

    We report a novel staining technique for human brain slices that distinguishes clearly gray from white matter. Previously described techniques using either Prussian blue (Berlin blue) or phthalocyanine dyes usually have included a hot phenol pretreatment to prevent white matter staining. The technique we describe here does not require hot phenol pretreatment and allows the use of brains stored for postmortem periods of one to two years prior to staining. Our technique involves staining with copper(II) phthalocyanine-tetrasulfonic acid tetrasodium salt 1% in water for 2 h followed by acetic acid treatment; this produces excellent blue staining of gray matter with little white matter staining. The stained brain slices are excellent for teaching human brain anatomy and/or pathology, or for research purposes. PMID:18946763

  5. SYPRO Orange and SYPRO Red Protein Gel StainsMP 06650 Revised: 17-January-2003

    E-print Network

    Lebendiker, Mario

    can be visualized using a standard 300 nm UV transilluminator or a laser scanner (Figure 2). $ Low somewhat lower back- ground fluorescence. Both dyes are efficiently excited by UV or broadband illumination a laser scanner, choose the dye with the excitation maximum most closely matching the excitation light

  6. Gram's Stain Does Not Cross the Bacterial Cytoplasmic Membrane.

    PubMed

    Wilhelm, Michael J; Sheffield, Joel B; Sharifian Gh, Mohammad; Wu, Yajing; Spahr, Christian; Gonella, Grazia; Xu, Bolei; Dai, Hai-Lung

    2015-07-17

    For well over a century, Hans Christian Gram's famous staining protocol has been the standard go-to diagnostic for characterizing unknown bacteria. Despite continuous and ubiquitous use, we now demonstrate that the current understanding of the molecular mechanism for this differential stain is largely incorrect. Using the fully complementary time-resolved methods: second-harmonic light-scattering and bright-field transmission microscopy, we present a real-time and membrane specific quantitative characterization of the bacterial uptake of crystal-violet (CV), the dye used in Gram's protocol. Our observations contradict the currently accepted mechanism which depicts that, for both Gram-negative and Gram-positive bacteria, CV readily traverses the peptidoglycan mesh (PM) and cytoplasmic membrane (CM) before equilibrating within the cytosol. We find that not only is CV unable to traverse the CM but, on the time-scale of the Gram-stain procedure, CV is kinetically trapped within the PM. Our results indicate that CV, rather than dyes which rapidly traverse the PM, is uniquely suited as the Gram stain. PMID:25879387

  7. ENHANCED DAPI STAINING FOR CRYPTOSPORIDIUM IN WATER SAMPLES

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Method 1623 is used to detect and quantify the presence of {ital Cryptosporidium} spp. oocysts in water. The protocol consists of concentrating a sample, staining this concentrate with a fluorescent antibody, and examining the sample mi...

  8. Confusion over live/dead stainings for the detection of vital microorganisms in oral biofilms - which stain is suitable?

    PubMed Central

    2014-01-01

    Background There is confusion over the definition of the term “viability state(s)” of microorganisms. “Viability staining” or “vital staining techniques” are used to distinguish live from dead bacteria. These stainings, first established on planctonic bacteria, may have serious shortcomings when applied to multispecies biofilms. Results of staining techniques should be compared with appropriate microbiological data. Discussion Many terms describe “vitality states” of microorganisms, however, several of them are misleading. Authors define “viable” as “capable to grow”. Accordingly, staining methods are substitutes, since no staining can prove viability. The reliability of a commercial “viability” staining assay (Molecular Probes) is discussed based on the corresponding product information sheet: (I) Staining principle; (II) Concentrations of bacteria; (III) Calculation of live/dead proportions in vitro. Results of the “viability” kit are dependent on the stains’ concentration and on their relation to the number of bacteria in the test. Generally this staining system is not suitable for multispecies biofilms, thus incorrect statements have been published by users of this technique. To compare the results of the staining with bacterial parameters appropriate techniques should be selected. The assessment of Colony Forming Units is insufficient, rather the calculation of Plating Efficiency is necessary. Vital fluorescence staining with Fluorescein Diacetate and Ethidium Bromide seems to be the best proven and suitable method in biofilm research. Regarding the mutagenicity of staining components users should be aware that not only Ethidium Bromide might be harmful, but also a variety of other substances of which the toxicity and mutagenicity is not reported. Summary –?The nomenclature regarding “viability” and “vitality” should be used carefully. –?The manual of the commercial “viability” kit itself points out that the kit is not suitable for natural multispecies biofilm research, as supported by an array of literature. –?Results obtained with various stains are influenced by the relationship between bacterial counts and the amount of stain used in the test. Corresponding vitality data are prone to artificial shifting. –?As microbiological parameter the Plating Efficiency should be used for comparison. –?Ethidium Bromide is mutagenic. Researchers should be aware that alternative staining compounds may also be or even are mutagenic. PMID:24410850

  9. Fluorescent dye technique as an alternative to gfp-labeled plasmid for visualization of Escherichia coli O157:H7 cells on romaine lettuce leaves following sanitizer treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The task of imaging Escherichia coli O157:H7 cells on artificially inoculated produce often requires genetic modification of the cells through the introduction of gfp-labeled plasmid. However, these modified cells do not behave as the parent cells and the auto fluorescence of lettuce leaves interfe...

  10. Ultra Pseudo-Stokes Shift Near Infrared Dyes Based on Energy Transfer

    PubMed Central

    Han, Junyan; Engler, Anthony; Qi, Jianjun

    2012-01-01

    Novel fluorescent dyes with ultra pseudo-Stokes Shift were prepared based on intramolecular energy transfer between a fluorescent donor and a Cyanine-7 acceptor. The prepared dyes could be excited at ~ 320 nm and emit fluorescence at ~ 780 nm. The energy transfer efficiencies of the system are found to be > 94 %. PMID:23316093

  11. Efficient Blind Spectral Unmixing of Fluorescently Labeled Samples Using Multi-Layer Non-Negative Matrix Factorization

    PubMed Central

    Zudaire, Isabel; Ortiz-de-Solorzano, Carlos

    2013-01-01

    The ample variety of labeling dyes and staining methods available in fluorescence microscopy has enabled biologists to advance in the understanding of living organisms at cellular and molecular level. When two or more fluorescent dyes are used in the same preparation, or one dye is used in the presence of autofluorescence, the separation of the fluorescent emissions can become problematic. Various approaches have been recently proposed to solve this problem. Among them, blind non-negative matrix factorization is gaining interest since it requires little assumptions about the spectra and concentration of the fluorochromes. In this paper, we propose a novel algorithm for blind spectral separation that addresses some of the shortcomings of existing solutions: namely, their dependency on the initialization and their slow convergence. We apply this new algorithm to two relevant problems in fluorescence microscopy: autofluorescence elimination and spectral unmixing of multi-labeled samples. Our results show that our new algorithm performs well when compared with the state-of-the-art approaches for a much faster implementation. PMID:24260120

  12. Dye Painting with Fiber Reactive Dyes

    ERIC Educational Resources Information Center

    Benjamin-Murray, Betsy

    1977-01-01

    In her description of how to use dyes directly onto fabrics the author lists materials to be used, directions for mixing dyes, techniques for applying dyes, references for additional reading and sources for dye materials. Preceding the activity with several lessons in design and other textile techniques with the dye process will ensure a…

  13. Retinal tolerance to dyes

    PubMed Central

    Lüke, C; Lüke, M; Dietlein, T S; Hueber, A; Jordan, J; Sickel, W; Kirchhof, B

    2005-01-01

    Background: Dye solutions for intraoperative staining of epiretinal membranes and the internal limiting membrane improve the visualisation of these thin structures and facilitate their removal. In the present study the authors investigated the effects of indocyanine green 0.05%, trypan blue 0.15%, and patent blue 0.48% on bovine retinal function. Methods: Bovine retina preparations were perfused with a standard solution and the electroretinogram (ERG) was recorded repeatedly. After recording of stable ERG amplitudes the nutrient solution was substituted by one of the dye solutions. The duration of retinal exposure to a dye solution was varied between 10 seconds and 2 minutes. Thereupon, the preparation was reperfused with standard solution for at least 115 minutes. The percentage of b-wave reduction after exposition was calculated. Results: Reductions of the b-wave amplitude were found for each dye solution tested. The effects after application of patent blue and indocyanine green were completely reversible within the recovery time for an exposure period of 60 and 30 seconds, respectively. The application of trypan blue lead to a loss of the b-wave when the retina was exposed for 15 seconds or longer. This effect was only partly reversible within the recovery time. Conclusion: The ERG showed toxic effects of trypan blue after a short period of retinal exposure. The intraocular application of trypan blue should be limited to selected cases. However, intraocular application of indocyanine green and patent blue in a sufficient concentration and taking account of a short period of retinal exposure seems possible. PMID:16113379

  14. Measurement of Mitochondrial Membrane Potential Using Fluorescent Rhodamine Derivatives

    Microsoft Academic Search

    Russell C. Scaduto; Lee W. Grotyohann

    1999-01-01

    We investigated the use of rhodamine 123 (R123), tetramethylrhodamine methyl ester (TMRM), and tetramethylrhodamine ethyl ester (TMRE) as fluorescent probes to monitor the membrane potential of mitochondria. These indicator dyes are lipophilic cations accumulated by mitochondria in proportion to ??. Upon accumulation, all three dyes exhibit a red shift in both their absorption and fluorescence emission spectra. The fluorescence intensity

  15. Silver stain for electron microscopy

    NASA Technical Reports Server (NTRS)

    Corbett, R. L.

    1972-01-01

    Ammoniacal silver stain used for light microscopy was adapted advantageously for use with very thin biological sections required for electron microscopy. Silver stain can be performed in short time, has more contrast, and is especially useful for low power electron microscopy.

  16. Staining Associated with Oxhorn Bucida (\\

    Microsoft Academic Search

    DOUGLAS L. CALDWELL

    ADDITIONAL INDEX WORDS. Characoma nilotica, Eriophyes, caterpillars, Combretaceae, Noctuidae, galls Oxhorn bucida (Bucida buceras L.), also known as black olive, is used as a shade tree in southern Florida landscapes and street plantings. One negative aspect associated with this tree is a rusty staining of driveways and other objects beneath the canopy. This report documents that the objectionable staining is

  17. Molecular cytogenetics using fluorescence in situ hybridization

    SciTech Connect

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  18. Acid polysaccharide content of frog rod outer segments determined by metachromatic toluidine blue staining

    Microsoft Academic Search

    R. E. Drzymala; P. A. Liebman; G. Romhanyi

    1982-01-01

    Sulfonation of periodate-oxidized vicinal hydroxyl groups on a polysaccharide backbone allows binding of toluidine blue (aldehyde bisulfite-toluidine blue or ABT staining) with a concurrent metachromatic shift of the dye's absorption peak from 630 nm (monomer) to 580 nm (isolated dimer interaction at vicinal sulfonate groups) or 540 nm (dye polymer interaction). A molar absorptivity of 2.358±0.134×104 at 540 nm for

  19. FRET Enhanced Fluorescent Nanodiamonds

    PubMed Central

    Fudala, Rafal; Raut, Sangram; Maliwal, Badri P.; Zerda, T. W.; Gryczynski, Ignacy; Simanek, Eric E; Borejdo, Julian; Rich, Ryan; Akopova, Irina; Gryczynski, Zygmunt

    2013-01-01

    Fluorescent nanodiamonds (FNDs) are one of the new and very promising biocompatible nanomaterials that can be used both as fluorescence imaging agent and a highly versatile platform for controlled functionalization to target and deliver a wide spectrum of therapeutic agents. Among the remarkable fluorescence properties are excellent photo-stability, emission between 600–700nm, quantum yield of 1 and moderately long fluorescence lifetimes. However the low absorption cross section of fluorescent (N-V)? centers limits FNDs' brightness. In this work we show that an approach based on the Forster resonance energy transfer (FRET) may significantly enhance the fluorescence signal observed from a single ND. We demonstrate that organic dyes (fluorophores) attached to the FND surface can efficiently transfer the excitation energy to (N-V)? centers. Multiple dyes positioned in close proximity to the ND facile surface may serve as harvesting antennas transferring excitation energy to the fluorescent centers. We propose that, with the help of some of the functional groups present on the FND surface, we can either directly link flurophores or use scalable dendrimer chemistry to position many organic dyes at a calibrated distance. Also, the remaining multiple functional groups will be still available for particle targeting and drug delivery. This opens a new way for designing a new type of theranostics particles of ultra-high brightness, high photostability, specific targeting, and high capacity for drug delivery. PMID:22394126

  20. Monofunctional Carbocyanine Dyes for Bio- and Bioorthogonal Conjugation

    PubMed Central

    Shao, Fangwei; Weissleder, Ralph; Hilderbrand, Scott A

    2009-01-01

    A facile synthetic route to prepare monofunctional carbocyanine dyes for biological application is developed. Three pentamethine carbocyanine dyes have been successfully modified with a variety of functional groups such as: carboxylic acids, azides, or alkynes. The new dyes are characterized by strong NIR fluorescence emission, high extinction coefficients and good quantum yields. The azide and alkyne dyes have potential utility as components in bioorthogonal labeling schemes via [2+3] dipolar cycloaddition “click” reactions. The application of one derivative, CyAM-5 alkyne, for bioorthogonal labeling is demonstrated. Fluorescence microscopy shows coupling of CyAM-5 alkyne to Chinese hamster ovary (CHO) cells preincubated with azide modified glycans. PMID:19053316

  1. Measurement of time of travel in streams by dye tracing

    USGS Publications Warehouse

    Kilpatrick, F.A.; Wilson, James F.

