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

NASA Astrophysics Data System (ADS)

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.

Hara, Shigemitsu; Tanoue, Eiichiro



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


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

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



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

PubMed Central

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

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



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

PubMed Central

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

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



A Novel Staining Protocol for Multiparameter Assessment of Cell Heterogeneity in Phormidium Populations (Cyanobacteria) Employing Fluorescent Dyes  

PubMed Central

Bacterial populations display high heterogeneity in viability and physiological activity at the single-cell level, especially under stressful conditions. We demonstrate a novel staining protocol for multiparameter assessment of individual cells in physiologically heterogeneous populations of cyanobacteria. The protocol employs fluorescent probes, i.e., redox dye 5-cyano-2,3-ditolyl tetrazolium chloride, ‘dead cell’ nucleic acid stain SYTOX Green, and DNA-specific fluorochrome 4?,6-diamidino-2-phenylindole, combined with microscopy image analysis. Our method allows simultaneous estimates of cellular respiration activity, membrane and nucleoid integrity, and allows the detection of photosynthetic pigments fluorescence along with morphological observations. The staining protocol has been adjusted for, both, laboratory and natural populations of the genus Phormidium (Oscillatoriales), and tested on 4 field-collected samples and 12 laboratory strains of cyanobacteria. Based on the mentioned cellular functions we suggest classification of cells in cyanobacterial populations into four categories: (i) active and intact; (ii) injured but active; (iii) metabolically inactive but intact; (iv) inactive and injured, or dead. PMID:23437052

Tashyreva, Daria; Elster, Josef; Billi, Daniela



A simple, rapid and low-cost staining method for gel-electrophoresis separated phosphoproteins via the fluorescent purpurin dye.  


A novel fluorescence detection method for phosphoproteins in 1-D and 2-D SDS-PAGE by using purpurin is developed in this study. Phosphoproteins as low as 4-8 ng could be specifically detected by purpurin within 60 min, and the detection limit is similar to or better than that of Pro-Q Diamond staining. Only 2 steps (staining and destaining) are needed for purpurin staining without requiring excessive fixing and washing steps, and for single use, $0.8 is enough for purpurin staining. By comprehensively comparing with Pro-Q Diamond staining, it is concluded that purpurin staining is a simple, rapid and low-cost staining method for a broad application to the research of phosphoproteins. PMID:25325196

Cong, Weitao; Shen, Jiayi; Xuan, Yuanhu; Zhu, Xinliang; Ni, Maowei; Zhu, Zhongxin; Hong, Guoying; Lu, Xianghong; Jin, Litai



Exploring the dynamics of fluorescence staining of bacteria with cyanine dyes for the development of kinetic assays  

NASA Astrophysics Data System (ADS)

Bacterial infections continue to be one of the major health risks in the United States. The common occurrence of such infection is one of the major contributors to the high cost of health care and significant patient mortality. The work presented in this thesis describes spectroscopic studies that will contribute to the development of a fluorescent assay that may allow the rapid identification of bacterial species. Herein, the optical interactions between six bacterial species and a series of thiacyanine dyes are investigated. The interactions between the dyes and the bacterial species are hypothesized to be species-specific. For this thesis, two Gram-negative strains, Escherichia coli (E. coli) TOP10 and Enterobacter aerogenes; two Gram-positive bacterial strains, Bacillus sphaericus and Bacillus subtilis; and two Bacillus endospores, B. globigii and B. thuringiensis, were used to test the proposed hypothesis. A series of three thiacyanine dyes---3,3'-diethylthiacyanine iodide (THIA), 3,3'-diethylthiacarbocyanine iodide (THC) and thiazole orange (THO)---were used as fluorescent probes. The basis of our spectroscopic study was to explore the bacterium-induced interactions of the bacterial cells with the individual thiacyanine dyes or with a mixture of the three dyes. Steady-state absorption spectroscopy revealed that the different bacterial species altered the absorption properties of the dyes. Mixed-dye solutions gave unique absorption patterns for each bacteria tested, with competitive binding observed between the bacteria and spectrophotometric probes (thiacyanine dyes). Emission spectroscopy recorded changes in the emission spectra of THIA following the introduction of bacterial cells. Experimental results revealed that the emission enhancement of the dyes resulted from increases in the emission quantum yield of the thiacyanine dyes upon binding to the bacteria cellular components. The recorded emission enhancement data were fitted to an exponential (mono-exponential or bi-exponential) function, and time constants were extracted by regressing on the experimental data. The addition of the TWEEN surfactants decreased the rate at which the dyes interacted with the bacterial cells, which typically resulted in larger time constants derived from an exponential fit. ANOVA analysis of the time constants confirmed that the values of the time constants clustered in a narrow range and were independent of dye concentration and weakly dependent on cell density.

Thomas, Marlon Sheldon


Detection of glycoproteins in polyacrylamide gels and on electroblots using Pro-Q Emerald 488 dye, a fluorescent periodate Schiff-base stain.  


Pro-Q Emerald 488 glycoprotein stain reacts with periodic acid-oxidized carbohydrate groups, generating a bright green-fluorescent signal on glycoproteins. The stain permits detection of less than 5-18 ng of glycoprotein per band, depending upon the nature and the degree of protein glycosylation, making it roughly 8-16-fold more sensitive than the standard colorimetric periodic acid-Schiff base method using acidic fuchsin dye (pararosaniline). The green-fluorescent signal from Pro-Q Emerald 488 stain may optimally be visualized using charge-coupled device/xenon arc lamp-based imaging systems or 470-488 nm laser-based gel scanners. Though glycoprotein detection may be performed on transfer membranes, direct detection in gels avoids electroblotting and the specificity of staining is better in gels. After detecting glycoproteins with Pro-Q Emerald 488 dye, total protein profiles may subsequently be detected using SYPRO Ruby protein gel stain. Using computer-assisted registration techniques, images may then be merged to generate differential display maps. PMID:12601726

Hart, Courtenay; Schulenberg, Birte; Steinberg, Thomas H; Leung, Wai-Yee; Patton, Wayne F



Chromosome characterization using single fluorescent dye  


Chromosomes are characterized by fluorescent emissions from a single fluorescent dye that is excited over two different wavelengths. A mixture containing chromosomes is stained with a single dye selected from the group consisting of TOTO and YOYO and the stained chromosomes are placed in a flow cytometer. The fluorescent dye is excited sequentially by a first light having a wavelength in the ultraviolet range to excite the TOTO or YOYO to fluoresce at a first intensity and by a second light having a wavelength effective to excite the TOTO or YOYO dye to fluoresce at a second intensity. Specific chromosomes may be identified and sorted by intensity relationships between the first and second fluorescence emissions.

Crissman, Harry A. (Los Alamos, NM); Hirons, Gregory T. (Irvine, CA)



21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2012 CFR




21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2013 CFR




21 CFR 864.1850 - Dye and chemical solution stains.  




21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2011 CFR




21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2010 CFR




Nile red: a selective fluorescent stain for intracellular lipid droplets  

Microsoft Academic Search

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.




Development of an affordable dye-stained microalbuminuria screening test  

Microsoft Academic Search

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

Pierrot Lundimu Tugirimana; Joris R. Delanghe



Standardization of the Feulgen-Schiff technique. Staining characteristics of pure fuchsin dyes; a cytophotometric investigation.  


Four fuchsin analogues (Pararosaniline, Rosaniline. Magenta II and New Fuchsin) usually found in Basic Fuchsin have been applied as chemically pure dyes to the Feulgen-technique. Total nuclear absorption and wavelength of the absorption maximum were measured by microspectrophotometry in Feulgen stained cytological and plastic embedded histological liver samples, and in lymphocyte nuclei in human peripheral blood smears; absorption spectra of Feulgen stained DNA-polyacrylamide films were determined by spectrophotometry. The grey value distribution of tetraploid liver cell nuclei was calculated with an image analyzer. The staining characteristics of the pure dyes were compared to commercial fuchsin samples from various suppliers. Reverse phase thin layer chromatography was used for characterization and qualitative separation of commercial batches. Pure fuchsin analogues were all equally suitable for Feulgen staining: with respect of staining intensity all pure fuchsin dyes gave nearly identical results with a bathochromic shift of the absorption maximum from Pararosaniline to New Fuchsin of about 8 microns. Differences in staining results observed among the commercial dyes were due to varying dye content, contamination with an acridine-like fluorescent compound or simply mislabelling of samples. Pure Pararosaniline is recommended for a standard Feulgen technique. PMID:2732097

Schulte, E; Wittekind, D



Investigating fluorescent dyes in fluorescence-assisted screenings.  


Screening of bead-based peptide libraries against fluorescent dye-labeled target proteins was found to be significantly influenced by the dye characteristics. Commercially available red fluorescent dyes with net negative charges adversely showed strong interactions with library beads. The introduction of zwitterionic dyes significantly reduced the unwanted interactions, which sheds light upon using the right fluorescent probe for acquisition of reliable results in various fluorescence-assisted applications. PMID:25340456

Jee, Joo-Eun; Lim, Jaehong; Hyun, Hoon; Oon, Jessica; Ong, Yong Siang; Massif, Cedrik; Chang, Young-Tae; Choi, Hak Soo; Lee, Su Seong



Lucifer dyes-highly fluorescent dyes for biological tracing  

Microsoft Academic Search

Lucifer dyes are intensely fluorescent 4-aminonaphthalimides which are readily visible in living cells at concentrations and levels of illumination at which they are nontoxic. Because of their low molecular weight they frequently pass from one cell to another; this widespread phenomenon, termed dye-coupling, is thought to reveal functional relationships between cells. Lucifer dyes can also be used for ultrastructural tracing

Walter W. Stewart



Use of fluorescent staining and flow cytometry for monitoring physiological changes in solventogenic clostridia.  


Physiological changes in populations of Clostridium beijerinckii and Clostridium tetanomorphum were monitored by fluorescence staining and flow cytometry. To estimate the number of metabolically active cells in exponential growth, a combination of the dyes propidium iodide and carboxy fluorescein diacetate appeared to be a good choice for both species. During stationary phase, these stains did not reflect physiological changes sufficiently and therefore additional labeling with bis-(1,3-dibutylbarbituric acid) trimethineoxonol was applied. Results of fluorescence staining in solventogenic batch fermentations were compared with substrate-use data, the concentration of key metabolites and growth curves. We demonstrate that measurements by all methods were mutually compatible. PMID:24211310

Patakova, Petra; Linhova, Michaela; Vykydalova, Pavla; Branska, Barbora; Rychtera, Mojmir; Melzoch, Karel



Sizing of single fluorescently stained DNA fragments by scanning microscopy  

PubMed Central

We describe an approach to determine DNA fragment sizes based on the fluorescence detection of single adsorbed fragments on specifically coated glass cover slips. The brightness of single fragments stained with the DNA bisintercalation dye TOTO-1 is determined by scanning the surface with a confocal microscope. The brightness of adsorbed fragments is found to be proportional to the fragment length. The method needs only minute amount of DNA, beyond inexpensive and easily available surface coatings, like poly-l-lysine, 3-aminoproyltriethoxysilane and polyornithine, are utilizable. We performed DNA-sizing of fragment lengths between 2 and 14 kb. Further, we resolved the size distribution before and after an enzymatic restriction digest. At this a separation of buffers or enzymes was unnecessary. DNA sizes were determined within an uncertainty of 7–14%. The proposed method is straightforward and can be applied to standardized microtiter plates. PMID:14602931

Laib, Stephan; Rankl, Michael; Ruckstuhl, Thomas; Seeger, Stefan



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

SciTech Connect

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. 4 figs.

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



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


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.

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



Evaluation of fluorescent stains for visualizing extracellular DNA in biofilms.  


Here we determine an optimal technique for the visualization of extracellular DNA in bacterial biofilms using the fluorescent eDNA stain TOTO-1 and the counterstain SYTO 60. This technique allows for more sensitive eDNA visualization than other fluorescent staining methods currently in use. PMID:25017901

Okshevsky, Mira; Meyer, Rikke Louise



Improved Charge-Transfer Fluorescent Dyes  

NASA Technical Reports Server (NTRS)

Improved charge-transfer fluorescent dyes have been developed for use as molecular probes. These dyes are based on benzofuran nuclei with attached phenyl groups substituted with, variously, electron donors, electron acceptors, or combinations of donors and acceptors. Optionally, these dyes could be incorporated as parts of polymer backbones or as pendant groups or attached to certain surfaces via self-assembly-based methods. These dyes exhibit high fluorescence quantum yields -- ranging from 0.2 to 0.98, depending upon solvents and chemical structures. The wavelengths, quantum yields, intensities, and lifetimes of the fluorescence emitted by these dyes vary with (and, hence, can be used as indicators of) the polarities of solvents in which they are dissolved: In solvents of increasing polarity, fluorescence spectra shift to longer wavelengths, fluorescence quantum yields decrease, and fluorescence lifetimes increase. The wavelengths, quantum yields, intensities, and lifetimes are also expected to be sensitive to viscosities and/or glass-transition temperatures. Some chemical species -- especially amines, amino acids, and metal ions -- quench the fluorescence of these dyes, with consequent reductions in intensities, quantum yields, and lifetimes. As a result, the dyes can be used to detect these species. Another useful characteristic of these dyes is a capability for both two-photon and one-photon absorption. Typically, these dyes absorb single photons in the ultraviolet region of the spectrum (wavelengths < 400 nm) and emit photons in the long-wavelength ultraviolet, visible, and, when dissolved in some solvents, near-infrared regions. In addition, these dyes can be excited by two-photon absorption at near-infrared wavelengths (600 to 800 nm) to produce fluorescence spectra identical to those obtained in response to excitation by single photons at half the corresponding wavelengths (300 to 400 nm). While many prior fluorescent dyes exhibit high quantum yields, solvent-polarity- dependent fluorescence behavior, susceptibility to quenching by certain chemical species, and/or two-photon fluorescence, none of them has the combination of all of these attributes. Because the present dyes do have all of these attributes, they have potential utility as molecular probes in a variety of applications. Examples include (1) monitoring curing and deterioration of polymers; (2) monitoring protein expression; (3) high-throughput screening of drugs; (4) monitoring such chemical species as glucose, amines, amino acids, and metal ions; and (5) photodynamic therapy of cancers and other diseases.

Meador, Michael



Facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy.  


A method to fluorescently stain the surfaces of both Gram-negative and Gram-positive bacterial cells compatible with super-resolution fluorescence microscopy is presented. This method utilizes a commercially-available fluorescent probe to label primary amines at the surface of the cell. We demonstrate efficient staining of two bacterial strains, the Gram-negative Shewanella oneidensis MR-1 and the Gram-positive Bacillus subtilis 168. Using structured illumination microscopy and stochastic optical reconstruction microscopy, which require high quantum yield or specialized dyes, we show that this staining method may be used to resolve the bacterial cell surface with sub-diffraction-limited resolution. We further use this method to identify localization patterns of nanomaterials, specifically cadmium selenide quantum dots, following interaction with bacterial cells. PMID:24816810

Gunsolus, Ian L; Hu, Dehong; Mihai, Cosmin; Lohse, Samuel E; Lee, Chang-soo; Torelli, Marco D; Hamers, Robert J; Murhpy, Catherine J; Orr, Galya; Haynes, Christy L



Assessment of fluorescein-based fluorescent dyes for tracing Neotyphodium endophytes in planta.  


Fluorescent dyes were assessed for their ability to stain viable hyphae of the fungi Neotyphodium lolii and N. coenophialum, symbiotic endophytes of the Pooideae grasses Lolium perenne and Festuca arundinacea, respectively. The fluorescein-based fluorophores; fluorescein diacetate (FDA), 5(6)-carboxy-fluorescein diacetate (CFDA), 5-chloromethylfluorescein diacetate (CMFDA) and the chitin-binding stain, Calcofluor while M2R, were assessed for staining of endophyte hyphae in vitro from axenic fungal cultures and in planta, including epidermal leaf sheath peels, nodes, ovaries, embryos and meristems. CMFDA produced the greatest intensity of staining of fungal hyphae and gave excellent contrast in planta compared to the plant cells. Compared to the other dyes, CMFDA was also the least affected by photo bleaching and continued to fluoresce up to 2 h after initial excitation. None of the fluorescent dyes stained fungal hyphae in seed. PMID:22802389

Card, Stuart D; Tapper, Brian A; Lloyd-West, Catherine; Wright, Kathryn M



Simultaneous observation of collagen and elastin in normal and pathological tissues: analysis of Sirius-red-stained sections by fluorescence microscopy  

Microsoft Academic Search

In order to observe collagen and elastic fibers simultaneously, sections of human aorta, skin, lung, liver, and bladder were stained by Sirius red and analyzed by fluorescence microscopy. In all cases, the fibers of collagen presented the characteristic fluorescent red-orange color that results from the interaction of this extracellular protein with the dye, whereas elastic fibers showed strong green fluorescence

L. F. Borges; S. R. Taboga; P. S. Gutierrez



Fluorescence emission spectra of calcofluor stained yeast cell suspensions: heuristic assessment of basis spectra for their linear unmixing.  


Fluorescence emission spectra of yeast cell suspensions stained with calcofluor have recently been identified as promising markers of variations in the quality of yeast cell wall. It is shown in this paper how the raw fluorescence spectra of calcofluor can be transformed to reliable spectral signatures of cell wall quality, which are independent of actual dye-to-cell concentrations of examined cell suspensions. Moreover, the presented approach makes it possible to assess basis fluorescence spectra that allows for the spectral unmixing of raw fluorescence spectra in terms of respective fluorescence contributions of calcofluor solvated in the suspension medium and bound to yeast cell walls. PMID:22538834

Plášek, Jaromír; Dostál, Marek; Gášková, Dana



Fluorescent indicator dyes for calcium ions  

NASA Technical Reports Server (NTRS)

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.

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



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


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

Gelperin, A; Flores, J



Differential dichrome staining of tissue culture monolayers: alternate dyes and possible mechanism.  


A polyacid-dependent dichrome has been devised which will differentiate epithelial from mesenchymal cells in young dividing primary cultures. Epithelial cells and colonies and nuclei are stained with metanil yellow, the stain is fixed and differentiated with phosphotungstic acid, and the mesenchymal elements are stained with toluidine blue. Several other dyes are tested for substitution in this method. Biebrich scarlet and aniline blue could be substituted for the metanil yellow; Bismarck brown T, Janus green B, crystal violet, and neutral red could be substituted for the basic dye. PMID:89718

Everett, M M; Miller, W A



Identification of active fluorescence stained bacteria by Raman spectroscopy  

NASA Astrophysics Data System (ADS)

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.

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



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

NASA Astrophysics Data System (ADS)

Imaging techniques are a vital part of clinical diagnostics, biomedical research and nanotechnology. Optical molecular imaging makes use of relatively harmless, low-energy light and technically straightforward instrumentation. Self-illuminating, chemiluminescent systems are particularly attractive because 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 are 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, interlocked fluorescent and chemiluminescent dye molecules that have a squaraine chromophore encapsulated inside a macrocycle endoperoxide. Squaraine rotaxane endoperoxides 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.

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.



Hair ignition by dye laser for port-wine stain: risk factors evaluated.  


Flashlamp-pumped pulsed dye laser is the preferred treatment for port-wine stain. Vascular hemoglobin and epidermal melanin are competing sites for dye laser absorption and damage. The case presented illustrates the potential hazard of ignition induced by dye laser treatment on the face of a patient receiving inhalation anesthesia. A 6-year-old girl with almost black hair was treated for a port-wine stain covering most of the right half of her face. She was treated with dye laser under general anesthesia administered by mask. A laser pulse close to the upper part of the eyebrow induced a blaze and the eyebrow was instantly destroyed by the fire. Regrowth of the eyebrow was complete after a few months. Hair specimens of various colors were exposed experimentally to dye laser irradiation in room and oxygen-saturated atmospheres. Risk factors of ignition are high laser dosage, a high oxygen level, repeated pulses and dark colored hair. PMID:11357290

Molin, L; Hallgren, S



An easy method for cutting and fluorescent staining of thin roots  

PubMed Central

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

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



Improved Coomassie Blue Dye-Based Fast Staining Protocol for Proteins Separated by SDS-PAGE  

PubMed Central

The time required to visualize proteins using Coomassie Blue dye has been significantly reduced with the introduction of fast staining protocols based on staining with a Coomassie Blue dye solution at boiling temperatures. However, fast stainings suffer from high gel backgrounds, reducing the signal-to-noise ratio and limiting the number of detectable spots in the case of 2D SDS-PAGE. The aim of this work was to eliminate the high gel background, and thus improve fast staining protocols based on Coomassie Blue dye. We show that merely replacing water with a 4 mM EDTA washing solution at boiling temperatures, results in a transparent gel background within 50 to 60 minutes of destaining. Moreover, when a combination of imidazole-zinc reverse staining and Coomassie Blue-based fast staining is used the sensitivity is improved significantly; nanogram amounts of proteins can be detected using 1D SDS-PAGE, and about 30% to 60% more spots can be detected with 2D SDS-PAGE in plasma, platelet, and rat brain tissue samples. This work represents an optimized fast staining protocol with improved sensitivity, requiring between 60 to 75 minutes to complete protein visualization. PMID:24278455

Majek, Pavel; Riedelova-Reicheltova, Zuzana; Pecankova, Klara; Dyr, Jan E.



Synthesize dye-bioconjugates to visualize cancer cells using fluorescence microscopy  

NASA Astrophysics Data System (ADS)

The clinical diagnosis of most cancers is based on evaluation of histology microscopic slide to view the size and shape of cellular nuclei, and morphological structure of tissue. To achieve this goal in vivo and in deep tissue, near infrared (NIR) dyes-bovine serum albumin (BSA) and immunoglobulin G (IgG) conjugates were synthesized. The spectral study show that the absorption and fluorescence of the dye-conjugates are in the "tissue optical window" between 650 nm and 1100 nm. The internalization and pinocytosis of the synthesized compound were investigated in cell level using fluorescence microscopy to obtain the optimal concentration and staining time scale.

Pu, Yang; Tang, Rui; Xue, Jianpeng; Wang, W. B.; Xu, Baogang; Shen, Duanwen; Bloch, Sharon; Zhou, Mingzhou; Achilefu, S.; Alfano, R. R.



Utility of Green Fluorescent Nucleic Acid Dyes and Aluminum Oxide Membrane Filters for Rapid Epifluorescence Enumeration of Soil and Sediment Bacteria  

PubMed Central

High background fluorescence and unspecific staining hampered the epifluorescence enumeration of bacteria in 45% of the tested soil and sediment samples with 4?,6-diamidino-2-phenylindole (DAPI) and polycarbonate membrane filters. These problems of the determination of total cell counts can be circumvented by using green fluorescent high-affinity nucleic acid dyes and aluminum oxide membrane filters. Due to the bright staining of cells, we recommend SYBR Green II as dye. PMID:9835595

Weinbauer, Markus G.; Beckmann, Christiane; Höfle, Manfred G.



Novel fluorescent dyes for single DNA molecule techniques.  


To answer the demands of scientific and medical imaging issues, the family of nucleic acid fluorescent dyes is constantly enlarging. Most of the developed dyes reveal high qualities in bulk solution assays but are inefficient to produce a strong and sufficiently stable signal to enable the application of single-molecule techniques. Therefore, we tested 12 novel monomeric and homodimeric cyanine dyes for potential single DNA molecule imaging. Although their qualities in bulk solutions have already been described, nothing was known about their behavior on a single-molecule level. All 12 dyes demonstrated strong emission when intercalated into single DNA molecules and stretched on a silanized surface, which makes them the perfect choice for fluorescent microscopy imaging. A comparison of their fluorescence intensity and photostability with the most applicable dyes in single-molecule techniques, fluorescent dyes YOYO-1 and POPO-3, was carried out. They all exhibited a strong signal, comparable to that of YOYO-1. However, in contrast to YOYO-1, which is visualized under a green filter only, their emission permits red filter visualization. As their photostability highly exceeds that of similar spectrum POPO-3 dye, the studied dyes stand out as the best choice for a broad range of solid surface single-molecule applications when yellow to red DNA backbone fluorescence is needed. PMID:23415397

Zarkov, Alexander; Vasilev, Aleksey; Deligeorgiev, Todor; Stoynov, Stoyno; Nedelcheva-Veleva, Marina



Drying of Cryptosporidium oocysts and Giardia cysts to slides abrogates use of vital dyes for viability staining.  


Vital dye staining has long been used to assess viability of Cryptosporidium oocysts and Giardia cysts, with staining and enumeration in suspension. Some recent studies, however, have dried samples to microscope slides prior to staining. Here we demonstrate that this approach may considerably underestimate parasite viability in the original sample. PMID:24239946

Robertson, Lucy J; Casaert, Stijn; Valdez-Nava, Yazel; Ehsan, Md Amimul; Claerebout, Edwin



NIR fluorescent dyes: versatile vehicles for marker and probe applications  

NASA Astrophysics Data System (ADS)

The use of the NIR spectral region (650-900 nm) is advantageous due to the inherently lower background interference and the high molar absorptivities of NIR chromophores. Near-Infrared (NIR) dyes are increasingly used in the biological and medical field. The binding characteristics of NIR dyes to biomolecules are possibly controlled by several factors, including hydrophobicity, size and charge just to mention a few parameters. Binding characteristics of symmetric carbocyanines and found that the hydrophobic nature of the NIR dye is only partially responsible for the binding strength. Upon binding to biomolecules significant fluorescence enhancement can be observed for symmetrical carbocyanines. This fluorescence amplification facilitates the detection of the NIR dye and enhances its utility as NIR reporter. This manuscript discusses some probe and marker applications of such NIR fluorescent dyes. One application discussed here is the use of NIR dyes as markers. For labeling applications the fluorescence intensity of the NIR fluorescent label can significantly be increased by enclosing several dye molecules in nanoparticles. To decrease self quenching dyes that have relatively large Stokes' shift needs to be used. This is achieved by substituting meso position halogens with amino moiety. This substitution can also serve as a linker to covalently attach the dye molecule to the nanoparticle backbone. We report here on the preparation of NIR fluorescent silica nanoparticles. Silica nanoparticles that are modified with aminoreactive moieties can be used as bright fluorescent labels in bioanalytical applications. A new bioanalytical technique to detect and monitor the catalytic activity of the sulfur assimilating enzyme using NIR dyes is reported as well. In this spectroscopic bioanalytical assay a family of Fischer based n-butyl sulfonate substituted dyes that exhibit distinct variation in absorbance and fluorescence properties and strong binding to serum albumin as its sulfonic acid moiety is modified to less water soluble moiety was identified. In polar solvents, these water soluble compounds are strongly fluorescent, however form the less soluble aggregated species with virtual loss of fluorescence when the sulfonate groups are cleaved by enzymatic activity to form the corresponding straight chain alkyl aldehyde derivatives. To achieve this conversion in vitro photo-reduced riboflavin mononucleotide (FMN) with a glucose/ glucose-oxygenase oxygen scavenging system was utilized. The reduced FMN serves as a key substrate in the enzymatic desulfonation. Once the FMNH2 was produced the desulfonation reaction was characterized by using Laser Induced Fluorescence Capillary Zone Electropheresis (LIF-CZE). This method can be utilized as an assay to detect the enzyme activity in vitro with the possibilities of in vivo applications.

Patonay, Gabor; Chapman, Gala; Beckford, Garfield; Henary, Maged



Dimethylformamide interferes with Coomassie dye staining of proteins on blue native gel electrophoresis.  


Blue native gel electrophoresis (BN-PAGE) is used extensively for characterization of mitochondrial respiratory complexes and uses the binding of Coomassie brilliant blue G-250 to visualize proteins. Oxidative modification of sulfhydryl groups of such proteins can be evaluated by labeling with iodoacetamide conjugated to biotin (BIAM) and detected with streptavidin peroxidase on Western blots following BN-PAGE. However, dissolving BIAM in dimethylformamide, a recommended solvent, reduces Coomassie blue G staining to proteins during BN-PAGE. This interference is prevented by dissolving BIAM in dimethyl sulfoxide. Precautions in the use of the dye for protein staining subsequent to BIAM labeling are discussed. PMID:24662748

Raghupathy, V; Oommen, Anna; Ramachandran, Anup



X-34, A Fluorescent Derivative of Congo Red: A Novel Histochemical Stain for Alzheimer's Disease Pathology  

Microsoft Academic Search

SUMMARY X-34, a lipophilic, highly fluorescent derivative of Congo red, was examined as a histochemical stain for pathological changes in Alzheimer's disease (AD). X-34 in- tensely stained neuritic and diffuse plaques, neurofibrillary tangles (NFTs), neuropil threads, and cerebrovascular amyloid. Comparison to standard methods of demonstrating AD pathology showed that X-34 correlated well with Bielschowsky and thioflavin-S stain- ing. X-34 staining

Scot D. Styren; Ronald L. Hamilton; Gisele C. Styren; William E. Klunk



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

PubMed Central

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

Werz, Emma



Fluorescent ester dye-based assays for the in vitro measurement of Neospora caninum proliferation.  