    1989-01-01

    The use of fluorescent dyes and tracing techniques provides a means for measuring the time-of-travel and dispersion characteristics of steady and gradually varied flow in streams. Measurements of the dispersion and concentration of dyes give insight into the behavior of soluble contaminants that may be introduced into a stream. This manual describes methods of measuring time of travel of water and waterborne solutes by dye tracing. The fluorescent dyes, measuring equipment used, and the field and laboratory procedures are also described. Methods of analysis and presentation to illustrate time-oftravel and dispersion characteristics of streams are provided.

  2. Chemical enhancement of footwear impressions in blood on fabric - part 1: protein stains.

    PubMed

    Farrugia, Kevin J; Savage, Kathleen A; Bandey, Helen; Nic Daéid, Niamh

    2011-09-01

    A range of protein stains were utilised for the enhancement of footwear impressions on a variety of fabric types of different colours with blood as a contaminant. A semi-automated stamping device was used to deliver test impressions at a set force to minimise the variability between impressions; multiple impressions were produced and enhanced by each reagent to determine the repeatability of the enhancement. Results indicated that while most protein stains used in this study successfully enhanced impressions in blood on light coloured fabrics, background staining caused interference on natural fabrics. Enhancement on dark coloured fabrics was only achieved using fluorescent protein stains, as non-fluorescent protein stains provided poor contrast. A further comparison was performed with commercially available protein staining solutions and solutions prepared within the laboratory from the appropriate chemicals. Both solutions performed equally well, though it is recommended to use freshly prepared solutions whenever possible. PMID:21889106

  3. Theory of pulsed dye lasers including dye-molecule rotational relaxation

    SciTech Connect

    Haas, R.A.; Rotter, M.D. (Department of Applied Science, University of California, Davis-Livermore, L-794, P.O. Box 808, Livermore, California 94550 (US) Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550)

    1991-02-01

    In this paper a phenomenological semiclassical theory of pulsed-laser-pumped dye-laser light amplifiers is presented. The theory accounts for the broadband radiation absorption and emission characteristics of dye molecules in liquid solvents. Dye-molecule fluorescence, vibrational, rotational, and electric polarization relaxation processes are represented by phenomenological relaxation rates. In general, it is found that due to dye-molecule rotational relaxation the laser-pumped dye medium is optically anisotropic. The pump- and dye-laser beams propagate through the dye medium as essentially transverse electromagnetic waves whose amplitude and polarization state changes. The theory is applicable to pulse durations {tau}{approx lt}10--100 ns including the ultrashort pulse regime. The regime {tau}{approx gt}1 ps in which the pump- and dye-laser pulse lengths are long compared to the dye-molecule vibrational and electric polarization relaxation times is considered in detail. Amplification of partially polarized quasimonochromatic light is described by a self-consistent set of equations for the components of the pump- and dye-laser light coherency matrices and the orientation populations of the lowest vibronic levels of the dye molecule's {ital S}{sub 0} and {ital S}{sub 1} electronic states.

  4. Removing Stains from Washable Fabrics.

    E-print Network

    Beard, Ann Vanderpoorten

    1988-01-01

    ) . are set by alkalies such as ammonia; others (blood and vomit) are set by alcohol. Avoid using chemi cals unless you are certain they will work on the stain you are treating. ? Never mix stain removers, especially ammonia and bleach. If more than one... of a ring. Use small amounts of re mover with quick light strokes. ? Flush the stain away by adding remover slowly to the spot from the wrong side of the fabric. ? When using any bleach, do not try to bleach just a spot on a colored garment. Bleach...

  5. Dyeing properties of natural dyes extracted from eucalyptus

    Microsoft Academic Search

    S. Ali; N. Nisar; T. Hussain

    2007-01-01

    A natural dye was extracted from Eucalyptus camaldulensis and was used to dye cotton by direct dyeing method at different dyeing conditions. Then, the fastness properties of dyeing with different dyeing techniques were compared.

  6. Distamycin A\\/DAPI staining of heterochromatin in male meiosis of man

    Microsoft Academic Search

    T. Haaf; H. Miiller; M. Schmid

    1986-01-01

    The sequential staining with distamycin A\\/DAPI provides an ideal method for studying the behaviour of heterochromatic regions in human male meiosis. The various meiotic and postmeiotic stages were found to have different staining qualities. Although all heterochromatic regions in human pachytene cells show specific DA\\/DAPI fluorescence, bright and clearly stained heterochromatic blocks can be distinguished from small DA\\/DAPI spots. Pachytene

  7. Rapid, one step staining procedures for analysis of cellular DNA and protein by single and dual laser flow cytometry

    SciTech Connect

    Crissman, H.A.; Steinkamp, J.A.

    1982-01-01

    Detailed, simplified techniques are described for simultaneous staining and analysis of DNA and protein in a number of mammalian cell types. Cell staining involves the addition of appropriate dye mixtures to unfixed or ethanol-fixed cells and subsequent analysis of cell populations in the staining reagents generally within 10 to 20 minutes. The approach is novel in that no centrifugation steps are involved during the staining procedure, thus, eliminating cell clumping and cell loss and making the procedures appropriate for samples containing limited numbers of cells. For single wavelength analysis, staining of DNA and protein in ethanol-fixed cells was accomplished with a dye solution containing propidium iodide, fluorescein isothimocyanate and RNase. After 20 minutes at room temperature cells were analyzed using the 488 nanometer (nm) laser excitation line. For dual laser analysis the following dye combinations were employed without RNase: mithramycin-rhodamine 640, mithramycin-substituted rhodamine isothiocyanate, Hoechst 33342-rhodamine 640 and Hoechst 33342-rhodamine isothiocyanate. Unfixed cells were also stained with the Hoechst 33342-rhodamine 640 dye combination. Mithramycin was excited at 457.9 nm, Hoechst 33342 at 333-363 nm, and rhodamine dyes at 568 nm. Cell types analyzed included Chinese hamster ovary cells, cultured mouse colon 26 cells, mouse embryo forelimb bud cells, and rat cell obtained by lung lavage.

  8. Haemolymph flows in the wings of pierid butterflies visualized by vital staining (insecta, lepidoptera)

    Microsoft Academic Search

    Lutz Thilo Wasserthal

    1983-01-01

    The flow of stained haemolymph was photographed in the wings of resting Pieris rapae, Pieris brassicae, and Gonepteryx rhamni under UV-radiation at definite intervals after abdominal application of fluorescent tetracycline. There is no circular route in the wing. All wing veins are supplied with stained haemolymph from their own bases without preference to single veins. In freely resting Pieris with

  9. Lenticular mitoprotection. Part A: Monitoring mitochondrial depolarization with JC-1 and artifactual fluorescence by the glycogen synthase kinase-3? inhibitor, SB216763

    PubMed Central

    Brooks, Morgan M.; Neelam, Sudha; Fudala, Rafal; Gryczynski, Ignacy

    2013-01-01

    Purpose Dissipation of the electrochemical gradient across the inner mitochondrial membrane results in mitochondrial membrane permeability transition (mMPT), a potential early marker for the onset of apoptosis. In this study, we demonstrate a role for glycogen synthase kinase-3? (GSK-3?) in regulating mMPT. Using direct inhibition of GSK-3? with the GSK-3? inhibitor SB216763, mitochondria may be prevented from depolarizing (hereafter referred to as mitoprotection). Cells treated with SB216763 showed an artifact of fluorescence similar to the green emission spectrum of the JC-1 dye. We demonstrate the novel use of spectral deconvolution to negate the interfering contributing fluorescence by SB216763, thus allowing an unfettered analysis of the JC-1 dye to determine the mitochondrial membrane potential. Methods Secondary cultures of virally transfected human lens epithelial cells (HLE-B3) were exposed to acute hypoxic conditions (approximately 1% O2) followed by exposure to atmospheric oxygen (approximately 21% O2). The fluorescent dye JC-1 was used to monitor the extent of mitochondrial depolarization upon exposure of inhibitor treatment relative to the control cells (mock inhibition) in atmospheric oxygen. Annexin V-fluorescein isothiocyanate/propidium iodide staining was implemented to determine cell viability. Results Treatment of HLE-B3 cells with SB216763 (12 µM), when challenged by oxidative stress, suppressed mitochondrial depolarization relative to control cells as demonstrated with JC-1 fluorescent dye analysis. Neither the control nor the SB216763-treated HLE-B3 cells tested positive with annexin V-fluorescein isothiocyanate/propidium iodide staining under the conditions of the experiment. Conclusions Inhibition of GSK-3? activity by SB216763 blocked mMPT relative to the slow but consistent depolarization observed with the control cells. We conclude that inhibition of GSK-3? activity by the GSK-3? inhibitor SB216763 provides positive protection against mitochondrial depolarization. PMID:23825920

  10. Imaging of nucleolar RNA in living cells using a highly photostable deep-red fluorescent probe.

    PubMed

    Zhou, Bingjiang; Liu, Weimin; Zhang, Hongyan; Wu, Jiasheng; Liu, Sha; Xu, Haitao; Wang, Pengfei

    2015-06-15

    A new crescent-shape fluorescent probe (named here as CP) that selectively stains RNA in nucleoli of living cells is prepared. CP shows a deep-red emission (658 nm) and a large Stokes shift because of the introduction of rigid-conjugated coumarin moiety into the molecular structure. Cell imaging experiments indicate that CP can rapidly stain nucleoli in living cells by binding with nucleolar RNA, showing performance superior to commercially available nucleoli dye SYTO RNASelect in terms of high photostability and selectivity. More significantly, these excellent properties together with low cytotoxicity enable CP to monitor nucleolar RNA changes during mitosis, and after treating with anti-cancer drugs cisplatin, actinomycin D and ?-amanitin. Thus, CP could be a potential tool for real-time, long-term visualization of the dynamic changes for nucleolar RNA and evaluation of the therapeutic effect for anti-cancer drugs that targeted RNA polymerase I (Pol I). PMID:25569876

  11. Ultrafast tissue staining with chemical tags.

    PubMed

    Kohl, Johannes; Ng, Julian; Cachero, Sebastian; Ciabatti, Ernesto; Dolan, Michael-John; Sutcliffe, Ben; Tozer, Adam; Ruehle, Sabine; Krueger, Daniel; Frechter, Shahar; Branco, Tiago; Tripodi, Marco; Jefferis, Gregory S X E

    2014-09-01

    Genetically encoded fluorescent proteins and immunostaining are widely used to detect cellular and subcellular structures in fixed biological samples. However, for thick or whole-mount tissue, each approach suffers from limitations, including limited spectral flexibility and lower signal or slow speed, poor penetration, and high background labeling, respectively. We have overcome these limitations by using transgenically expressed chemical tags for rapid, even, high-signal and low-background labeling of thick biological tissues. We first construct a platform of widely applicable transgenic Drosophila reporter lines, demonstrating that chemical labeling can accelerate staining of whole-mount fly brains by a factor of 100. Using viral vectors to deliver chemical tags into the mouse brain, we then demonstrate that this labeling strategy works well in mice. Thus this tag-based approach drastically improves the speed and specificity of labeling genetically marked cells in intact and/or thick biological samples. PMID:25157152

  12. EGF receptor-targeting peptide conjugate incorporating a near-IR fluorescent dye and a novel 1,4,7-triazacyclononane-based (64)Cu(II) chelator assembled via click chemistry.

    PubMed

    Viehweger, Katrin; Barbaro, Lisa; García, Karina Pombo; Joshi, Tanmaya; Geipel, Gerhard; Steinbach, Jörg; Stephan, Holger; Spiccia, Leone; Graham, Bim

    2014-05-21

    A new Boc-protected 1,4,7-triazacyclononane (TACN)-based pro-chelator compound featuring a "clickable" azidomethylpyridine pendant has been developed as a building block for the construction of multimodal imaging agents. Conjugation to a model alkyne (propargyl alcohol), followed by deprotection, generates a pentadentate ligand, as confirmed by X-ray crystallographic analysis of the corresponding distorted square-pyramidal Cu(II) complex. The ligand exhibits rapid (64)Cu(II)-binding kinetics (>95% radiochemical yield in <5 min) and a high resistance to demetalation. It may thus prove suitable for use in (64)Cu(II)-based in vivo positron emission tomography (PET). The new chelating building block has been applied to the construction of a bimodal (PET/fluorescence) peptide-based imaging probe targeting the epidermal growth factor (EGF) receptor, which is highly overexpressed on the surface of several types of cancer cells. The probe consists of a hexapeptide sequence, Leu-Ala-Arg-Leu-Leu-Thr (designated "D4"), followed by a Cys-?-Ala-?-Ala spacer, then a ?-homopropargylglycine residue with the TACN-based chelator "clicked" to its side chain. A sulfonated near-infrared (NIR) fluorescent cyanine dye (sulfo-Cy5) was introduced at the N-terminus to study the EGF receptor-binding ability of the probe by laser-fluorescence spectroscopy. Binding was also confirmed by coimmunoprecipitation methods, and an apparent dissociation constant (Kd) of ca. 10 nM was determined from radioactivity-based measurements of probe binding to two EGF receptor-expressing cell lines (FaDu and A431). The probe is shown to be a biased or partial allosteric agonist of the EGF receptor, inducing phosphorylation of Thr669 and Tyr992, but not the Tyr845, Tyr998, Tyr1045, Tyr1068, or Tyr1148 residues of the receptor, in the absence of the orthosteric EGF ligand. Additionally, the probe was found to suppress the EGF-stimulated autophosphorylation of these latter residues, indicating that it is also a noncompetitive antagonist. PMID:24758412

  13. Ultrasensitive fluorescence detection of DNA sequencing gels

    SciTech Connect

    Mathies, R.A.

    1991-01-01

    During the three years of this grant we have: (1) Developed and applied a new theory for optimizing high-sensitivity fluorescence detection. (2) Developed and patented a new high-sensitivity confocal-fluorescence laser-excited gel-scanner. (3) Applied this scanner to the development of a new class of versatile and sensitive fluorescent dyes for DNA detection. (4) Developed methods for the detection of single fluorescent molecules by fluorescence burst detection. 11 refs., 10 figs.

  14. Novel aminobenzanthrone dyes for amyloid fibril detection

    NASA Astrophysics Data System (ADS)

    Vus, Kateryna; Trusova, Valeriya; Gorbenko, Galyna; Kirilova, Elena; Kirilov, Georgiy; Kalnina, Inta; Kinnunen, Paavo

    2012-04-01

    A series of novel fluorescent aminobenzanthrone dyes have been tested for their ability to identify and characterize the oligomeric and fibrillar aggregates of lysozyme. The parameters of the dye binding to native, oligomeric and fibrillar protein have been calculated from the results of fluorimetric titration. Furthermore, several additional quantities reflecting the preference of the probe to either pre-fibrillar or fibrillar protein aggregates, have been evaluated. Based on the comparative analysis of the recovered parameters, AM4 was recommended for selective detection of protein pre-fibrillar assemblies, while the dyes AM1, AM2, AM3 were selected as the most prospective amyloid tracers.

  15. DNA nanoconjugates Labeling TiO2 Nanoparticles with Dyes for Optical

    E-print Network

    Brown, Eric

    DNA nanoconjugates Labeling TiO2 Nanoparticles with Dyes for Optical Fluorescence Microscopy. Woloschak* Visualization of nanoparticles without intrinsic optical fluorescence prop- erties) nanoparticles. These nanoparticles, when electronically linked to single-stranded DNA oligonucleotides, have

  16. Database of two-dimensional polyacrylamide gel electrophoresis of proteins labeled with CyDye DIGE Fluor saturation dye.

    PubMed

    Fujii, Kazuyasu; Kondo, Tadashi; Yokoo, Hideki; Okano, Tetsuya; Yamada, Masayo; Yamada, Tesshi; Iwatsuki, Keiji; Hirohashi, Setsuo

    2006-03-01

    CyDye DIGE Fluor saturation dye (saturation dye, GE Healthcare Amersham Biosciences) enables highly sensitive 2-D PAGE. As the dye reacts with all reduced cysteine thiols, 2-D PAGE can be performed with a lower amount of protein, compared with CyDye DIGE Fluor minimal dye (GE Healthcare Amersham Biosciences), the sensitivity of which is equivalent to that of silver staining. We constructed a 2-D map of the saturation dye-labeled proteins of a liver cancer cell line (HepG2) and identified by MS 92 proteins corresponding to 123 protein spots. Functional classification revealed that the identified proteins had chaperone, protein binding, nucleotide binding, metal ion binding, isomerase activity, and motor activity. The functional distribution and the cysteine contents of the proteins were similar to those in the most comprehensive 2-D database of hepatoma cells (Seow et al.., Electrophoresis 2000, 21, 1787-1813), where silver staining was used for protein visualization. Hierarchical clustering on the basis of the quantitative expression profiles of the 123 characterized spots labeled with two charge- and mass-matched saturation dyes (Cy3 and Cy5) discriminated between nine hepatocellular carcinoma cell lines and primary cultured hepatocytes from five individuals, suggesting the utility of saturation dye and our database for proteomic studies of liver cancer. PMID:16429455

  17. Certain tricyclic and pentacyclic-hetero nitrogen rhodol dyes

    DOEpatents

    Haugland, Richard P. (Eugene, OR); Whitaker, James E. (Eugene, OR)

    1993-01-01

    Novel fluorescent dyes based on the rhodol structure are provided. The new reagents contain functional groups capable of forming a stable fluorescent product with functional groups typically found in biomolecules or polymers including amines, phenols, thiols, acids, aldehydes and ketones. Reactive groups in the rhodol dyes include activated esters, isothiocyanates, amines, hydrazines, halides, acids, azides, maleimides, aldehydes, alcohols, acrylamides and haloacetamides. The products are detected by their absorbance or fluorescence properties. The spectral properties of the fluorescent dyes are sufficiently similar in wavelengths and intensity to fluorescein or rhodamine derivatives as to permit use of the same equipment. The dyes, however, show less spectral sensitivity to pH in the physiological range than does fluorescein, have higher solubility in non-polar solvents and have improved photostability and quantum yields.

  18. LUMINESCENCE LIFETIME INSTRUMENTATION DEVELOPMENT FOR MULTI-DYE ANALYSIS

    E-print Network

    Shadfan, Adam

    2011-08-08

    ) dyes: highly fuorescent, multicolored probes for cellular imaging, Chemistry ? A European Journal 14 (2008) 5812-5819. [14] X. Chen, X. Wang, S. Wang, W. Shi, K. Wang, H. Ma, A highly selective and sensitive fluorescence probe for the hypochlorite...

  19. Design of novel dyes towards the near-infrared 

    E-print Network

    Loudet, Aurore

    2009-05-15

    -bond energy transfer cassette featuring two fluorescein units as donor, and an aza-BODIPY dye as acceptor, was then synthesized and its preliminary spectroscopic properties examined. This cassette exhibited absorption and fluorescence characteristics that were...

  20. Water-soluble benzophenoxazine dyes: syntheses, derivatization and photophysical studies

    E-print Network

    Jose, Jiney

    2007-04-25

    -bond energy transfer cassettes. Structural modifications prevented aggregation in water and improved their fluorescence properties in water. Their absorption and emission were studied in both organic and aqueous media. Two of the three dyes have superior...

  1. The choice of a masking agent in the histochemical staining of metals

    Microsoft Academic Search

    Y. Sumi; T. Muraki; T. Suzuki

    1983-01-01

    Summary  The masking effects of standard masking agents (aminopolycarboxylic acids, carboxylic acids and phosphates) have been investigated in both test-tube experiments and tissue sections in order to ascertain the factors which must be considered when choosing a masking agent for the histochemical staining of a metal. The masking effectsin vitro were determined by spectrophotometry through the complexing of the dye Chrome

  2. Vital fluorescent labeling for confocal scanning microscopic study of living cell invasion

    NASA Astrophysics Data System (ADS)

    Wang, Allan Z.; Chen, Jian M.; Fisher, Gregory W.; Wang, Jane C.

    1997-07-01

    Invasion by cells with malignant or transformed phenotypes precedes destruction of adjacent tissue and fatal cell metastasis. State-of-the-art confocal laser scanning technology facilitates both in vitro and in vivo research into cell invasion and metastasis. In particular, studies performed with living cells yield more precise information than those with fixed cells, giving new insight into cell invasion and metastasis. We have tested a variety of vital florescent dyes and fluorogenic protease substrates in our studies of invasion of cartilage by transformed synoviocytes or osteosarcoma cells. The fluorescent dyes tested include Calcein acetoxy methyl-FITC (Calcein), Hoechst 33342 (Hoechst), CellTracker, DiI, DiO, DiD, and ethidium bromide (EB). The fluorogenic protease substrate used Meoxysuccinyl-Gly-Pro-Leu-Gly-Pro-AFC (MOS-GPLGP-AFC) for detection of collagenase activity. We found that Calcein-FITC labeling permitted the clearest direct observation of the penetration of transformed synoviocytes and osteosarcoma cells into cartilage. Even better results were obtained when chondrocyte nuclei were counter-stained with Hoechst 33342. During the invasion process, collagenase activity was observed around the synoviocyte in the cartilage matrix labeled with the fluorogenic collagenase substrate. We concluded that of the vital fluorescent dyes tested, a combined application of Calcein-FITC, Hoechst 23223, and MOS- GPLGP-AFC is most appropriate for the study of the cell invasion process.

  3. A novel protocol of whole mount electro-immunofluorescence staining

    PubMed Central

    Liu, Hongshan

    2009-01-01

    Purpose To develop a new method of whole mount immunostaining that improves the penetration of staining reagents into the cornea and decreases non-specific binding and background. Methods Adult mouse corneas were fixed overnight in 4% paraformaldehyde or a mixture of 4% paraformaldehyde and 0.2% glutaraldehyde in 0.1 M phosphate buffer, pH 7.4, at 4 °C. After washing with 0.1% Triton X-100, corneas were embedded in 1% solidified agarose in a plastic column and fluorescent staining reagents, e.g., FITC-IgG (Fluorescein isothiocyanate- immunoglobulinG) conjugates in 0.5% solidified agarose was overlaid onto the specimens. The column was directionally immersed in a submarine gel electrophoresis apparatus filled with Tris-glycine buffer (TGB, pH=7.4) and electrophoresed at 4–10 mA for 10–24 h. For comparison, conventional protocols of immune fluorescent staining were also employed. The outcomes were evaluated by confocal microscopy. Results Antibody conjugates recognizing extracellular matrix (ECM) components, integral membrane protein, and intracellular structural proteins were used in whole mount corneas. The images of confocal laser scanning microscopy (CLSM) displayed a uniform distribution pattern of keratocan in corneal stroma, which is similar to that of section-staining. Anti-?-tubulin antibodies bound to microtubes that are distributed within the whole cell body of superficial corneal epithelium cells and stromal keratocytes, but it was found perinuclear of corneal epithelial wing layers and endothelium; integral membrane protein, FAK (focal adhesion kinase), specifically labeled stromal cells of keratectomy corneas that healed for three weeks. In comparison, conventional protocols of immune fluorescent staining using the same antibody conjugates were also employed but did not yield satisfactory results. It was found that IgG conjugates examined did not readily penetrate into stroma and/or intact corneal epithelium. Phalloidin is a small molecule that can readily penetrate into deep tissue and preferentially binds to F-actin. After the whole mount electrofluorescent staining of phalloidin-rhodamine in the mouse cornea, the results were the same as conventional whole mount staining during the healing of epithelial debridement. The cytoplasmic protrusion formed by lamellipodia and filopodia can be clearly demonstrated. Conclusions These results indicate that the whole mount electro-immunofluorescent staining allows the detection of antigens in all layers of cornea, i.e., epithelium, stroma, and endothelium. PMID:19262742

  4. Digital separation of diaminobenzidine-stained tissues via an automatic color-filtering for immunohistochemical quantification.

    PubMed

    Fu, Rong; Ma, Xiaomian; Bian, Zhaoying; Ma, Jianhua

    2015-02-01

    The digital separation of diaminobenzidine (DAB)-stained tissues from hematoxylin background is an important pre-processing step to analyze immunostains. In most stain separation methods, specific color channels (for example: RGB, HSI, CMYK) or color deconvolution matrices are used to obtain different tissue contrasts between DAB- and hematoxylin-stained areas. However, these methods could produce incomplete separation or color changes because the color spectra of stains and co-localized stains overlap in histological images. Therefore, we proposed an automatic color-filtering to separate hematoxylin- and DAB-stained tissues. In implantation, the RGB images of DAB-labeled immunostains are first converted to 8-bit BN images by a mathematical translation to produce the largest contrast between brown DAB-stained tissues and blue hematoxylin-stained tissues. The first valley in the histogram revised by nonuniform quantization is set as the cut-off point to obtain a brown filter. DAB-stained tissues are accurately delineated from the background counterstain, resulting in DAB-only-image and De-DAB-image. Subsequently, a blue filter is designed in the CIE-Lab color space to further delineate the hematoxylin-stained tissues from the De-DAB-image. Finally, the average values of the remaining pixels of the De-DAB-image are set as the background color of the DAB-only-image to manage uneven dyeing and provide DAB-stained-image for adaptive immunohistochemistry quantitation. Extensive experimental results demonstrated that the proposed method has significant advantages compared with existing methods in terms of complete stain separation without changing the color in DAB-stained areas. PMID:25780744

  5. Whole Blood Cell Staining Device

    NASA Technical Reports Server (NTRS)

    Sams, Clarence F.; Clift, Vaughan L.; McDonald, Kelly E.

    2000-01-01

    An apparatus and method for staining particular cell markers is disclosed. The apparatus includes a flexible tube that is reversibly pinched into compartments with one or more clamps. Each compartment of the tube contains a separate reagent and is in selective fluid communication with adjoining compartments.

  6. Stain Free Total Protein Staining is a Superior Loading Control to ?-Actin for Western Blots

    PubMed Central

    Gilda, Jennifer E.; Gomes, Aldrin V.

    2013-01-01

    Semi-Quantification of proteins using Western blots typically involves normalization against housekeeping genes such as ?-actin. More recently, ponceau S and Coomassie blue staining have both been shown to be suitable alternatives to housekeeping genes as loading controls. Stain free total protein staining offers the advantage of no staining or destaining steps. Evaluation of the use of Stain free staining as an alternative to ?-actin or the protein stain ponceau S showed that Stain free staining was superior to ?-actin and as good as or better than ponceau S staining as a loading control for Western blots. PMID:23747530

  7. [Fluorescence development of blood fingerprint].