Techniques for the measurement of parasite loads in different experimental models have evolved throughout the years. The quantification of stained slides using regular cytological stains is currently the most common technique. However, this modality of evaluation is labor-intensive, and the interpretation of the results is subjective because the successes of the assays mainly rely on the abilities of the professionals involved. Moreover, the novel genetic manipulation techniques that are commonly applied for closely related Toxoplasma gondii have not yet been developed for Neospora caninum. Thus, we aimed to develop a simple protocol for parasite quantification using pre-stained N. caninum tachyzoites and fluorescent probes based on ester compounds (i.e., CFSE and DDAO). For this purpose, we employed a quantification procedure based on flow cytometry analysis. Pre-stained parasites were also examined with a fluorescent microscope, which revealed that both dyes were detectable. Direct comparison of the numbers of CFSE+ and DDAO+ cells to the values obtained with classical cytology techniques yielded statistically comparable results that also accorded with genomic DNA amplification results. Although the fluorescence emitted by DDAO was more intense and provided better discrimination between the populations of parasitized cells, CFSE+ tachyzoites were detected for several days. In conclusion, this study describes a simple, fast, low-cost and reproducible protocol for N. caninum quantification that is based on parasite pre-staining with fluorescent ester-based probes. PMID:25095733

Mota, Caroline M; Ferreira, Marcela D; Costa, Lourenço F; Barros, Patrício S C; Silva, Murilo V; Santiago, Fernanda M; Mineo, José R; Mineo, Tiago W P



Development of a fluorogenic probe based on a DNA staining dye for continuous monitoring of the histone deacetylase reaction.  


We designed a simple, rapid, and continuous method for the detection of the activity of histone deacetylases (HDACs), which are key enzymes involved in epigenetic gene regulation, using a DNA-based fluorogenic probe. We designed and synthesized a fluorogenic probe, BOXTO-GK(Ac)G, which is a DNA staining dye-peptide conjugate containing an acetylated lysine. The DNA-dependent fluorescence of BOXTO-GK(Ac)G was greatly enhanced upon deacetylation of the acetylated lysine moiety, owing to the increased DNA binding ability of the probe. The HDAC reaction was detected through a simple procedure that combined this probe with DNA. Our detection system monitored the enzymatic reaction in real time and could be applied to the inhibition assay. These findings demonstrated that our system might be a useful tool for the analysis of HDAC function and for the evaluation of the inhibitor potencies of drug candidates that target HDACs. PMID:25004201

Minoshima, Masafumi; Matsumoto, Tetsuaki; Kikuchi, Kazuya



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


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.

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



Multimodal fluorescence microscopy of prion strain specific PrP deposits stained by thiophene-based amyloid ligands.  


The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies. PMID:24831803

Magnusson, Karin; Simon, Rozalyn; Sjölander, Daniel; Sigurdson, Christina J; Hammarström, Per; Nilsson, K Peter R



Development of Highly Fluorescent Materials Based on Thiophenylimidazole Dyes  

NASA Technical Reports Server (NTRS)

Organic fluorescent materials are expected to find many potential applications in optical devices and photo-functionalized materials. Although many investigations have been focused on heterocyclic compounds such as coumarins, bipyridines, rhodamines, and pyrrole derivatives, little is known for fluorescent imidazole materials. We discovered that one particular class of imidazole derivatives is highly fluorescent. A series of monomeric and polymeric based fluorescent dyes were prepared containing a thiophene unit at the second position of the imidazole ring. Dependence of fluorescence efficiency on parameters such as solvent polarity and substituent groups has been investigated. It was found that a formyl group at the 2-position of the thiophene ring dramatically enhance fluorescence properties. Ion recognition probes indicated their potential as sensor materials. These fluorophores have flexibility for introduction of versatile substituent groups that could improve the fluorescence efficiency and sensor properties.

Santos, Javier; Bu, Xiu R.; Mintz, Eric A.; Meador, Michael A. (Technical Monitor)



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

PubMed Central

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

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



Approximate analytic solutions for the optical pumping of fluorescent dyes  

NASA Technical Reports Server (NTRS)

A general technique for solving a system of rate equations describing the interaction of an electromagnetic field and a molecular system is presented. The method is used to obtain approximate time-dependent solutions for the upper-level population of fluorescent dyes in the presence of a pump field.

Lawandy, N. M.



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


Using an optical imaging technique with voltage-sensitive dyes (VSDs), we investigated 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 fluorescence VSDs 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

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



Fluorescent Staining of Tea Pathogenic Fungi in Tea Leaves Using Fluorescein-labeled Lectin  

NASA Astrophysics Data System (ADS)

Fluorochrome-labeled lectin, fluorescein conjugated wheat germ agglutinin (F-WGA) was applied to stain tea pathogenic fungi in tea leaf tissue. Infected leaves were fixed and decolorized with a mixture of ethanol and acetic acid, and cleared with 10% KOH for whole mount before staining with F-WGA. Hyphae of Pestalotiopsis longiseta, Pseudocercospora ocellata, Botrytis cinerea and Colletotrichum theae-sinensis fluoresced brightly in whole mount and sectioned samples of infected leaf tissue. In browned tissue, hyphae did not fluoresce frequently in whole mount sample. Autofluorescence of leaf tissue was strong in browned tissue of sections, it was removed by 10% KOH treatment before staining. Penetration hyphae of C. theae-sinensis in cell wall of trichome and hyphae in basal part of trichome did not fluoresced frequently. In whole mount samples of tea leaf infected with Exobasidium vexans and E. reticulatum, hymenia appeared on leaf surface fluoresced, but hyphae in leaf tissue did not fluoresce. In sectioned samples, hyphae fluoresced brightly when sections were treated with 10% KOH before staining.

Yamada, Kengo; Yoshida, Katsuyuki; Sonoda, Ryoichi


Phosphoprotein staining for sodium dodecyl sulfate-polyacrylamide gel electrophoresis using fluorescent reagent morin hydrate.  


A fluorescence-based stain with 3,5,7,2',4'-pentahydroxyflavone (morin hydrate, MH) was designed to stain phosphoproteins in one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Al(3+) was applied as a "fixed bridge," providing an efficient energy transfer channel between phosphoprotein and MH, to produce a strong fluorescent complex for the determination of phosphoprotein. As little as 62.5ng of ?-casein (7 or 8 phosphates) and ?-casein (5 phosphates), 125ng of ovalbumin (2 phosphates), and ?-casein (1 phosphate) could be visualized with a wide linear dynamic range. In comparison with conventional methods, MH stain is a time-saving method that takes just 90min. It also has good compatibility with routine protein stainings such as Coomassie Brilliant Blue R (CBBR) and SYPRO Ruby for total protein analysis. PMID:23274386

Wang, Xu; Hwang, Sun-Young; Cong, Wei-Tao; Jin, Li-Tai; Choi, Jung-Kap



Design, Syntheses and Applications of Fluorescent Dyes  

E-print Network

. They were then used as acceptors to prepare water-soluble through-bond energy transfer cassettes. All the cassettes had complete energy transfer and high quantum yields in MeOH. A few also had good fluorescence properties in aqueous media and even...

Wu, Liangxing



Simultaneous Fluorescent Gram Staining and Activity Assessment of Activated Sludge Bacteria  

Microsoft Academic Search

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

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



Fluorescent dye-doped silica nanoparticles: new tools for bioapplications.  


The need to decipher various biological events has led to the elucidation of the molecular mechanisms underlying a number of disease processes. Consequently, the detection and simultaneous monitoring of chemical interactions between biological targets has become indispensable in medical diagnosis, targeted therapeutics, and molecular biology. Multiplexed applications employing nanomaterials, which represent the integration of nanotechnology and biology, have changed the bioanalytical outlook and provided various promising tools. Among these nanomaterials, fluorescent dye-doped silica nanoparticles have demonstrated excellent potential for use in advanced bioanalysis to facilitate deeper understanding of biology and medicine at the molecular level. In particular, silica nanoparticles have been applied to diagnostics and therapeutic applications in cancer and gene/drug delivery. This feature article summarizes recent developments in the synthesis, biocompatibility, and bioapplications of fluorescent dye-doped silica nanoparticles. PMID:22258619

Bae, Se Won; Tan, Weihong; Hong, Jong-In



Controlling the fluorescence lifetime of dyes in nanostructured geometries  

NASA Astrophysics Data System (ADS)

In this paper we show that the coupling of common red/near infrared emitting dyes with a well-defined photonic environment, comparable to Drexhage's structure, is effective to enhance or inhibit the molecular spontaneous emission rate. The fluorescent dye molecules were adsorbed at the air-polystyrene interface and spaced at known distances (20-200 nm) from the polystyrene-silver interface. The experimental decay rates of molecules were successfully modelled using a classical electrodynamics model that treats the emitter as a forced, damped electric dipole oscillator interacting with its nanoenvironment through its near field. Our results help establish a basis for characterising near-fields in nano-optics and controlling fluorescing species.

Astilean, S.; Garrett, S.; Andrew, P.; Barnes, W. L.



Fluorescent performance of electrospun polyimide web mixed with hemicyanine dye  

Microsoft Academic Search

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

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



A novel method for monitoring tumor proliferation in vivo using fluorescent dye DiD.  


Monitoring single cell proliferation in vivo is difficult, but optimizing this technique is essential in order to expand our knowledge of the regulation of tumor proliferation. In this study, we used a lipophilic fluorescent dye, DiD, that rapidly and stably integrates into the phospholipid cell membrane. We cultured DiD-stained prostate cancer cell lines for 10 days and isolated cells by flow cytometry based on expression levels of DiD. We found that a decrease in DiD intensity was correlated to the reduction of EdU, where the DiD-high population proliferated more slowly than the DiD-low population and the DiD-low population exhibited a higher mitotic index. We also found that DiD was detected after 3 weeks of implantation in an in vivo setting. Importantly, DiD dye did not have any effect on normal cell growth, whereas a gold standard fluorescent dye for measuring cell proliferation, CFSE, slowed cell proliferation. Although further study is indicated, DiD can be useful for identifying the molecular mechanisms underlying tumor proliferation in vivo. PMID:24700602

Yumoto, Kenji; Berry, Janice E; Taichman, Russell S; Shiozawa, Yusuke



Quantitative amplification of genomic DNA from histological tissue sections after staining with nuclear dyes and laser capture microdissection.  


Laser capture microdissection (LCM) allows the selective sampling of tissue from histological sections. A prerequisite for this technique is the availability of histological dyes that do not interfere with downstream analysis of the sampled genetic material. We have examined the effect of four histological nuclear dyes (methyl green, hematoxylin, toluidine blue O, azure B) on TaqMan polymerase chain reaction amplification of beta-actin genomic DNA prepared from fixed and frozen tissue. Tissue sampled from the histological sections by manual dissection was compared with tissue sampled by LCM. As previously reported, when manually dissected tissue sections were analyzed, polymerase chain reaction amplification of DNA after hematoxylin staining was inferior to that after staining with the other dyes. In contrast, when tissue sampled by LCM was examined, DNA recovery after hematoxylin staining was equivalent to the recovery after methyl green staining. We conclude that DNA recovery from LCM-sampled tissue is independent of the histological stain chosen to highlight nuclear detail. PMID:11227068

Ehrig, T; Abdulkadir, S A; Dintzis, S M; Milbrandt, J; Watson, M A



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

PubMed Central

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

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.



Modulated photophysics of a cationic DNA-staining dye inside protein bovine serum albumin: study of binding interaction and structural changes of protein.  


The binding affinity of cationic DNA-staining dye, propidium iodide, with transport protein, bovine serum albumin, has been explored using UV-vis absorption, fluorescence, and circular dichroism spectroscopy. Steady state and time resolved fluorescence studies authenticate that fluorescence quenching of bovine serum albumin by propidium iodide is due to bovine serum albumin-propidium iodide complex formation. Thermodynamic parameters obtained from temperature dependent spectral studies cast light on binding interaction between the probe and protein. Site marker competitive binding has been encountered using phenylbutazone and flufenamic acid for site I and site II, respectively. Energy transfer efficiency and distance between bovine serum albumin and propidium iodide have been determined using Förster mechanism. Structural stabilization or destabilization of protein by propidium iodide has been investigated by urea denaturation study. The circular dichroism study as well as FT-IR measurement demonstrates some configurational changes of the protein in presence of the dye. Docking studies support the experimental data thereby reinforcing the binding site of the probe to the subdomain IIA of bovine serum albumin. PMID:24216153

Samanta, Anuva; Jana, Sankar; Ray, Debarati; Guchhait, Nikhil



Improved Dye Stability in Single-Molecule Fluorescence Experiments  

NASA Astrophysics Data System (ADS)

Complex biological systems challenge existing single-molecule methods. In particular, dye stability limits observation time in singlemolecule fluorescence applications. Current approaches to improving dye performance involve the addition of enzymatic oxygen scavenging systems and small molecule additives. We present an enzymatic oxygen scavenging system that improves dye stability in single-molecule experiments. Compared to the currently-employed glucose-oxidase/catalase system, the protocatechuate-3,4-dioxygenase system achieves lower dissolved oxygen concentration and stabilizes single Cy3, Cy5, and Alexa488 fluorophores. Moreover, this system possesses none of the limitations associated with the glucose oxidase/catalase system. We also tested the effects of small molecule additives in this system. Biological reducing agents significantly destabilize the Cy5 fluorophore as a function of reducing potential. In contrast, anti-oxidants stabilize the Cy3 and Alexa488 fluorophores. We recommend use of the protocatechuate-3,4,-dioxygenase system with antioxidant additives, and in the absence of biological reducing agents. This system should have wide application to single-molecule fluorescence experiments.

EcheverrÍa Aitken, Colin; Marshall, R. Andrew; Pugi, Joseph D.


Synthetic routes to fluorescent dyes exhibiting large Stokes shifts.  


Derivatives of isomeric 2-(hydroxytolyl)-4,6-dimethylamino-1,3,5-triazines have been synthesized in high yields in a controlled manner using a multistep reaction sequence. Iodination of either 2-(1'-hydroxy-6'-methylphen-2'-yl)- or 2-(1'-hydroxy-4'-methylphen-2'-yl)-4,6-dimethylamino-1,3,5-triazine with ICl provides species differing in the positioning of the iodo group relative to the hydroxyl which readily undergo Suzuki, Sonogashira, and Heck reactions under Pd(0) catalysis. Thus, thienyl, bisthienyl, and 3,4-ethylenedioxythienyl groups have been directly grafted, while unsubstituted polycyclic aromatics such as pyrene and perylene have been linked via alkyne bridges, as have ethynyldifluoroborondipyrromethane (BODIPY) dyes prepared in situ. The presence of a hydrogen bond in the ground state involving the hydroxyl substituent has been established by proton NMR and several X-ray structure determinations. All of the new dyes with a simple substituent (phenyl, thienyl) exhibited a pronounced green fluorescence resulting from an intramolecular proton transfer in the excited state (ESIPT) which produces a large Stokes shift (>10,000 cm(-1)). With other dyes, the fluorescence of the keto form responsible for the ESIPT process could be used as the input energy in efficient intramolecular energy transfer processes. Replacing perylene with pyrene allowed reversal of the direction of energy transfer from the polyaromatic module to the keto form. PMID:22834858

Rihn, Sandra; Retailleau, Pascal; De Nicola, Antoinette; Ulrich, Gilles; Ziessel, Raymond



Exclusion of cytoplasmic fragments in flow cytometric analysis of lymph node samples from dogs with lymphoma using membrane-permeable violet laser-excitable DNA-binding fluorescent dye (DyeCycle Violet)  

PubMed Central

Background Cytoplasmic fragments derived from fragile neoplastic lymphocytes are common in samples of lymph nodes collected from dogs with lymphoma. These cytoplasmic fragments interfere with accurate gating of target cells and quantification protocols used for flow cytometry because of their variable size and expression of lymphoid cell surface antigens on their membranes. Objective The aim of this study was to develop a method to efficiently exclude cytoplasmic fragments from flow cytometric analysis of canine lymph nodes in which lymphoma was present. Methods Single-cell suspensions of neoplastic cells were prepared from biopsy samples and fine-needle aspirates of lymph nodes from 23 dogs with lymphoma. Suspensions were stained using a violet laser-excitable (405 nm) membrane-permeable DNA-binding fluorescent dye (DyeCycle Violet, DCV), incubated with antibodies against CD3, CD5, CD21, CD22, and CD45, and then stained with 7-amino-actinomycin D, an argon-excitable (488 nm) membrane-impermeable DNA-binding fluorescent dye. Multi-parameter flow cytometry was used for analysis based on selective uptake and laser-activated fluorescence of these dyes. Results Cytoplasmic fragments, which were DCV-negative and CD45-positive, and dead cells, which were positive for 7-amino-actinomycin D, were efficiently separated from neoplastic cells. Conclusion Staining with DyeCycle Violet is a useful method to improve flow cytometric gating methods and quantitative analyses of lymph node samples from dogs with lymphoma. PMID:21198735

Ito, Daisuke; O'Brien, Timothy D.; Modiano, Jaime F.



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

Microsoft Academic Search

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

A Gelperin; J Flores



Influence of pulsewidth on the efficiency of pulsed dye laser (PDL) treatment of port-wine stains  

NASA Astrophysics Data System (ADS)

In order to destroy selectively cutaneous vessels with a dye laser, the exposition time has to be shorter than the thermal relaxation time of the target tissue. Within this frame of time longer pulses are found to be more efficient in bleaching portwine stains than shorter ones. Two pulses of different length but with identical power density are compared in their therapeutical efficiency by means of reflectometry. There were no relevant differences neither in terms of lightness, redness nor in yellowness. If the increment and the irradiance is the same, a pulse stretching form 200 microsecond(s) to 260 microsecond(s) does not influence decisively the therapeutical effect in portwine stains.

Strempel, Hartmut; Klein, Guy



An investigation of the fixation and staining of lipids by a combination of malachite green or other triphenylmethane dyes with glutaraldehyde.  


Mixtures of the monocationic triphenylmethane dyes, malachite green or crystal violet, with glutaraldehyde, retained and stained phospholipid droplets in chloroplasts of leaves of Lolium multiflorum Lam. These dyes also stained trilinolenin; phosphatidic acid dioleoyl, dipalmitoyl; phosphatidylcholine dioleoyl, dilinoleoyl; and phosphatidylethanolamine dioleoyl on filter paper models. In this model system the dipalmitoyl derivatives of phosphatidylcholine and phosphatidylethanolamine did not stain well, if at all. Washing of the dyed samples with 0.5 M sodium chloride solution did not remove the colour, suggesting that the interaction is unlikely to be purely ionic. Except with trilinolenin, the colour and possibly the lipid samples were removed from the filter paper model system on washing with 100% ethyl alcohol. Other triphenylmethane dyes (methyl green, light green and fast green FCF) did not retain phospholipid droplets in tissue. Fast green did, however, stain phospholipids in the model system. Two quinone-imine dyes, neutral red and toluidine blue O, while staining phospholipids in the model system did not retain droplets on the chloroplasts but did assist in the retention and staining of cell membranes. The basis of the reaction between lipid and dye is discussed in relation to the structural formulae of the dyes and model lipids. It is possible that there is an interaction between the hydrophobic fatty acid ester side chains of the lipid and the dyes. Neither the phosphate nor the polyhydric alcohol moieties of the lipid seem to be essential for staining or retention of lipid. PMID:2473211

Lawton, J R



Topography and response timing of intact cerebellum stained with absorbance voltage-sensitive dye.  


Physiological activity of the turtle cerebellar cortex (Cb), maintained in vitro, was recorded during microstimulation of inferior olive (IO). Previous single-electrode responses to such stimulation showed similar latencies across a limited region of Cb, yet those recordings lacked spatial and temporal resolution and the recording depth was variable. The topography and timing of those responses were reexamined using photodiode optical recordings. Because turtle Cb is thin and unfoliated, its entire surface can be stained by a voltage-sensitive dye and transilluminated to measure changes in its local absorbance. Microstimulation of the IO evoked widespread depolarization from the rostral to the caudal edge of the contralateral Cb. The time course of responses measured at a single photodiode matched that of single-microelectrode responses in the corresponding Cb locus. The largest and most readily evoked response was a sagittal band centered about 0.7 mm from the midline. Focal white-matter (WM) microstimulation on the ventricular surface also activated sagittal bands, whereas stimulation of adjacent granule cells evoked a radial patch of activation. In contrast, molecular-layer (ML) microstimulation evoked transverse beams of activation, centered on the rostrocaudal stimulus position, which traveled bidirectionally across the midline to the lateral edges of the Cb. A timing analysis demonstrated that both IO and WM microstimulation evoked responses with a nearly simultaneous onset along a sagittal band, whereas ML microstimulation evoked a slowly propagating wave traveling about 25 cm/s. The response similarity to IO and WM microstimulation suggests that the responses to WM microstimulation are dominated by activation of its climbing fibers. The Cb's role in the generation of precise motor control may result from these temporal and topographic differences in orthogonally oriented pathways. Optical recordings of the turtle's thin flat Cb can provide insights into that role. PMID:19004999

Brown, Michael E; Ariel, Michael



Clinical feasibility of various optical instruments for quantitative evaluation of pulsed-dye laser treatment of port wine stain skin  

Microsoft Academic Search

For quantitative prediction and evaluation of pulsed dye laser therapy of port wine stain (PWS) skin, the CIE L*a*b* color difference, DeltaE*, has been utilized to characterize numerically the color differences between normal untreated and treated PWS skin. Three optical instruments (Minolta chromameter CR-200, a cross-polarized diffuse reflectance imaging system, and visual reflectance spectrometers) are compared to investigate their clinical

Chang-Seok Kim; Byungjo Jung; Bernard Choi; Wim Verkruysse; Rong Zhang; John S. Nelson



pH-Sensitive Fluorescent Dyes: Are They Really pH-Sensitive in Cells?  

PubMed Central

Chemically synthesized near-infrared (NIR) aza-BODIPY dyes displayed OFF/ON fluorescence at acidic pH (pKa = 6.2-6.6) through the suppression of photoinduced electron transfer (PET) and/or internal charge transfer (ICT) process. The apparent pKas of the dyes were shifted well above physiological pH in hydrophobic microenvironment, which led to “turned-on” fluorescence in micelles and liposomes at neutral and basic pH. Bovine serum albumin (BSA) also activated the fluorescence, though to a much less extent. When these small molecular dyes entered cells, instead of being fluorescent only in acidic organelles, the whole cytoplasm exhibited fluorescence, with signal/background ratio as high as ?10 in no-wash live cell imaging. The dye 1 labeled cells remained highly fluorescent even after 3 days. Moreover, slight variations of the dye structure resulted in significantly different intracellular fluorescence behaviors, possibly due to their different cellular uptake and intracellular activation capabilities. After separation of cellular components, the fraction of plasma membrane and endoplasmic reticulum (ER) showed the highest fluorescence, further confirming the fluorescence activation by membrane structures. The fluorescence intensity of these dyes at different intracellular pH (6.80 and 8.00) did not differ significantly, indicating that intracellular pH did not play a critical role. Altogether, we showed here for the first time that the fluorescence of pH-sensitive aza-BODIPY dyes were switched intracellularly not by acidic pH, but by intracellular membranes (and proteins as well). The excellent membrane permeability, ultra high fluorescence contrast ratio, persistent fluorescent signal, and minimum biological interference of dye 1 make it an ideal choice for live cell imaging and in vivo cell tracking. These findings also imply that the intracellular fluorescent properties of pH-sensitive dyes should be carefully examined before used as pH indicators. PMID:23464828

Zhang, Xiao-Xiang; Wang, Zhe; Yue, Xuyi; Ma, Ying; Kiesewetter, Dale O.; Chen, Xiaoyuan



The use of live fluorescence staining techniques in surgery: a review.  


Intraoperative fluorescence may allow improvements to existing surgical procedures or offer scope for new operations. Despite articles describing its use dating back more than a decade, its emergence as a commonly used adjunct is still anticipated. While awareness and availability of special equipment may limit the uptake of these techniques, intraoperative fluorescence could represent a key innovation in the future of surgery. Further awareness of techniques and more clinical trials are needed to promote a wide base of clinical expertise from which further innovations can be made. This literature review begins with a discussion of the physics and chemistry of fluorophores and the properties needed for use in clinical practice. Uses in the majority of surgical specialties will be considered and the current literature addressed. Common uses include delineating hollow visci such as blood vessels or demonstrating pathology such as tumors. Fluorescent stains used have been safe, effective, and often easier to use than the established methods. Finally, novel materials such as antibodies and nanoparticles will be mentioned as new developments on the horizon of intraoperative fluorescent staining. PMID:23617319

Roberts, Harry W; Donati-Bourne, Jack F; Wilson, Victoria L F; Wilton, Joanne C



Imaging of interferences between cellular particles and the fluorescent dye Merocyanine-540 during normoxia and anoxia  

NASA Astrophysics Data System (ADS)

Subcellular particles (mitochondria, cellular pigments etc.) are mainly responsible for light scattering in living tissues in relation to the functional state. 2-D images clarify the respective tissue status during normoxia or anoxia such as the redox state of cytochromes. We realized tissue imaging of twelve isolated perfused rat livers stained with Merocyanine-540 during normoxia, hypoxia and anoxia. Merocyanine-spectra have shown a maximum fluorescence peak at 596 +/- 2 nm. The optical response increased under desoxygenation and decreased under reoxygenation and might be correlated to electrical potential alterations. Furthermore, we record oscillations with frequencies over 7/sec (420/min) which might be correlated to intracellular processes. The additional use of dyes for tissue imaging gives us the opportunity of new insights into organ function.

Mahlke, Christine; Dammann, Marc; Steinbach, Valerie; Stingl, Maria-Theresa; Kessler, Manfred D.



Synthesis, characterization and fluorescence studies of novel tetrachloroperylene-azo hybrid dyes.  


Novel rylene-azo hybrid dyes have been synthesized by condensation of azo-dyes with tetrachloroperylene dianhydride, possessing stupendous thermal, chemical and photochemical stability. Phenolic azo dyes are used for the nucleophilic replacement of chlorine substituents at 1,6,7,12-positions of perylene 3,4,9,10-dianhydride system. The absorption maxima (?(max)) of these dyes have been determined in diverse solvents such as water, ethanol, methanol, ethyl acetate and N, N-dimethylformamide. Fluorescence spectra are taken in water and highest fluorescence was exhibited by dyes containing carboxylic groups. The ?(max) and fluorescence of these dyes is greatly affected by polarity of solvents. The structures of newly synthesized rylene-azo hybrid dyes have been confirmed by UV, FTIR and (1)HNMR spectroscopy. PMID:24912451

Saeed, Aamer; Shabir, Ghulam



Non-specific fluorescent whitener stains in the rapid recognition of pulmonary dirofilariasis: a report of 20 cases  

Microsoft Academic Search

BACKGROUND--Solitary lung nodules in humans caused by the dog parasite Dirofilaria immitis are steadily increasing in number. The organisms can be easily missed in haematoxylin and eosin stained tissue when they are degenerated and pale staining. METHODS--The value of Tinopal CBS-X (TCBS-X) and Calcofluor white (CFW), two rapid, inexpensive, simple non-specific fluorescent whitening stains, were assessed in the identification of

L K Green; M Q Ansari; M R Schwartz; J Y Ro; L C Alpert



Direct confocal acquisition of fluorescence from X-gal staining on thick tissue sections  

PubMed Central

X-gal staining is a common procedure used in the histochemical monitoring of gene expression by light microscopy. However, this procedure does not permit the direct confocal acquisition of images, thus preventing the identification of labelled cells on the depth (Z) axis of tissue sections and leading sometimes to erroneous conclusions in co-localization and gene expression studies. Here we report a technique, based on X-gal fluorescence emission and mathematically-based optical correction, to obtain high quality fluorescence confocal images. This method, combined with immunofluorescence, makes it possible to unequivocally identify X-gal-labelled cells in tissue sections, emerging as a valuable tool in gene expression and cell tracing analysis. PMID:24121824

Levitsky, Konstantin L.; Toledo-Aral, Juan Jose; Lopez-Barneo, Jose; Villadiego, Javier



Intracellular distribution of the fluorescent dye nonyl acridine orange responds to the mitochondrial membrane potential: implications for assays of cardiolipin and mitochondrial mass.  


Cardiolipin, a polyunsaturated acidic phospholipid, is found exclusively in bacterial and mitochondrial membranes where it is intimately associated with the enzyme complexes of the respiratory chain. Cardiolipin structure and concentration are central to the function of these enzyme complexes and damage to the phospholipid may have consequences for mitochondrial function. The fluorescent dye, 10 nonyl acridine orange (NAO), has been shown to bind cardiolipin in vitro and is frequently used as a stain in living cells to assay cardiolipin content. Additionally, NAO staining has been used to measure the mitochondrial content of cells as dye binding to mitochondria is reportedly independent of the membrane potential. We used confocal microscopy to examine the properties of NAO in cortical astrocytes, neonatal cardiomyocytes and in isolated brain mitochondria. We show that NAO, a lipophilic cation, stained mitochondria selectively. However, the accumulation of the dye was clearly dependent upon the mitochondrial membrane potential and depolarisation of mitochondria induced a redistribution of dye. Moreover, depolarisation of mitochondria prior to NAO staining also resulted in a reduced NAO signal. These observations demonstrate that loading and retention of NAO is dependant upon membrane potential, and that the dye cannot be used as an assay of either cardiolipin or mitochondrial mass in living cells. PMID:12124423

Jacobson, Jake; Duchen, Michael R; Heales, Simon J R



A shortcut organic dye-based staining method for the detection of DNA both in agarose and polyacrylamide gel electrophoresis.  


In this study, we describe a brief, sensitive and safe organic dye-based staining method for the visualization of DNA both in agarose and polyacrylamide gels by using Victoria Pure Blue BO (VPBBO). Down to 0.8-1.6 ng of ? DNA/HindIII markers in agarose gels and 0.4-0.8 ng of pUC18 DNA/Mspl markers in polyacrylamide gels can be successfully detected within 15 and 10 min by the new developed technique, respectively. Moreover, the mechanism of the VPBBO staining was investigated and further confirmed by electrospray ionization mass spectrometry (ESI-MS) and molecular docking. The results indicated that the interaction between VPBBO and DNA is mainly due to groove binding. PMID:23296513

Cong, Weitao; Chen, Mao; Zhu, Zhongxin; Liu, Zhiguo; Nan, Jia; Ye, Weijian; Ni, Maowei; Zhao, Ting; Jin, Litai



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

SciTech Connect

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.

Abdel-Kareem, O. [Conservation Department, Faculty of Archaeology, Cairo University (Egypt); Eltokhy, A.; Harith, M. A. [National Institute of Laser Enhanced Science, Cairo University (Egypt)



Estrogen receptor-targeted optical imaging of breast cancer cells with near-infrared fluorescent dye  

NASA Astrophysics Data System (ADS)

Molecular imaging provides the in vivo characterization of cellular molecular events involved in normal and pathologic processes. With the advent of optical molecular imaging, specific molecules, proteins and genes may be tagged with a luminescent reporter and visualized in small animals. This powerful new tool has pushed in vivo optical imaging to the forefront as it allows for direct determination of drug bio-distribution and uptake kinetics as well as an indicator of biochemical activity and drug efficacy. Although optical imaging encompasses diverse techniques and makes use of various wavelengths of light, a great deal of excitement in molecular research lies in the use of tomographic and fluorescence techniques to image living tissues with near-infrared (NIR) light. Nonionizing, noninvasive near-infrared optical imaging has great potential to become promising alternative for breast cancer detection. Fluorescence spectroscopy studies of human tissue suggest that a variety of lesions show distinct fluorescence spectra compared to those of normal tissue. It has also been shown that exogenous dyes exhibit selective uptake in neoplastic lesions and may offer the best contrast for optical imaging. Use of exogenous agents would provide fluorescent markers, which could serve to detect embedded tumors in the breast. In particular, the ability to monitor the fluorescent yield and lifetime may also enable biochemical specificity if the fluorophore is sensitive to a specific metabolite, such as oxygen. As a first step, we have synthesized and characterized one such NIR fluorescent dye conjugate, which could potentially be used to detect estrogen receptors (ER)[2] . 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. The ester formed was found to have an extra binding ability with the receptor cites as compared to ICG, which was established by the partition coefficient studies. The replacement of the sodium ion in the ester by a larger glucosammonium ion was found to enhance the hydrophilicity and reduce the toxic effect on the cell lines. The excitation and emission peaks for the conjugate were recorded in the NIR region as 750nm and 788nm respectively. The ester was found nontoxic on adenocarcinoma breast cancer cell lines MCF-7/MDA-MB-231. Specific binding and endocytosis of the estrogen-labeled conjugate was studied on the MCF-7 (ER positive) and MDA-MB-231 (ER negative). Conjugate staining of MCF-7 cells showed ~ 4-fold increase in signal intensity compared to MDA-MB- 231. Further, estrogen molecules were found to be specifically localized to the nuclear region of MCF-7 cells, whereas MDA-MB-231 showed plasma membrane staining. This technique offers the potential of noninvasive detection of hormone receptor status in breast cancer cells and would help in decreasing the load of unnecessary biopsies. Here, we have reported the progress made in the development of a novel NIR external contrast agent and the work is in progress to use this conjugate for the molecular based, diagnostic imaging of breast cancer.

Jose, Iven; Deodhar, Kodand; Chiplunkar, Shuba V.; Patkar, Meena



Staining diatoms with rhodamine dyes: control of emission colour in photonic biocomposites  

PubMed Central

The incorporation of rhodamine dyes in the cell wall of diatoms Coscinodiscus granii and Coscinodiscus wailesii for the production of luminescent hybrid nanostructures is investigated. By systematic variation of the substitution pattern of the rhodamine core, we found that carbonic acids are considerably better suited than esters because of their physiological compatibility. The amino substitution pattern that controls the optical properties of the chromophore has no critical influence on dye uptake and incorporation, thus a variety of biocomposites with different emission maxima can be prepared. Applications in biomineralization studies as well as in materials science are envisioned. PMID:21865248

Kucki, Melanie; Fuhrmann-Lieker, Thomas



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

NASA Astrophysics Data System (ADS)

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.

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



On the nature of Romanowsky-Giemsa staining and the Romanowsky-Giemsa effect. I. Model experiments on the specificity of Azures B-Eosin Y stain as compared with other thiazine dye-Eosin Y combinations  

Microsoft Academic Search

Summary  After incorporation into a polyacrylamide matrix, the biopolymers DNA, RNA, heparin, hyaluronic acid, collagen and the synthetic polymers poly(U) and poly(A, U) were stained with the pure thiazine dyes, Methylene Blue, the Azures and Thionin alone and combined with Eosin Y. Satisfactory spectrophotometric agreement was obtained between the staining reactions of the biopolymers in the artificial matrix and those in

D. H. Wittekind; T. Gehring



pH-Dependence of the Absorption and Fluorescent Properties of Fluorone Dyes in Aqueous Solutions  

NASA Astrophysics Data System (ADS)

A series of fluorone dyes (fluorescein, eosin Y, erythrosin B) in aqueous solution is investigated by the absorption, fluorescence spectroscopic and time-resolved methods. Based on an analysis of the absorption spectrum amplitude, the fluorescence quantum yield, and the fluorescence lifetime vs. pH, the dissociation constants of the dyes in the ground and excited states are calculated. Quantitative and qualitative differences in the character of ionic equilibrium between fluorescein and its halogenated derivatives - eosin Y and erythrosin B - are revealed. The polarized fluorescence method has shown that the hydrodynamic diameter changes in a series of fluorone dyes due to both the increase of the bond length upon halogenation and the influence of solvation shell upon the change of the dye ionic species.

Slyusareva, E. A.; Gerasimova, M. A.



Local delivery of fluorescent dye for fiber-optics confocal microscopy of the living heart  

PubMed Central

Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-heart surgery. FCM relies on fluorescent dyes. The current clinical approach of dye delivery is based on systemic injection, which is associated with high dye consumption, and adverse clinical events. In this study, we investigated approaches for local dye delivery during FCM imaging based on dye carriers attached to the imaging probe. Using three-dimensional confocal microscopy, automated bench tests, and FCM imaging we quantitatively characterized dye release of carriers composed of open-pore foam only and foam loaded with agarose hydrogel. In addition, we compared local dye delivery with a model of systemic dye delivery in the isolated perfused rodent heart. We measured the signal-to-noise ratio (SNR) of images acquired in various regions of the heart. Our evaluations showed that foam-agarose dye carriers exhibited a prolonged dye release vs. foam-only carriers. Foam-agarose dye carriers allowed reliable imaging of 5–9 lines, which is comparable to 4–8 min of continuous dye release. Our study in the living heart revealed that the SNR of FCM images using local and systemic dye delivery is not different. However, we observed differences in the imaged tissue microstructure with the two approaches. Structural features characteristic of microvasculature were solely observed for systemic dye delivery. Our findings suggest that local dye delivery approach for FCM imaging constitutes an important alternative to systemic dye delivery. We suggest that the approach for local dye delivery will facilitate clinical translation of FCM, for instance, for FCM imaging during pediatric heart surgery.

Huang, Chao; Kaza, Aditya K.; Hitchcock, Robert W.; Sachse, Frank B.



Solvatochromic behavior on the absorption and fluorescence spectra of Rose Bengal dye in various solvents  

Microsoft Academic Search

The absorption and fluorescence spectra of Rose Bengal dye were studied in various solvents. It was found that solvent effects on the absorption wavelength are consistent with the solvatochromic model of Kamlet, Abboud and Taft. The solvent polarizability value ?* was found to have a linear relationship with the absorption wavelength of the dye in various solvents. Additionally, the normalized

M. A. Rauf; John P. Graham; Saeed B. Bukallah; Mariam A. S. Al-Saedi



Characterizing the Interaction Between DNA and GelRed Fluorescent Stain  

E-print Network

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 agreemen...

Crisafuli, F A P; Rocha, M S



Further studies on absorption changes arising in dye-stained nerves during excitation  

Microsoft Academic Search

Summary Changes in light absorption during nerve excitation (absorption responses) were detected from the crab leg nerve, the rabbit vagus, and the rat superior cervical ganglion (SCG) stained with a merocyanine-rhodanine. Dependences of the responses on the wavelength and polarization of the incident light (absorption spectra) showed characteristic features with the respective nerves. In the crab nerve, the pattern of

Akira Warashina



Ultrafast fluorescence polarization spectroscopy of near infrared dye in picosecond dynamic range: model and simulation  

NASA Astrophysics Data System (ADS)

Near-infrared (NIR) dyes which absorb and emit light within the range from 700 to 900 nm have several benefits in biological studies. However, because of short fluorescence lifetime in picosecond range, no significant efforts have been made to recognize the theory of these dyes in time-resolved polarization dynamics. For the first time, a set of first-order linear differential equations was developed to model fluorescence polarization dynamics of NIR dye in picoseconds range and verify it by the ultrafast spectra obtained by streak camera.

Pu, Yang



Rapid Enumeration of Active Legionella pneumophila in Freshwater Environments by the Microcolony Method Combined with Direct Fluorescent Antibody Staining  

PubMed Central

In this study, a microcolony technique was combined with direct fluorescent antibody staining for the specific detection and enumeration of Legionella pneumophila in freshwater samples with growth activity. This method allowed the detection of active L. pneumophila (within 48 h) in 91 bath water samples collected from 30 bathing facilities, with similar sensitivity of a conventional plate-counting method. These results suggest that the microcolony method combined with fluorescent antibody staining could be useful as a monitoring technique for the prevention of Legionnaires’ disease through the early detection of L. pneumophila in freshwater. PMID:22446304

Baba, Takashi; Inoue, Naoko; Yamaguchi, Nobuyasu; Nasu, Masao



Comparison of Chemicon SimulFluor Direct Fluorescent Antibody Staining with Cell Culture and Shell Vial Direct Immunoperoxidase Staining for Detection of Herpes Simplex Virus and with Cytospin Direct Immunofluorescence Staining for Detection of Varicella-Zoster Virus  

Microsoft Academic Search

A new rapid direct immunofluorescence assay, the SimulFluor direct fluorescent-antibody (DFA) assay, which can simultaneously detect herpes simplex virus types 1 and 2 (HSV-1 and -2) and varicella-zoster virus (VZV), was evaluated in comparison with our current standard procedures of (i) shell vial direct immuno- peroxidase (shell vial IP) staining and cell culture for detection of HSV and (ii) cytospin




pH switchable and fluorescent ratiometric squarylium indocyanine dyes as extremely alkaline solution sensors.  


pH indicators based on optical analysis play an important role in monitoring pH changes. Squarylium indocyanine (SICy) dyes have been developed to be used as extremely alkaline solution sensors. The absorbance and fluorescence intensities of the SICy dyes were quenched at a pH value of 13, and then recovered by adding acid to adjust the pH to 7. This reversible switching process could be repeated several times without significant loss of fluorescence. NMR and mass spectrometry analyses demonstrate nucleophilic addition of hydroxide ions to the N heterocycle. This study opens a new avenue to the design of fluorescent ratiometrics in extremely alkaline systems. PMID:24121360

Li, Jie; Ji, Chendong; Yang, Wantai; Yin, Meizhen



Fluorescent dye conjugates of rabbit arylsulfatase A as a biological tracer for protein endocytosis.  


Fluorescent dye conjugates of arylsulfatase A (ASA) from rabbit liver were prepared at pH 9.0 in 0.1 M sodium bicarbonate buffer. The modification of amino or sulphadryl groups by dichlorotriazinylamino-fluorescein or Lucifer yellow fluorescent dyes did not alter the characteristic features of the enzyme molecule such as enzyme activity, dimerization of the protein molecule at pH 4.5 and anomalous kinetics of the native enzyme. The fluorescence intensity of the Lucifer yellow enzyme conjugates were quenched when the pH of the protein solution was changed from pH 7.5 to 4.5. Therefore, the Lucifer yellow enzyme conjugate can be used to study the kinetics of pH-dependent association and dissociation of the ASA. Availability of such fluorescent dyes conjugates of ASA or other lysosomal enzyme may be used as a biological tracer to study the receptor dependent endocytosis of enzyme molecules. PMID:23636651

Hassan, Md Imtaiyaz; Waheed, Abdul; Ahmad, Faizan; Van Etten, Robert L



Use of fluorescent NIR dyes in silica nanoparticles and as enzyme substrates in bioanalytical applications  

NASA Astrophysics Data System (ADS)

Near-Infrared (NIR) absorbing carbocyanine dyes have been increasingly used in analytical, biological and medical fields as they can be useful for developing bioanalytical and biomedical methods. The utilization of the NIR spectral region (650-900 nm) is advantageous and is due to the inherently lower background interference and the high molar absorptivities of NIR chromophores. NIR dyes typically have relatively lower fluorescent quantum yield as compared to visible fluorophores, but much higher molar absorptivities which more than compensates for the lower quantum yields regarding detection limits. Fluorescence intensity of NIR dyes significantly increases by enclosing several dye molecules in silica nanoparticles. Self quenching may become a problem for carbocyanines at such high concentrations that may be present in the silica nanoparticles. Dyes that have large Stokes' shift can significantly decrease this problem. Increased Stokes' shift for carbocyanines dyes can be achieved by substituting meso position halogens with a linker containing aliphatic or aromatic amino moiety which also serves as a covalent linker for attaching the dye molecule to the nanoparticle backbone. The primary applications of these particles are for bright fluorescent labels to be used in bioanalytical applications such as immunochemistry, flow cytometry, etc. This work also discusses the use of NIR dyes as enzyme substrates. NIR dyes can be used as enzyme substrates and hence for characterization of enzyme activity. The well characterized alkenesulfonate monooxygenase enzyme was chosen for these studies. Carbocyanines containing alkylsulfonate moieties do not exhibit significant fluorescence change upon binding to biomolecules however otherwise identical NIR dye analogs that contain alkylaldehyde moiety at the same position do exhibit changes which can be utilized for characterization of alkenesulfonate monooxygenase enzyme activity using near infrared dyes as substrates. In this study a new class of sulfonated penta- and heptamethine dyes were used as substrates in vitro utilizing a photo-reduced riboflavin mononucleotide (FMN) with a glucose/ glucose-oxygenase oxygen scavenging system. Laser Induced Fluorescence (LIF) detected CZE was utilized to detect the sulfonated and de-sulfonated carbocyanines. The lower fluorescence quantum yield of the less water soluble alkylaldehyde analogs was detected and enzyme activity was characterized.

Patonay, Gabor; Chapman, Gala; Beckford, Garfield; Henary, Maged; Ellis, Holly



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

PubMed Central

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

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



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


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

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



Characterizing the Interaction Between DNA and GelRed Fluorescent Stain  

E-print Network

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.

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



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

PubMed Central

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

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



Journal of Fluorescence. Vol. 8. No. 1. 1998 Fluorescence of Organic Dyes in Lipid Membranes: Site of  

E-print Network

, which varied the viscosity and refractive index of the aqueous solution. The combined effect to the aqueous phase, for which the fluorescence lifetime increased systematically with sucrose (viscosity effect. The variation of the lifetime of the membrane-bound dye was studied as a function of the sucrose concentration

Mallela, Krishna M. G.


Investigation on fluorescence quenching of dyes by graphite oxide and graphene  

NASA Astrophysics Data System (ADS)

Rhodamine B (Rh B), eosin (E) and methylene blue (MB) were used as a probe to investigate the molecular structure and charge of the dyes on the sensitized efficiency of graphite oxide (GO) and graphene (G). The structure of the prepared GO and G were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. To study the electron transfer between dyes and GO or G, UV-vis absorption spectra (UV-vis), steady state fluorescence spectra (FL) and time resolved fluorescence spectra have been determined. It has been found that the electron transfer from the excited dyes to G was more efficient than to GO, and the transfer from excited MB to G was easier than to Rh B and E, because of the different electrostatic attraction between the dye and G.

Liu, Yan; Liu, Chun-yan; Liu, Yun



Determination of torasemide by fluorescence quenching method with some dihalogenated fluorescein dyes as probes  

NASA Astrophysics Data System (ADS)

A novel fluorescence quenching method for the determination of torasemide (TOR) with some dihalogenated fluorescein dyes as fluorescence probes was developed. In acidulous medium, TOR could interact with some dihalogenated fluorescein dyes such as dichlorofluorescein (DCF), dibromofluorescein (DBF) and diiodofluorescein (DIF) to form binary complexes, which could lead to fluorescence quenching of above dihalogenated fluorescein dyes. The maximum fluorescence emission wavelengths were located at 532 nm (TOR-DCF), 535 nm (TOR-DBF) and 554 nm (TOR-DIF). The relative fluorescence intensities (?F = F0 - F) were proportional to the concentration of TOR in certain ranges. The detection limits were 4.8 ng mL-1 for TOR-DCF system, 9.8 ng mL-1 for TOR-DBF system and 35.1 ng mL-1 for TOR-DIF system. The optimum reaction conditions, influencing factors were studied; and the effect of coexisting substances was investigated owing to the highest sensitivity of TOR-DCF system. In addition, the reaction mechanism, composition and structure of the complex were discussed by quantum chemical calculation and Job's method. The fluorescence quenching of dihalogenated fluorescein dyes by TOR was a static quenching process judging from the effect of temperature and the Stern-Volmer plots. The method was satisfactorily applied to the determination of TOR in tablets and human urine samples.

Cui, Zhiping; Liu, Shaopu; Liu, Zhongfang; Li, Yuanfang; Hu, Xiaoli; Tian, Jing



Carboxylate-modified squaraine dye doped silica fluorescent pH nanosensors  

Microsoft Academic Search

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

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



Treatment of resistant port wine stains (PWS) with pulsed dye laser and non-contact vacuum: a pilot study.  


The blanching of resistant port wine stains (PWS) with a pulsed dye laser (PDL) requires a large number of treatments, resulting in substantial discomfort to patients, many of them children. Pneumatic skin flattening (PSF - Serenity Pro) is a new technology that generates a vacuum over the skin and reduces pain in laser-based treatments of the skin, while creating contact between the skin and an upper window. The same technology can be utilized to increase skin blood fraction while operated in a non-contact mode. The objective of this study was to test the enhancement in the efficacy of PWS treatment with PDL and Serenity Pro while vacuum is being utilized in the non-contact, blood-enrichment mode. Fifteen patients with resistant PWS underwent 1-4 treatments (interval of 5-20 weeks) under general anesthesia with a 595-nm PDL at 10-14 J/cm(2), 1.5-3 ms pulse duration, and 7-mm spot size. Lesion blanching with DCD chilling and with vacuum were photographed and compared. Better blanching of various degrees was observed on resistant PWS with the blood-enrichment technique in seven out of 11 patients who returned for follow-up. There were no cases of decrease in efficacy. Blood enrichment with the Serenity Pro non-contact vacuum technology has the potential of enhancing the capability of treating resistant port wine stains in over 50% of cases. Further studies will better quantify the number of treatments necessary for better lesion clearance. The vacuum-assisted technique may be of particular importance in view of the fact that achieving complete lesion clearance remains a challenge in PWS treatments. PMID:20013138

Kautz, Gerd; Kautz, Ingrid; Segal, Jenny; Zehren, Sabrina



TiO2-nanotube-based dye-sensitized solar cells containing fluorescent material.  


We fabricated a dye-sensitized solar cells (DSCs) with TiO2 nanotube arrays obtained by anodization of Ti foil. Vertical structure of TiO2 nanotube arrays is very attractive due to a high electron transfer from dye to electrode. To improve the power conversion efficiency, fluorescent material, F-6377, was applied in TiO2-nanotube-based DSCs to use a light spectrum efficiently. Fluorescent material was absorbed the different wavelength of 460 nm from the light absorbed by N719 dye. Fluorescent material to emit the absorbed light energy provided an additional light for dye in DSCs and additional electrons was generated. Thickness of TiO2 nanotube arrays grown by anodic oxidation was 15 microm. N719 dye and 13(-)/l(-) electrolyte were used to fabricate the DSCs. The short circuit current densities (J(sc)) and the power conversion efficiency in DSCs with fluorescent were 10.8 mA/cm2 and 2.48%, respectively. Electrochemical impedance spectroscopy (EIS) was observed to understand an electron transfer and life time. PMID:23858885

Kim, Woong-Rae; Lee, Young-Joon; Park, Hun; Lee, Jae-Joon; Choi, Won-Youl



An improved technique for selective silver staining of nucleolar organizer regions in human chromosomes  

Microsoft Academic Search

A reliable technique for staining human chromosomal nucleolar organizers (NOR's) with silver solutions is described. The NOR's can be selectively stained dark brown by silver solutions leaving the chromosome arms unstained and available for counterstaining with orcein or Giemsa dyes. Unequivocal identification of chromosome pairs bearing NOR's can be achieved using fluorescent banding techniques followed by silver staining. The silver

S. E. Bloom; C. Goodpasture



Research Focus High-throughput screens for fluorescent dye discovery  

E-print Network

, there are no such clear candidate target proteins. Antibodies have other disadvantages, in- cluding intricate staining, diverse libraries of structurally related compounds [8]. High-throughput screens employ automation to test

Carpenter, Anne E.


A method for evaluating the use of fluorescent dyes to track proliferation in cell lines by dye dilution.  


Labeling nonquiescent cells with carboxyfluorescein succinimidyl ester (CFSE)-like dyes gives rise to a population width exceeding the threshold for resolving division peaks by flow cytometry. Width is a function of biological heterogeneity plus extrinsic and intrinsic error sources associated with the measurement process. Optimal cytometer performance minimizes extrinsic error, but reducing intrinsic error to the point of facilitating peak resolution requires careful fluorochrome selection and fluorescent cell sorting. In this study, we labeled the Jurkat and A549 cell lines with CFSE, CellTraceViolet (CTV), and eFluor 670 proliferation dye (EPD) to test if we could resolve division peaks in culture after reducing the labeled input widths by cell sorting. Reanalysis of the sorted populations to ascertain the level of reduction achieved always led to widths exceeding the gated limits due to the contribution of errors. Measuring detector-specific extrinsic error by sorting uniform fluorescent particles with similar spectral properties to the tracking dyes allowed us to determine the intrinsic error for each dye and cell type using a simple mathematical approach. We found that cell intrinsic error ultimately dictated whether we could resolve division peaks, and that as this increased, the required sort gate width to resolve any division peaks decreased to the point whereby issues with yield made A549 unsuitable for this approach. Finally, attempts to improve yields by setting two concurrent sort gates on the fluorescence distribution enriched for cells in different stages of the cell cycle that had nonequivalent proliferative properties in culture and thus should be practiced with caution. PMID:24166880

Begum, Julfa; Day, William; Henderson, Carl; Purewal, Sukhveer; Cerveira, Joana; Summers, Huw; Rees, Paul; Davies, Derek; Filby, Andrew



Energy Transfer in a Nanoscale Multichromophoric System: Fluorescent Dye-Doped Conjugated Polymer Nanoparticles  

PubMed Central

We report on the fluorescence properties and the combined effects of energy diffusion and energy transfer in polyfluorene nanoparticles doped with a variety of fluorescent dyes. As the doping host, polyfluorene possesses extraordinary “light harvesting” ability, resulting in higher per-particle brightness as compared to dye-loaded silica nanoparticles of similar dimensions. Both the steady-state fluorescence spectra and time-resolved fluorescence measurements indicate highly efficient energy transfer from the host polymer to the acceptor dye molecules. A model that takes into account the combined effects of energy diffusion, Förster transfer, and particle size was developed. Comparisons of experimental data to the model results elucidate the importance of particle size and energy diffusion within the polymer in determining the optical properties of the doped conjugated polymer nanoparticles. Fluorescence quantum yields of ~40% and peak extinction coefficients of 1.5 × 109 M?1cm?1 were determined for aqueous suspensions of ~30 nm diameter polymer nanoparticles doped with perylene or coumarin 6 (2 wt %). Photobleaching experiments indicate that energy transfer phenomena strongly influence the photostability of these dye-doped nanoparticles. Significant features of these nanoparticles include the high brightness, highly red-shifted emission spectrum, and excellent photostability, which are promising for biological labeling and sensing applications. In addition, the nanoparticles are a useful model system for studying energy transfer in dense, nanostructured, multichromophoric systems. PMID:19221582

Wu, Changfeng; Zheng, Yueli; Szymanski, Craig; McNeill, Jason



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

E-print Network

DOI: 10.1002/chem.200501541 Squaraine-Derived Rotaxanes: Highly Stable, Fluorescent Near-IR Dyes with optical imaging is restricted tissue penetration, however, it is pre- dicted that low-energy, near-IR (NIR, there is no organic NIR dye that has all of these desirable properties.[5] Abstract: Squaraines are fluorescent, near-IR

Smith, Bradley D.


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

PubMed Central

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

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



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

PubMed Central

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

Thyrhaug, Erling; S?rensen, Thomas Just; Gryczynski, Ignacy; Gryczynski, Zygmunt; Laursen, Bo W.



Deposition of Contaminated Sediments in Boston Harbor Studied Using Fluorescent Dye and Particle Tracers  

NASA Astrophysics Data System (ADS)

The residence time of water and suspended particles in Fort Point Channel, a sub-region of Boston Harbor containing a major combined sewer overflow and highly contaminated sediment, was determined during three field surveys by measuring the disappearance of fluorescent tracers from the water column. Flushing by advective movement was quantified using Rhodamine WT dye, a dissolved tracer which has negligible interaction with suspended sediment. The fate of suspended particles was inferred from measured concentrations of fluorescent pigment particles which were initially well mixed with Rhodamine dye and which have a size range and settling velocity comparable to the sewage particles of interest. Dye and particle concentrations were measured by fluorescent spectroscopy of water samples obtained throughout the channel over a week following tracer introduction. Dye measurements indicate that channel water is replaced on a scale of 1-2·7 days, depending on tidal amplitude and phase during tracer release, and the magnitude of freshwater inflow. Ratios of normalized particle concentration to dye concentration suggest effective deposition velocities of 1·5-3·3 m day -1; this is an order of magnitude faster than observed in laboratory settling columns suggesting that removal of suspended tracer particles from Fort Point Channel during our surveys may have been the result of scavenging by a bottom ' fluff ' layer. This finding is consistent with our previous observation of particle deposition in Salem Sound, Massachusetts, U.S.A. and in controlled laboratory studies of particle aggregation at the sediment-water interface.

Adams, E. E.; Stolzenbach, K. D.; Lee, J.-J.; Caroli, J.; Funk, D.



Kinetics of staining and bleaching  

Microsoft Academic Search

Kinetics of staining and stain removal have been studied with food dyes and natural colorants. Kinetics of staining indicate\\u000a that the staining agent is adsorbed on the fiber surface and diffuses into the interior of the fibers. Similarities exist\\u000a between staining and dyeing mechanisms of cotton, polyester and nylon fibers. Stain removal by nonoxidative detergency involves\\u000a diffusion of the staining

Erik Kissa; Jenny M. Dohner; Ward R. Gibson; Donna Strickman



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


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. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24652745

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



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


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

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



60.1 / A. Muravsky 60.1: Optical Rewritable Electronic Paper with Fluorescent Dye  

E-print Network

60.1 / A. Muravsky 60.1: Optical Rewritable Electronic Paper with Fluorescent Dye Doped Liquid) electronic paper is the joint result of advanced photoalignment of liquid crystals, optical engineering substrates are glued together with UV-epoxy NOA65, Norland. The cell is filled in vacuum with liquid crystal


Deposition of Contaminated Sediments in Boston Harbor Studied Using Fluorescent Dye and Particle Tracers  

Microsoft Academic Search

The residence time of water and suspended particles in Fort Point Channel, a sub-region of Boston Harbor containing a major combined sewer overflow and highly contaminated sediment, was determined during three field surveys by measuring the disappearance of fluorescent tracers from the water column. Flushing by advective movement was quantified using Rhodamine WT dye, a dissolved tracer which has negligible

E. E. Adams; K. D. Stolzenbach; J. J. Lee; J. Caroli; D. Funk



Protoplast derived tobacco cells can survive capillary microinjection of the fluorescent dye Lucifer Yellow  

Microsoft Academic Search

Summary The first steps to successful microinjection in plant cells of different types of macromolecules (RNA, DNA and protein) are reported. Evidence is also given that plant cells can survive the mechanical injury of the injection procedure. By attaching the cells to coverslips with polylysine, the progeny of an individual cell can be followed microscopically. Using the fluorescent dye Lucifer

H.-H. Steinbiss; Priska Stabel



Development of Thermally Stable and Highly Fluorescent IR Dyes  

NASA Technical Reports Server (NTRS)

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.

Bu, Xiu R.



An optical nanocavity incorporating a fluorescent organic dye having a high quality factor.  


We have fabricated an L3 optical nanocavity operating at visible wavelengths that is coated with a thin-film of a fluorescent molecular-dye. The cavity was directly fabricated into a pre-etched, free-standing silicon-nitride (SiN) membrane and had a quality factor of Q = 2650. This relatively high Q-factor approaches the theoretical limit that can be expected from an L3 nanocavity using silicon nitride as a dielectric material and is achieved as a result of the solvent-free cavity-fabrication protocol that we have developed. We show that the fluorescence from a red-emitting fluorescent dye coated onto the cavity surface undergoes strong emission intensity enhancement at a series of discrete wavelengths corresponding to the cavity modes. Three dimensional finite difference time domain (FDTD) calculations are used to predict the mode structure of the cavities with excellent agreement demonstrated between theory and experiment. PMID:20499907

Adawi, Ali M; Murshidy, Mohamed M; Fry, Paul W; Lidzey, David G



FITC-Conjugated Cyclic RGD Peptides as Fluorescent Probes for Staining Integrin ?v?3/?v?5 in Tumor Tissues.  