    PubMed

    Li, D Z; Zhang, Z L; Liu, L

    2001-10-01

    In this article we compared benzidine with derivative methods of developing blood fingerprint and put forward a new fluorescence method. Combination and nature were briefly discussed. Blood fingerprint was developed distinctly through strong oxidation agent destroying ferroheme, depositing pearl protein by blood stain activation and protein decoration method. Fifteen fluorescence agents for developing latent blood fingerprint were exploited. Development theory of blood fingerprint was discussed systematically, including all kinds of affected factors of blood fingerprint fluorescence development. The method, main characteristics and developing effect of blood stain activation and protein decoration for developing blood fingerprint were explained. PMID:12945329

  8. The hazards of DAPI photoconversion: effects of dye, mounting media and fixative, and how to minimize the problem.

    PubMed

    Jež, Mojca; Bas, Tuba; Veber, Matija; Košir, Andrej; Dominko, Tanja; Page, Raymond; Rožman, Primož

    2013-01-01

    Immunocytochemistry is a powerful tool for detection and visualization of specific molecules in living or fixed cells, their localization and their relative abundance. One of the most commonly used fluorescent DNA dyes in immunocytochemistry applications is 4',6-diamidino-2-phenylindole dihydrochloride, known as DAPI. DAPI binds strongly to DNA and is used extensively for visualizing cell nuclei. It is excited by UV light and emits characteristic blue fluorescence. Here, we report a phenomenon based on an apparent photoconversion of DAPI that results in detection of a DAPI signal using a standard filter set for detection of green emission due to blue excitation. When a sample stained with DAPI only was first imaged with the green filter set (FITC/GFP), only a weak cytoplasmic autofluorescence was observed. Next, we imaged the sample with a DAPI filter set, obtaining a strong nuclear DAPI signal as expected. Upon reimaging the same samples with a FITC/GFP filter set, robust nuclear fluorescence was observed. We conclude that excitation with UV results in a photoconversion of DAPI that leads to detection of DAPI due to excitation and emission in the FITC/GFP channel. This phenomenon can affect data interpretation and lead to false-positive results when used together with fluorochrome-labeled nuclear proteins detected with blue excitation and green emission. In order to avoid misinterpretations, extra precaution should be taken to prepare staining solutions with low DAPI concentration and DAPI (UV excitation) images should be acquired after all other higher wavelength images. Of various DNA dyes tested, Hoechst 33342 exhibited the lowest photoconversion while that for DAPI and Hoechst 33258 was much stronger. Different fixation methods did not substantially affect the strength of photoconversion. We also suggest avoiding the use of mounting medium with high glycerol concentrations since glycerol showed the strongest impact on photoconversion. This photoconversion effect cannot be avoided even when using narrow bandpass filter sets. PMID:23064788

  9. Just Dyeing to Find Out.

    ERIC Educational Resources Information Center

    Monhardt, Becky Meyer

    1996-01-01

    Presents a multidisciplinary unit on natural dyes designed to take advantage of the natural curiosity of middle school students. Discusses history of dyes, natural dyes, preparation of dyes, and the dyeing process. (JRH)

  10. Interactions of voltage-sensing dyes with membranes. II. Spectrophotometric and electrical correlates of cyanine-dye adsorption to membranes.

    PubMed Central

    Krasne, S

    1980-01-01

    The adsorption to bilayer membranes of the thiadicarbocyanine dyes, diSCn(5), has been studied as a function of the membrane's surface-charge density, the aqueous ionic strength, and the length (n) of the hydrocarbon side chain of the dye. "Probe" measurements in planar bilayers, microelectrophoresis of liposomes, and measurement of changes in dye absorbance and fluorescence in liposomes were used to study dye adsorption to membranes. These measurements indicated that the membrane:water partition coefficient for the dye monomer increases with the length of the hydrocarbon side chain. However, the formation of large aggregates in the aqueous phase also increases with increasing chain length and ionic strength so that the actual dye adsorbing to the membrane goes through a maximum at high but not at low ionic strengths. More dye adsorbs to negatively charged than neutral membranes. Membrane-bound dye spectra were easily resolved in negatively charged liposomes where it was observed that these dyes could exist as monomers, dimers, and large aggregates. For diSC1(5) a spectral peak was observed at low but not high ionic strengths (i.e. the conditions in which this dye appears to form voltage-gated channels) corresponding to small aggregates which appeared to adsorb to the membrane. Finally, the adsorption of these dyes to membranes results in more positive electrostatic potentials composed primarily of dye-induced "boundary" potentials and somewhat less of "double-layer" potentials. PMID:7260283

  11. Optofluidic ring resonator dye lasers

    NASA Astrophysics Data System (ADS)

    Sun, Yuze; Suter, Jonathan D.; Fan, Xudong

    2010-02-01

    We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

  12. Absolute tracer dye concentration using airborne laser-induced water Raman backscatter

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Swift, R. N.

    1981-01-01

    The use of simultaneous airborne-laser-induced dye fluorescence and water Raman backscatter to measure the absolute concentration of an ocean-dispersed tracer dye is discussed. Theoretical considerations of the calculation of dye concentration by the numerical comparison of airborne laser-induced fluorescence spectra with laboratory spectra for known dye concentrations using the 3400/cm OH-stretch water Raman scatter as a calibration signal are presented which show that minimum errors are obtained and no data concerning water mass transmission properties are required when the laser wavelength is chosen to yield a Raman signal near the dye emission band. Results of field experiments conducted with an airborne conical scan lidar over a site in New York Bight into which rhodamine dye had been injected in a study of oil spill dispersion are then indicated which resulted in a contour map of dye concentrations, with a minimum detectable dye concentration of approximately 2 ppb by weight.

  13. Membrane electric properties by combined patch clamp and fluorescence ratio imaging in single neurons.

    PubMed Central

    Zhang, J; Davidson, R M; Wei, M D; Loew, L M

    1998-01-01

    An experimental method has been established to measure the electric properties of a cell membrane by combination of patch clamp and dual-wavelength ratio imaging of a fluorescent potentiometric dye, 1-(3-sulfonatopropyl)-4-[beta[2-(di-n-octylamino)-6-naphthyl]vinyl ]pyridinium betaine (di-8-ANEPPS). Pairs of fluorescence images from the dye-stained membrane of neuroblastoma N1E-115 cells excited at two wavelengths were initially obtained to calculate ratio images corresponding to the resting transmembrane potential. Subsequently, a whole-cell patch was established and the membrane potential clamped to levels varying from -100 to +60 mV; at each voltage, a pair of dual-wavelength images were acquired to develop a calibration of the fluorescence ratio. Using this method, the resting potentials could accurately be measured showing that the differentiated cells were 17 mV more polarized than undifferentiated cells. The combination of electrical and optical methods can also follow changes in other membrane electric properties, such as dipole potential, and thus permit a detailed analysis of the membrane electrical properties underlying the voltage regulation of ion channels. PMID:9449308

  14. Calibrating the imaging and therapy performance of magneto-fluorescent gold nanoshells for breast cancer

    NASA Astrophysics Data System (ADS)

    Dowell, Adam; Chen, Wenxue; Biswal, Nrusingh; Ayala-Orozco, Ciceron; Giuliano, Mario; Schiff, Rachel; Halas, Naomi J.; Joshi, Amit

    2012-03-01

    Gold nanoshells with NIR plasmon resonance can be modified to simultaneously enhance conjugated NIR fluorescence dyes and T2 contrast of embedded iron-oxide nanoparticles, and molecularly targeted to breast and other cancers. We calibrated the theranostic performance of magneto-fluorescent nanoshells, and contrasted the performance of molecularly targeted and untargeted nanoshells for breast cancer therapy, employing MCF-7L and their HER2 overexpressing derivative MCF-7/HER2-18 breast cancer cells as in vitro model systems. Silica core gold nanoshells with plasmon resonance on ~810 nm were doped with NIR dye ICG and ~10 nm iron-oxide nanoparticles in a ~20 nm epilayer of silica. A subset of nanoshells was conjugated to antibodies targeting HER2. Cell viability with varying laser power levels in presence and absence of bare and HER2-targeted nanoshells was assessed by calcein and propidium iodide staining. For MCF-7L cells, increasing power resulted in increased cell death (F=5.63, p=0.0018), and bare nanoshells caused more cell death than HER2-targeted nanoshells or laser treatment alone (F=30.13, p<0.001). For MCF-7/HER2-18 cells, death was greater with HER2-targeted nanoshells and was independent of laser power. This study demonstrates the capability of magneto-fluorescent nanocomplexes for imaging and therapy of breast cancer cells, and the advantages of targeting receptors unique to cancer cells.

  15. Local tuning of organic light-emitting diode color by dye droplet application

    Microsoft Academic Search

    T. R. Hebner; J. C. Sturm

    1998-01-01

    We have demonstrated that fluorescent dyes may be introduced into previously fabricated polymer thin films by local application of a dye-containing droplet. The UV fluorescence spectra of the films and the spectra of organic light-emitting diodes made from these films can be successfully tuned by this method. The technique has been implemented by ink-jet printing of the dye droplet.

  16. Triggering of leukocytes by phase contrast in imaging cytometry with scanning fluorescence microscope (SFM)

    NASA Astrophysics Data System (ADS)

    Bocsi, József; Pierzchalski, Arkadiusz; Marecka, Monika; Malkusch, Wolf; Tárnok, Attila

    2009-02-01

    Slide-based cytometry (SBC) leads to breakthrough in cytometry of cells in tissues, culture and suspension. Carl Zeiss Imaging Solutions' new automated SFM combines imaging with cytometry. A critical step in image analysis is selection of appropriate triggering signal to detect all objects. Without correct target cell definition analysis is hampered. DNA-staining is among the most common triggering signals. However, the majority of DNA-dyes yield massive spillover into other fluorescence channels limiting their application. By microscopy objects of >5?m diameter can be easily detected by phase-contrast signal (PCS) without any staining. Aim was to establish PCS - triggering for cell identification. Axio Imager.Z1 motorized SFM was used (high-resolution digital camera, AxioCam MRm; AxioVision software: automatic multi-channel scanning, analysis). Leukocytes were stained with FITC (CD4, CD8) and APC (CD3) labelled antibodies in combinations using whole blood method. Samples were scanned in three channels (PCS/FITC/APC). Exposition-times for PCS were set as low as possible; the detection efficiency was verified by fluorescence. CD45-stained leukocytes were counted and compared to the number of PCS detected events. Leukocyte subtyping was compared with other cytometers. In focus the PCS of cells showed ring-form that was not optimal for cell definition. Out of focus PCS allows more effective qualitative and quantitative cell analyses. PCS was an accurate triggering signal for leukocytes enabling cell counting and discrimination of leukocytes from platelets. Leukocyte subpopulation frequencies were comparable to those obtained by other cytometers. In conclusion PCS is a suitable trigger-signal not interfering with fluorescence detection.

  17. Salt stains from evaporating droplets

    PubMed Central

    Shahidzadeh, Noushine; Schut, Marthe F. L.; Desarnaud, Julie; Prat, Marc; Bonn, Daniel

    2015-01-01

    The study of the behavior of sessile droplets on solid substrates is not only associated with common everyday phenomena, such as the coffee stain effect, limescale deposits on our bathroom walls , but also very important in many applications such as purification of pharmaceuticals, de-icing of airplanes, inkjet printing and coating applications. In many of these processes, a phase change happens within the drop because of solvent evaporation, temperature changes or chemical reactions, which consequently lead to liquid to solid transitions in the droplets. Here we show that crystallization patterns of evaporating of water drops containing dissolved salts are different from the stains reported for evaporating colloidal suspensions. This happens because during the solvent evaporation, the salts crystallize and grow during the drying. Our results show that the patterns of the resulting salt crystal stains are mainly governed by wetting properties of the emerging crystal as well as the pathway of nucleation and growth, and are independent of the evaporation rate and thermal conductivity of the substrates. PMID:26012481

  18. Salt stains from evaporating droplets.

    PubMed

    Shahidzadeh, Noushine; Schut, Marthe F L; Desarnaud, Julie; Prat, Marc; Bonn, Daniel

    2015-01-01

    The study of the behavior of sessile droplets on solid substrates is not only associated with common everyday phenomena, such as the coffee stain effect, limescale deposits on our bathroom walls , but also very important in many applications such as purification of pharmaceuticals, de-icing of airplanes, inkjet printing and coating applications. In many of these processes, a phase change happens within the drop because of solvent evaporation, temperature changes or chemical reactions, which consequently lead to liquid to solid transitions in the droplets. Here we show that crystallization patterns of evaporating of water drops containing dissolved salts are different from the stains reported for evaporating colloidal suspensions. This happens because during the solvent evaporation, the salts crystallize and grow during the drying. Our results show that the patterns of the resulting salt crystal stains are mainly governed by wetting properties of the emerging crystal as well as the pathway of nucleation and growth, and are independent of the evaporation rate and thermal conductivity of the substrates. PMID:26012481

  19. Al adjuvants can be tracked in viable cells by lumogallion staining.

    PubMed

    Mile, Irene; Svensson, Andreas; Darabi, Anna; Mold, Matthew; Siesjö, Peter; Eriksson, Hĺkan

    2015-07-01

    The mechanism behind the adjuvant effect of aluminum salts is poorly understood notwithstanding that aluminum salts have been used for decades in clinical vaccines. In an aqueous environment and at a nearly neutral pH, the aluminum salts form particulate aggregates, and one plausible explanation of the lack of information regarding the mechanisms could be the absence of an efficient method of tracking phagocytosed aluminum adjuvants and thereby the intracellular location of the adjuvant. In this paper, we want to report upon the use of lumogallion staining enabling the detection of phagocytosed aluminum adjuvants inside viable cells. Including micromolar concentrations of lumogallion in the culture medium resulted in a strong fluorescence signal from cells that had phagocytosed the aluminum adjuvant. The fluorescence appeared as spots in the cytoplasm and by confocal microscopy and co-staining with probes presenting fluorescence in the far-red region of the spectrum, aluminum adjuvants could to a certain extent be identified as localized in acidic vesicles, i.e., lysosomes. Staining and detection of intracellular aluminum adjuvants was achieved not only by diffusion of lumogallion into the cytoplasm, thereby highlighting the presence of the adjuvant, but also by pre-staining the aluminum adjuvant prior to incubation with cells. Pre-staining of aluminum adjuvants resulted in bright fluorescent particulate aggregates that remained fluorescent for weeks and with only a minor reduction of fluorescence upon extensive washing or incubation with cells. Both aluminum oxyhydroxide and aluminum hydroxyphosphate, two of the most commonly used aluminum adjuvants in clinical vaccines, could be pre-stained with lumogallion and were easily tracked intracellularly after incubation with phagocytosing cells. Staining of viable cells using lumogallion will be a useful method in investigations of the mechanisms behind aluminum adjuvants' differentiation of antigen-presenting cells into inflammatory cells. Information will be gained regarding the phagosomal pathways and the events inside the phagosomes, and thereby the ultimate fate of phagocytosed aluminum adjuvants could be resolved. PMID:25896212

  20. Dyes designed for high sensitivity detection of double-stranded DNA

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Oakland, CA)

    1998-01-01

    Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a cationic chain. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye.

  1. Dyes designed for high sensitivity detection of double-stranded DNA

    DOEpatents

    Glazer, Alexander N. (Orinda, CA); Benson, Scott C. (Albany, CA)

    1994-01-01

    Novel fluorescent dyes are provided, characterized by having a fluorophore joined to a polycationic chain of at least two positive charges. The dyes are found to provide for high enhancement upon binding to nucleic acid and have strong binding affinities to the nucleic acid, as compared to the fluorophore without the polycationic chain. The dyes find use in detection of dsDNA in gel electrophoresis and solution at substantially higher sensitivities using substantially less dye.

  2. Cyanine dyes as optical contrast agents for ophthalmological surgery.

    PubMed

    Langhals, Heinz; Varja, Ana; Laubichler, Peter; Kernt, Marcus; Eibl, Kirsten; Haritoglou, Christos

    2011-06-01

    Cyanine dyes were prepared as optical contrast media for supporting the surgery of the lamina limitans interna (LLI) of the retina and other structures of the human eye. Their absorption spectra were adapted both to the spectral sensitivity of the human eye and to standard illumination. The contrast could be further amplified by the application of the strong fluorescence of the dyes used. The binding of the dyes to various surfaces was studied. No toxic effects could be detected for the applied dyes. PMID:21524061

  3. Reporter dyes demonstrate functional expression of multidrug resistance proteins in the marine flatworm Macrostomum lignano: the sponge-derived dye Ageladine A is not a substrate of these transporters.

    PubMed

    Tietje, Kristin; Rivera-Ingraham, Georgina; Petters, Charlotte; Abele, Doris; Dringen, Ralf; Bickmeyer, Ulf

    2013-10-01

    The marine plathyhelminth Macrostomum lignano was recently isolated from Adriatic shore sediments where it experiences a wide variety of environmental challenges, ranging from hypoxia and reoxygenation, feeding on toxic algae, to exposure to anthropogenic contaminants. As multidrug resistance transporters constitute the first line of defense against toxins and toxicants we have studied the presence of such transporters in M. lignano in living animals by applying optical methods and pharmacological inhibitors that had been developed for mammalian cells. Application of the MDR1 inhibitor Verapamil or of the MRP1 inhibitors MK571 or Probenecid increased the intracellular fluorescence of the reporter dyes Fura-2 am, Calcein am, Fluo-3 am in the worms, but did not affect their staining with the dyes Rhodamine B, CMFDA or Ageladine A. The marine sponge alkaloid Ageladine A remained intracellularly trapped for several days in the worms, suggesting that it does not serve as substrate of multidrug resistance exporters. In addition, Ageladine A did not affect multidrug resistance-associated protein (MRP)-mediated dye export from M. lignano or the MRP1-mediated glutathione (GSH) export from cultured rat brain astrocytes. The data obtained demonstrate that life-imaging is a useful tool to address physiological drug export from intact marine transparent flatworms by using multiphoton scanning microscopy. PMID:24135911

  4. Whole Mount Fluorescent Antibody Staining of Drosophila Embryos Leslie Vosshall

    E-print Network

    % ethanol for 5 minutes, then 30% ethanol for 5 minutes. Alternatively, if all fixed embryos are to be used. If embryos have been previously fixed and dehydrated and are in 70% ethanol, rehydrate by incubating in 50

  5. Ultrasound for wool dyeing and finishing.

    PubMed

    McNeil, S J; McCall, R A

    2011-01-01

    The effects of ultrasound at 35-39 kHz on several wool dyeing and finishing processes have been investigated as a way of reducing environmental impact. Ultrasound improved the effectiveness of cleaning scoured wool in water and to a lesser extent in water-nonionic surfactant. Scanning electron microscopy did not indicate any surface damage. Fluorescence microscopy revealed increased levels of sulphydryl groups on the wool surface suggesting ultrasound caused the removal of thioester-bound lipids. Ultrasound pre-treatment increased the effectiveness of subsequent oxidative-reductive bleaching, but had no effect on the uptake of acid levelling and acid milling dyes. The pre-treatment retarded the uptake of reactive dye, possibly by increasing the crystallinity of the fibre or removing surface bound lipids. Ultrasound did not improve dyeing under conditions that are currently used in industry, but did show potential to reduce the chemical and energy requirements of dyeing wool with reactive and acid milling dyes, but not acid levelling dyes. PMID:20675174

  6. FM-dyes as experimental probes for dissecting vesicle trafficking in living plant cells

    Microsoft Academic Search

    S. Bolte; C. Talbot; Y. Boutte; O. Catrice; N. D. Read; B. Satiat-Jeunemaitre

    2004-01-01

    Summary FM-dyes are widely used to study endocytosis, vesicle traffick- ing and organelle organization in living eukaryotic cells. The increasing use of FM-dyes in plant cells has provoked much debate with regard to their suitability as endocytosis markers, which organelles they stain and the precise pathways they follow through the vesicle trafficking network. A primary aim of this article is

  7. Volume shrinkage of bone, brain and muscle tissue in sample preparation for micro-CT and light sheet fluorescence microscopy (LSFM).

    PubMed

    Buytaert, Jan; Goyens, Jana; De Greef, Daniel; Aerts, Peter; Dirckx, Joris

    2014-08-01

    Two methods are especially suited for tomographic imaging with histological detail of macroscopic samples that consist of multiple tissue types (bone, muscle, nerve or fat): Light sheet (based) fluorescence microscopy (LSFM) and micro-computed tomography (micro-CT). Micro-CT requires staining with heavy chemical elements (and thus fixation and sometimes dehydration) in order to make soft tissue imageable when measured alongside denser structures. LSMF requires fixation, decalcification, dehydration, clearing and staining with a fluorescent dye. The specimen preparation of both imaging methods is prone to shrinkage, which is often not mentioned, let alone quantified. In this paper the presence and degree of shrinkage are quantitatively identified for the selected preparation methods/stains. LSFM delivers a volume shrinkage of 17% for bone, 56% for muscle and 62% for brain tissue. The three most popular micro-CT stains (phosphotungstic acid, iodine with potassium iodide, and iodine in absolute ethanol) deliver a volume shrinkage ranging from 10 to 56% for muscle and 27-66% for brain, while bone does not shrink in micro-CT preparation. PMID:24963987

  8. Quirks of dye nomenclature. 4. Fuchsine: four shades of magenta.

    PubMed

    Cooksey, C J; Dronsfield, A T

    2015-05-01

    Fuchsine, also called magenta, was the second coal tar dye to be produced after mauveine. Fuchsine is composed of a mixture of up to four triphenylmethane dyes that differ only in the number of substituent methyl groups. Unlike mauveine, fuchsine still is widely used today as a biological stain. We describe the progress of fuchsine from its birth as the second coal tar dye, through a variety of modes of manufacture and industrial application, to its current use. We discuss complexities of nomenclature and identification, and the hazards and risks of its various applications. PMID:25555311

  9. Differentiation of cartilage and bone in human fetal temporal bones with Luxol fast blue stain.

    PubMed

    Declau, F; Moeneclaey, L; Forton, G; Marquet, J

    1988-01-01

    A modified Luxol fast blue technique was used to study the development of the temporal bone. This staining method makes it possible to make a clear distinction between the primitive cartilage present and the new forming bone. Although these tissues both contain a significant amount of collagen, their staining properties with the Luxol dyes are widely dissimilar, due to the different physicochemical properties of the collagen types involved in these tissues. The differentiation of mesenchymatous tissue into ligaments and joints can also be very clearly demonstrated with this technique. In studying the endochondral ossification process of the otic capsule and middle ear, the modified Luxol fast blue stain is a valuable technique that is complementary to more conventional staining methods. PMID:2460074

  10. Assessing Nezara viridula (Hemiptera: Pentatomidae) feeding damage in macadamia nuts by using a biological stain.

    PubMed

    Golden, Mary; Follett, Peter A; Wright, Mark G

    2006-06-01

    Damage caused by southern green stink bug, Nezara viridula (L.), to macadamia nuts, Macadamia integrifolia Maiden & Betche, is normally determined after nuts are harvested and processed, which may be many months after damage occurred in the field. We developed a method using ruthenium red dye to stain stink bug feeding probes and indirectly assess feeding activity in macadamia nuts. By using the staining method, feeding probes were easily detected on the husk, shell, and kernel. Husk probing was highly correlated (0.80-0.90) with feeding and damage to the kernel. Failure rate to detect kernel damage from stained husk probes was generally <6%. The staining method was equally effective for immature and mature nuts; therefore, N. viridula feeding activity can be monitored throughout the season to evaluate pest management tactics and forecast outbreak populations. PMID:16813317

  11. Monitoring of labeled antisense oligonucleotides within living cells by using a multifrequency phase/modulation approach for fluorescence lifetime measurements

    NASA Astrophysics Data System (ADS)

    Kocisova, E.; Sureau, F.; Praus, P.; Rosenberg, I.; Stepanek, J.; Turpin, P.-Y.

    2003-06-01

    A multifrequency phase/modulation method has been developed for our UV confocal laser microspectrofluorimeter (modulation frequency 1-200 MHz) for fluorescence lifetime measurements. This technique enables excited state lifetimes of mixed fluorescent components to be resolved and the fluorescence spectral contribution of each species to be determined without using any model spectra. This approach is very efficient for analyzing intracellular multicomponent fluorescence signals. Our effort is focused on the elucidation of the intracellular behavior of synthetic modified oligonucleotides - potential drugs for antisense and/or antigene strategies of curing viral and malignant diseases. A novel type single stranded dT 15 oligomer analogue containing isopolar, non-isosteric, phosphonate-based internucleotide linkages (3'-O-P-CH 2-O-5'), labeled with tetramethylrhodamine dye at the 3'-end, has been utilized. This method, along with fluorescence micro-imaging, was used to monitor uptake, distribution and stability of our modified oligonucleotide inside living cells. Binding to Escort™ vector leads to an homogeneous intracellular distribution of fluorescent labeled oligonucleotide, including nucleus staining, while point distribution only is achieved for its free form.

  12. Transient partial permeabilization with saponin enables cellular barcoding prior to surface marker staining1

    PubMed Central

    Behbehani, Gregory K.; Thom, Colin; Zunder, Eli R.; Finck, Rachel; Gaudilliere, Brice; Fragiadakis, Gabriela K.; Fantl, Wendy J.; Nolan, Garry P.

    2015-01-01

    Fluorescent cellular barcoding and mass-tag cellular barcoding are cytometric methods that enable high sample throughput, minimize inter-sample variation, and reduce reagent consumption. Previously employed barcoding protocols require that barcoding be performed after surface marker staining, complicating combining the technique with measurement of alcohol-sensitive surface epitopes. This report describes a method of barcoding fixed cells after a transient partial permeabilization with 0.02% saponin that results in efficient and consistent barcode staining with fluorescent or mass-tagged reagents while preserving surface marker staining. This approach simplifies barcoding protocols and allows direct comparison of surface marker staining of multiple samples without concern for variations in the antibody cocktail volume, antigen-antibody ratio, or machine sensitivity. Using this protocol, cellular barcoding can be used to reliably detect subtle differences in surface marker expression. PMID:25274027

  13. Improving fluorescence diagnosis of cancer by SLIM

    NASA Astrophysics Data System (ADS)

    Rück, Angelika; Dolp, Frank; Kinzler, Ingrid; Hauser, Carmen; Scalfi-Happ, Claudia

    2006-02-01

    Although during the last years, significant progress was made in cancer diagnosis, using either intrinsic or specially designed fluorophores, still problems exist, due to difficulties in spectral separation of highly overlapping probes or in lack of specificity. Many of the problems could be circumvented by focusing on time-resolved methods. In combination with spectral resolved detection (spectral fluorescence lifetime imaging, SLIM) highly sophisticated fluorescence lifetime imaging can be performed which might improve specificity of cell diagnosis. To record lifetime images (?-mapping) with spectral resolution a setup was realized consisting of a laser scanning microscope equipped with a 16 channel array for time-correlated single photon counting (TCSPC) and a spectrograph in front of the array. A Ti:Saphir laser can be used for excitation or alternatively ps diode lasers. With this system the time- and spectral-resolved fluorescence characteristics of different fluorophores were investigated in solution and in cell culture. As an example, not only the mitochondria staining dye rhodamine 123 could be easily distinguished from DAPI, which intercalates into nucleic acids, but also different binding sites of DAPI. This was proved by the appearance of different lifetime components within different spectral channels. Another example is Photofrin, a photosensitizer which is approved for bladder cancer and for palliative lung and esophageal cancer in 20 countries, including the United States, Canada and many European countries. Photofrin is a complex mixture of different monomeric and aggregated porphyrins. The phototoxic efficiency during photodynamic therapy (PDT) seems to be correlated with the relative amounts of monomers and aggregates. With SLIM different lifetimes could be attributed to various, spectrally highly overlapping compounds. In addition, a detailed analysis of the autofluorescence by SLIM could explain changes of mitochondrial metabolism during Photofrin-PDT.