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

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



Plasmonic properties and enhanced fluorescence of gold and dye-doped silica nanoparticle aggregates  

NASA Astrophysics Data System (ADS)

The development of metal-enhanced fluorescence has prompted a great interest in augmenting the photophysical properties of fluorescent molecules with noble metal nanostructures. Our research efforts, outlined in this dissertation, focus on augmenting properties of fluorophores by conjugation with gold nanostructures. The project goals are split into two separate efforts; the enhancement in brightness of fluorophores and long distance non-radiative energy transfer between fluorophores. We believe that interacting dye-doped silica nanoparticles with gold nanoparticles can facilitate both of these phenomena. Our primary research interest is focused on optimizing brightness, as this goal should open a path to studying the second goal of non-radiative energy transfer. The two major challenges to this are constructing suitable nanomaterials and functionalizing them to promote plasmonically active complexes. The synthesis of dye-doped layered silica nanoparticles allows for control over the discrete location of the dye and a substrate that can be surface functionalized. Controlling the exact location of the dye is important to create a silica spacer, which promotes productive interactions with metal nanostructures. Furthermore, the synthesis of silica nanoparticles allows for various fluorophores to be studied in similar environments (removing solvent and other chemo-sensitive issues). Functionalizing the surface of silica nanoparticles allows control over the degree of silica and gold nanoparticle aggregation in solution. Heteroaggregation in solution is useful for producing well-aggregated clusters of many gold around a single silica nanoparticle. The dye-doped surface functionalized silica nanoparticles can than be mixed efficiently with gold nanomaterials. Aggregating multiple gold nanospheres around a single dye-doped silica nanoparticle can dramatically increase the fluorescent brightness of the sample via metal-enhanced fluorescence due to increase plasmonic scattering. Our aim is to promote heteroaggregation with functionalized silica nanoparticles while minimizing homoaggregation of silica-silica or gold-gold species. Reproducible production of multiple gold nanospheres about a dye-doped silica nanoparticle should lead to dramatic fluorescence brightness enhancements in solution. Gold nanorods can potentially be used to establish radiationless energy transfer between hetero dye-doped silica nanoparticles via gold nanorod plasmon mediated FRET by aggregating two different dye-doped silica nanoparticles preferentially at opposite ends of the nanorod. End-cap binding is accomplished by tuning the strength of gold binding ligands that functionalize the surface of the silica nanoparticles. The gold nanorod can then theoretically serve as a waveguide by employing the longitudinal plasmon as a non-radiative energy transfer agent between the two different fluorophores, giving rise to a new ultrafast signaling paradigm. Heteroaggregation of dye-doped silica nanoparticles and gold nanorods can be potentially employed to as nano waveguides. Construction and aggregation of functionalized silica and gold nano-materials provides an opportunity to advance the field of fluorescence. The synthesis of gold nano-particles allows control over their size and shape, which give rise to useful optical and electronic properties. Silica nanoparticles provide a framework allowing control over a requisite distance for increasing beneficial and deceasing non-radiative dye-metal interactions as well fluorophore protection. Our aim is to take advantage of fine-tuned synthetic control of functionalized nanomaterials to realize the great potential of solution based metal-enhanced fluorescence for future applications.

Green, Nathaniel Scott


Effect of Fluorescent Dyes on In Vitro-Differentiated, Late-Stage Plasmodium falciparum Gametocytes.  


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 (IC50s < 200 nM). MitoRed showed the highest activity against gametocytes, with IC50s 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

Gebru, Tamirat; Mordmüller, Benjamin; Held, Jana



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

SciTech Connect

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.

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



Leakage responses to L-NAME differ with the fluorescent dye used to label albumin.  


Nitric oxide synthase (NOS) inhibitors have been reported to increase as well as to decrease microvascular transport of macromolecules in a variety of models. This study was performed to determine whether the influence of NOS inhibition on albumin leakage was dependent on the fluorescent dyes used to label albumin. Albumin leakage was assessed in rat mesenteric venules during control conditions and after exposure to the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME). Albumin was labeled with any one of four dyes: FITC, sulforhodamine 101 [Texas Red (TR)], dichlorotriazinyl aminofluorescein (DTAF), or Oregon Green 514 (OG). Superfusion with L-NAME (10(-4) M) was accompanied by an increase in leakage of FITC-labeled albumin (n = 12) but not of albumin labeled with DTAF (n = 10), TR (n = 10), or OG (n = 4). In vessels perfused with both FITC- and TR-labeled albumin (n = 12), superfusion with L-NAME increased leakage of FITC- but not TR-labeled albumin. In conclusion, albumin leakage responses to L-NAME differ among various fluorescent dyes. Therefore, caution is advised in comparison of albumin leakage results that utilize different fluorescent dyes. PMID:9887048

Rumbaut, R E; Harris, N R; Sial, A J; Huxley, V H; Granger, D N



Removal of dye-based ink stains from ivory: evaluation of cleaning results based on wavelength dependency and laser type  

Microsoft Academic Search

The removal of ink stains from elephant ivory and related materials can present an intractable problem for the conservator. This research evaluates laser energy as a tool for ivory conservation and highlights the differences between removing stains that penetrate the substrate, as opposed to surface accretions, using a range of laser wavelengths. Samples of ink-stained ivory were prepared and treated

Odile Madden; Paraskevi Pouli; Meg Abraham; Costas Fotakis



Hybrid microtubes of polyoxometalate and fluorescence dye with tunable photoluminescence.  


Fluorescent microtubes based on ?-Keggin tungstosilicate and fluorescein (SiW(12)-F) have been obtained by using a simple method, which present tunable photoluminescence from sky blue to green to red by variation of excitation light. The SiW(12) component can inhibit photobleaching of fluorescein. PMID:22453234

Zhang, Huanqiu; Peng, Jun; Shen, Yan; Yu, Xia; Zhang, Fang; Mei, Jilan; Li, Bin; Zhang, Liming



Electrochromism and Solvatochromism in Fluorescence Response of Organic Dyes: A Nanoscopic View  

Microsoft Academic Search

\\u000a \\u000a Abstract  Methods are described that allow prediction and understanding of solvatochromism and fluorescence quenching of dyes embedded\\u000a in a nanometer-scale medium, e.g., solvent, protein, and membranes. Spectra of the dye are calculated at the microscopic level\\u000a using quantum mechanics coupled to the point charges representing the medium by Coulombic potentials, while the whole system\\u000a propagates by classical molecular mechanics. This view

Patrik R. Callis


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

NASA Astrophysics Data System (ADS)

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.

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



A Method for Activity Staining after Native Polyacrylamide Gel Electrophoresis Using a Coupled Enzyme Assay and Fluorescence Detection: Application to the Analysis of Several Glycolytic Enzymes  

Microsoft Academic Search

We describe a method for the detection of isoforms of several glycolytic enzymes by activity staining after native PAGE. The staining is based on coupled enzyme assays carried out on the gel after electrophoresis and is linked to the disappearance of NADH, which is visualized by fluorescence. This method offers reliable and sensitive detection for phosphoenolpyruvate carboxylase, PPi-dependent phosphofructokinase, and

Jean Rivoal; Christopher R. Smith; Trevor F. Moraes; David H. Turpin; William C. Plaxton



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


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

Gambier, R M; Mulcahy, D L



Quantitative Amplification of Genomic DNA from Histological Tissue Sections after Staining with Nuclear Dyes and Laser Capture Microdissection  

Microsoft Academic Search

Laser capture microdissection (LCM) allows the selec- tive sampling of tissue from histological sections. A prerequisite for this technique is the availability of histological dyes that do not interfere with down- stream analysis of the sampled genetic material. We have examined the effect of four histological nuclear dyes (methyl green, hematoxylin, toluidine blue O, azure B) on TaqMan polymerase chain

Torsten Ehrig; Sarki A. Abdulkadir; Suzanne M. Dintzis; Jeffrey Milbrandt; Mark A. Watson



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  

Microsoft Academic Search

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

Setsuo Hirohashi; Tadashi Kondo



Novel class of pyrylium dyes with high efficiency in lasing and two-photon absorption fluorescence  

NASA Astrophysics Data System (ADS)

We report the synthesis of a promising class of pyrylium dyes concerning laser and two-photon absorption action. Three representatives of this class, 4-(2,4-dichlorophenyl)-2,6-bisphenylpyrylium tetrafluoroborate, 4-phenyl-2,6-bis(4-methoxyphenyl)pyrylium tetrafluoroborate, and 4-(2,4-dichlorophenyl)-2,6-bis(4-biphenyl)pyrylium tetrafluoroborate, were investigated. Each dye was synthesized by a convenient and inexpensive method. Efficient laser action was shown at ˜500, ˜560, ˜615 nm. Changing the conjugation length i.e. the length of the oligophenyl moiety, or introducing various substituents on the aromatic rings, the emission maximum can be controlled. Two-photon absorption induced fluorescence was also observed. These pyrylium dyes constitute excellent candidates for laser technology and two-photon absorption applications.

Fakis, M.; Polyzos, J.; Tsigaridas, G.; Parthenios, J.; Fragos, A.; Giannetas, V.; Persephonis, P.; Mikroyannidis, J.



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

NASA Technical Reports Server (NTRS)

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.

Betterton, Eric A.; Gast, Karl



Fluorescence quenching and photocatalytic degradation of textile dyeing waste water by silver nanoparticles  

NASA Astrophysics Data System (ADS)

Silver nanoparticles (Ag NPs) of different sizes have been prepared by chemical reduction method and characterized using UV-vis spectroscopy and transmission electron microscopy (HRTEM). Fluorescence spectral analysis showed that the quenching of fluorescence of textile dyeing waste water (TDW) has been found to decrease with decrease in the size of the Ag NPs. Experimental results show that the silver nanoparticles can quench the fluorescence emission of adsorbed TDW effectively. The fluorescence interaction between Ag NPs (acceptor) and TDW (donor) confirms the Förster Resonance Energy Transfer (FRET) mechanism. Long range dipole-dipole interaction between the excited donor and ground state acceptor molecules is the dominant mechanism responsible for the energy transfer. Furthermore, photocatalytic degradation of TDW was measured spectrophotometrically by using silver as nanocatalyst under UV light illumination. The kinetic study revealed that synthesized Ag NPs was found to be effective in degrading TDW.

Kavitha, S. R.; Umadevi, M.; Janani, S. R.; Balakrishnan, T.; Ramanibai, R.



Fluorescence quenching and photocatalytic degradation of textile dyeing waste water by silver nanoparticles.  


Silver nanoparticles (Ag NPs) of different sizes have been prepared by chemical reduction method and characterized using UV-vis spectroscopy and transmission electron microscopy (HRTEM). Fluorescence spectral analysis showed that the quenching of fluorescence of textile dyeing waste water (TDW) has been found to decrease with decrease in the size of the Ag NPs. Experimental results show that the silver nanoparticles can quench the fluorescence emission of adsorbed TDW effectively. The fluorescence interaction between Ag NPs (acceptor) and TDW (donor) confirms the Förster Resonance Energy Transfer (FRET) mechanism. Long range dipole-dipole interaction between the excited donor and ground state acceptor molecules is the dominant mechanism responsible for the energy transfer. Furthermore, photocatalytic degradation of TDW was measured spectrophotometrically by using silver as nanocatalyst under UV light illumination. The kinetic study revealed that synthesized Ag NPs was found to be effective in degrading TDW. PMID:24632164

Kavitha, S R; Umadevi, M; Janani, S R; Balakrishnan, T; Ramanibai, R



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

NASA Astrophysics Data System (ADS)

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.

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



Quantitative diagnosis of cervical neoplasia using fluorescence lifetime imaging on haematoxylin and eosin stained tissue sections.  


The use of conventional fluorescence microscopy for characterizing tissue pathological states is limited by overlapping spectra and the dependence on excitation power and fluorophore concentration. Fluorescence lifetime imaging microscopy (FLIM) can overcome these limitations due to its insensitivity to fluorophore concentration, excitation power and spectral similarity. This study investigates the diagnosis of early cervical cancer using FLIM and a neural network extreme learning machine classifier. A concurrently high sensitivity and specificity of 92.8% and 80.2%, respectively, were achieved. The results suggest that the proposed technique can be used to supplement the traditional histopathological examination of early cervical cancer. PMID:23281280

Gu, Jun; Fu, Chit Yaw; Ng, Beng Koon; Gulam Razul, Sirajudeen so; Lim, Soo Kim



Removing Stains from Washable Fabrics.  

E-print Network

protein and dye. d. Special stains needing unique treatment be cause of chemical make-up or physical characteristics. (Examples: chewing gum, iodine, lead pencil) Stain Removal Products Bleaches Chlorine bleaches contain a hypochlorite com pound... Beer Combination 8 Wet 8 Protein 8 Tannin 8 Chewing gum Benzoil peroxide Special 9 Special 9 Chocolate Blood Combination 8 Wet 8 Dye 8 Protein 8 4 Stain Page Numbers Stain Page Numbers Cocoa Feces Combination 8 Wet 8 Dye 8 Protein 8 Coffee...

Beard, Ann Vanderpoorten



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

PubMed Central

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



Fabrication of Dye-sensitized Solar Cells and Fluorescence Quenching Study Using Thiophene Based Copolymers  

Microsoft Academic Search

Photovoltaic performance of dye sensitized solar cells fabricated with a commercially available thiophene based copolymer was investigated. Poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(bithiophene)], a highly soluble polythiophene, was used as a sensitizer. An open-circuit voltage of 0.64 V and a short-circuit current density of 0.36 mA\\/cm were measured. The incident photon to current conversion efficiency for the polymer was measured. Fluorescence from the other polythiophene,

Soumitra Satapathi; Fadong Yan; Robinson Anandakathir; Ke Yang; Lian Li; Ravi Mosurkal; Lynne A. Samuelson; Jayant Kumar




Microsoft Academic Search

In this study, the separation properties of alizarin, purpurin, carmine and morin were explored using capillary electrophoresis (CE). A 30 cm capillary (10 µm i.d.) and an applied voltage of 16-20 kV was used to separate the dyes prior to post-column detection in a sheath flow cuvette using laser-induced fluorescence (LIF). Two lasers were used for excitation; a 488 nm argon ion laser and

Douglas M. Goltz; Shokoufeh Ahmadi; Ghodrattolah Absalan; Douglas B. Craig



Fluorescent monomers as building blocks for dye labeled polymers: synthesis and application in energy conversion, biolabeling and sensors.  


This review focuses on side-chain functionalized polymers derived from direct (co)polymerization of fluorescent dyes. This overview about polymerizable dyes includes 1,8-naphthalimides, fluoresceins, rhodamines, coumarins, azo-dyes, oxadiazoles, diverse aromatic dyes as well as selected other dyes that cannot be classified within these groups. The discussed dyes have been functionalized with a polymerizable unit in order to apply straight-forward polymerization procedures. Therefore, the center of attention is set to the optical properties of the polymerizable dyes and the applicable polymerization techniques. Furthermore, the various applications (i.e., in biomedicine and pharmacy, as thermo-responsive materials and energy transfer materials, for dispersion of carbon nanotubes and others) of each polymer are discussed. PMID:23482971

Breul, Alexander M; Hager, Martin D; Schubert, Ulrich S



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

NASA Astrophysics Data System (ADS)

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 440-460 nm 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.

Saeed, Aamer; Shabir, Ghulam



Determination of blood plasma fluorescence extinction coefficients for dyes used in three-compartment binding model  

NASA Astrophysics Data System (ADS)

A three-compartment kinetic model for the binding of a ligand to its receptor in tumor tissue has been explained and the kinetic rates of the model are currently being investigated. In order to determine the plasma excretion rates of the dyes of interest, the fluorescence extinction coefficients must be determined. The fluorescence extinction coefficients of the IRDye700DX-carboxylate (IRDye700DX-C) and IRDye800CW-conjugated to EGFR (IRDye800CW-EGF) have been to be 7.98 ×106 ?M-1 cm-1 and 4.73x106 ?M-1 cm-1, respectively. We determined that the linear range of these dyes in the blood plasma of a mouse was 0 - 0.26 ?M. Administration of 1 nmol of each of these dyes to a mouse weighing 25-30g (0.04 ?M - 0.033 ?M, respectively) will result in blood plasma fluorescence in the linear and readable range.

Samkoe, Kimberley S.; Sexton, Kristian; Tichauer, Kenneth; Davis, Scott C.; O'Hara, Julia A.; Hasan, Tayyaba; Pogue, Brian W.



Lower limits of fluorescein and indocyanine green dye for digital cSLO fluorescence angiography  

PubMed Central

Background: With the advent of digital confocal scanning laser ophthalmoscopy it is possible to detect low levels of fluorescence. Here we used a novel confocal scanning laser ophthalmoscope (cSLO) to determine lower limits of dye required for fluorescein (FL) and indocyanine green (ICG) angiography. Methods: A cSLO (Heidelberg retina angiograph 2, Heidelberg Engineering, Dossenheim, Germany) with an optically pumped solid state laser (488 nm) for FL and a diode laser (790 nm) for ICG angiography (FL/ICG-A) was used. 62 FL-As were performed in 53 patients and 45 ICG-As were performed in 39 patients with neovascular age related macular degeneration. The volume and overall dye content of bolus injections was gradually tapered (FL: 500 mg, 250 mg, 200 mg, 166 mg, 100 mg; ICG: 25 mg, 20 mg, 15 mg, 10 mg, 5 mg, 2.5 mg), while dye concentrations were kept constant at 100 mg/ml for FL and at 5 mg/ml for ICG. Images were obtained 1, 5, 15, and 30 minutes after dye injection. Image quality was evaluated by two independent readers using standardised criteria. Results: For amounts down to 166 mg for FL and to 5 mg for ICG, sufficient image quality was achieved during all phases following injection. Only late phase images showed less contrast compared to typically used dye amounts, which was irrelevant for interpretation and clinical management. Conclusions: With the increased sensitivity of this novel cSLO system, amounts of injected dye during FL-A can be reduced to one third for FL and to one fifth for ICG without relevant loss of image quality or information compared to conventionally used dye levels. These amounts can be used for routine angiography and allow relevant savings for units performing FL-A. PMID:16299141

Bindewald, A; Stuhrmann, O; Roth, F; Schmitz-Valckenberg, S; Helb, H-M; Wegener, A; Eter, N; Holz, F G



Conjugates of a Photoactivated Rhodamine with Biopolymers for Cell Staining  

PubMed Central

Conjugates of the photoactivated rhodamine dyes with biopolymers (proteins, polysaccharides, and nucleic acids) are important tools for microscopic investigation of biological tissue. In this study, a precursor of the photoactivated fluorescent dye (PFD) has been successfully used for staining of numerous mammalian cells lines and for conjugate formation with chitosan (“Chitosan-PFD”) and histone H1 (“Histone H1.3-PFD”). The intensive fluorescence has been observed after photoactivation of these conjugates inside cells (A431, HaCaT, HEK239, HBL-100, and MDCK). Developed procedures and obtained data are important for further application of novel precursors of fluorescent dyes (“caged” dyes) for microscopic probing of biological objects. Thus, the synthesized “Chitosan-PFD” and “Histone H1-PFD” have been successfully applied in this study for intracellular transport visualization by fluorescent microscopy. PMID:25383365

Zaitsev, Sergei Yu.; Shaposhnikov, Mikhail N.; Solovyeva, Daria O.; Solovyeva, Valeria V.; Rizvanov, Albert A.



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


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

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



Blood analyte sensing using fluorescent dye-loaded red blood cells  

NASA Astrophysics Data System (ADS)

Measurement of blood analytes provides crucial information about a patient's health. Some such analytes, such as glucose in the case of diabetes, require long-term or near-continuous monitoring for proper disease management. However, current monitoring techniques are far from ideal: multiple-per-day finger stick tests are inconvenient and painful for the patient; implantable sensors have short functional life spans (i.e., 3-7 days). Due to analyte transporters on red blood cell (RBC) membranes that equilibrate intracellular and extracellular analyte levels, RBCs serve as an attractive alternative for encapsulating analyte sensors. Once reintroduced to the blood stream, the functionalized RBCs may continue to live for the remainder of their life span (120 days for humans). They are biodegradable and biocompatible, thereby eliminating the immune system response common for many implanted devices. The proposed sensing system utilizes the ability of the RBCs to swell in response to a decrease in the osmolarity of the extracellular solution. Just before lysis, they develop small pores on the scale of tens of nanometers. While at low temperature, analyte-sensitive dyes in the extracellular solution diffuse into the perforated RBCs and become entrapped upon restoration of temperature and osmolarity. Since the fluorescent signal from the entrapped dye reports on changes in the analyte level of the extracellular solution via the RBC transporters, interactions between the RBCs and the dye are critical to the efficacy of this technique. In this work, we study the use of a near infrared pH sensitive dye encapsulated within RBCs and assess the ability to measure dye fluorescence in vivo.

Ritter, Sarah C.; Shao, Xiaole; Cooley, Nicholas; Milanick, Mark A.; Glass, Timothy E.; Meissner, Kenith E.



Immunological Studies on a Freeze-Substitution Method of Preparing Tissue for Fluorescent Antibody Staining  

PubMed Central

(1) A freeze-substitution, wax embedding method for preparing tissue for fluorescent antibody studies is described. (2) Solutions of ovalbumin and ? globulin were subjected to the whole embedding procedure and their solubility and immunological reactivity estimated quantitatively. It was found that over 60 per cent of these proteins remained soluble after embedding. The precipitating power of the soluble fraction of ovalbumin and antibody globulin was found to be reduced by half. The insoluble fraction of antibody globulin bound more antigen than would be precipitated at equivalence. ImagesFIG. 4FIG. 5 PMID:13686329

Balfour, Brigid M.



The study of polyplex formation and stability by time-resolved fluorescence spectroscopy of SYBR Green I-stained DNA.  


Polyplexes are nanoparticles formed by the self-assembly of DNA/RNA and cationic polymers specifically designed to deliver exogenous genetic material to cells by a process called transfection. There is a general consensus that a subtle balance between sufficient extracellular protection and intracellular release of nucleic acids is a key factor for successful gene delivery. Therefore, there is a strong need to develop suitable tools and techniques for enabling the monitoring of the stability of polyplexes in the biological environment they face during transfection. In this work we propose time-resolved fluorescence spectroscopy in combination with SYBR Green I-DNA dye as a reliable tool for the in-depth characterization of the DNA/vector complexation state. As a proof of concept, we provide essential information on the assembly and disassembly of complexes formed between DNA and each of three cationic polymers, namely a novel promising chitosan-graft-branched polyethylenimine copolymer (Chi-g-bPEI), one of its building block 2 kDa bPEI and the gold standard transfectant 25 kDa bPEI. Our results highlight the higher information content provided by the time-resolved studies of SYBR Green I/DNA, as compared to conventional steady state measurements of ethidium bromide/DNA that enabled us to draw relationships among fluorescence lifetime, polyplex structural changes and transfection efficiency. PMID:25308511

D'Andrea, Cosimo; Pezzoli, Daniele; Malloggi, Chiara; Candeo, Alessia; Capelli, Giulio; Bassi, Andrea; Volonterio, Alessandro; Taroni, Paola; Candiani, Gabriele



Dynamic staining of Bacillus endospores with Thioflavin T.  


Rapid detection and identification of endospores presents a range of complex challenges. Dynamic staining approach, developed in our lab, utilizes the time-course fluorescence enhancement of an amyloid-staining dye, Thioflavin T (ThT), after mixing with intact endospores. We examined the kinetics of staining Bacillus atrophaeus and Bacillus thuringiensis endospores, and the rates of staining were different for the two bacilli when intact endospores were treated with ThT. This finding demonstrates an avenue for attaining information about the sporulated bacterial species without lysing, germinating or other pretreatment steps. PMID:23365938

Upadhyayula, Srigokul; Lam, Samuel; Ha, Alice; Malik-Chaudhry, Harbani K; Vullev, Valentine I



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

NASA Astrophysics Data System (ADS)

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.

Gogoi, Madhulekha; Deb, Pritam



Quantification of AAV Particle Titers by Infrared Fluorescence Scanning of Coomassie-Stained Sodium Dodecyl Sulfate-Polyacrylamide Gels  

PubMed Central

Abstract Adeno-associated virus (AAV)-based vectors have gained increasing attention as gene delivery vehicles in basic and preclinical studies as well as in human gene therapy trials. Especially for the latter two—for both safety and therapeutic efficacy reasons—a detailed characterization of all relevant parameters of the vector preparation is essential. Two important parameters that are routinely used to analyze recombinant AAV vectors are (1) the titer of viral particles containing a (recombinant) viral genome and (2) the purity of the vector preparation, most commonly assessed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) followed by silver staining. An important, third parameter, the titer of total viral particles, that is, the combined titer of both genome-containing and empty viral capsids, is rarely determined. Here, we describe a simple and inexpensive method that allows the simultaneous assessment of both vector purity and the determination of the total viral particle titer. This method, which was validated by comparison with established methods to determine viral particle titers, is based on the fact that Coomassie Brilliant Blue, when bound to proteins, fluoresces in the infrared spectrum. Viral samples are separated by SDS–PAGE followed by Coomassie Brilliant Blue staining and gel analysis with an infrared laser-scanning device. In combination with a protein standard, our method allows the rapid and accurate determination of viral particle titers simultaneously with the assessment of vector purity. PMID:22816378

Kohlbrenner, Erik; Henckaerts, Els; Rapti, Kleopatra; Gordon, Ronald E.; Linden, R. Michael; Hajjar, Roger J.



Determining the active region model parameter from dye staining experiments for characterizing the preferential flow heterogeneity in unsaturated soils  

Microsoft Academic Search

The active region model (ARM) has been developed as a practical and effective approach for characterizing and representing\\u000a preferential flow patterns in unsaturated soils. However, studies on methods to determine the ARM parameter (?) are very limited. The major objective of this work was to refine the methods for determining the ARM parameter (?) using the data from field-scale dye

Feng Sheng; Huihai Liu; Renduo Zhang; Kang Wang


Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified ?-Cyclodextrin Polymer  

PubMed Central

A water soluble azo dye modified ?-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs) of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified ?-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2,4-dichlorophenol, with a sensitivity factor of 0.35 compared to 0.05 and 0.12 for phenol and 4-chlorophenol, respectively. The stability constants (Ks) of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 103 M?1 for 2,4-dichlorophenol and 1.120 × 102 M?1 for 4-chlorophenol. PMID:22163864

Ncube, Phendukani; Krause, Rui W.; Mamba, Bhekie B.



Stable biocompatible cross-linked fluorescent polymeric nanoparticles based on AIE dye and itaconic anhydride.  


Self-assembly of polymeric materials to form nanoparticles is a particularly promising strategy for various biomedical applications, however, these self-assembling systems often encounter the critical micelle concentration (CMC) issue, as the nanoparticles is usually unstable at low concentration. Therefore, stable cross-linked fluorescent polymeric nanoparticles (FPNs) were covalently constructed from an aggregation induced emission (AIE) dye, itaconic anhydride, poly(ethylene glycol) monomethyl ether methacylate and polyethylenimine. These obtained PhE-ITA-20%(80%) FPNs were fully characterized by a series of techniques including (1)H NMR spectra, UV-vis absorption spectra, fluorescence spectra, FT-IR spectra, transmission electron microscopy, gel permeation chromatography, and dynamic light scattering. Such FPNs emitted intense fluorescence due to the introduction of aggregation induced emission dye. More importantly, the FPNs were found extremely stable in physiological solution even below the CMC owing to their cross-linked architectures. Biocompatibility evaluation and cell uptake behavior of the FPNs were further investigated to explore their potential biomedical applications, the demonstrated excellent biocompatibility made them promising for cell imaging. PMID:24973146

Li, Haiyin; Zhang, Xiqi; Zhang, Xiaoyong; Yang, Bin; Wei, Yen



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

Microsoft Academic Search

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

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



A method for assaying perchlorate concentration in microbial cultures using the fluorescent dye resazurin.  


Low concentrations (microg/L) of the perchlorate anion, ClO(4)(-), have been measured in surface and ground water supplies in many locations throughout the United States. Perchlorate is known to affect the function of the thyroid gland in mammals and its toxicity primarily results from its inhibition of thyroid hormone output. The major sources of perchlorate contamination in surface and ground waters are defense contractors, military installations, propellant manufacturers and agriculture. The currently accepted method of perchlorate analysis, recommended by the US EPA, is neither fast nor easy to use and requires purchase of an expensive high performance ion chromatograph (IC). The novel method described here uses dye resazurin to measure perchlorate reduction by bacterial cultures and bacterial consortia in a high-throughput, multi-well, culture plate format. The method is based on the observation that perchlorate reduction and the decrease of resazurin fluorescence occur simultaneously in perchlorate degrading cultures. The bioassays were performed in anaerobic serum bottles or 96-well plates with constant shaking, using a minimal ATCC medium with 10 mM acetate as electron donor/carbon source and 200 ppm perchlorate as an electron acceptor. Fluorescence measurements with excitation at 570 nm and emission at 590 nm were taken in 20 min intervals. Changes in perchlorate concentration were confirmed using IC. Based on the experimental data, a simple model showing the correlation between perchlorate concentration in microbial culture and resazurin fluorescence level was proposed. Other dyes including redox indicators, reactive azo dyes and electron shuttle chemicals were also tested for comparison and were found less useful. PMID:20109501

Kucharzyk, Katarzyna H; Crawford, Ronald L; Paszczynski, Andrzej J; Hess, Thomas F



The use of fluorescent dyes as tracers in highly saline groundwater  

NASA Astrophysics Data System (ADS)

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.

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



Direct, live imaging of cortical spreading depression and anoxic depolarisation using a fluorescent, voltage-sensitive dye.  


Perilesion depolarisations, whether transient anoxic depolarisation (AD) or spreading depression (SD), occur in stroke models and in patients with acute brain ischaemia, but their contribution to lesion progression remains unclear. As these phenomena correspond to waves of cellular depolarisation, we have developed a technique for their live imaging with a fluorescent voltage-sensitive (VS) dye (RH-1838). Method development and validation were performed in two different preparations: chicken retina, to avoid any vascular interference; and cranial window exposing the cortical surface of anaesthetised rats. Spreading depression was produced by high-K medium, and AD by complete terminal ischaemia in rats. After dye loading, the preparation was illuminated at its excitation wavelength and fluorescence changes were recorded sequentially with a charge-coupled device camera. No light was recorded when the VS dye was omitted, ruling out the contribution of any endogenous fluorophore. With both preparations, the changes in VS dye fluorescence with SD were analogous to those of the DC (direct current) potential recorded with glass electrodes. Although some blood quenching of the emitted light was identified, the VS dye signatures of SD had a good signal-to-noise ratio and were reproducible. The changes in VS dye fluorescence associated with AD were more complex because of additional interferents, especially transient brain swelling with subsequent shrinkage. However, the kinetics of the AD-associated changes in VS dye fluorescence was also analogous to that of the DC potential. In conclusion, this method provides the imaging equivalent of electrical extracellular DC potential recording, with the SD and AD negative shifts translating directly to fluorescence increase. PMID:17971792

Farkas, Eszter; Pratt, Rosalind; Sengpiel, Frank; Obrenovitch, Tihomir P



Making blind robots see: the synergy between fluorescent dyes and imaging devices in automated proteomics.  


Proteomics investigations endeavor to provide a global understanding of gene product synthesis rate, degradation rate, functional competence, posttranslational modification, subcellular distribution and physical interactions with other cell components. Protein expression encompasses an enormous dynamic range. Since rare proteins cannot be amplified by any type of PCR method, sensitive detection is critical to proteome projects. Fluorescence methods deliver streamlined detection protocols, superior detection sensitivity, broad linear dynamic range and excellent compatibility with modern microchemical identification methods such as mass spectrometry. Two general approaches to fluorescence detection of proteins are currently practiced: the covalent derivatization of proteins with fluorophores or noncovalent interaction of fluorophores either via the SDS micelle or through direct electrostatic interaction with proteins. One approach for quantifying fluorescence is to use a photomultiplier tube detector combined with a laser light scanner. In addition, fluorescence imaging is performed using a charge-coupled device camera combined with a UV light or xenon arc source. Fluorescent dyes with bimodal excitation spectra may be broadly implemented on a wide range of analytical imaging devices, permitting their widespread application to proteomics studies and incorporation into semiautomated analysis environments. PMID:10818702

Patton, W F



Four-color single molecule fluorescence with noncovalent dye labeling to monitor dynamic multimolecular complexes  

PubMed Central

To allow studies of conformational changes within multi-molecular complexes, we present a simultaneous, 4-color single molecule fluorescence methodology implemented with total internal reflection illumination and camera based, wide-field detection. We further demonstrate labeling histidine-tagged proteins non-covalently with tris-Nitrilotriacetic acid (tris-NTA) conjugated dyes to achieve single molecule detection. We combine these methods to co-localize the mismatch repair protein MutS? on DNA while monitoring MutS?-induced DNA bending using Förster resonance energy transfer (FRET) and to monitor assembly of membrane-tethered SNARE protein complexes. PMID:21091445

DeRocco, Vanessa C.; Anderson, Trevor; Piehler, Jacob; Erie, Dorothy A.; Weninger, Keith



TiO 2 nano-porous photoelectrochemical cells (PECs) sensitized with mixed cationic/anionic dye systems: Role of the second cationic fluorescent dye on the photocurrent enhancement  

NASA Astrophysics Data System (ADS)

Bromopyrogallol red (BPR), an anionic dye material was used in nano-porous photoelectrochemical cells as the sensitizer in conjunction with a fluorescent cationic dye, rhodamineB (RhB) and acridine orange (AO). The overlap between absorption and emission spectra of BPR/RhB and the formation of a strong associated complex influences the photoelectron transfer rate to be enhanced and to produce enhanced photovoltaic properties. Fluorescence quenching studies indicate that photoexcited cationic dye materials deactivate efficiently by BPR following different mechanisms. FTIR and rR spectroscopic evidences suggest that the electrostatic interaction of fluorescent cationic dye takes place from the -SO3- group of the BPR molecule.

Jayaweera, P. M.; Rajapaksha, R. M. S. P.; Tennakone, K.



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

PubMed Central

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.

Popenko, Oleksandr



Fluorescent dye particles as pollen analogues for measuring pollen dispersal in an insect-pollinated forest herb.  


In flowering plants, pollen dispersal is often the major contributing component to gene flow, hence a key parameter in conservation genetics and population biology. A cost-effective method to assess pollen dispersal consists of monitoring the dispersal of fluorescent dyes used as pollen analogues. However, few comparisons between dye dispersal and realized pollen dispersal have been performed to validate the method. We investigated pollen dispersal in two small populations of the insect-pollinated herb Primula elatior from urban forest fragments using direct (paternity analyses based on microsatellite DNA markers) and indirect (fluorescent dyes) methods. We compared these methods using two approaches, testing for the difference between the distance distributions of observed dispersal events and estimating parameters of a dispersal model, and related these results to dye dispersal patterns in three large populations. Dye and realized (based on paternity inference) pollen dispersal showed exponential decay distributions, with 74.2-94.8% of the depositions occurring at <50 m and a few longer distance dispersal events (up to 151 m). No significant difference in curve shape was found between dye and realized pollen dispersal distributions. The best-fitting parameters characterizing the dye dispersal model were consistent with those obtained for realized pollen dispersal. Hence, the fluorescent dye method may be considered as reliable to infer realized pollen dispersal for forest herbs such as P. elatior. However, our simulations reveal that large sample sizes are needed to detect moderate differences between dye and realized pollen dispersal patterns because the estimation of dispersal parameters suffers low precision. PMID:20703887

Van Rossum, Fabienne; Stiers, Iris; Van Geert, Anja; Triest, Ludwig; Hardy, Olivier J



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

NASA Technical Reports Server (NTRS)

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.

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



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


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

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



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

NASA Astrophysics Data System (ADS)

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.

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



Flow Cytometric Enumeration of Bacteria Using TO-PRO®-3 Iodide as a Single-Stain Viability Dye.  


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

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



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


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

Amer, Eynas; Gren, Per; Sjödahl, Mikael



Computational and experimental characterization of a fluorescent dye for detection of potassium ion concentration.  


The fluorescence of the SKC-513 ((E)-N-(9-(4-(1,4,7,10,13-pentaoxa-16-azacyclooctadecan-16-yl)phenyl)-6-(butyl(3-sulfopropyl)amino)-3H-xanthen-3-ylidene)-N-(3-sulfopropyl)butan-1-aminium) dye is shown experimentally to have high sensitivity to binding of the K(+) ion. Computations are used to explore the potential origins of this sensitivity and to make some suggestions regarding structural improvements. In the absence of K(+), excitation is to two nearly degenerate states, a neutral (N) excited state with a high oscillator strength, and a charge-transfer (CT) state with a lower oscillator strength. Binding of K(+) destabilizes the CT state, raising its energy far above the N state. The increase in fluorescence quantum yield upon binding of K(+) is attributed to the increased energy of the CT state suppressing a nonradiative pathway mediated by the CT state. The near degeneracy of the N and CT excited states can be understood by considering SKC-513 as a reduced symmetry version of a parent molecule with 3-fold symmetry. Computations show that acceptor-donor substituents can be used to alter the relative energies of the N and CT state, whereas a methylene spacer between the heterocycle and phenylene groups can be used to increase the coupling between these states. These modifications provide synthetic handles with which to optimize the dye for K(+) detection. PMID:25216181

Tanha, Matteus; Chakraborty, Subhasish K; Gabris, Beth; Waggoner, Alan S; Salama, Guy; Yaron, David



Apparatus for eliminating background interference in fluorescence measurements  


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.

Martin, J.C.; Jett, J.H.



Apparatus for eliminating background interference in fluorescence measurements  


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. 8 figs.

Martin, J.C.; Jett, J.H.



Heavy-atom modified near-IR fluorescent dyes for DNA sequencing applications: synthesis and photophysical characterization  

NASA Astrophysics Data System (ADS)

A series of near-IR fluorescent dyes have been prepared which contain an intramolecular heavy atom for altering the photophysics to produce a set of probes appropriate for single lane DNA sequencing applications. The identification of the terminal nucleotide base will be affected by temporal discrimination using fluorescence lifetime determination. The heavy-atom modification consists of an intramolecular halogen (mono- or disubstituted) situated on a remote section of the chromophore in order to minimize the perturbation on the photophysics. The series of dyes prepared showed similar absorption and emission maxima as well as fluorescence quantum yields that were similar. However, the lifetimes of these dyes were found to vary with the identity of the halogen substitution, yielding an apparent inverse heavy atom effect, with the heavier atom showing the longest fluorescence lifetime. Nanosecond flash photolysis spectroscopy of these dyes indicated that the intersystem crossing rates in the series increased with the heavier atom, consistent with known heavy-atom effects. The apparent inverse heavy atom effect resulted from decreases in the internal conversion rate of the base chromophore, with the heavier atom showing a smaller rate of internal conversion compared to that of the dye with the lighter heavy-atom modification.

Flanagan, James H., Jr.; Romero, Sarah E.; Legendre, Benjamin L., Jr.; Hammer, Robert P.; Soper, Steven A.



Quantification of free cysteines in membrane and soluble proteins using a fluorescent dye and thermal unfolding  

PubMed Central

Cysteine is an extremely useful site for selective attachment of labels to proteins for many applications, including the study of protein structure in solution by electron paramagnetic resonance (EPR), fluorescence spectroscopy and medical imaging. The demand for quantitative data for these applications means that it is important to determine the extent of the cysteine labeling. The efficiency of labeling is sensitive to the 3D context of cysteine within the protein. Where the label or modification is not directly measurable by optical or magnetic spectroscopy, for example, in cysteine modification to dehydroalanine, assessing labeling efficiency is difficult. We describe a simple assay for determining the efficiency of modification of cysteine residues, which is based on an approach previously used to determine membrane protein stability. The assay involves a reaction between the thermally unfolded protein and a thiol-specific coumarin fluorophore that is only fluorescent upon conjugation with thiols. Monitoring fluorescence during thermal denaturation of the protein in the presence of the dye identifies the temperature at which the maximum fluorescence occurs; this temperature differs among proteins. Comparison of the fluorescence intensity at the identified temperature between modified, unmodified (positive control) and cysteine-less protein (negative control) allows for the quantification of free cysteine. We have quantified both site-directed spin labeling and dehydroalanine formation. The method relies on a commonly available fluorescence 96-well plate reader, which rapidly screens numerous samples within 1.5 h and uses <100 ?g of material. The approach is robust for both soluble and detergent-solubilized membrane proteins. PMID:24091556

Hagelueken, Gregor; Naismith, James H



Comparison of Pollen Transfer Dynamics by Multiple Floral Visitors: Experiments with Pollen and Fluorescent Dye  

PubMed Central

• Background and Aims Most plant species are visited by a diversity of floral visitors. Pollen transfer of the four most common pollinating bee species and one nectar-robbing bee of the distylous plant Gelsemium sempervirens were compared. • Methods Naturally occurring pollen loads carried by the common floral visitor species of G. sempervirens were compared. In addition, dyed pollen donor flowers and sequences of four emasculated recipient flowers in field cages were used to estimate pollen transfer, and the utility of fluorescent dye powder as an analogue for pollen transfer was determined. • Key Results Xylocopa virginica, Osmia lignaria and Habropoda laboriosa carried the most G. sempervirens pollen on their bodies, followed by Bombus bimaculatus and Apis mellifera. However, B. bimaculatus, O. lignaria and H. laboriosa transferred significantly more pollen than A. mellifera. Nectar-robbing X. virginica transferred the least pollen, even when visiting legitimately. Dye particles were strongly correlated with pollen grains on a stigma, and therefore provide a good analogue for pollen in this system. The ratio of pollen?:?dye across stigmas was not affected by bee species or interactions between bee species and floral morphology. However, dye transfer was more sensitive than pollen transfer to differences in floral morphology. • Conclusions The results from this study add to a growing body of literature highlighting that floral visitors vary in pollination effectiveness, and that visitors carrying the most pollen on their bodies may not always be the most efficient at depositing pollen on stigmas. Understanding the magnitude of variability in pollinator quality is one important factor for predicting how different pollinator taxa may influence the evolution of floral traits. PMID:16299005




Understanding Romanowsky staining  

Microsoft Academic Search

Normal blood smears were stained by the standardised azure B-eosin Y Romanowsky procedure recently introduced by the ICSH, and the classical picture resulted. The effects of varying the times and temperature of staining, the composition of the solvent (buffer concentration, methanol content, & pH), the concentration of the dyes, and the mode of fixation were studied. The results are best

R. W. Horobin; K. J. Walter



Ratiometric optical temperature sensor using two fluorescent dyes dissolved in an ionic liquid encapsulated by Parylene film.  


A temperature sensor that uses temperature-sensitive fluorescent dyes is developed. The droplet sensor has a diameter of 40 µm and uses 1 g/L of Rhodamine B (RhB) and 0.5 g/L of Rhodamine 110 (Rh110), which are fluorescent dyes that are dissolved in an ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate) to function as temperature indicators. This ionic liquid is encapsulated using vacuum Parylene film deposition (which is known as the Parylene-on-liquid-deposition (PoLD) method). The droplet is sealed by the chemically stable and impermeable Parylene film, which prevents the dye from interacting with the molecules in the solution and keeps the volume and concentration of the fluorescent material fixed. The two fluorescent dyes enable the temperature to be measured ratiometrically such that the droplet sensor can be used in various applications, such as the wireless temperature measurement of microregions. The sensor can measure the temperature of such microregions with an accuracy of 1.9 °C, a precision of 3.7 °C, and a fluorescence intensity change sensitivity of 1.0%/K. The sensor can measure temperatures at different sensor depths in water, ranging from 0 to 850 µm. The droplet sensor is fabricated using microelectromechanical system (MEMS) technology and is highly applicable to lab-on-a-chip devices. PMID:23535716

Kan, Tetsuo; Aoki, Hironori; Binh-Khiem, Nguyen; Matsumoto, Kiyoshi; Shimoyama, Isao



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

PubMed Central

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

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



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


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

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



How Long Will I Be Blue? Prolonged Skin Staining Following Sentinel Lymph Node Biopsy Using Intradermal Patent Blue Dye  

PubMed Central

Summary Background Blue dye used for sentinel lymph node biopsy (SLNB) in breast cancer patients may cause prolonged skin discoloration at the site of injection. The aim of this study was to assess the duration of such skin discoloration. Patients and Methods 236 consecutive patients who had undergone breast conserving surgery and SLNB for breast cancer were reviewed prospectively from January 2007 to December 2009. Results Of the 236 patients, 2 had undergone bilateral surgery, and 41 had been examined in consecutive yearly reviews. Blue discoloration remained visible at the injection site after 12, 24, and > 36 months in 36.5, 23.6, and 8.6% of the patients, respectively. Conclusion The use of patent blue for identification of the sentinel lymph node in patients undergoing breast cancer surgery may result in prolonged discoloration of the skin at the injection site. PMID:24415970

Gumus, Metehan; Gumus, Hatice; Jones, Sue E; Jones, Peter A; Sever, Ali R; Weeks, Jennifer



Fluorescent nanomicelles for selective detection of Sudan dye in Pluronic F127 aqueous media.  


Novel self-assembled water-soluble nanomicelles that contain fluorescent conjugated polymers (poly(9,9-dioctylfluorene) (PFO) or poly[2,7-(9,9-dihexylfluorene)-alt-4,4'-phenylether] (PF-PE)) have been obtained and used as the highly sensitive/selective platform for Sudan dye detection. The Fluorescent nanomicelles exhibited a highly selective fluorescence quenching by the prohibited food additive Sudan I, while not for the natural pigments: Capsanthin and Beta-carotene, due to the more suitable matching of the LUMOs (lowest unoccupied molecular orbital) of the conjugated polymers with that of Sudan I molecules. The Stern-Volmer constants (K(SV)) of PF-PE/F127 and PFO/F127 for Sudan I were 1,040,480 and 665,000 M(-1), respectively, which were more than 100 times higher than those of the same conjugated polymers in the orgainc solvents. The significantly enhanced sensitivity was due to the collective effect of the F127 micelles to both chromophore and analyte, through which the fluorophone-analyte binding interaction is significantly strengthened and efficient photoinduced charge transfer occurs. The as-proposed materials and approach may be potentially applied in the real-time food safety screening. PMID:24625370

Ye, Xinliang; Zhang, Jie; Chen, Hui; Wang, Xiaohui; Huang, Fei



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

NASA Astrophysics Data System (ADS)

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.

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



Application of photoacoustic, photothermal and fluorescence spectroscopies in signal enhancement and the kinetics, chemistry and photophysics of several dyes  

SciTech Connect

Modified photoacoustic and photothermal spectroscopies are applied in analytical studies of liquid and solid systems. Quenching of benzophenone by potassium iodide is used to demonstrate application of time resolved photothermal spectroscopies in study of fast (submicrosecond) deexcitation processes. Inherently weak X-ray photoacoustic signals at a synchrotron are enhanced by the introduction of a volatile liquid into a gas-microphone photoacoustic cell. Traditionally, photoacoustic signals have been detected either by gas coupling with a microphone or with a piezoelectric detector. However, optically detected photoacoustic signals have been used in the determination of physical properties of a liquid sample system and are successfully applied to the study of deexcitation processes of a number of dye molecules. Photothermal beam deflection photoacoustic (PBDPA), fluorescence and absorbance measurements are utilized to study the chemistry and photophysics of cresyl violet in aqueous, aqueous micellar and methanolic solutions. A concentration dependence of the fluorescence quantum yield of cresyl violet is investigated. Aspects of chemistry and photophysics relating to potential use of several diazo dyes as photothermal sensitizing dyes in photodynamic therapy are explored experimentally and discussed. Photothermal beam deflection, fluorescence and absorbance measurements are again utilized. The dyes are found to have a number of interesting chemical and photophysical properties. They are also determined to be ideal photothermal sensitizing dye candidates.

Isak, S.J.



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

NASA Astrophysics Data System (ADS)

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.

Panova, Ina G.; Tatikolov, Alexander S.



Subcritical water and dynamic sonication-assisted solvent extraction of fluorescent whitening agents and azo dyes in paper samples  

Microsoft Academic Search

Two low-volume solvent continuous extraction methods are applied to the extraction of paper matrices. In the methods reported here, a complex mixture of fluorescent whitening agents (FWAs) and azo dyes (AZOs) used in paper materials intended to come into contact with foodstuffs was extracted by using subcritical water extraction (SWE) and dynamic sonication-assisted solvent extraction (DSASE). Rationale for the work

Mario de los Santos; Ramón Batlle; Jesús Salafranca; Cristina Nerín



Fluorescent carbocyanine dyes allow living neurons of identified origin to be studied in long-term cultures  

Microsoft Academic Search

A prerequisite for many studies of neurons in culture is a means of determining their original identity. We needed such a technique to study the in- teractions in vitro between a class of spinal cord neu- rons, sympathetic preganglionic neurons, and their normal target, neurons from the sympathetic chain. Here, we describe how we use two highly fluorescent carbocyanine dyes,

Marcia G. Honig; Richard I. Hume



Synthesis and characterization of monodisperse, mesoporous, and magnetic sub-micron particles doped with a near-infrared fluorescent dye  

NASA Astrophysics Data System (ADS)

Recently, multifunctional silica nanoparticles have been investigated extensively for their potential use in biomedical applications. We have prepared sub-micron monodisperse and stable multifunctional mesoporous silica particles with a high level of magnetization and fluorescence in the near infrared region using an one-pot synthesis technique. Commercial magnetite nanocrystals and a conjugated-NIR-dye were incorporated inside the particles during the silica condensation reaction. The particles were then coated with polyethyleneglycol to stop aggregation. X-ray diffraction, N 2 adsorption analysis, TEM, fluorescence and absorbance measurements were used to structurally characterize the particles. These mesoporous silica spheres have a large surface area (1978 m 2/g) with 3.40 nm pore diameter and a high fluorescence in the near infrared region at ?=700 nm. To explore the potential of these particles for drug delivery applications, the pore accessibility to hydrophobic drugs was simulated by successfully trapping a hydrophobic ruthenium dye complex inside the particle with an estimated concentration of 3 wt%. Fluorescence imaging confirmed the presence of both NIR dye and the post-grafted ruthenium dye complex inside the particles. These particles moved at approximately 150 ?m/s under the influence of a magnetic field, hence demonstrating the multifunctionality and potential for biomedical applications in targeting and imaging.

Le Guével, Xavier; Nooney, Robert; McDonagh, Colette; MacCraith, Brian D.




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...


Laser induced dye fluorescence to evaluate mass transfer to a droplet  

SciTech Connect

This paper presents a novel technique for mass transfer rate measurements in single oscillating drops. The experiments involve the use of a Laser-Induced Fluorescence (LIF) species concentration method to aid in the observation of concentration profiles in a given liquid-liquid system. The technique is being developed to allow measurements of the effect of oscillating fields (from electrical or acoustical forces) on the mass transfer to droplets. The fluid system used in the experiments consists of a solution of Freon 113 (Trichloro trifluoroethane) and octyl alcohol as the droplet phase and an aqueous solution of sucrose as the continuous phase. Rhodamine B, one of the most commonly used laser dyes, is used as the tracer to study the interfacial mass transfer. Experimental results are compared to numerical models for a droplet in a slowly flowing outside phase.

Carleson, T.E.; Katamneni, S.; Budwig, R.; Martinez, J. [Univ. of Idaho, Moscow, ID (United States)



Carboxylate-modified squaraine dye doped silica fluorescent pH nanosensors.  


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( + ), Mg(2 + ), Ca(2 + ), Sr(2 + ), Al(3 + ), V(5 + ), Cr(3 + ), Cr(6 + ), Mn(2 + ), Fe(2 + ), Fe(3 + ), Co(2 + ), Ni(3 + ), Cu(2 + ), Zn(2 + ), As(3 + ), Se(4 + ), Mo(6 + ), Ag( + ), Cd(2 + ), La(3 + ), Er(3 + ), Ir(3 + ), Hg( + ), Hg(2 + ), and Pb(2 + ) 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. PMID:20431191

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



Counting fluorescent dye molecules on DNA origami by means of photon statistics.  


Obtaining quantitative information about molecular assemblies with high spatial and temporal resolution is a challenging task in fluorescence microscopy. Single-molecule techniques build on the ability to count molecules one by one. Here, a method is presented that extends recent approaches to analyze the statistics of coincidently emitted photons to enable reliable counting of molecules in the range of 1-20. This method does not require photochemistry such as blinking or bleaching. DNA origami structures are labeled with up to 36 dye molecules as a new evaluation tool to characterize this counting by a photon statistics approach. Labeled DNA origami has a well-defined labeling stoichiometry and ensures equal brightness for all dyes incorporated. Bias and precision of the estimating algorithm are determined, along with the minimal acquisition time required for robust estimation. Complexes containing up to 18 molecules can be investigated non-invasively within 150 ms. The method might become a quantifying add-on for confocal microscopes and could be especially powerful in combination with STED/RESOLFT-type microscopy. PMID:23794455

Kurz, Anton; Schmied, Jürgen J; Grußmayer, Kristin S; Holzmeister, Phil; Tinnefeld, Philip; Herten, Dirk-Peter



The use of fluorescent-protein conjugates for staining brain capillaries in hypo- and hyperthermia (26-42 degrees).  


The temperature dependency of cerebrocortical capillary diameter (CD), number perfused with fluorescent tracer (CN), and intercapillary distance (ICD) has been investigated for three body temperatures (26, 37, and 42 degrees), in order to analyze the influence of undesired cooling or warming which frequently occurs in animal experiments and humans (freezing, heat disposal, fever, etc.). The capillary bed (Wistar-Frömter rats, N = 92, ketaminxylazin anesthesia) was visualized with a double staining method using serum proteins coupled with either FITC (fluorescein isothiocyanate) or RB-200 (rhodamine-lissamin) injected ia immediately before decapitation. CD (6.1 +/- 0.3 micron, 37 degrees) increased during cooling by about 18%, during warming by about 13%. CN (313 +/- 83/mm2, 37 degrees) showed a 12% increase in response to temperature reduction and 18% after elevation. ICD was characterized by small insignificant changes of the mean values (44.2 +/- 5.5 micron, 37 degrees) at 26 degrees and 42 degrees. Mean cerebrocortical surface PO2 (sPO2) ranging between 15 and 22 mm Hg (37 degrees) increased slightly during warming or decreased during cooling. The sPO2 histogram showed a Gaussian-like shape in the range 0-40 mm Hg at low temperatures (26-34 degrees) and a left-shifted frequency distribution between 34-42 degrees. It was interesting to note that above 38 degrees sporadically high sPO2 values were registered in the range 40-80 mm Hg. Nevertheless, despite pronounced temperature variations, the net effect between O2 transport and consumption was balanced to such an extent that tissue anoxia was not detected within the rat cerebro-cortex. PMID:2448592

Metzger, H P; Brüggemann, H; Plewnia, A



Amyloid Histology Stain for Rapid Bacterial Endospore Imaging ? †  

PubMed Central

Bacterial endospores are some of the most resilient forms of life known to us, with their persistent survival capability resulting from a complex and effective structural organization. The outer membrane of endospores is surrounded by the densely packed endospore coat and exosporium, containing amyloid or amyloid-like proteins. In fact, it is the impenetrable composition of the endospore coat and the exosporium that makes staining methodologies for endospore detection complex and challenging. Therefore, a plausible strategy for facile and expedient staining would be to target components of the protective surface layers of the endospores. Instead of targeting endogenous markers encapsulated in the spores, here we demonstrated staining of these dormant life entities that targets the amyloid domains, i.e., the very surface components that make the coats of these species impenetrable. Using an amyloid staining dye, thioflavin T (ThT), we examined this strategy. A short incubation of bacillus endospore suspensions with ThT, under ambient conditions, resulted in (i) an enhancement of the fluorescence of ThT and (ii) the accumulation of ThT in the endospores, affording fluorescence images with excellent contrast ratios. Fluorescence images revealed that ThT tends to accumulate in the surface regions of the endospores. The observed fluorescence enhancement and dye accumulation, coupled with the sensitivity of emission techniques, provide an effective and rapid means of staining endospores without the inconvenience of pre- or posttreatment of samples. PMID:21653779

Xia, Bing; Upadhyayula, Srigokul; Nunez, Vicente; Landsman, Pavel; Lam, Samuel; Malik, Harbani; Gupta, Sharad; Sarshar, Mohammad; Hu, Jingqiu; Anvari, Bahman; Jones, Guilford; Vullev, Valentine I.



Time-resolved fluorescence for breast cancer detection using an octreotate-indocyanine green derivative dye conjugate  

NASA Astrophysics Data System (ADS)

Time-resolved fluorescence was used to investigate malignant and normal adjacent breast tissues stained with a conjugate of indocyanine green and octreotate. A marked increase in fluorescence lifetime intensity was seen in the breast cancer sample compared to the normal sample. The fluorescent lifetimes were also investigated and showed similar fluorescence decay curves in stained malignant and normal breast tissue. These results confirm that somatostatin receptors occur on human breast carcinomas, suggest that the presence of somatostatin receptors should be investigated as a marker of breast cancer aggressiveness, and suggest that this conjugate might be used to detect the presence of residual breast cancer after surgery, allowing better assessment of tumor margins and reducing the need for second or repeat biopsies in selected patients. These results may also provide clues for designing future treatment options for breast cancer patients.

Sordillo, Laura A.; Das, B. B.; Pu, Yang; Liang, Kexian; Milione, Giovanni; Sordillo, Peter P.; Achilefu, Sam; Alfano, R. R.


Synthesis of water-soluble, ring-substituted squaraine dyes and their evaluation as fluorescent probes and labels.  


A series of ring-substituted squaraines absorbing and emitting in the red and NIR spectral region was synthesized and their spectral and photophysical properties (quantum yields, fluorescence lifetimes) and photostabilities were measured and compared to Cy5, a commonly used fluorescent label. The absorption maxima in aqueous media were found to be between 628 and 667 nm and the emission maxima are between 642 and 685 nm. Squaraine dyes exhibit high extinction coefficients (163,000-265,000 M(-1) cm(-1)) and lower quantum yields (2-7%) in aqueous buffer but high quantum yields (up to 45%) and long fluorescence lifetimes (up to 3.3 ns) in presence of BSA. Dicyanomethylene- and thio-substituted squaraines exhibit an additional absorption around 400 nm with extinction coefficients between 21,500 and 44,500 M(-1) cm(-1). These dyes are excitable not only with red but also with blue diode lasers or light emitting diodes. Due to the favourable spectral and photophysical properties these dyes can be used as fluorescent probes and labels for intensity- and fluorescence lifetime-based biomedical applications. PMID:17723402

Tatarets, Anatoliy L; Fedyunyayeva, Irina A; Dyubko, Tatyana S; Povrozin, Yevgeniy A; Doroshenko, Andrey O; Terpetschnig, Ewald A; Patsenker, Leonid D



Fluorescent dye-labelled polymer synthesis by nitroxide mediated radical polymerization  

NASA Astrophysics Data System (ADS)

New applications of polymers at advanced technologies demand increased requirements on their properties. These properties are influenced by molecular as well as supramolecular structure. Controlled radical polymerization mediated by stable nitroxides (NMP) or substituted alkoxyamines offers simple method for preparation of polymers with programmable structure of macromolecules which possess remarkable better physical as well as chemical properties. They can be used as a macro initiators for the synthesis of block copolymers. At the present time it has been generally accepted that the extent of "livingness" is high for all conversions [1-4]. To verify this statement a series of fluorescent dye-labelled regulators has been synthesized, spectrally characterized and used as the mediators of styrene and n-butyl acrylate polymerization. Direct quantification of dormant species concentration (extent of livingness) and calculation of molar mass of marked polymers was performed by absorption and/or emission spectroscopy. Controlled radical polymerization mediated by stable nitroxides bearing fluorescence mark represents unconventional approach for monitoring and evaluation of mechanism and kinetics of polymerization process. Results indicate that the extent of livingness is strongly influenced by conversion as well as mediator concentration. There is a clear tendency toward to decreasing amount of dormant species with increasing monomer conversion. Moreover, lower mediator concentration decreases livingness of polymerization process.