  14. Problem Solving: Pencil Box Staining

    NSDL National Science Digital Library

    WGHB Boston

    2013-01-01

    This professional development video clip shows students engaged in the first Common Core Practice Standard—Make sense of problems and persevere in solving them as learners make a decision about how much stain will be needed to cover the surface area of twenty-six completed boxes. Additional resources include a video transcript, teaching tips, and a link to a professional development reflection activity based upon the video. A related clip (cataloged separately) shows the same exploration by the same students but Common Core Practice Standard # #5-Use appropriate tools strategically is evident.

  15. Oxazine dye-conjugated dna oligonucleotides: Förster resonance energy transfer in view of molecular dye-DNA interactions.

    PubMed

    Kupstat, Annette; Ritschel, Thomas; Kumke, Michael U

    2011-12-21

    In this work, the photophysical properties of two oxazine dyes (ATTO 610 and ATTO 680) covalently attached via a C6-amino linker to the 5'-end of short single-stranded as well as double-stranded DNA (ssDNA and dsDNA, respectively) of different lengths were investigated. The two oxazine dyes were chosen because of the excellent spectral overlap, the high extinction coefficients, and the high fluorescence quantum yield of ATTO 610, making them an attractive Förster resonance energy transfer (FRET) pair for bioanalytical applications in the far-red spectral range. To identify possible molecular dye-DNA interactions that cause photophysical alterations, we performed a detailed spectroscopic study, including time-resolved fluorescence anisotropy and fluorescence correlation spectroscopy measurements. As an effect of the DNA conjugation, the absorption and fluorescence maxima of both dyes were bathochromically shifted and the fluorescence decay times were increased. Moreover, the absorption of conjugated ATTO 610 was spectrally broadened, and a dual fluorescence emission was observed. Steric interactions with ssDNA as well as dsDNA were found for both dyes. The dye-DNA interactions were strengthened from ssDNA to dsDNA conjugates, pointing toward interactions with specific dsDNA domains (such as the top of the double helix). Although these interactions partially blocked the dye-linker rotation, a free (unhindered) rotational mobility of at least one dye facilitated the appropriate alignment of the transition dipole moments in doubly labeled ATTO 610/ATTO 680-dsDNA conjugates for the performance of successful FRET. Considering the high linker flexibility for the determination of the donor-acceptor distances, good accordance between theoretical and experimental FRET parameters was obtained. The considerably large Förster distance of ~7 nm recommends the application of this FRET pair not only for the detection of binding reactions between nucleic acids in living cells but also for monitoring interactions of larger biomolecules such as proteins. PMID:22073970

  16. Dye permeability and alkaline phosphatase activity of testicular capillaries in the postnatal rat

    Microsoft Academic Search

    Martti Kormano

    1967-01-01

    Staining of testicular and epididymal tissues after intravenous, intraperitoneal or subcutaneous administration of a number of dyes was investigated in rats at different stages of postnatal development. After light green injections heavy staining of both testis and epididymis was visible to the naked eye in neonatal animals up to the age of 10 days, while in rats over 15 days

  17. Methods for chromosome-specific staining

    DOEpatents

    Gray, J.W.; Pinkel, D.

    1995-09-05

    Methods and compositions for chromosome-specific staining are provided. Compositions comprise heterogeneous mixtures of labeled nucleic acid fragments having substantially complementary base sequences to unique sequence regions of the chromosomal DNA for which their associated staining reagent is specific. Methods include ways for making the chromosome-specific staining compositions of the invention, and methods for applying the staining compositions to chromosomes. 3 figs.

  18. Original article Blue-stain fungi associated

    E-print Network

    Paris-Sud XI, Université de

    Original article Blue-stain fungi associated with Tomicus piniperda in Sweden and preliminary to determine the development of blue-staining of sapwood. Fungi were isolated from samples of inner bark and blue-stained sapwood in connection with galleries of T piniperda. Samples were also taken from beetle

  19. Absolute tracer dye concentration using airborne laser-induced water Raman backscatter.

    PubMed

    Hoge, F E; Swift, R N

    1981-04-01

    Reported here for the first time is the use of simultaneous airborne laser-induced dye fluorescence and the 3400-cm(-1) OH-stretch water Raman backscatter spectra to yield the absolute concentration of an ocean-dispersed tracer dye. Using a straightforward theoretical model, the concentration is calculated by numerically comparing the airborne laser-induced fluorescence and Raman backscatter spectra to similar laboratory data for a known dye concentration measured under comparable environmental and instrumental conditions. The dye is assumed to be uniformly mixed throughout the water column together with other interfering, fluorescent, organic matter. A minimum detectable integrated water column dye concentration of approximately 2 ppb by weight as limited by background and instrument noise is obtained. A dye concentration contour map produced from the conical scan lidar data is given. PMID:20309284

  20. Intradermal Indocyanine Green for In Vivo Fluorescence Laser Scanning Microscopy of Human Skin: A Pilot Study

    PubMed Central

    Jonak, Constanze; Skvara, Hans; Kunstfeld, Rainer; Trautinger, Franz; Schmid, Johannes A.

    2011-01-01

    Background In clinical diagnostics, as well as in routine dermatology, the increased need for non-invasive diagnosis is currently satisfied by reflectance laser scanning microscopy. However, this technique has some limitations as it relies solely on differences in the reflection properties of epidermal and dermal structures. To date, the superior method of fluorescence laser scanning microscopy is not generally applied in dermatology and predominantly restricted to fluorescein as fluorescent tracer, which has a number of limitations. Therefore, we searched for an alternative fluorophore matching a novel skin imaging device to advance this promising diagnostic approach. Methodology/Principal Findings Using a Vivascope®-1500 Multilaser microscope, we found that the fluorophore Indocyanine-Green (ICG) is well suited as a fluorescent marker for skin imaging in vivo after intradermal injection. ICG is one of few fluorescent dyes approved for use in humans. Its fluorescence properties are compatible with the application of a near-infrared laser, which penetrates deeper into the tissue than the standard 488 nm laser for fluorescein. ICG-fluorescence turned out to be much more stable than fluorescein in vivo, persisting for more than 48 hours without significant photobleaching whereas fluorescein fades within 2 hours. The well-defined intercellular staining pattern of ICG allows automated cell-recognition algorithms, which we accomplished with the free software CellProfiler, providing the possibility of quantitative high-content imaging. Furthermore, we demonstrate the superiority of ICG-based fluorescence microscopy for selected skin pathologies, including dermal nevi, irritant contact dermatitis and necrotic skin. Conclusions/Significance Our results introduce a novel in vivo skin imaging technique using ICG, which delivers a stable intercellular fluorescence signal ideal for morphological assessment down to sub-cellular detail. The application of ICG in combination with the near infrared laser opens new ways for minimal-invasive diagnosis and monitoring of skin disorders. PMID:21904601

  1. Nanosecond fluorescence spectroscopy

    SciTech Connect

    Leskovar, B.

    1985-03-01

    This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are discussed. A short comparison of the most important deconvolution methods for numerical analysis of experimental data is given particularly with respect to the signal-to-noise ratio of the fluorescence signal. 22 refs., 8 figs.

  2. Fluorescent radiation converter

    NASA Technical Reports Server (NTRS)

    Viehmann, W.

    1980-01-01

    Fluorescent radiation converter used optically transparent substrate. One side of substrate is coated with plastic film containing fluorescent organic dyes that absorb optical radiation at one wavelength and emit it at longer one. Coating is formulated to respond to specific wavelengths. Emitted radiation is reflected internally inside substrate, amplifying intensity that reaches radiation detector. Converter can be made in several shapes and size; round and square bars coated all round their lengths are useful in converting relatively intense radiation and transmitting it through substrate over lengthy distances.

  3. Epi-Fluorescence Microscopy

    PubMed Central

    Webb, Donna J.; Brown, Claire M.

    2012-01-01

    Epi-fluorescence microscopy is available in most life sciences research laboratories, and when optimized can be a central laboratory tool. In this chapter, the epi-fluorescence light path is introduced and the various components are discussed in detail. Recommendations are made for incident lamp light sources, excitation and emission filters, dichroic mirrors, objective lenses, and charge-coupled device (CCD) cameras in order to obtain the most sensitive epi-fluorescence microscope. The even illumination of metal-halide lamps combined with new “hard” coated filters and mirrors, a high resolution monochrome CCD camera, and a high NA objective lens are all recommended for high resolution and high sensitivity fluorescence imaging. Recommendations are also made for multicolor imaging with the use of monochrome cameras, motorized filter turrets, individual filter cubes, and corresponding dyes that are the best choice for sensitive, high resolution multicolor imaging. Images should be collected using Nyquist sampling and should be corrected for background intensity contributions and nonuniform illumination across the field of view. Photostable fluorescent probes and proteins that absorb a lot of light (i.e., high extinction co-efficients) and generate a lot of fluorescence signal (i.e., high quantum yields) are optimal. A neuronal immune-fluorescence labeling protocol is also presented. Finally, in order to maximize the utility of sensitive wide-field microscopes and generate the highest resolution images with high signal-to-noise, advice for combining wide-field epi-fluorescence imaging with restorative image deconvolution is presented. PMID:23026996

  4. Epi-fluorescence microscopy.

    PubMed

    Webb, Donna J; Brown, Claire M

    2013-01-01

    Epi-fluorescence microscopy is available in most life sciences research laboratories, and when optimized can be a central laboratory tool. In this chapter, the epi-fluorescence light path is introduced and the various components are discussed in detail. Recommendations are made for incident lamp light sources, excitation and emission filters, dichroic mirrors, objective lenses, and charge-coupled device (CCD) cameras in order to obtain the most sensitive epi-fluorescence microscope. The even illumination of metal-halide lamps combined with new "hard" coated filters and mirrors, a high resolution monochrome CCD camera, and a high NA objective lens are all recommended for high resolution and high sensitivity fluorescence imaging. Recommendations are also made for multicolor imaging with the use of monochrome cameras, motorized filter turrets, individual filter cubes, and corresponding dyes being the best choice for sensitive, high resolution multicolor imaging. Images should be collected using Nyquist sampling and images should be corrected for background intensity contributions and nonuniform illumination across the field of view. Photostable fluorescent probes and proteins that absorb a lot of light (i.e., high extinction co-efficients) and generate a lot of fluorescence signal (i.e., high quantum yields) are optimal. A neuronal immune-fluorescence labeling protocol is also presented. Finally, in order to maximize the utility of sensitive wide-field microscopes and generate the highest resolution images with high signal-to-noise, advice for combining wide-field epi-fluorescence imaging with restorative image deconvolution is presented. PMID:23026996

  5. Design, Syntheses and Applications of Fluorescent Dyes 

    E-print Network

    Wu, Liangxing

    2010-10-12

    , Angie Medina and Jade Kennedy for their assistance through out all these years. Thanks to my friends and former colleagues Drs. Sam Reyes and Yu Li Angell for their friendship and help. Thanks also go to all the current Burgess group members...

  6. Design, Syntheses and Applications of Fluorescent Dyes

    E-print Network

    Wu, Liangxing

    2010-10-12

    catalyzed the ligation of biotin to the AP which can be fused to proteins of interest. A ketone isostere of biotin was also transferred to the AP, providing a unique functionality for subsequent derivatization with different probes. Transglutaminases...

  7. THERMAL STABILITY FLUORESCENT DYES AS GEOTHERMALTRACERS

    E-print Network

    Stanford University

    this project. To him I'm deeply indebted. I wish also to thank Costantinos V. Chrysikopoulos, Professors Roland;ABSTRACT This work attempted to determine the effect of temperature on tbe fluores- cence of rhodamine WT

  8. Acridine orange staining reaction as an index of physiological activity in Escherichia coli

    NASA Technical Reports Server (NTRS)

    McFeters, G. A.; Singh, A.; Byun, S.; Callis, P. R.; Williams, S.

    1991-01-01

    The assumption that the acridine orange (AO) color reaction may be used as an index of physiological activity was investigated in laboratory grown Escherichia coli. Spectrofluorometric observations of purified nucleic acids, ribosomes and the microscopic color of bacteriophage-infected cells stained with AO confirmed the theory that single-stranded nucleic acids emit orange to red fluorescence while those that are double-stranded fluoresce green in vivo. Bacteria growing actively in a rich medium could be distinguished from cells in stationary phase by the AO reaction. Cells from log phase appeared red, whereas those in stationary phase were green. However, this differentiation was not seen when the bacteria were grown in a minimal medium or when a variation of the staining method was used. Also, shifting bacteria in stationary phase to starvation conditions rapidly changed their AO staining reaction. Boiling and exposure to lethal concentrations of azide and formalin resulted in stationary-phase cells that appeared red after staining but bacteria killed with chlorine remained green. These findings indicate that the AO staining reaction may be suggestive of physiological activity under defined conditions. However, variables in staining and fixation procedures as well as uncertainties associated with mixed bacterial populations in environmental samples may produce results that are not consistent with the classical interpretation of this reaction. The importance of validating the putative physiological implications of this staining reaction is stressed.

  9. SELECTIVE "STAINING" FOR ELECTRON MICROGRAPHY

    PubMed Central

    Mudd, Stuart; Anderson, Thomas F.