Kollár, Jozef; Chmela, Štefan; Hr?ková, Ľudmila; Hrdlovi?, Pavol



Wood stains  


Wood stains are products used for wood finishing. Wood stain poisoning occurs when someone swallows these substances. This is ... Various wood stains Note: This list does not include all sources of wood stain.


Oxidative synthesis of highly fluorescent boron/nitrogen co-doped carbon nanodots enabling detection of photosensitizer and carcinogenic dye.  


Current research efforts have demonstrated the facile hydrothermal oxidative synthetic route to develop highly fluorescent boron/nitrogen co-doped carbon nanodots (CNDs). During this process, N-(4-hydroxyphenyl)glycine served as a source of N doping and a carbon precursor as well, while boric acid H3BO3 is used as an oxidizing agent in the N2 environment. Surface passivation through ultrasonic treatment of CNDs was performed to induce modifications by using various surface passivating agents. Polyethyleneimine (PEI) remarkably enhanced the fluorescence performance and monodispersity of polymerized carbon nanodots (P-CNDs) in aqueous phase with an enhanced quantum yield of 23.71%, along with an increase in size from ~3 nm to ~200 nm. For characterization of CNDs and P-CNDs, UV, infrared, photoluminescence, transmission electron microscopy, x-ray photoelectron spectra, and atomic force microscopy techniques were utilized. Application potentials of synthesized P-CNDs were developed via introduction of protoporphyrin (PPD, a photosensitizer) which has great doping affinity with polymer PEI to switch-off the fluorescence of P-CNDs, leading to the production of dye-doped nanoprobes. Fluorescence resonance energy transfer (FRET) was also observed during dye-doping, and PPD was detected with a limit of detection (LOD, 3?) of 15 pM. The fluorescence recovery of this switched-off nanoprobe was made possible by using Sudan red III (carcinogenic dye), which was oxidized by PPD doped in P-CNDs. Sudan red III was detected in the concentration range of 9.9 pM-0.37 nM. Meanwhile, it was also confirmed that the dye-doped nanoprobe is highly selective and exceptionally sensitive to detect this carcinogenic agent in commercial products with a LOD (3?) of 90 fM. PMID:24083490

Jahan, Shanaz; Mansoor, Farrukh; Naz, Shagufta; Lei, Jianping; Kanwal, Shamsa



Use of Fluorescence Imaging in Combination with Patent Blue Dye versus Patent Blue Dye Alone in Sentinel Lymph Node Biopsy in Breast Cancer  

PubMed Central

Purpose Near-infrared fluorescence imaging with indocyanine green (ICG) has the potential to improve sentinel lymph node (SLN) mapping in breast cancer. In this clinical trial, we compared the potential value of ICG combined with blue dye with that of blue dye alone for detecting SLNs. Methods Patients undergoing SLN biopsy (SLNB) between November 2010 and November 2013 were included. Up to December 2011, SLNs were detected by using patent blue (PB) alone, and since January 2012, by using PB in combination with ICG. The patients were divided into the following two groups: group A (ICG-PB; n=96) and group B (PB; n=73), and SLN detection parameters were compared between the groups. All patients underwent level I and II axillary dissections after SLNB. Results In group A, the SLN detection rate was 96.9% (93/96), the accuracy of detection was 98.9% (92/93), and the false-negative rate (FNR) was 3.4% (1/29). In group B, the SLN detection rate was 84.9% (62/73), the accuracy of detection was 96.8% (60/62), and the FNR was 11.1% (2/18). The ICG-PB group showed significantly superior results compared to the PB group for SLN detection (p=0.005) and a greatly improved FNR. Conclusion The combined fluorescence and blue dye-based tracer technique was superior to the use of blue dye alone for identifying SLNs, and for predicting axillary lymph node status in patients with breast cancer; in addition, the combined technique had reduced false-negative results. PMID:25320623

Tong, Meng; Gao, Wei



Bioconjugatable azo-based dark-quencher dyes: synthesis and application to protease-activatable far-red fluorescent probes.  


We describe the efficient synthesis and one-step derivatization of novel, nonfluorescent azo dyes based on the Black Hole Quencher-3 (BHQ-3) scaffold. These dyes were equipped with various reactive and/or bioconjugatable groups (azido, ?-iodoacetyl, ketone, terminal alkyne, vicinal diol). The azido derivative was found to be highly reactive in the context of copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions and allowed easy synthetic access to the first water-soluble (sulfonated derivative) and aldehyde-modified BHQ-3 dyes, the direct preparation of which failed by means of conventional azo-coupling reactions. The aldehyde- and ?-iodoacetyl-containing fluorescence quenchers were readily conjugated to aminooxy- and cysteine-containing peptides by the formation of a stable oxime or thioether linkage, respectively. Further fluorescent labeling of the resultant peptide conjugates with red- or far-red-emitting rhodamine or cyanine dyes through sequential and/or one-pot bioconjugations, led to novel Förster resonance energy transfer (FRET) based probes suitable for the in vivo detection and imaging of urokinase plasminogen activator, a key protease in cancer invasion and metastasis. PMID:23255474

Chevalier, Arnaud; Massif, Cédrik; Renard, Pierre-Yves; Romieu, Anthony



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

NASA Astrophysics Data System (ADS)

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.

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



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


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

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



Fluorescence modulation and photodegradation characteristics of safranin O dye in the presence of ZnS nanoparticles  

Microsoft Academic Search

ZnS nanoparticles were synthesized using a chemical precipitation method and were characterized with FTIR, transmission electron microscope (TEM), X-ray diffraction analysis (XRD) and UV–vis absorption. XRD analysis shows that the diameter of the particles is 1.6nm. The interaction between ZnS nanoparticles and safranin O (SO) dye was studied with UV–vis absorption as well as fluorescence emission and excitation spectra. The

Maged El-Kemary; Hany El-Shamy



Tricolour fluorescence detection of sequence-specific DNA with a new molecular beacon and a nucleic acid dye TOTO-3.  


We have developed a tricolor fluorescence quantitative method for sequence-specific DNA detection using a new molecular beacon (MB) and a nucleic acid dye TOTO-3. This new MB is designed with two fluorophores of FAM and TAMRA instead of one fluorophore and one quencher of traditional MB, and a nucleotide with guanine base is attached directly to FAM as a quencher. In the absence of target DNA, MBs are in the stem-loop state. The fluorescence of FAM is absorbed by TAMRA, and the fluorescence of TAMRA is quenched by guanine base. Meanwhile, the interaction between TOTO-3 and MBs is very weak. In the presence of target DNA, MBs hybridize with target DNA to form a double-stranded structure. TAMRA is separated from FAM and guanine base, and the fluorescence of FAM and TAMRA recovers simultaneously. At the same time TOTO-3 binds to double-stranded DNA, the fluorescence of TOTO-3 significantly enhances. In this strategy, the false-positive signals of MBs caused by non-specific interactions can be distinguished by the change of the ratio of the total fluorescence intensities of FAM and TAMRA to that of TOTO-3 at different concentrations of target DNA. In the simple sample, the detection of target DNA can be achieved with the total fluorescence intensity of three dyes, which results in a significant improvement of the detection sensitivity. In the complex sample, the detection of target DNA can be achieved with the fluorescence intensity of TOTO-3 which can overcome the false-positive signals of MBs and improve the detection accuracy. PMID:23113317

Xiang, Dongshan; Zhang, Cuiling; Chen, Lu; Ji, Xinghu; He, Zhike



One trinucleus dimethine cyanine dye: Experimental and theoretical studies on molecular structure as well as absorption and fluorescence properties  

NASA Astrophysics Data System (ADS)

A kind of trinucleus dimethine cyanine dye: 1-methyl-2,6-bis[2-(furan-2-yl)vinyl]pyridinium iodide (1) was synthesized and characterized by 1H NMR, 13C NMR, IR, MS, UV-Vis spectroscopy and elemental analysis. The crystals of dye 1, obtained from slow evaporation of solvent acetone, crystallized in the triclinic space group P - 1 with a = 9.6501(16) Å, b = 10.2308(17) Å, c = 10.7341(17) Å, V = 887.2(3) Å3, and Z = 2 (at 298(2) K), and it was stabilized by the hydrogen bonds and intermolecular face-to-face ?⋯? aromatic stacking interactions. Crystallographic, IR, 1H NMR and UV-Vis data of dye 1 were compared with the results of density functional theory (DFT) method, and the calculated molecular geometries, vibrational bands, 1H NMR chemical shifts and UV-Vis maximum absorption were consistent with the experimental results. The fluorescence spectra were predicted in four different solvents with CIS/PCM methods. Compared with experimental values, the absolute deviations of emission maxima were -17.4 nm in chloroform, 6.3 nm in DMSO, 4.9 nm in methanol, and 6.8 nm in water, respectively. And the experimental fluorescence spectra were nicely reproduced by the simulated fluorescence spectra for each solvent.

Zhang, D. D.; Wang, L. Y.; Su, J. J.; Zhang, X. F.; Lei, Y. B.; Zhai, G. H.; Wen, Z. Y.



Charge-recombination fluorescence from push-pull electronic systems constructed around amino-substituted styryl-BODIPY dyes.  


A small series of donor-acceptor molecular dyads has been synthesized and fully characterized. In each case, the acceptor is a dicyanovinyl unit and the donor is a boron dipyrromethene (BODIPY) dye equipped with a single styryl arm bearing a terminal amino group. In the absence of the acceptor, the BODIPY-based dyes are strongly fluorescent in the far-red region and the relaxed excited-singlet states possess significant charge-transfer character. As such, the emission maxima depend on both the solvent polarity and temperature. With the corresponding push-pull molecules, there is a low-energy charge-transfer state that can be observed by both absorption and emission spectroscopy. Here, charge-recombination fluorescence is weak and decays over a few hundred picoseconds or so to recover the ground state. Overall, these results permit evaluation of the factors affecting the probability of charge-recombination fluorescence in push-pull dyes. The photophysical studies are supported by cyclic voltammetry and DFT calculations. PMID:24038505

Nano, Adela; Ziessel, Raymond; Stachelek, Patrycya; Harriman, Anthony



Volume labeling with Alexa Fluor dyes and surface functionalization of highly sensitive fluorescent silica (SiO2) nanoparticles  

NASA Astrophysics Data System (ADS)

A new synthesis approach is described that allows the direct incorporation of fluorescent labels into the volume or body of SiO2 nanoparticles. In this process, fluorescent Alexa Fluor dyes with different emission wavelengths were covalently incorporated into the SiO2 nanoparticles during their formation by the hydrolysis of tetraethoxysilane. The dye molecules were homogeneously distributed throughout the SiO2 nanoparticles. The quantum yields of the Alexa Fluor volume-labeled SiO2 nanoparticles were much higher than nanoparticles labeled using conventional organic dyes. The size of the resulting nanoparticles was controlled using microemulsion reaction media with sizes in the range of 20-100 nm and a polydispersity of <15%. In comparison with conventional surface tagged particles created by post-synthesis modification, this process maintains the physical and surface chemical properties that have the most pronounced effect on colloidal stability and interactions with their surroundings. These volume-labeled nanoparticles have proven to be extremely robust, showing excellent signal strength, negligible photobleaching, and minimal loss of functional organic components. The native or ``free'' surface of the volume-labeled particles can be altered to achieve a specific surface functionality without altering fluorescence. Their utility was demonstrated for visualizing the association of surface-modified fluorescent particles with cultured macrophages. Differences in particle agglomeration and cell association were clearly associated with differences in observed nanoparticle toxicity. The capacity to maintain particle fluorescence while making significant changes to surface chemistry makes these particles extremely versatile and useful for studies of particle agglomeration, uptake, and transport in environmental and biological systems.A new synthesis approach is described that allows the direct incorporation of fluorescent labels into the volume or body of SiO2 nanoparticles. In this process, fluorescent Alexa Fluor dyes with different emission wavelengths were covalently incorporated into the SiO2 nanoparticles during their formation by the hydrolysis of tetraethoxysilane. The dye molecules were homogeneously distributed throughout the SiO2 nanoparticles. The quantum yields of the Alexa Fluor volume-labeled SiO2 nanoparticles were much higher than nanoparticles labeled using conventional organic dyes. The size of the resulting nanoparticles was controlled using microemulsion reaction media with sizes in the range of 20-100 nm and a polydispersity of <15%. In comparison with conventional surface tagged particles created by post-synthesis modification, this process maintains the physical and surface chemical properties that have the most pronounced effect on colloidal stability and interactions with their surroundings. These volume-labeled nanoparticles have proven to be extremely robust, showing excellent signal strength, negligible photobleaching, and minimal loss of functional organic components. The native or ``free'' surface of the volume-labeled particles can be altered to achieve a specific surface functionality without altering fluorescence. Their utility was demonstrated for visualizing the association of surface-modified fluorescent particles with cultured macrophages. Differences in particle agglomeration and cell association were clearly associated with differences in observed nanoparticle toxicity. The capacity to maintain particle fluorescence while making significant changes to surface chemistry makes these particles extremely versatile and useful for studies of particle agglomeration, uptake, and transport in environmental and biological systems. Electronic supplementary information (ESI) available: Cell culture preparation for dose/response imaging experiments. See DOI: 10.1039/c3nr02639f

Wang, Wei; Nallathamby, Prakash D.; Foster, Carmen M.; Morrell-Falvey, Jennifer L.; Mortensen, Ninell P.; Doktycz, Mitchel J.; Gu, Baohua; Retterer, Scott T.



Volume Labeling with Alexa-Fluor Dyes and Surface Functionalization of Highly Sensitive Fluorescent SiO2 Nanoparticles  

SciTech Connect

A new synthesis approach is described that allows the direct incorporation of fluorescent labels into the volume or body of SiO2 nanoparticles. In this process, fluorescent Alexa Fluor dyes with different emission wavelengths were covalently incorporated into the SiO2 nanoparticles during their formation by the hydrolysis of tetraethoxysilane. The dye molecules were homogeneously distributed throughout the SiO2 nanoparticles. The quantum yields of the Alexa Fluor volume-labeled SiO2 nanoparticles were much higher than nanoparticles labeled using conventional organic dyes. The size of the resulting nanoparticles was controlled using microemulsion reaction media with sizes in the range of 20-100 nm and a polydispersity of <15%. In comparison with conventional surface tagged particles created by post-synthesis modification, this process maintains the physical and surface chemical properties that have the most pronounced effect on colloidal stability and interactions with their surroundings. These volume-labeled nanoparticles have proven to be extremely robust, showing excellent signal strength, negligible photobleaching, and minimal loss of functional organic components. The native or free surface of the volume-labeled particles can be altered to achieve a specific surface functionality without altering fluorescence. Their utility was demonstrated for visualizing the association of surface modified fluorescent particles with cultured macrophages. Differences in particle agglomeration and cell association were clearly associated with differences in observed nanoparticle toxicity. The capacity to maintain particle fluorescence while making significant changes to surface chemistry makes these particles extremely versatile and useful for studies of particle agglomeration, uptake, and transport in environmental and biological systems.

Wang, Wei [ORNL] [ORNL; Foster, Carmen M [ORNL] [ORNL; Morrell-Falvey, Jennifer L [ORNL] [ORNL; Nallathamby, Prakash D [ORNL] [ORNL; Mortensen, Ninell P [ORNL] [ORNL; Doktycz, Mitchel John [ORNL] [ORNL; Gu, Baohua [ORNL] [ORNL; Retterer, Scott T [ORNL] [ORNL; Gu, Baohua [ORNL] [ORNL



Non-fluorescent RNA in situ hybridization combined with antibody staining to visualize multiple gene expression patterns in the embryonic brain of Drosophila.  


In Drosophila, the brain arises from about 100 neural stem cells (called neuroblasts) per hemisphere which originate from the neuroectoderm. Products of developmental control genes are expressed in spatially restricted domains in the neuroectoderm and provide positional cues that determine the formation and identity of neuroblasts. Here, we present a protocol for non-fluorescent double in situ hybridization combined with antibody staining which allows the simultaneous representation of gene expression patterns in Drosophila embryos in up to three different colors. Such visible multiple stainings are especially useful to analyze the expression and regulatory interactions of developmental control genes during early embryonic brain development. We also provide protocols for whole mount and flat preparations of Drosophila embryos, which allow a more detailed analysis of gene expression patterns in relation to the cellular context of the early brain (and facilitate the identification of individual brain neuroblasts) using conventional light microscopy. PMID:24048924

Jussen, David; Urbach, Rolf



Real-time probing of ?-amyloid self-assembly and inhibition using fluorescence self-quenching between neighbouring dyes.  


The fluorescence response of the Thioflavin-T (ThT) dye and derivatives has become the standard tool for detecting ?-amyloid aggregates (A?) in solution. However, it is accepted that ThT-based methods suffer from important drawbacks. Some of these are due to the cationic structure of ThT, which limits its application at slightly acidic conditions; whereas some limitations are related to the general use of an extrinsic-dye sensing strategy and its intrinsic requirement for the formation of a sensor-binding site during the aggregation process. Here, we introduce fluorescence-self-quenching (FSQ) between N-terminally tagged peptides as a strategy to overcome some of these limitations. Using a combination of steady-state, picosecond time-resolved fluorescence and transmission electron microscopy, we characterize the fluorescence response of HiLyte fluor 555-labelled A? peptides and demonstrate that A? self-assembly organizes the covalently attached probes in close proximity to trigger the self-quenching sensing process over a broad range of conditions. Importantly, we prove that N-terminal tagging of ?-amyloid peptides does not alter the self-assembly kinetics or the resulting aggregated structures. We also tested the ability of FSQ-based methods to monitor the inhibition of A?1-42 aggregation using the small heat-shock protein Hsp20 as a model system. Overall, FSQ-based strategies for amyloid-sensing fill the gap between current morphology-specific protocols using extrinsic dyes, and highly-specialized single-molecule techniques that are difficult to implement in high-throughput analytical determinations. When performed in Förster resonance energy transfer (FRET) format, the method becomes a ratiometric platform to gain insights into amyloid structure and for standardizing in vitro studies of amyloid aggregation. PMID:24170094

Quinn, Steven D; Dalgarno, Paul A; Cameron, Ryan T; Hedley, Gordon J; Hacker, Christian; Lucocq, John M; Baillie, George S; Samuel, Ifor D W; Penedo, J Carlos



Synchronous fluorescence and UV–vis spectroscopic studies of interactions between the tetracycline antibiotic, aluminium ions and DNA with the aid of the Methylene Blue dye probe  

Microsoft Academic Search

Synchronous fluorescence spectroscopy (SFS) was applied for the investigation of interactions of the antibiotic, tetracycline (TC), with DNA in the presence of aluminium ions (Al3+). The study was facilitated by the use of the Methylene Blue (MB) dye probe, and the interpretation of the spectral data with the aid of the chemometrics method, parallel factor analysis (PARAFAC). Three-way synchronous fluorescence

Yongnian Ni; Daiqin Lin; Serge Kokot



Base-assisted one-pot synthesis of N,N',N"-triaryltriazatriangulenium dyes: enhanced fluorescence efficiency by steric constraints.  


In this paper we report the first synthesis of cationic N,N',N"-triaryltriazatriangulenium dyes (Ar(3)-TATA(+)). Previously, only alkyl-substituted triazatriangulenium derivatives (R(3)-TATA(+)) were known, a consequence of the low reactivity of anilines in the aromatic nucleophilic substitution reaction leading to the formation of the TATA(+) core. The synthesis of Ar(3)-TATA(+) was achieved by heating the tris(2,6-dimethoxyphenyl)methylium ion (DMP(3)C(+)) in various anilines in the presence of NaH. In the solvent-free reaction all three aryl substituents could be introduced despite the low reactivity of the anilines. The symmetric Ar(3)-TATA(+) derivatives with Ar = phenyl (2), 4-methoxyphenyl (3), and 4-bromophenyl (4) were synthesized. Single crystal structures of 2 and 4 were obtained as BF(4)(-) salts, where torsional angles larger than 80° were observed between the TATA(+) chromophore and the aryl substituents. The photophysical properties were studied in solution and in thin films. The results show that the Ar(3)-TATA(+) dyes have a surprising 3-fold increase in fluorescence quantum yields when compared to the parent alkyl-substituted R(3)-TATA(+) salts. With a high quantum yield (>50%) and emission in the red (?(fl) = 560 nm) the Ar(3)-TATA(+) dyes represent a promising new addition to the family of superstable cationic triangulenium dyes. Additionally, the synthesized tribromo derivative 4 is shown to be a potential triagonal synthon for polymers and other macromolecules. PMID:22616844

Hammershøj, Peter; Sørensen, Thomas Just; Han, Bao-Hang; Laursen, Bo W



Role of rare earth oxide nanoparticles (CeO2 and La2O3) in suppressing the photobleaching of fluorescent organic dyes.  


Aqueous solutions with Rhodamine dye, and fluorescently labeled polymer samples of fibrin and collagen were mixed with aqueous dispersions of cerium oxide, lanthanum oxide, iron (II) oxide nanoparticles, and OxyFluor, a commonly used reagent for suppressing photobleaching. From time dependent studies of the fluorescence from these samples, we observed that the dyes in samples containing rare earth oxide nanoparticles exhibited significantly slower rates of fluorescence decay compared to control samples without additives, or containing OxyFluor or iron oxide nanoparticles. We posit that this may be related to the oxygen free radical scavenging properties of rare earth oxides. PMID:24706286

Guha, Anubhav; Basu, Anindita



Stain Reagent Reversible Stain Kits  

E-print Network

are not visible before destain- ing with methanol/acetic acid to remove the characteristic background stainingGelCode ® Blue Stain Reagent GelCode ® SilverSNAP TM Stain GelCode ® E-Zinc TM Reversible Stain Kits Technical Review Gel Stains F E A T U R I N G . . . #12;P r o t e i n S t a i n i n g Only

Lebendiker, Mario


Molecular cytogenetic analysis of the crucian carp, Carassius carassius (Linnaeus, 1758) (Teleostei, Cyprinidae), using chromosome staining and fluorescence in situ hybridisation with rDNA probes  

PubMed Central

Abstract The crucian carp Carassius carassius (Linnaeus, 1758) is a species with restricted and decreasing distribution in Europe. Six males and six females of the species from the Baltic Sea basin in Poland were examined to show sequentially CMA3/AgNO3 staining pattern, DAPI staining, and, for the first time in literature, molecular cytogenetic analysis using double-colour fluorescence in situ hybridisation (FISH) with 28S and 5S rDNA probes. The karyotype consisted of 20 m, 36 sm and 44 sta chromosomes, NF=156. The AgNO3 stained NORs were most frequently located terminally in the short arms of two sm and two sta elements, and CMA3-positive sites were also observed suggesting abundant GC-rich repetitive DNA in the regions. Other CMA3-positive sites in the short arms of six to ten sm and sta chromosomes were detected. The results based on 28S rDNA FISH confirmed the location of rDNA sites. DAPI-negative staining of NORs suggested the scarcity of AT-rich DNA in the regions. FISH with 5S rDNA probe revealed 8–14 loci (ten and 12 in respectively 49 and 29% of metaphases). They were located in two sm and eight to ten sta chromosomes and six of them were larger than others. Simultaneously, mapping of the two rDNA families on the chromosomes of C. carassius revealed that both 28S and 5S rDNA probes were located in different chromosomes. Molecular cytogenetic data of C. carassius presented here for the first time give an important insight into the structure of chromosomes of this polyploid and declining species and may be useful in its systematics.

Spoz, Aneta; Boron, Alicja; Porycka, Katarzyna; Karolewska, Monika; Ito, Daisuke; Abe, Syuiti; Kirtiklis, Lech; Juchno, Dorota



Dye remover poisoning  


... remover is a chemical used to remove dye stains. Dye remover poisoning occurs when someone swallows this ... by IV Medicines to treat pain Oxygen Surgical removal of burned skin (skin debridement) Washing of the ...



E-print Network

in laser dyes in a solid state system. This chromophore has been successfully made into a blue ASE polymer-fiber harmonic (SH) (533nm) and the optical parametric amplifi- cation (OPA) wavelengths from a tunable Ti

Collins, Gary S.


Size- and Shape-Dependent Fluorescence Quenching of Gold Nanoparticles on Perylene Dye.  

National Technical Information Service (NTIS)

Organo-soluble decane thiol monolayer-protected gold nanoparticles of different shapes and sizes are homogenously mixed with strong fl uorescent perylene diimide (PDI) dye molecules in both solution and solid states. The effect of the doped gold nanoparti...

A. Urbas, C. Xue, L. Dai, Q. Li Y. Xue



[Brief counting method of airborne Cryptomeria japonica pollen by a combination of fluorescence antibody staining and flow cytometry].  


Airborne pollens collected in a pollen collector (Virtual Impactor) was treated with a fluorescein isothiocyanate-labeled monoclonal antibody (KW-S10) which was strictly specific to Japanese cedar pollen antigen (Cry j I). Flow cytometric analysis revealed that the intensity of fluorescence of the pollen samples treated with the antibody was greater than that of non-treated reference pollen or the antibody treated Hinoki-cypress pollen. By use of this method, it may be possible to display the airborne pollen concentration within 20 min after sampling. PMID:1492796

Takahashi, Y; Yoshimura, S; Masago, H; Inouye, K; Shirai, T; Nagoya, T; Sakaguchi, M; Inouye, S; Katagiri, S



Determination of Gaseous Sulfur Dioxide and Its Derivatives via Fluorescence Enhancement Based on Cyanine Dye Functionalized Carbon Nanodots.  


The development of convenient methods for sulfur dioxide and its derivatives analysis is critically important because SO2 causes worldwide serious environmental problems and human diseases. In this work, we show an unprecedented example of an energy-transfer-based fluorescence nanoprobe for selective and quantitative detection of SO2, through molecular engineering of the fluorescent carbon nanodots by a cyanine dye which have a unique reactivity to bisulfite, achieving a detection limit of 1.8 ?M with a linear relationship (R(2) = 0.9987). The specific detection was not interfered with other potential coexisted species. In addition, the probe is demonstrated for the determination of SO2 gas in aqueous solution as well as for visually monitoring of SO2 gas in air. This nanomaterial based probe is easily prepared, fast responding, and thus potentially attractive for extensive application for the determination of SO2 and other similar air pollutants. PMID:25242201

Sun, Mingtai; Yu, Huan; Zhang, Kui; Zhang, Yajiao; Yan, Yehan; Huang, Dejian; Wang, Suhua



DNA complexes with dyes designed for energy transfer as fluorescent markers  


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.

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



DNA complexes with dyes designed for energy transfer as fluorescent markers  


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.

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



DNA complexes with dyes designed for energy transfer as fluorescent markers  


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.

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



DNA complexes with dyes designed for energy transfer as fluorescent markers  


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.

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



DNA complexes with dyes designed for energy transfer as fluorescent markers  


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.

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



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


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

Ordoudi, S A; Tsimidou, M Z



Rational design of a new fluorescent 'ON/OFF' xanthene dye for phosphate detection in live cells.  


A new fluorescein derivative with ON/OFF features, 9-[1-(4-tert-butyl-2-methoxyphenyl)]-6-hydroxy-3H-xanthen-3-one (Granada Green, GG), was designed and synthesised. The new dye has spectral characteristics similar to those of other xanthenic derivatives but shows a higher pK(a) value for the equilibrium between its neutral and anionic forms. In addition, GG undergoes the same phosphate-mediated excited state proton transfer (ESPT) reaction as other xanthenic derivatives, giving rise to fluorescence decay traces that are dependent on both the phosphate concentration and pH of the medium. The phosphate-mediated ESPT reaction was employed to detect changes in the phosphate concentrations in live, permeabilised MC3T3-E1 preosteoblasts at pH 7.35. Its high pK(a) value indicates that this new dye is more sensitive as an intracellular phosphate sensor than other previously tested dyes, as experimentally demonstrated by its ability to detect a wider range of phosphate concentrations in biomimetic media and by the increased ratio of the phosphate concentration/decay time. PMID:25017473

Martínez-Peragón, A; Miguel, D; Orte, A; Mota, A J; Ruedas-Rama, M J; Justicia, J; Alvarez-Pez, J M; Cuerva, J M; Crovetto, L



In-situ investigation of adsorption of dye and coadsorbates on TiO2 films using QCM-D, fluorescence and AFM techniques  

NASA Astrophysics Data System (ADS)

Simultaneous adsorption of dye molecules and coadsorbates is important for the fabrication of high-efficiency dyesensitized solar cells, but its mechanism is not well understood. Herein, we use a quartz crystal microbalance with dissipation technique (QCM-D) to study dynamically and quantitatively the sensitization of TiO2 in situ. We investigate dye loading for a ruthenium(II) polypyridyl complex (Z907), of a triphenylamine-based D-?-A dye (Y123), and of a ullazine sensitizer (JD21), as well as the simultaneous adsorption of the latter two with the coadsorbate chenodeoxycholic acid. By combining the QCM-D technique with fluorescence measurements, we quantify molar ratios between the dye and coadsorbate. Furthermore, we will present first studies using liquid-phase AFM on the adsorbed dye monolayer, thus obtaining complementary microscopic information that may lead to understanding of the adsorption mechanism on the molecular scale.