    1942-01-01

    The physical basis of contrast and image formation in electron micrography is considered in relation to the possibility of recording selective chemical effects on cell components. A technology of selective microchemical analysis, equivalent to differential staining, is suggested as practicable in electron micrography. Electron pictures of bacteria after exposure to salts of heavy metals have shown the bacterial inner protoplasm, but not the cell walls, to be selectively darkened; shrinkage, coagulation, or escape of protoplasm from the injured cells may result and be recorded in the electron micrographs. Recording of the action of germicidal agents on individual bacterial cells is indicated as one promising field of application of microchemical analysis with the aid of the electron microscope. PMID:19871216

  10. SYPRO Ruby Protein Gel Stain Advanced staining technology for 2-D gels and proteomics

    E-print Network

    Lebendiker, Mario

    SYPRO Ruby Protein Gel Stain Advanced staining technology for 2-D gels and proteomics ® Detection steps Broad linear quantitation range and consistent gel-to-gel staining allow for accurate protein especially for the analysis of proteins in 2-D polyacrylamide gels, SYPRO Ruby protein gel stain is ideal

  11. Combined silver Perls's stain for differential staining of ringed sideroblasts and marrow iron

    Microsoft Academic Search

    K T Tham; J B Cousar

    1993-01-01

    During a study of nucleolar organiser regions, a modified silver stain was found to be a sensitive marker for the iron in ringed sideroblasts, more so than Perls's stain when the marrow iron stores were low. To enhance the usefulness of the silver stain, a combined silver Perls method was developed. This stains the ringed sideroblast iron black and haemosiderin

  12. Stimulated laser induced fluorescence holography for imaging fluorescent species

    NASA Astrophysics Data System (ADS)

    Amer, Eynas; Gren, Per; Sjödahl, Mikael

    2013-01-01

    In this paper pulsed digital holographic detection is coupled to the stimulated laser induced fluorescence (LIF) effect for imaging fluorescent species. A frequency tripled Q-switched Nd-YAG laser (wavelength 355 nm, pulse duration 12 ns) has been used to pump Coumarin 153 dye solved in ethanol. Simultaneously a frequency doubled pulse (532 nm) from the same laser is used to probe the solvent resulting in a gain through stimulated emission. The resulting gain of the probe beam is recorded using digital holography by blending it with a reference beam on the detector. Intensity maps were calculated from the recorded digital holograms and used to calculate the gain of the probe beam due to stimulated fluorescence emission which is coupled to the concentration of the dye. The results show that the amplification of the probe beam (532 nm) due to stimulated LIF emission is seen in the intensity maps. The gain is about 40% at a dye concentration of 0.32 g/L and decreases to be about 20% at a dye concentration of 0.04 g/L for a probe beam energy density of 0.1 mJ/cm2. Spectroscopic measurements have been carried out to confirm the holographic results. The results show that stimulated LIF holography is a promising technique for quantitative imaging of fluorescent species.

  13. Plasmonic Molecular Nanohybrids—Spectral Dependence of Fluorescence Quenching

    PubMed Central

    Olejnik, Maria; Bujak, ?ukasz; Mackowski, Sebastian

    2012-01-01

    We demonstrate strong spectral dependence of the efficiency of fluorescence quenching in molecular systems composed of organic dyes and gold nanoparticles. In order to probe the coupling with metallic nanoparticles we use dyes with varied spectral overlap between the plasmon resonance and their absorption. Hybrid molecular structures were obtained via conjugation of metallic nanoparticles with the dyes using biotin-streptavidin linkage. For dyes featuring absorption above the plasmon excitation in gold nanoparticles, laser excitation induces minute changes in the fluorescence intensity and its lifetime for both conjugated and non-conjugated mixtures, which are the reference. In contrast, when the absorption of the dye overlaps with the plasmon resonance, the effect is quite dramatic, reaching 85% and 95% fluorescence quenching for non-conjugated and conjugated mixtures, respectively. The degree of fluorescence quenching strongly depends upon the concentration of metallic nanoparticles. Importantly, the origin of the fluorescence quenching is different in the case of the conjugated mixture, as evidenced by time-resolved fluorescence. For conjugated mixtures of dyes resonant with plasmon, excitation features two-exponential decay. This is in contrast to the single exponential decay measured for the off-resonant configuration. The results provide valuable insight into spectral dependence of the fluorescence quenching in molecular assemblies involving organic dyes and metallic nanoparticles. PMID:22312301

  14. NEW METHOD TO DETERMINE 'GIARDIA' CYST VIABILITY: CORRELATION OF FLUORESCEIN DIACETATE AND PROPIDIUM IODIDE STAINING WITH ANIMAL INFECTIVITY

    EPA Science Inventory

    The viability of Giardia muris cysts was studied using the fluorogenic dyes, fluorescein diacetate (FDA) and propidium iodide (PI). Using the mouse model for giardiasis, FDA or PI stained cysts were inoculated into neonatal mice. Feces were examined at days 3, 5, 8, and 11 post-i...

  15. Fluorescent Particles For Flow Testing

    NASA Technical Reports Server (NTRS)

    Bonnell, Jeremy L.; Stern, Susan M.; Torkelson, Jan R.

    1995-01-01

    Small alumina spheres coated with fluorescent dye used in flow testing of transparent plastic model of check valve. Entrained fluroescent particles make flows visible. After completion of flow test, particles remaining in valve easily detectable and removed for measurement of their sizes.

  16. Sensitivity and specificity of Congo red staining according to Romhányi. Comparison with Puchtler's or Bennhold's methods.

    PubMed

    Bély, Miklós; Makovitzky, Josef

    2006-01-01

    The sensitivity and specificity of various Congo red staining methods is very important in the diagnosis of amyloidosis. When using a less sensitive staining method, some true positive cases of amyloidosis remain undetected. A more highly specific method potentially detects more cases and reveals amyloidosis in an earlier stage of deposition. In this paper, the Congo red staining method according to Romhányi is discussed in comparison with Puchtler's and Bennhold's methods. Using Romhányi's technique, there is no alcoholic differentiation, and thus no dye molecules are washed off the amyloid filaments. The binding of the oriented dye molecules is optimal for polarization microscopy. With this method, the polar hydrophilic mounting medium, gum Arabic is used. Mounted in this carbohydrate-containing, hydrophilic medium, the Congo red molecules are oriented parallel to the surface of the amyloid filaments and the sign is linear positive, corresponding to an additive character of topo-optical staining reactions. Otherwise, the Congo red molecules are oriented perpendicular to the surface of collagen, reducing the intensity of birefringence and even inducing an inversion of the original sign of the collagen birefringence. With alcoholic differentiation, Congo red dye molecules are extracted and this decreases the birefringence of amyloid deposits, i.e. minimal amyloid deposits may be missed. Using the apolar hydrophobic mounting medium, Canada balsam, an axis-parallel arrangement of Congo red dye molecules on the surface of collagen fibers and amyloid will occur, resulting in an additive topo-optical reaction with a green polarization color and a false positive diagnosis of amyloidosis ("phantom amyloidosis"). PMID:16714051

  17. Optofluidic dye lasers

    Microsoft Academic Search

    Zhenyu Li; Demetri Psaltis

    2008-01-01

    Optofluidic dye lasers are microfabricated liquid dye lasers enabled by the microfluidics technology. The integration of dye\\u000a lasers with microfluidics not only facilitates the implementation of complete “lab-on-a-chip” systems, but also allows the\\u000a dynamical control of the laser properties which is not achievable with solid-state optical components. We review the recent\\u000a demonstrations of on-chip liquid dye lasers and some of

  18. Staining sectioned biological specimens for transmission electron microscopy: conventional and en bloc stains.

    PubMed

    Ellis, E Ann

    2014-01-01

    Post-staining of ultrathin sections and/or en bloc staining of specimens is necessary for differential contrast and improved resolution of cellular structures. Often specimens are fixed and stained with osmium tetroxide during fixation, but additional contrast is the result of additional heavy metal stains on the sections. The most common post-staining of sections is done on grids by aqueous uranyl acetate followed by lead citrate. When it is apparent that simple, aqueous uranium and lead post-staining is not adequate, other stains are invoked. These procedures can be as simple as en bloc staining with uranyl acetate after primary fixation and osmication. Over the years, several other treatments have been developed for use with the primary fixation or during dehydration. Tannic acid, paraphenylenediamine (PPD), and malachite green can all serve as en bloc stains and can contribute to overall improved visualization of ultrastructural details in biological specimens. Tannic acid and PPD improve membrane preservation, and malachite green is a phospholipid stain. All of these stains are compatible with aqueous fixatives and should be considered when the usual stains are not satisfactory. Marinozzi rings and microwave-assisted post-staining offer alternatives to traditional grid staining. In addition, stain precipitates on grids often can be removed by treatment with 10 % (v/v) acetic acid. PMID:24357359

  19. Cross-reactions between Corynebacterium sepedonicum and Arthrobacter polychromogenes in immunofluorescence staining

    Microsoft Academic Search

    A. Calzolari; C. Bazzi; U. Mazzucchi

    1982-01-01

    In a comparative serological study using indirect fluorescence antibody staining (IFAS) on three strains ofCorynebacterium sepedonicum and eleven strains of the genusArthrobacter, onlyA. polychromogenes cross-reacted withC. sepedonicum. The antiserum titre was 1?2000 and its dilution was critical for identifying cross-reactions. At dilutions higher than 1?500, onlyC. sepedonicum showed intense fluorescence and sharp edges of the walls; species ofArthrobacter gave reactions

  20. Early morphea mimicking acquired port-wine stain.

    PubMed

    Pickert, Amanda J; Carpentieri, David; Price, Harper; Hansen, Ronald C

    2014-01-01

    We report the case of a 2.5-year-old girl with linear morphea initially diagnosed as an acquired port-wine stain (PWS). She underwent three treatments to the right face using the pulsed dye laser (PDL) before sclerotic changes were observed and the correct diagnosis was confirmed with histopathology. Treatment using the PDL reduced the skin erythema but did not prevent subsequent sclerosis. The sclerosis became most prominent superior to the patient's right ear in an area not treated using the laser. A review of the English-language medical literature identified no cases of morphea triggered using a PDL, but there were several reports of early morphea misdiagnosed as an acquired PWS. Briefly, we review those cases, as well as morphea subtypes, and comment on how the pathophysiology of morphea may lend itself to an early underrecognized inflammatory presentation, delaying diagnosis. PMID:23627630

  1. Measurement and model assessment of fluorescence lifetime sensing in multiply scattering media 

    E-print Network

    Kuwana, Eddy

    2005-08-29

    ) the generation of fluorescence from dyes exhibiting multi-exponential or more complex kinetics and (ii) its propagation in scattering media. In the preliminary study, fluorescence lifetime spectroscopy is investigated in tissue-like scattering solution. Two...

  2. Liposome-Cell Interaction: Transfer and Intracellular Release of a Trapped Fluorescent Marker

    Microsoft Academic Search

    J. N. Weinstein; S. Yoshikami; P. Henkart; R. Blumenthal; W. A. Hagins

    1977-01-01

    When small, unilamellar lipid vesicles containing a high concentration of the fluorescent dye 6-carboxyfluorescein are incubated with either frog retinas or human lymphocytes, fluorescence distributes widely throughout each cell. Since \\

  3. Effect of wavelength and dye selection on biosensor response

    NASA Astrophysics Data System (ADS)

    Ligler, Frances S.; Breslin, Kristen A.; Cao, Lynn K.; Anderson, George P.

    1995-05-01

    The availability of low cost laser diodes and new fluorescent dyes has made portable biosensors a reality. Previously, we have examined the variation in the fluorescent signal generated in an antigen-antibody reaction when the antigen is labeled with dyes exciting at different wavelengths. In this study, we looked at the effect of changing dyes and wavelengths on a sandwich immunoassay for the F1 antigen from Yersinia pestis, the etiologic agent of plaque. The F1 immunoassay has previously been demonstrated to work in serum, plasma, and even whole blood, when performed using a fiber optic biosensor. In this study, we demonstrated that changing to cyanine dyes enhanced the sensitivity of the detection without altering the immunochemistry of the assay.

  4. Photophysics and photochemistry of xanthene dyes in polymer solutions and films

    SciTech Connect

    Kamat, P.V.; Fox, M.A.

    1984-05-24

    The singlet and triplet lifetimes of erythrosin B and rose bengal, two representative xanthene dyes, are significantly increased by enclosing the dye in a cage of poly(4-vinylpyridine) (PVP). The fluorescence yield, controlled by the rate of intersystem crossing, is also increased by such encapsulation. Parallel effects are observed upon adding the polymer to an ethanolic solution of the xanthene or upon loading the dye into a polymer matrix dispersed on a metal oxide surface. The effect of the polymer on static quenching of the excited dye and the implications of dye-loaded polymer films in solar energy conversion are discussed.

  5. Thermochromism and fluorescence in dyed PEO films

    NASA Astrophysics Data System (ADS)

    Kamath, Archana; S, Raghu; V, Mini; C, Sharanappa; H, Devendrappa

    2015-06-01

    The optical absorbance spectra of solution casted pure & methyl blue (MB) dyed polyethylene oxide (PEO) films were recorded in a wavelength range from 190-1100nm at different temperatures. The absorbance was found to increases with increasing temperature. Fluorescence micrographs confirmed the interaction between polymer and dye and also revealed decreased crystallinity of the sample. Fluorescence quantum yield has been calculated with the help of fluorescence spectra.

  6. Degradation of environment pollutant dyes using phytosynthesized metal nanocatalysts.

    PubMed

    MeenaKumari, M; Philip, Daizy

    2015-01-25

    We present for the first time biogenic reduction and stabilization of gold and silver ions at room temperature using fruit juice of Punica granatum. The formation, morphology and crystalline structure of the synthesized nanoparticles are determined using UV-Visible, XRD and TEM. An attempt to reveal the partial role of phenolic hydroxyls in the reduction of Au(3+) and Ag(+) is done through FTIR analysis. The synthesized nanoparticles are used as potential catalysts in the degradation of a cationic phenothiazine dye, an anionic mono azo dye and a cationic fluorescent dye. The calculated values of percentage removal of dyes and the rate constants from pseudo first order kinetic data fit give a comparative study on degradation of organic dyes in presence of prepared gold and silver nanoparticles. PMID:25128675

  7. Probes labelled with energy transfer coupled dyes

    DOEpatents

    Mathies, R.A.; Glazer, A.; Ju, J.

    1997-11-18

    Compositions are provided comprising sets of fluorescent labels carrying pairs of donor and acceptor dye molecules, designed for efficient excitation of the donors at a single wavelength and emission from the acceptor in each of the pairs at different wavelengths. The different molecules having different donor-acceptor pairs can be modified to have substantially the same mobility under separation conditions, by varying the distance between the donor and acceptor in a given pair. Particularly, the fluorescent compositions find use as labels in sequencing nucleic acids. 7 figs.

  8. Probes labelled with energy transfer coupled dyes

    DOEpatents

    Mathies, Richard A. (El Cerrito, CA); Glazer, Alexander (Orinda, CA); Ju, Jingyue (Berkeley, CA)

    1997-01-01

    Compositions are provided comprising sets of fluorescent labels carrying pairs of donor and acceptor dye molecules, designed for efficient excitation of the donors at a single wavelength and emission from the acceptor in each of the pairs at different wavelengths. The different molecules having different donor-acceptor pairs can be modified to have substantially the same mobility under separation conditions, by varying the distance between the donor and acceptor in a given pair. Particularly, the fluorescent compositions find use as labels in sequencing nucleic acids.

  9. Photolysis of rhodamine-WT dye

    USGS Publications Warehouse

    Tai, D.Y.; Rathbun, R.E.

    1988-01-01

    Photolysis of rhodamine-WT dye under natural sunlight conditions was determined by measuring the loss of fluorescence as a function of time. Rate coefficients at 30?? north latitude ranged from 4.77 x 10-2 day-1 for summer to 3.16 x 10-2 day-1 for winter. Experimental coefficients were in good agreement with values calculated using a laboratory-determined value of the quantum yield.

  10. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    PubMed Central

    Zhang, Yi; Yang, Jian

    2013-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology. PMID:23710326

  11. Effect of silver NPs plasmon on optical properties of fluorescein dye

    NASA Astrophysics Data System (ADS)

    Ragab, Alaa EL-din E. A.; Gadallah, A.; Mohamed, Mona B.; Azzouz, I. M.

    2013-11-01

    In this work we studied the effect of silver nanoparticles "AgNPs" on the optical properties of fluoretain-->rescein dye. Fluorescein dye solutions have been mixed with different concentrations of colloidal AgNPs. Absorption and fluorescence enhancement of fluorescein dye molecules was detected in the presence of AgNPs. Fluorescence enhancement of the dye molecules was observed with a maximal enhancement factor of about 3-fold. Enhancement of the rate of radiative transition was also detected. The enhancement mechanisms are attributed to a modification of the local density of electromagnetic modes in the vicinity of AgNPs at energies resonant with surface Plasmon. The ability of fluorophore-metal mixture to actively enhance the dye's luminescence could leads to new opportunities for technological development of light emitting and photonic devices. It also may have applications in the fields of bio-technology and medical diagnostics as new class of fluorescence based sensing.

  12. Choosing dyes for cw-STED nanoscopy using self-assembled nanorulers

    PubMed Central

    Beater, Susanne; Holzmeister, Phil; Pibiri, Enrico

    2014-01-01

    Superresolution microscopy is currently revolutionizing optical imaging. A key factor for getting images of highest quality is – besides a well-performing imaging system – the labeling of the sample. We compared the fluorescent dyes Abberior Star 488, Alexa 488, Chromeo 488 and Oregon Green 488 for use in continuous wave (cw-)STED microscopy in aqueous buffer and in a durable polymer matrix. To optimize comparability, we designed DNA origami standards labeled with the fluorescent dyes including a bead-like DNA origami with dyes focused on one spot and a DNA origami with two marks at a designed distance of ?100 nm. Our data show that all dyes are well suited for cw-STED microscopy but that the optimal dye depends on the embedding medium. The precise comparison enabled by DNA origami nanorulers indicates that these structures have matured from the proof-of-concept to easily applicable tools in fluorescence microscopy. PMID:24599511

  13. Structural, photophysical and lasing properties of pyrromethene dyes

    NASA Astrophysics Data System (ADS)

    Arbeloa, F. López; Bańuelos, J.; Martínez, V.; Arbeloa, T.; Arbeloa, I. López

    The molecular structure and the photophysical properties of pyrromethene-BF2 (PM) dyes are studied with the aim of finding the best structural and environmental conditions which optimize the laser performance of these dyes. To this end, UV-Vis absorption and fluorescence spectra and fluorescence decay curves of several PM dyes are registered in a multitude of solvents with different physicochemical properties and in polymeric solid matrices. Quantum mechanical calculations at different levels are also applied in order to explain the photophysical behaviour of these dyes. The studied pyrromethenes incorporate alkyl (methyl, ethyl and tert-butyl), sulfonate, cyano, and acetoxy- and methacryloyloxy-polymethylene groups in different positions of the chromophore. In the last case, the presence of the polymerizable acryloyl group facilitates the covalent linkage of the chromophore to a polymeric chain, of special technological interest in the development of tunable dye lasers in the solid state. From the experimental results and the theoretical calculations, we discuss different mechanisms of internal conversion for PM dyes, such as the loss in the planarity of the chromophore, the electron flow through the delocalized ?-system, the vibrational coupling and the formation of an intramolecular charge transfer state. The present work demonstrates the good correlation between the photophysical and the lasing properties of PM dyes with different structural (substituents) and environmental (solvents and polymers) conditions.

  14. Theoretical structures and binding energies of RNA-RNA/cyanine dyes and spectroscopic properties of cyanine dyes

    NASA Astrophysics Data System (ADS)

    Salaeh, Salsabila; Chong, Wei Lim; Dokmaisrijan, Supaporn; Payaka, Apirak; Yana, Janchai; Nimmanpipug, Piyarat; Lee, Vannajan Sanghiran; Dumri, Kanchana; Anh, Dau Hung

    2014-10-01

    Cyanine dyes have been widely used as a fluorescence probe for biomolecules and protein labeling. The mostly used cyanine dyes for nucleic acids labeling are DiSC2(3), DiSC2(5), and DiSC2(7). The possible structures and binding energies of RNA-RNA/Cyanine dyes were predicted theoretically using AutoDock Vina. The results showed that cyanine dyes and bases of RNA-RNA have the van der Waals and pi-pi interactions. The maximum absorption wavelength in the visible region obtained from the TD-DFT calculations of all cyanine dyes in the absence of the RNA-RNA double strand showed the bathochromic shift.

  15. Testing a dual-fluorescence assay to monitor the viability of filamentous cyanobacteria.

    PubMed

    Johnson, Tylor J; Hildreth, Michael B; Gu, Liping; Zhou, Ruanbao; Gibbons, William R

    2015-06-01

    Filamentous cyanobacteria are currently being engineered to produce long-chain organic compounds, including 3rd generation biofuels. Because of their filamentous morphology, standard methods to quantify viability (e.g., plate counts) are not possible. This study investigated a dual-fluorescence assay based upon the LIVE/DEAD® BacLight™ Bacterial Viability Kit to quantify the percent viability of filamentous cyanobacteria using a microplate reader in a high throughput 96-well plate format. The manufacturer's protocol calls for an optical density normalization step to equalize the numbers of viable and non-viable cells used to generate calibration curves. Unfortunately, the isopropanol treatment used to generate non-viable cells released a blue pigment that altered absorbance readings of the non-viable cell solution, resulting in an inaccurate calibration curve. Thus we omitted this optical density normalization step, and carefully divided cell cultures into two equal fractions before the isopropanol treatment. While the resulting calibration curves had relatively high correlation coefficients, their use in various experiments resulted in viability estimates ranging from below 0% to far above 100%. We traced this to the apparent inaccuracy of the propidium iodide (PI) dye that was to stain only non-viable cells. Through further analysis via microplate reader, as well as confocal and wide-field epi-fluorescence microscopy, we observed non-specific binding of PI in viable filamentous cyanobacteria. While PI will not work for filamentous cyanobacteria, it is possible that other fluorochrome dyes could be used to selectively stain non-viable cells. This will be essential in future studies for screening mutants and optimizing photobioreactor system performance for filamentous cyanobacteria. PMID:25889626

  16. Manganese oxide and docetaxel co-loaded fluorescent polymer nanoparticles for dual modal imaging and chemotherapy of breast cancer.

    PubMed

    Abbasi, Azhar Z; Prasad, Preethy; Cai, Ping; He, Chunsheng; Foltz, Warren D; Amini, Mohammad Ali; Gordijo, Claudia R; Rauth, Andrew M; Wu, Xiao Yu

    2015-07-10

    Multifunctional nanoparticles (NPs) have found important applications in diagnosis, chemotherapy, and image-guided surgery of tumors. In this work, we have developed polymeric theranostic NPs (PTNPs) containing the anticancer drug docetaxel (DTX), a fluorescent dye, and magnetic manganese oxide (MnO) NPs for dual modal imaging and chemotherapy. PTNPs ~150nm in diameter were synthesized by co-loading hydrophobic DTX and MnO NPs ~5nm in diameter, into the matrix of a fluorescent dye-labeled amphiphilic polymer. The PTNPs enabled high loading efficiency and sustained in vitro release of DTX. Energy-dependent cellular uptake and extended cytoplasmic retention of the PTNPs in MDA-MB-231 human breast cancer cells were observed by fluorescence microscopy examination. DTX-loaded PTNPs exhibited higher cytotoxicity than free DTX with a 3 to 4.4-fold decrease in drug dose required for 50% cell growth inhibition. The hydrophilic backbone of the amphiphilic polymer improved the fluidity of PTNPs which enhanced the longitudinal relaxivity (r1) of loaded MnO NPs by 2.7-fold with r1=2.4mM(-1)s(-1). Whole body fluorescence imaging (FI) and magnetic resonance imaging (MRI) showed significant accumulation and prolonged retention of PTNPs in orthotopic MDA-MB-231 breast tumors. These results suggest that the new amphiphilic polymer-based PTNP system, able to simultaneously deliver a poorly soluble anticancer drug, enhance MRI contrast, and stain tumor tissue by fluorescence, is a good candidate for cancer theranostic applications. PMID:25908171

  17. Applications of SYPRO Orange and SYPRO Red Protein Gel Stains

    Microsoft Academic Search

    Thomas H. Steinberg; Richard P. Haugland; Victoria L. Singer

    1996-01-01

    We have further characterized the sensitivity and specificity of SYPRO Orange protein gel stain and SYPRO Red protein gel stain with native and 2-dimensional polyacrylamide gels and for staining gels prior to Western blot analysis. We found that nucleic acids are not stained by the SYPRO protein gel stains, in contrast to results obtained with commonly used silver staining techniques.

  18. Pro-Q Diamond Phosphoprotein Gel Stain

    E-print Network

    Lebendiker, Mario

    Pro-Q Diamond Phosphoprotein Gel Stain In-gel Detection Technology for Protein Phosphorylation and phosphoproteomics, the Pro-Q Diamond phos- phoprotein gel stain is a breakthrough technology that provides a simple phosphoproteins, the Pro-Q Diamond signal is linear over three orders of magnitude and the strength of the signal

  19. Mineral Stains at the No Name Prospect

    USGS Multimedia Gallery

    USGS scientist Art Bookstrom looks at greenish copper stain and pale pink cobalt bloom on limonite-stained meta-siltite and meta-argillite at the No Name prospect, near Iron Creek, in the southeastern part of the Idaho cobalt belt, in east-central Idaho....

  20. Toluidine blue staining as an adjunctive tool for early diagnosis of dysplastic changes in the oral mucosa

    PubMed Central

    Pallagatti, Shambulingappa; Sheikh, Soheyl; Aggarwal, Amit; Gupta, Deepak; Singh, Ravinder; Handa, Roopika; Mago, Jyoti

    2013-01-01

    Prognosis of oropharyngeal squamous cell carcinoma depends on early diagnosis, despite advanced surgical techniques, the 5-year survival rate remains ~40-50%. Unfortunately, it is usually detected when it becomes symptomatic. This requires treatment which gives rise to a high rate of morbidity and mortality and, furthermore, early detection of oro-pharyngeal pre-malignant lesions is important to improve the survival rate and quality of life. Since dysplasia and in situ carcinoma contain much more DNA and RNA than the normal surrounding epithelium, the use of in vivo staining, by means of toluidine blue dye, is based on the fact that it is an acidophilic dye that selectively stains acidic tissue components such as DNA and RNA. Toluidine blue staining is considered to be sensitive in identifying early oro-pharyngeal premalignant and malignant lesions. In the present study, the use of toluidine blue staining was taken into consideration to identify clinically doubtful oro-pharyngeal lesions and to compare toluidine blue stain and with the histological evaluation. Key words:Early detection, improved survival, pre-cancer, toluidine blue, vital staining. PMID:24455079