Harms, Hauke A.; Tétreault, Nicolas; Voitchovsky, Kislon; Stellacci, Francesco; Grätzel, Michael



Application of a Vital Fluorescent Staining Method for Simultaneous, Near-Real-Time Concentration Monitoring of Two Bacterial Strains in an Atlantic Coastal Plain Aquifer in Oyster, Virginia  

PubMed Central

Two differentially labeled bacterial strains were monitored in near-real time during two field-scale bacterial transport experiments in a shallow aquifer in July 2000 and July 2001. Comamonas sp. strain DA001 and Acidovorax sp. strain OY-107 were grown and labeled with the vital fluorescent stain TAMRA/SE (5 [and -6]-carboxytetramethylrhodamine, succinimidyl ester) or CFDA/SE (5 [and -6]-carboxyfluorescein diacetate, succinimidyl ester). Fluorescently labeled cells and a conservative bromide tracer were introduced into a suboxic superficial aquifer, followed by groundwater collection from down-gradient multilevel samplers. Cells were enumerated in the field by microplate spectrofluorometry, with confirmatory analyses for selected samples done in the laboratory by epifluorescence microscopy, flow cytometry, and ferrographic capture. There was general agreement in the results from all of the vital-stain-based enumeration methods, with differences ranging from <10% up to 40% for the analysis of identical samples between different tracking methods. Field analysis by microplate spectrofluorometry was robust and efficient, allowing thousands of samples to be analyzed in quadruplicate for both of the injected strains. The near-real-time data acquisition allowed adjustments to the predetermined sampling schedule to be made. The microplate spectrofluorometry data sets for the July 2000 and July 2001 experiments allowed the transport of the injected cells to be related to the site hydrogeology and injection conditions and enabled the assessment of differences in the transport of the two strains. This near-real-time method should prove effective for a number of microbial ecology applications. PMID:15006793

Fuller, Mark E.; Mailloux, Brian J.; Streger, Sheryl H.; Hall, James A.; Zhang, Pengfei; Kovacik, William P.; Vainberg, Simon; Johnson, William P.; Onstott, Tullis C.; DeFlaun, Mary F.



Nano-confined squaraine dye assemblies: new photoacoustic and near-infrared fluorescence dual-modular imaging probes in vivo.  


For the purpose of near-infrared (NIR) fluorescence and photoacoustic (PA) tomography dual-modular imaging, self-assembly of squaraine (SQ) dyes is constructed in the hydrophobic phospholipid bilayers of liposomes (SQ?L) with variable mixing ratios of SQ and phospholipids from 1:500 to 1:10 (w/w). When doping minimal amounts of SQ, molecularly dispersed SQ in bilayers shows remarkable fluorescence. Interesting, the PA signal is enhanced with increase of SQ in the nanoconfined bilayer region, which is attributed to the formation of SQ-based H-aggregates and enhanced thermal conversion efficiency (?). SQ?L shows satisfactory chemical and thermal stabilities and photobleaching resistance. SQ?L is well-distributed in the cytoplasm of MCF-7 cells and its fluorescence signal remains for 7 days without dramatic quenching owing to the good stability of SQ?L. Furthermore, SQ?L is subjected to in vivo NIR fluorescence imaging to evaluate the whole-body biodistribution in organ level. Particularly, PA imaging with deeper tissue penetration capability is utilized to investigate the heterogeneous distribution SQ?L inside solid tumor. The majority of SQ?L are enriched in the area where the blood vessels are generated, implying that the liposomal nanocarriers exhibit lower tumor tissue penetration capability after the vascular leakage. This result is validated by histological examination of tumor tissue in parallel. PMID:25370305

Zhang, Di; Zhao, Ying-Xi; Qiao, Zeng-Ying; Mayerhöffer, Ulrich; Spenst, Peter; Li, Xiao-Jun; Würthner, Frank; Wang, Hao



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

SciTech Connect

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.

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



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

ERIC Educational Resources Information Center

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.

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



Evaluation of fluorescent dyes for the detection of mitochondrial membrane potential changes in cultured cardiomyocytes  

Microsoft Academic Search

Objective: Maintenance of the mitochondrial membrane potential (Dcm) is fundamental for the normal performance and survival of cells such as cardiomyocytes, that have a high energy requirement. Measurement of Dcm is therefore essential in order to develop an understanding of the molecular mechanisms controlling cardiomyocyte function. Here we have evaluated various potentiometric dyes for their ability to detect alterations of

Anthony Mathur; Ying Hong; Barbara K. Kemp; Alberto Alvarez Barrientos; Jorge D. Erusalimsky


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

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

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.



Criteria for selecting fluorescent dye tracers for soil hydrological applications using Uranine as an example  

EPA Science Inventory

Calibrating and verifying 2-D and 3-D vadose zone flow and transport models requires detailed information on water and solute redistribution. Among the different water flow and mass transfer determination methods, staining tracers have the best spatial resolution allowing visuali...


Improvement of amplified spontaneous emission by encapsulating green fluorescent dye in inverted-opal titania photonic crystals.  


Amplified spontaneous emission (ASE) characteristics of a green fluorescent dye (10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-[1] benzo- pyrano [6,7,8-ij]quinolizin-11-one) (C545T) encapsulated in a highly ordered three-dimensional (3D) inverted-opal titania (TiO(2)) photonic crystal (PC) microcavity were studied. Due to the utilization of a TiO(2) PC, the emission spectrum was greatly narrowed and the ASE threshold, gain, and loss were significantly improved. The threshold, gain, and loss reached 1.25 mJ pulse(-1) cm(-2), 34.69 cm(-1), and 16.9 cm(-1), respectively. The possible reason for the improvement in the ASE performance by the PC is attributed to the 3D photon localization by the microcavity effect of the PC. PMID:18709061

Zhang, Dingke; Wang, Yanping; Cao, Yanling; Ma, Dongge



Exploring chip-capillary electrophoresis-laser-induced fluorescence field-deployable platform flexibility: separations of fluorescent dyes by chip-based non-aqueous capillary electrophoresis.  


Microfluidic chip electrophoresis (chip-CE) is a separation method that is compatible with portable and on-site analysis, however, only few commercial chip-CE systems with laser-induced fluorescence (LIF) and light emitting diode (LED) fluorescence detection are available. They are established for several application tailored methods limited to specific biopolymers (DNA, RNA and proteins), and correspondingly the range of their applications has been limited. In this work we address the lack of commercially available research-type flexible chip-CE platforms by exploring the limits of using an application-tailored system equipped with chips and methods designed for DNA separations as a generic chip-CE platform - this is a very significant issue that has not been widely studied. In the investigated Agilent Bioanalyzer chip-CE system, the fixed components are the Agilent chips and the detection (LIF at 635 nm and LEDIF at 470 nm), while the chemistry (electrolyte) and the programming of all the high voltages are flexible. Using standard DNA chips, we show that a generic CE function of the system is easily possible and we demonstrate an extension of the applicability to non-aqueous CE (NACE). We studied the chip compatibility with organic solvents (i.e. MeOH, ACN, DMF and DMSO) and demonstrated the chip compatibility with DMSO as a non-volatile and non-hazardous solvent with satisfactory stability of migration times over 50h. The generic CE capability is illustrated with separations of fluorescent basic blue dyes methylene blue (MB), toluidine blue (TB), nile blue (NB) and brilliant cresyl blue (BC). Further, the effects of the composition of the background electrolyte (BGE) on the separation were studied, including the contents of water (0-30%) and buffer composition. In background electrolytes containing typically 80 mmol/L ammonium acetate and 870 mmol/L acetic acid in 100% DMSO baseline separation of the dyes were achieved in 40s. Linearity was documented in the range of 5-28 ?mol/L, 10-100 ?mol/L, 1.56-50 nmol/L and 5-75 nmol/L (r(2) values in the range 0.974-0.999), and limit of detection (LOD) values were 90 nmol/L, 1 ?mol/L 1.4 nmol/L, and 2 nmol/L for MB, TB, NB and BC, respectively. PMID:23510955

Nuchtavorn, Nantana; Smejkal, Petr; Breadmore, Michael C; Guijt, Rosanne M; Doble, Philip; Bek, Fritz; Foret, Frantisek; Suntornsuk, Leena; Macka, Mirek



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

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

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



Dye Like A Natural  

NSDL National Science Digital Library

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.

Yu, Julie



Dual color fluorescence quantitative detection of specific single-stranded DNA with molecular beacons and nucleic acid dye SYBR Green I.  


We have developed a dual color fluorescence quantitative detection method for specific single-stranded DNA with molecular beacons (MBs) and nucleic acid dye SYBR Green I by synchronous scanning fluorescence spectrometry. It is demonstrated by a reverse-transcription oligonucleotide sequence (target DNA, 33 bases) of RNA fragment of human immunodeficiency virus (HIV) as a model system. In the absence of target DNA, the MBs are in the stem-closed state, the fluorescence of 5-carboxy-X-rhodamine (ROX) is quenched by black hole quencher-2 (BHQ-2), and the interaction between SYBR Green I and the MBs is very weak. At this time the fluorescence signals of ROX and SYBR Green I are all very weak. In the presence of target DNA, MBs hybridize with target DNA and form a double-strand structure, the fluorophore ROX is separated from the quencher BHQ-2, and the fluorescence of ROX recovers. At the same time, SYBR Green I binds to hybridized dsDNA, whose fluorescence intensity is significantly enhanced. Thus, dual color fluorescence quantitative detection for the target DNA can be realized by synchronous scanning fluorescence spectrometry. In this strategy, the fluorescence signal of SYBR Green I is far larger than that of ROX, so the quantitative analysis of target DNA with the fluorescence intensity of SYBR Green I can significantly improve the detection sensitivity. In addition, the false-positive signals of MBs do not affect the fluorescence signals of nucleic acid dye SYBR Green I. Thereby, in the analysis of complex samples, quantitative analysis of target DNA with SYBR Green I can avoid the false-positive signals of MBs and improve the detection accuracy. PMID:22763945

Xiang, Dong-Shan; Zhou, Guo-Hua; Luo, Ming; Ji, Xing-Hu; He, Zhi-Ke



Determination of the Number of Respiring Thiobacillus ferrooxidans Cells in Water Samples by Using Combined Fluorescent Antibody-2-(p-Iodophenyl)-3-(p-Nitrophenyl)-5-Phenyltetrazolium Chloride Staining  

PubMed Central

Fluorescent antibody staining was combined with 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride reduction in a procedure termed FAINT to allow for the direct microscopic determination of specific actively respiring populations of bacteria in a variety of aquatic habitats. The FAINT procedure is simple, precise, and appropriate for use in a wide variety of autecological studies. The distribution of Thiobacillus ferrooxidans was examined by FAINT enumerations in both acidic and nonacidic sites. Comparisons among the FAINT technique and fluorescent antibody staining alone or most-probable-number determinations in 9K broth showed that the use of most-probable-number determinations resulted in an underestimation of the number of viable cells by one to three orders of magnitude, whereas fluorescent antibody counts resulted in an overestimation of the number of viable T. ferrooxidans. The amount of difference was not consistent but varied, depending on the sample site. PMID:16345938

Baker, Katherine H.; Mills, Aaron L.



Fluorescent dye ProteoStat to detect and discriminate intracellular amyloid-like aggregates in Escherichia coli.  


The formation of amyloid aggregates is linked to the onset of an increasing number of human disorders. Thus, there is an increasing need for methodologies able to provide insights into protein deposition and its modulation. Many approaches exist to study amyloids in vitro, but the techniques available for the study of amyloid aggregation in cells are still limited and non-specific. In this study we developed a methodology for the detection of amyloid-like aggregates inside cells that discriminates these ordered assemblies from other intracellular aggregates. We chose bacteria as model system, since the inclusion bodies formed by amyloid proteins in the cytosol of bacteria resemble toxic amyloids both structurally and functionally. Using confocal microscopy, fluorescence spectroscopy, and flow cytometry, we show that the recently developed red fluorescent dye ProteoStat can detect the presence of intracellular amyloid-like deposits in living bacterial cells with high specificity, even when the target proteins are expressed at low levels. This methodology allows quantitation of the intracellular amyloid content, shows the potential to replace in vitro screenings in the search for therapeutic anti-amyloidogenic compounds, and might be useful for identifying conditions that prevent the aggregation of therapeutic recombinant proteins. PMID:25112199

Navarro, Susanna; Ventura, Salvador



application note Fluorescent protein staining  

E-print Network

Biosciences Products used: Hoefer miniVE Vertical Electrophoresis System 80-6418-77 Ettan IPGPhor IEF System 80-6414-02 Ettan DALTtwelve Large Vertical System 80-6466-27 Typhoon 9410 Variable Mode Imager for the first dimension and EttanTM DALTtwelve electrophoresis system for the second dimension. ImmobilineTM Dry

Lebendiker, Mario


Solid-phase synthesis of BODIPY dyes and development of an immunoglobulin fluorescent sensor.  


The diversification of the BODIPY scaffold has been hindered by its controversial adaptability to solid-phase chemistry. Herein we report the first solid-phase synthesis of a BODIPY library in high purities. We screened the library against a set of proteins, identified an immunoglobulin fluorescent sensor (Ig Orange) and confirmed its binding by SPR experiments. PMID:21701752

Vendrell, Marc; Krishna, Gaddamanugu Gopi; Ghosh, Krishna Kanta; Zhai, Duanting; Lee, Jun-Seok; Zhu, Qing; Yau, Yin Hoe; Shochat, Susana Geifman; Kim, Hyori; Chung, Junho; Chang, Young-Tae



The use of fluorescent dyes as tracers in highly saline groundwater  

E-print Network

sorption was tested in four different salinities (from fresh rainwater to Dead Sea water) on five pure Naphthionate was found to be the best tracer for fresh and saline water, with minimal sorption in all cases 28 May 2008 KEYWORDS Artificial tracers; Saline groundwater; Sorption; Dead Sea brine; Fluorescent

Weisbrod, Noam


Fluorescence spectral properties of cyanine dye-labeled DNA oligomers on surfaces coated with silver particles  

PubMed Central

We examined the fluorescence spectral properties of DNA oligomers, labeled with Cy3 or Cy5, when bound to quartz surfaces coated with metallic silver particles. Prior to binding of labeled DNA the surfaces were treated with polylysine or 3-aminopropyl triethoxysilane or were coated with avidin for binding of biotinylated oligomers. The fluorescence intensities were increased an average of 8-fold on these surfaces. Despite the increased emission intensity, the photostability of the labeled DNA was the same or higher on the silver-coated surfaces than on the uncoated slides. The time-integrated intensities, that is the area under the intensity plots with continuous illumination, increased an average of 6-fold. In all cases the lifetimes were dramatically shortened on the silver particles, indicating an over 100-fold increase in the radiative decay rates. These results suggest the use of substrates containing silver particles for increased sensitivity of DNA detection on DNA arrays. PMID:12758251

Malicka, Joanna; Gryczynski, Ignacy; Fang, Jiyu; Lakowicz, Joseph R.



In situ measurement of airway surface liquid [K+] using a ratioable K+-sensitive fluorescent dye.  


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 (CFTR(inh)-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

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



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


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

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



Laser therapy in plastic surgery: decolorization in port wine stains  

NASA Astrophysics Data System (ADS)

For the first time laserotherapy is described as a method of port wine stain decolorization in plastic surgery. The authors present their 20-year experience in the treatment of port wine stains with the argon laser and dye laser.

Peszynski-Drews, Cezary; Wolf, Leszek



Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.  


Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits. PMID:20853746

Tarud, F; Aybar, M; Pizarro, G; Cienfuegos, R; Pastén, P



Evaluation of the Redox Dye 5-Cyano-2,3-Tolyl-Tetrazolium Chloride for Activity Studies by Simultaneous Use of Microautoradiography and Fluorescence In Situ Hybridization  

Microsoft Academic Search

Three microscopic in situ techniques were used simultaneously to investigate viability and activity on a single-cell level in activated sludge. The redox dye 5-cyano-2,3-tolyl-tetrazolium chloride (CTC) was compared with microautoradiography (MAR) and fluorescence in situ hybridization (FISH) to indicate activity of cells in Thiothrix filaments and in single floc-forming bacteria. The signals from MAR and FISH correlated well, whereas only

Jeppe Lund Nielsen; Marilena Aquino de Muro; Per Halkjær Nielsen



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

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

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



Exploring base-pair-specific optical properties of the DNA stain thiazole orange.  


Double-stranded DNA offers multiple binding sites to DNA stains. Measurements of noncovalently bound dye-nucleic acid complexes are, necessarily, measurements of an ensemble of chromophores. Thus, it is difficult to assign fluorescence properties to base-pair-specific binding modes of cyanine dyes or, vice versa, to obtain information about the local environment of cyanines in nucleic acids by using optical spectroscopy. The feasibility to stain DNA and simultaneously probe local perturbations by optical spectroscopy would be a valuable asset to nucleic acid research. So-called FIT probes (forced intercalation probes) were used to pinpoint the location of the DNA stain thiazole orange (TO) in PNADNA duplexes. A detailed analysis of the base-pair dependence of optical properties is provided and enforced binding of TO is compared with "classical" binding of free TO-PRO1. UV-visible absorbance, circular dichroism (CD) and fluorescence spectroscopy, and melting-curve analyses confirmed site-specific TO intercalation. Thiazole orange exhibited base-specific responses that are not observed in noncovalent dye-nucleic acid complexes, such as an extraordinary dependence of the TO extinction coefficient (+/-60 % variation of the averaged epsilon(max) of 57,000 M(-1) cm(-1)) on nearest-neighbor base pairs. TO signals hybridization, as shown by increases in the steady-state fluorescence emission. Studies of TO fluorescence lifetimes in FIT-PNA and in DNADNA and PNADNA complexes highlighted four different fluorescence-decay processes that may be closed or opened in response to matched or single-mismatched hybridization. A very fast decay process (0.04-0.07 ns) and a slow decay process (2.33-3.95 ns) provide reliable monitors of hybridization, and the opening of a fast decay channel (0.22-0.48 ns) that resulted in an attenuation of the fluorescence emission is observed upon the formation of mismatched base pairs. PMID:17024704

Jarikote, Dilip Venkatrao; Krebs, Nils; Tannert, Sebastian; Röder, Beate; Seitz, Oliver



Subcritical water and dynamic sonication-assisted solvent extraction of fluorescent whitening agents and azo dyes in paper samples.  


Two low-volume solvent continuous extraction methods are applied to the extraction of paper matrices. In the methods reported here, a complex mixture of fluorescent whitening agents (FWAs) and azo dyes (AZOs) used in paper materials intended to come into contact with foodstuffs was extracted by using subcritical water extraction (SWE) and dynamic sonication-assisted solvent extraction (DSASE). Rationale for the work is based upon migration concerns of these groups of analytes from the packaging to the packaged items, thus compromising their subjective and/or objective quality. In SWE, sample was extracted in 21 min with 0.5 mL of water, whereas the DSASE method required 11 min and used 7 mL of water. DSASE was further developed by incorporating an organic modifier in order to change water polarity, thus improving extraction of moderately polar analytes. This way, modified-DSASE used a total organic volume of 0.9 mL which represents a reduction of 200 times in organic solvent consumption (200 mL versus approximately 1.0 mL) and 11 times in extraction time (2h versus 11 min) compared to the existing methods. SWE was able to extract only 9 out of 12 test analytes with average recoveries between 10 and 25% whereas modified-DSASE succeed in extracting all the target analytes with an average recovery of 89%. Complete discussion and explanation concerning these differences are provided in the text. PMID:15739881

de los Santos, Mario; Batlle, Ramón; Salafranca, Jesús; Nerín, Cristina



Design of weak-donor alkyl-functionalized push-pull pyrene dyes exhibiting enhanced fluorescence quantum yields and unique on/off switching properties.  


We designed, synthesized, and evaluated environmentally responsive solvatochromic fluorescent dyes by incorporating weak push-pull moieties. The quantum yields of the push (alkyl)-pull (formyl) pyrene dyes were dramatically enhanced by the introduction of alkyl groups into formylpyrene (1-formylpyrene: ?(F) =0.10; 3,6,8-tri-n-butyl-1-formylpyrene: ?(F) =0.90; in MeOH). The new dyes exhibited unique sensitivity to solvent polarity and hydrogen-bond donor ability, and specific fluorescence turn-on/off properties (e.g., 3,6,8-tri-n-butyl-1-formylpyrene: ?(F) =0.004, 0.80, 0.37, and 0.90 in hexane, chloroform, DMSO, and MeOH, respectively). Here, the alkyl groups act as weak donors to suppress intersystem crossing by destabilizing the HOMOs of 1-formylpyrene while maintaining weak intramolecular charge-transfer properties. By using alkyl groups as weak donors, environmentally responsive, and in particular, pH-responsive fluorescent materials may be developed in the future. PMID:24801355

Niko, Yosuke; Sasaki, Shunsuke; Kawauchi, Susumu; Tokumaru, Katsumi; Konishi, Gen-Ichi



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)

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.

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



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

NASA Astrophysics Data System (ADS)

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.

Zähringer, Katharina



Purified azure B as a reticulocyte stain  

Microsoft Academic Search

A comparison has been made between reticulocyte preparations stained with purified azure B and with several commerically available batches of brilliant cresyl blue and new methylene blue. Marked variations were observed in the composition and staining performances of the various batches of the two commerically available dyes. Although there were no significant differences in reticulocyte counts obtained with these two

P N Marshall; S A Bentley; S M Lewis



Reverse fluorescent chromosome banding with chromomycin and DAPI  

Microsoft Academic Search

Two DNA binding guanine-specific antibiotics, chromomycin A3 (CMA) and the closely related mithramycin (MM), were used as chromosome fluorescent dyes. Root-tip metaphase chromosomes of three plant species and human metaphase chromosomes were sequentially stained with CMA or MM and the DNA binding AT-specific fluorochrome 4'-6-diamidino-2-phenylindole (DAPI). In some cases a non-fluorescent counterstain was used as contrasting agent: methyl green in

Dieter Schweizer



Plasma Membrane Lesions In Anthracycline-Resistant Tumor Cells Probed Using A Fluorescent Dye  

NASA Astrophysics Data System (ADS)

Human cancer cells selected for resistance to several structurally unrelated cytotoxic drugs are known to display plasma membrane alterations such as amplified levels of a variety of glycoproteins, modifications in lipid composition, alterations in membrane fluidity and increased cellular fragility to osmotic shock. We have studied the plasma membrane fluidity of HL60 human leukemia cells and MCF-7 human breast cancer cells that have been selected for acquired resistance against the cytocidal effects of the anthracycline anticancer drug Adriamycin. Fluidity measurements were accomplished by evaluating the fluorescence anisotropy of the plasma membrane specific probe trimethylamino-1,6-dipihenylhexatriene (TMA.DPH) bound to whole, living cells. TMA.DPH anisotropy values for MCF-7 sensitive and 12-fold resistant cells were 0.306 and 0.285, respectively, while anisotropy values for HL-60 sensitive and 80-fold resistant cells lines were 0.310 and 0.295, respectively. In all cases, cell viability exceeded 97% and anisotropy values were subject to a day-to-day uncertainty of +/-2%. Our results demonstrate that increased plasma membrane fluidity apparently accompanies the development of resistance in both cell lines. Because it is known that increased membrane fluidity results in significantly decreased Adriamycin binding in artificial membrane systems, we propose here that decreased drug associations with fluidized, plasma membrane lipid bilayer regions may be a mechanism which contributes, in part, to the reduced rates of drug accumulation observed in HL60 and MCF-7 cells resistant to Adriamycin.

Burke, Thomas G.; Doroshow, James H.



Straightforward access to water-soluble unsymmetrical sulfoxanthene dyes: application to the preparation of far-red fluorescent dyes with large stokes' shifts.  


An efficient synthesis of water-soluble unsymmetrical sulforhodamine/sulforhodol fluorophores containing a single julolidine fragment is presented. Owing to their valuable spectral properties in aqueous buffers, these dyes, especially those bearing a free aniline or phenol moiety, are valuable components of fluorogenic probes for a variety of biosensing applications. A further extension of this synthetic methodology to unusual phenols, namely 7-N,N-dialkylamino-4-hydroxy coumarins has enabled us to provide a new family water-soluble dyes of large Stokes' shift with far-red spectral features. PMID:24863167

Chevalier, Arnaud; Renard, Pierre-Yves; Romieu, Anthony



Sea dye marker provides visibility for 20 hours  

NASA Technical Reports Server (NTRS)

Sea dye marker block releases a visible slick which lasts at least twelve hours. The dye marker uses a fluorescent dye in a heat cured binder which, when immersed in seawater, releases the dye at a controlled rate.

De Laat, F.



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

SciTech Connect

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.

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



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

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

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




PubMed Central

Chemical studies have been carried out on the interaction of DNA with uranyl salts. The effect of variations in pH, salt concentration, and structural integrity of the DNA on the stoichiometry of the salt-substrate complex have been investigated. At pH 3.5 DNA interacts with uranyl ions in low concentration yielding a substrate metal ion complex with a UO2++/P mole ratio of about ½ and having a large association constant. At low pH's (about 2.3) the mole ratio decreases to about ?. Destruction of the structural integrity of the DNA by heating in HCHO solutions leads to a similar drop in the amount of metal ion bound. Raising the pH above 3.5 leads to an apparent increase in binding as does increasing the concentration of the salt solution. This additional binding has a lower association constant. Under similar conditions DNA binds about seven times more uranyl ion than bovine serum albumin, indicating useful selectivity in staining for electron microscopy. PMID:13788706

Zobel, C. Richard; Beer, Michael



Labeling the oily core of nanocapsules and lipid-core nanocapsules with a triglyceride conjugated to a fluorescent dye as a strategy to particle tracking in biological studies  

NASA Astrophysics Data System (ADS)

The synthesis of novel fluorescent materials represents a very important step to obtain labeled nanoformulations in order to evaluate their biological behavior. The strategy of conjugating a fluorescent dye with triacylglycerol allows that either particles differing regarding supramolecular structure, i.e., nanoemulsions, nanocapsules, lipid-core nanocapsules, or surface charge, i.e., cationic nanocapsules and anionic nanocapsules, can be tracked using the same labeled material. In this way, a rhodamine B-conjugated triglyceride was obtained to prepare fluorescent polymeric nanocapsules. Different formulations were obtained, nanocapsules (NC) or lipid-core nanocapsules (LNC), using the labeled oil and Eudragit RS100, Eudragit S100, or poly(caprolactone) (PCL), respectively. The rhodamine B was coupled with the ricinolein by activating the carboxylic function using a carbodiimide derivative. Thin layer chromatography, proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FTIR), UV-vis, and fluorescence spectroscopy were used to identify the new product. Fluorescent nanocapsule aqueous suspensions were prepared by the solvent displacement method. Their pH values were 4.6 (NC-RS100), 3.5 (NC-S100), and 5.0 (LNC-PCL). The volume-weighted mean diameter ( D 4.3) and polydispersity values were 150 nm and 1.05 (NC-RS100), 350 nm and 2.28 (NC-S100), and 270 nm and 1.67 (LNC-PCL). The mean diameters determined by photon correlation spectroscopy (PCS) ( z-average) were around 200 nm. The zeta potential values were +5.85 mV (NC-RS100), -21.12 mV (NC-S100), and -19.25 mV (LNC-PCL). The wavelengths of maximum fluorescence emission were 567 nm (NC-RS100 and LNC-PCL) and 574 nm (NC-S100). Fluorescence microscopy was used to evaluate the cell uptake (human macrophage cell line) of the fluorescent nanocapsules in order to show the applicability of the approach. When the cells were treated with the fluorescent nanocapsules, red emission was detected around the cell nucleus. We demonstrated that the rhodamine B-conjugated triglyceride is a promising new material to obtain versatile dye-labeled nanocarriers presenting different chemical nature in their surfaces.

Fiel, Luana Almeida; Contri, Renata Vidor; Bica, Juliane Freitas; Figueiró, Fabrício; Battastini, Ana Maria Oliveira; Guterres, Sílvia Stanisçuaski; Pohlmann, Adriana Raffin



Fluorescent hydrophobic zippers inside duplex DNA: interstrand stacking of perylene-3,4:9,10-tetracarboxylic acid bisimides as artificial DNA base dyes.  


Perylene-3,4:9,10-tetracarboxylic acid bisimides (PBs) were incorporated synthetically into oligonucleotides by using automated DNA building-block chemistry. The 2'-deoxyribofuranoside of the natural nucleosides was replaced by (S)-aminopropan-2,3-diol as an acyclic linker between the phosphodiester bridges that is tethered to one of the imide nitrogen atoms of the PB dye. The S configuration of this linker was chosen to mimic the stereochemical situation at the 3'-position of the natural 2'-deoxyribofuranosides. By using this strategy, up to six PB dyes were incorporated in the middle of 18-mer DNA duplexes by using interstrand alternating sequences of PBs with thymines or an abasic site analogue. Both PB dimers and PB hexamers as artificial base substitutions inside the duplexes yield characteristic excimer-type fluorescence. The stacking properties of the PB chromophores are modulated by the presence or absence of thymines opposite the PB modification site in the counterstrand. The interstrand PB dimers can be regarded as hydrophobically interacting base pairs, which display a characteristic fluorescence readout signal. Hence, for the PB hexamers, we proposed a zipperlike recognition motif that is formed inside duplex DNA. The PB zipper shows characteristic excimer-type emission as a fluorescence readout signal for the pairing interaction. PMID:18576414

Baumstark, Daniela; Wagenknecht, Hans-Achim



Polyethylenimine-capped Ag nanoparticle film as a platform for detecting charged dye molecules by surface-enhanced Raman scattering and metal-enhanced fluorescence.  


Many drugs are charged molecules and are weak bases or acids having counterions. Their binding to biological surfaces is generally difficult to assess by vibrational spectroscopy. In this work, we demonstrated the potential of surface-enhanced Raman scattering (SERS) conducted using a polyethylenimine (PEI)-capped Ag nanoparticle film for the quantification of an electrostatic adsorption process of charged drug molecules, by using charged dye molecules such as sulforhodamine B (SRB) and rhodamine-123 (R123) as model drugs. It was possible to detect small-sized anions such as SCN(-) at 1 × 10(-9) M by SERS because of the cationic property of PEI. We were subsequently able to detect a prototype anionic dye molecule, SRB, by SERS at a subnanomolar concentration. On the other hand, it was difficult to detect cationic dyes such as R123 because of the electrostatically repulsive interaction with PEI. Nonetheless, we found that even R123 could be detected at subnanomolar concentrations by SERS by depositing an anionic polyelectrolyte such as poly(sodium 4-styrenesulfonate) (PSS) and poly(acrylic acid) (PAA) onto the PEI-capped Ag nanoparticles. Another noteworthy point is that a subnanomolar detection limit can also be achieved by carefully monitoring the fluorescence background in the measured SERS spectra. This was possible because charged dyes were not in contact with Ag but formed ion pairs with either PEI or PSS (PAA), allowing metal-enhanced fluorescence (MEF). The PEI-capped Ag nanoparticle film can thus serve as a useful indicator to detect charged drug molecules by SERS and MEF. PMID:23043369

Kim, Kwan; Lee, Ji Won; Shin, Kuan Soo



Dendritic Polyglycerolsulfate Near Infrared Fluorescent (NIRF) Dye Conjugate for Non-Invasively Monitoring of Inflammation in an Allergic Asthma Mouse Model  

PubMed Central

Background Non-invasive in vivo imaging strategies are of high demand for longitudinal monitoring of inflammation during disease progression. In this study we present an imaging approach using near infrared fluorescence (NIRF) imaging in combination with a polyanionic macromolecular conjugate as a dedicated probe, known to target L- and P-selectin and C3/C5 complement factors. Methodology/Principal Findings We investigated the suitability of dendritic polyglycerol sulfates (dPGS), conjugated with a hydrophilic version of the indocyanine green label with 6 sulfonate groups (6S-ICG) to monitor sites of inflammation using an experimental mouse model of allergic asthma. Accumulation of the NIRF-conjugated dPGS (dPGS-NIRF) in the inflamed lungs was analyzed in and ex vivo in comparison with the free NIRF dye using optical imaging. Commercially available smart probes activated by matrix metalloproteinase's (MMP) and cathepsins were used as a comparative control. The fluorescence intensity ratio between lung areas of asthmatic and healthy mice was four times higher for the dPGS in comparison to the free dye in vivo at four hrs post intravenous administration. No significant difference in fluorescence intensity between healthy and asthmatic mice was observed 24 hrs post injection for dPGS-NIRF. At this time point ex-vivo scans of asthmatic mice confirmed that the fluorescence within the lungs was reduced to approximately 30% of the intensity observed at 4 hrs post injection. Conclusions/Significance Compared with smart-probes resulting in a high fluorescence level at 24 hrs post injection optical imaging with dPGS-NIRF conjugates is characterized by fast uptake of the probe at inflammatory sites and represents a novel approach to monitor lung inflammation as demonstrated in mice with allergic asthma. PMID:23437332

Dullin, Christian; Garrovo, Chiara; Bosnjak, Berislav; Licha, Kai; Welker, Pia; Epstein, Michelle M.; Alves, Frauke



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)

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.

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



Bench-Top Antigen Detection Technique that Utilizes Nanofiltration and Fluorescent Dyes which Emit and Absorb Light in the Near Infrared  

NASA Technical Reports Server (NTRS)

This article discusses the development of a bench-top technique to detect antigens in fluids. The technique involves the use of near infrared NIR fluorescent dyes conjugated to antibodies, centrifugation, nanofilters, and spectrometry. The system used to detect the antigens utilizes a spectrometer, fiber optic cables, NIR laser, and laptop computer thus making it portable and ideally suited for desk top analysis. Using IgM as an antigen and the secondary antibody, anti-IgM conjugated to the near infrared dye, IRDye (trademark) 800, for detection, we show that nanofiltration can efficiently and specifically separate antibody-antigen complexes in solution and that the complexes can be detected by a spectrometer and software using NIR laser excitation at 778 nm and NIR dye offset emission at 804 nm. The peak power detected at 778 nm for the excitation emission and at 804 nm for the offset emission is 879 pW (-60.06 dBm) and 35.7 pW (-74.5 dBm), respectively.

Varaljay-Spence, Vanessa A.; Scardelletti, Maximilian C.



Whole mount nuclear fluorescent imaging: convenient documentation of embryo morphology  

PubMed Central

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 widefield 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 of similar specimens 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

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



Two-stage desorption-controlled release of fluorescent dye and vitamin from solution-blown and electrospun nanofiber mats containing porogens.  


In the present work, a systematic study of the release kinetics of two embedded model drugs (one completely water soluble and one partially water soluble) from hydrophilic and hydrophobic nanofiber mats was conducted. Fluorescent dye Rhodamine B was used as a model hydrophilic drug in controlled release experiments after it was encapsulated in solution-blown soy-protein-containing hydrophilic nanofibers as well as in electrospun hydrophobic poly(ethylene terephthalate) (PET)-containing nanofibers. Vitamin B2 (riboflavin), a partially water-soluble model drug, was also encapsulated in hydrophobic PET-containing nanofiber mats, and its release kinetics was studied. The nanofiber mats were submerged in water, and the amount of drug released was tracked by fluorescence intensity. It was found that the release process saturates well below 100% release of the embedded compound. This is attributed to the fact that desorption is the limiting process in the release from biopolymer-containing nanofibers similar to the previously reported release from petroleum-derived polymer nanofibers. Release from monolithic as well as core-shell nanofibers was studied in the present work. Moreover, to facilitate the release and ultimately to approach 100% release, we also incorporated porogens, for example, poly(ethylene glycol), PEG. It was also found that the release rate can be controlled by the porogen choice in nanofibers. The effect of nanocracks created by leaching porogens on drug release was studied experimentally and evaluated theoretically, and the physical parameters characterizing the release process were established. The objective of the present work is a detailed experimental and theoretical investigation of controlled drug release from nanofibers facilitated by the presence of porogens. The novelty of this work is in forming nanofibers containing biodegradable and biocompatible soy proteins to facilitate controlled drug release as well as in measuring detailed quantitative characteristics of the desorption processes responsible for release of the model substance (fluorescent dye) and the vitamin (riboflavin) in the presence of porogens. PMID:24191694

Khansari, S; Duzyer, S; Sinha-Ray, S; Hockenberger, A; Yarin, A L; Pourdeyhimi, B



Ruthenium Red Colorimetric and Birefringent Staining of Amyloid-? Aggregates in Vitro and in Tg2576 Mice  

PubMed Central

Alzheimer’s disease (AD) is a devastating neurodegenerative disease most notably characterized by the misfolding of amyloid-? (A?) into fibrils and its accumulation into plaques. In this Article, we utilize the affinity of A? fibrils to bind metal cations and subsequently imprint their chirality to bound molecules to develop novel imaging compounds for staining A? aggregates. Here, we investigate the cationic dye ruthenium red (ammoniated ruthenium oxychloride) that binds calcium-binding proteins, as a labeling agent for A? deposits. Ruthenium red stained amyloid plaques red under light microscopy, and exhibited birefringence under crossed polarizers when bound to A? plaques in brain tissue sections from the Tg2576 mouse model of AD. Staining of A? plaques was confirmed via staining of the same sections with the fluorescent amyloid binding dye Thioflavin S. In addition, it was confirmed that divalent cations such as calcium displace ruthenium red, consistent with a mechanism of binding by electrostatic interaction. We further characterized the interaction of ruthenium red with synthetic A? fibrils using independent biophysical techniques. Ruthenium red exhibited birefringence and induced circular dichroic bands at 540 nm upon binding to A? fibrils due to induced chirality. Thus, the chirality and cation binding properties of A? aggregates could be capitalized for the development of novel amyloid labeling methods, adding to the arsenal of AD imaging techniques and diagnostic tools. PMID:23509974



Laser-excited fluorescence and fluorescence probes for diagnosing bulk damage in cable insulation  

NASA Astrophysics Data System (ADS)

Laser excited fluorescence (LEF) and fluorescence probes have been used to observe bulk damage in aged cross-linked polyethylene (XLPE) insulation of power transmission cable. 'Water trees' in the shape of bow-ties (50 micrometers to 1 mm) and striations near the cable core were observed under a microscope when the aged XLPE samples were irradiated by an Argon-ion laser. Changes in the bulk fluorescence of samples subjected to various aging conditions were observed as well. XLPE samples could be bulk-stained by soaking them in solutions of fluorescent dyes such as rhodamine 6G, Acridine Yellow G, resorufin and Nile Red in order to probe and highlight defects under similar LEF conditions. Resorufin proved useful for preferential staining of the water-trees making them flagrantly visible. Rhodamine 6G and Acridine Yellow G soaked samples provided evidence of chemical and/or physical changes surrounding these trees: A halo arising from dye fluorescence quenching could be observed surrounding the trees. The chemical and spectroscopic properties of fluorescent probes may provide insight into chemical/physical features of observed defects.

Ordonez, Ishmael D.; Crafton, J.; Murdock, R. H.; Hatfield, Lynn L.; Menzel, E. R.



Standardization of the Papanicolaou stain. I. A comparison of five nuclear stains.  


The staining characteristics of five nuclear stains used in a Papanicolaou staining procedure were investigated. Alcohol-fixed cervical smears were stained with a modified Papanicolaou procedure using hematoxylin, alcoholic thionin bromide, alcoholic Victoria blue B, gallocyanin or the thionin Feulgen reagent (thionin-SO2) as the nuclear stain. The same anionic counterstain was used for all slides, and the optical densities of cell nuclei and cytoplasm were measured with the IBAS 2000 image analyzer. Alcoholic thionin gave the most intense nuclear stain, with a very high reproducibility of the staining pattern. Hematoxylin showed the highest coefficient of variation of the staining intensity. Both hematoxylin and gallocyanin gave some nonspecific cytoplasmic staining. Thionin-SO2 allowed a quantitative assessment of DNA, but gave a low staining intensity. Staining with the metal complex dyes interfered with subsequent staining with the pararosaniline Feulgen reagent. Alcoholic thioinin is thus recommended as a nuclear stain for cervical cytology in the Papanicolaou procedure, both for image analysis and for visual microscopy. PMID:1695100

Schulte, E; Wittekind, D



A symmetrical fluorous dendron-cyanine dye-conjugated bimodal nanoprobe for quantitative 19F MRI and NIR fluorescence bioimaging.  


(19)F MRI and optical imaging are two powerful noninvasive molecular imaging modalities in biomedical applications. (19)F MRI has great potential for high resolution in vivo imaging, while fluorescent probes enable ultracontrast cellular/tissue imaging with high accuracy and sensitivity. A bimodal nanoprobe is developed, integrating the merits of (19)F MRI and fluorescence imaging into a single synthetic molecule, which is further engineered into nanoprobe, by addressing shortcomings of conventional contrast agents to explore the quantitative (19)F MRI and fluorescence imaging and cell tracking. Results show that this bimodal imaging nanoprobe presents high correlation of (19)F MR signal and NIR fluorescence intensity in vitro and in vivo. Additionally, this nanoprobe enables quantitative (19)F MR analysis, confirmed by a complementary fluorescence analysis. This unique feature can hardly be obtained by traditional (19)F MRI contrast agents. It is envisioned that this nanoprobe can hold great potential for quantitative and sensitive multi-modal molecular imaging. PMID:24789108

Wang, Zhe; Yue, Xuyi; Wang, Yu; Qian, Chunqi; Huang, Peng; Lizak, Marty; Niu, Gang; Wang, Fu; Rong, Pengfei; Kiesewetter, Dale O; Ma, Ying; Chen, Xiaoyuan



Enhancing the color gamut of white displays using novel deep-blue organic fluorescent dyes to form color-changed thin films with improved efficiency  

NASA Astrophysics Data System (ADS)

This study used the novel fluorescence based deep-blue-emitting molecule BPVPDA in an organic fluorescent color thin film to exhibit deep blue color with CIE coordinates of (0.13, 0.16). The developed original organic RGB color thin film technology enables the optimization of the distinctive features of an organic light emitting diode (OLED) and thin-film-transistor (TFT) LCD display. The color filter structure maintains the same high resolution to obtain a higher level of brightness in comparison with conventional organic RGB color thin film. The image-processing engine is designed to achieve a sharp text image for a TFT LCD with organic color thin films. The organic color thin films structure uses an organic dye dopant in a limpid photoresist. With this technology, the following characteristics can be obtained: 1. high color reproduction of gamut ratio, and 2. improved luminous efficiency with organic color fluorescent thin film. This performance is among the best results ever reported for a color-filter used on TFT-LCD or OLED.

Liu, Wei-Ting; Huang, Wen-Yao



Effect of different solvents on the performance of organic light-emitting device based on red-fluorescent ACY dye by spin coating method  

NASA Astrophysics Data System (ADS)

A small-molecular red-fluorescent dye of [7-diethylamino-3-(2-thienyl)chronmen-2-ylidene]-2,2-dicyanoviny-lamine (ACY) has been blended into blue-emitting poly(N-vinylcarbazole) (PVK) by using different solvents of chloroform and 1,2-dichloroethane. Photoluminescence characteristic of solvent effects were investigated mainly from the aspect of solvent polarity. To demonstrate the solvent effects in organic light emitting devices (OLEDs), devices with a structure of indium-tin-oxide (ITO)/PVK: ACY (x wt %)/tris(8-quinolinolato) aluminum (Alq3)/Mg: Ag were fabricated, in which the weight doping ratios are x = 0.3, 0.5 and 0.7. Using spin coating method, a blending system of PVK: ACY is dissolved in both chloroform and 1,2-dichloroethane with various doping concentrations. As a result, by choosing chloroform as solvent, a high electroluminescent (EL) performance device with a maximum luminance of 7698 cd/m2 at a driving voltage of 15.5 V was obtained, with a concentration proportion of PVK: ACY at 1000: 7. In the EL spectra of the OLEDs, red and green fluorescence of ACY and Alq3 were detected. It was found that by using 1,2-dichloroethane as a solvent, fluorescent quenching emerged with the enhancement of doping concentration. Energy transfer and Alq3 cations quencher theories were used to discuss different solvent effects on OLEDs.

Yu, Shuangjiang; Yu, Junsheng; Wang, Hong; Jiang, Yadong



Sequential double fluorescent detections of total proteins and phosphoproteins in SDS-PAGE.  


A fluorescent staining technique, using selective chelation with fluorophore and metal ion to the phosphate groups of phosphoproteins in SDS-PAGE is described. As a fluorescent dye and a metal ion, Fura 2 pentapotassium salt and Al(3+) were employed, respectively. The staining method, Fura 2 stain, has sensitivities of 16-32 ng of ?-casein and ?-casein, 62 ng of ovalbumin, phosvitin, and ?-casein using an ultraviolet transilluminator. Furthermore, Fura 2 stain is able to carry out continuative double detection of total proteins and phosphoproteins on the same gel within 3.5 h. Consequently, selective phosphoprotein and total protein detections could be obtained without other poststaining. Considering the low cost, simplicity, and speed, Fura 2 staining may provide great practicalities in routine phosphoproteomics research. PMID:24488794

Hwang, Sun-Young; Wang, Xu; Cong, Wei-Tao; Jin, Li-Tai; Choi, Jung-Kap



Stain Uses Recipe p-Anisaldehyde General purpose stain,  

E-print Network

Olefins and other readily oxidized groups. Dissolve 1.5 g KMnO4, 10 g K2CO3, and 1.25 mL 10% NaOH in 200 mL water. Cerium Sulfate General stain, particularly useful for alkaloids. Make an aqueous solution of 10% Cerium (IV) sulfate and 15% H2SO4. Morin Hydrate General reagent. Fluorescently active. Make up a 0.1 wt

Yao, Shao Q


DNA fragment sizing and sorting by laser-induced fluorescence  


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.

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)



Staining etched epoxy resin sections for light microscopy.  


Staining of etched sections for light microscopy is described. Azan staining was successful after treatment with potassium dichromate and the use of concentrated dye solutions. To remove osmium for hematoxylin-eosin staining, removal by reduction with ferrocene was used instead of oxidation. Highly selective differentiation after hematoxylin staining was achieved using p-toluenesulfonic acid-DMSO. To enhance eosin staining, a 2-bromoethylamine link between eosin and the tissue was used. Ferrocene also facilitated counterstaining of nuclei with hematoxylin after the PAS reaction. Periodic acid-methenamine silver staining was carried out without modification. PMID:7578588

Iwadare, T; Arai, T



3-Carboxy-6-chloro-7-hydroxycoumarin: a highly fluorescent, water-soluble violet-excitable dye for cell analysis.  


In our search for new violet-excitable dyes with improved photophysical and photochemical properties, we examined several halogen-substituted hydroxycoumarins and found that chlorinated derivatives are at least as bright as their fluorinated analogs. A monochlorinated hydroxycoumarin was found to have a high quantum yield (approximately 0.98), and human leucocyte-specific monoclonal antibodies (CD3, CD4, and CD45) conjugated with this dye exhibited reliable performance in flow cytometry assays. Additional studies were performed, with BD Horizon V450-antibody conjugates being included in eight-color cocktails aimed at subsetting lymphocytes and myeloid cells. Such cocktails can frequently be unstable due to the tendency of one or more components to lose structural integrity, photobleach, or develop unwanted affinities for another component. However, the cocktails employed in this study enabled several different applications to be run and established that multicolor reagent mixtures containing V450-antibody conjugates are functional and stable. PMID:19135024

Abrams, Barny; Diwu, Zhenjun; Guryev, Oleg; Aleshkov, Sergei; Hingorani, Ravi; Edinger, Mark; Lee, Rita; Link, Joe; Dubrovsky, Tim



Fluorescence studies of dye displacement from DNA by chromium(III) complexes: Evidence for cation induced DNA condensations  

Microsoft Academic Search

The interactions of 10 different chromium(III) complexes with isolated calf thymus DNA have been analysed by studying the electronic and fluoresence spectra of intercalated ethidiumbromide. Triply charged cationic complexes including: [Cr(urea)6]Cl3.3H2O, [Cr(1,10?phenanthroline)3](ClO4)3.2H2O, [Cr(2,2'?bipyridyl)3] (ClO4)3.2H2O, [Cr(ethylendiamine)3]Cl3.3.5H2O and [Cr(NH3)6](NO3)3 displaced the dye from DNA. Similar effects were observed in experiments using the non?intercalating dye bisbenzimidazole (\\

A. Kortenkamp; D. Beyersmann



Triggered dye release via photodissociation of nitric oxide from designed ruthenium nitrosyls: turn-ON fluorescence signaling of nitric oxide delivery.  


Two new fluorescein-tethered nitrosyls derived from designed tetradentate ligands with carboxamido-N donors have been synthesized and characterized by spectroscopic techniques. These two diamagnetic {Ru-NO}(6) nitrosyls, namely, [(Me(2)bpb)Ru(NO)(FlEt)] (1-FlEt, Me(2)bpb = 1,2-bis(pyridine-2-carboxamido)5-dimethylbenzene, FlEt = fluorescein ethyl ester) and [((OMe)(2)IQ1)Ru(NO)(FlEt)] (2-FlEt, (OMe)(2)IQ1 = 1,2-bis(isoquinoline-1-carboxamido)-4,5-dimethoxybenzene), display NO stretching frequencies (?(NO)) at 1846 and 1832 cm(-1) in addition to their FlEt carbonyl stretching frequencies (?(CO)) at 1715 and 1712 cm(-1), respectively. Coordination of the dye ligand enhances the absorptivity and NO photolability of these two nitrosyls in the visible region (450-600 nm) of light. Exposure to visible light promotes rapid loss of NO from both {Ru-NO}(6) nitrosyls to generate Ru(III) photoproducts in dry aprotic solvents, such as MeCN and DMF. The FlEt(-) moiety remains bound to the paramagnetic Ru(III) center in such cases, and hence, the photoproducts exhibit very weak fluorescence from the dye unit. In the presence of water, the Ru(III) photoproducts undergo further aquation and loss of the FlEt(-) moiety via protonation. These steps lead to turn-ON fluorescence (from the free FlEt unit) and provide a visual signal of the NO photorelease from 1-FlEt and 2-FlEt in aqueous media. PMID:21815610

Fry, Nicole L; Wei, Julia; Mascharak, Pradip K



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.  


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

Bathaie, S Z; Farajzade, A; Hoshyar, R



Investigation of Quenching Mechanism in Thermoreversible Fluorescent Recording Materials of Fluorescence Using Thermochromic Fluorescence Resonance Energy Transfer  

NASA Astrophysics Data System (ADS)

We demonstrated reversible thermosensitive recording of a fluorescent image (TRF) using a low-molecular-weight mixture consisting of a fluorescent dye, a fluoran dye, a developer, and a reversible matrix. In this material, reversible thermoresponsive disorder-crystal transition triggers a cyclical colorless-color change of a fluoran dye, which induces on-off switching of fluorescence resonance energy transfer (FRET) from a fluorescent dye to a fluoran dye. On-off switching of fluorescence is induced by heat-promoted off-on switching of FRET. Modulation of fluorescence is held at room temperature by utilizing thermal hysteresis, and nondestructive readout of the fluorescent image is accomplished in the presence of excitation light. Here, we investigate the on-off switching mechanism of fluorescence in this recording material. We analyzed the theoretical factor of emission quenching in the erasing state by comparing the theoretical overlap integral ? between fluorescent dyes and fluoran dyes on the basis of the FRET theory with experimental emission contrast for various combinations of fluorescent dyes and fluoran dyes. It was proved that fluorescence on-off switching occurs mainly by concentration quenching due to the aggregation of fluorescent dyes and FRET from isolated fluorescent dyes to colored fluoran dyes. The key issue to obtain both high-contrast fluorescence and high fluorescence quantum yield is to control these two factors.

Shuzo Hirata,; Martin Vacha,; Toshiyuki Watanabe,



Coffee stain on textiles. Mechanisms of staining and stain removal  

Microsoft Academic Search

Coffee stains on textiles are mainly caused by the water-soluble and acidic colored substances in coffee. The acidic nature\\u000a of coffee stain has been shown by ultraviolet and visible spectroscopy of coffee as a function of pH; ion-pair formation with\\u000a a cationic surfactant and titration with Hyamine 1622 and a surfactant-specific electrode; and precipitation of the colored\\u000a components in coffee

Erik Kissa



Nucleic acid stains as indicators of Giardia muris viability following cyst inactivation  

Microsoft Academic Search

A reliable viability assay for Giardia is required for the development of disinfection process design criteria and pathogen monitoring by water treatment utilities. Surveys of single-staining nucleic acid dyes (stain dead parasites only), and double-staining vital dye kits from Molecular Probes (stain live and dead parasites) were conducted to assess the viability of untreated, heat-killed, and chemically inactivated Giardia muris

R. Taghi-Kilani; L. L. Gyürék; P. J. Millard; G. R. Finch; M. Belosevic



Fluorescence Resonance Energy Transfer between organic dyes adsorbed onto nano-clay and Langmuir-Blodgett (LB) films  

NASA Astrophysics Data System (ADS)

In this communication we investigate two dyes N, N'-dioctadecyl thiacyanine perchlorate (NK) and octadecyl rhodamine B chloride (RhB) in Langmuir and Langmuir-Blodgett (LB) films with or with out a synthetic clay laponite. Observed changes in isotherms of RhB in absence and presence of nano-clay platelets indicate the incorporation of clay platelets onto RhB-clay hybrid films. AFM images confirm the incorporation of clay into hybrid films. FRET is observed in clay dispersion and LB films with and without clay. Efficiency of energy transfer is maximum in LB films with clay.

Hussain, Syed Arshad; Chakraborty, S.; Bhattacharjee, D.; Schoonheydt, R. A.



Analysis of Ground-Water Flow in the Madison Aquifer using Fluorescent Dyes Injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04  

USGS Publications Warehouse

The Madison aquifer, which contains fractures and solution openings in the Madison Limestone, is used extensively for water supplies for the city of Rapid City and other suburban communities in the Rapid City, S. Dak., area. The 48 square-mile study area includes the west-central and southwest parts of Rapid City and the outcrops of the Madison Limestone extending from south of Spring Creek to north of Rapid Creek. Recharge to the Madison Limestone occurs when streams lose flow as they cross the outcrop. The maximum net loss rate for Spring and Rapid Creek loss zones are 21 and 10 cubic feet per second (ft3/s), respectively. During 2003 and 2004, fluorescent dyes were injected in the Spring and Rapid Creek loss zones to estimate approximate locations of preferential flow paths in the Madison aquifer and to measure the response and transit times at wells and springs. Four injections of about 2 kilograms of fluorescein dye were made in the Spring Creek loss zone during 2003 (sites S1, S2, and S3) and 2004 (site S4). Injection at site S1 was made in streamflow just upstream from the loss zone over a 12-hour period when streamflow was about equal to the maximum loss rate. Injections at sites S2, S3, and S4 were made in specific swallow holes located in the Spring Creek loss zone. Injection at site R1 in 2004 of 3.5 kilograms of Rhodamine WT dye was made in streamflow just upstream from the Rapid Creek loss zone over about a 28-hour period. Selected combinations of 27 wells, 6 springs, and 3 stream sites were monitored with discrete samples following the injections. For injections at sites S1-S3, when Spring Creek streamflow was greater than or equal to 20 ft3/s, fluorescein was detected in samples from five wells that were located as much as about 2 miles from the loss zone. Time to first arrival (injection at site S1) ranged from less than 1 to less than 10 days. The maximum fluorescein concentration (injection at site S1) of 120 micrograms per liter (ug/L) at well CO, which is located adjacent to the loss zone, was similar to the concentration in the stream. Fluorescein arrived at well NON (injection at site S1), which is located about 2 miles northeast of the loss zone, within about 1.6 days, and the maximum concentration was 44 ug/L. For injection at site S4, when streamflow was about 12 ft3/s, fluorescein was detected in samples from six wells and time to first arrival ranged from 0.2 to 16 days. Following injection at site S4 in 2004, the length of time that dye remained in the capture zone of well NON, which is located approximately 2 miles from the loss zone, was almost an order of magnitude greater than in 2003. For injection at site R1, Rhodamine WT was detected at well DRU and spring TI-SP with time to first arrival of about 0.5 and 1.1 days and maximum concentrations of 6.2 and 0.91 ug/L, respectively. Well DRU and spring TI-SP are located near the center of the Rapid Creek loss zone where the creek has a large meander. Measurable concentrations were observed for spring TI-SP as many as 109 days after the dye injection. The direction of a conduit flow path in the Spring Creek area was to the northeast with ground-water velocities that ranged from 770 to 6,500 feet per day. In the Rapid Creek loss zone, a conduit flow path east of the loss zone was not evident from the dye injection.

Putnam, Larry D.; Long, Andrew J.



Wright-Giemsa and nonspecific esterase staining of cells.  


This appendix provides two protocols for staining cells. The stains used in the Wright-Giemsa protocol, the Romanowsky stains, are a mixture of methylene blue (and other closely related thiazine dyes) and eosin. The staining protocol is a two-stage method that allows for a more intense staining of the nuclei than would be possible if the Wright and Giemsa stains were mixed together. In the second protocol, nonspecific esterase stain are used to identify cell types containing esterases that have a characteristic ability to split esters under particular conditions. In the staining method given here, the substrate, a-naphthyl butyrate, is incubated with cells under conditions in which esterases present in monocytes/macrophages split the substrate to yield an intermediate that can be coupled with a substance, hexazotized pararosaniline, to yield a colored precipitate. Thus, this staining reaction can be used to identify monocytes/macrophages in cell preparations. PMID:18432655

Strober, W



Cyanine dyes as contrast agents for near-infrared imaging in vivo: acute tolerance, pharmacokinetics, and fluorescence imaging  

NASA Astrophysics Data System (ADS)

We compare pharmacokinetic, tolerance, and imaging properties of two near-IR contrast agents, indocyanine green (ICG) and 1,1'-bis-(4-sulfobutyl) indotricarbocyanine-5,5'-dicarboxylic acid diglucamide monosodium salt (SIDAG). ICG is a clinically approved imaging agent, and its derivative SIDAG is a more hydrophilic counterpart that has recently shown promising imaging properties in preclinical studies. The rather lipophilic ICG has a very short plasma half-life, thus limiting the time available to image body regions during its vascular circulation (e.g., the breast in optical mammography where scanning over several minutes is required). In order to change the physicochemical properties of the indotricarbocyanine dye backbone, several derivatives were synthesized with increasing hydrophilicity. The most hydrophilic dye SIDAG is selected for further biological characterization. The acute tolerance of SIDAG in mice is increased up to 60-fold compared to ICG. Contrary to ICG, the pharmacokinetic properties of SIDAG are shifted toward renal elimination, caused by the high hydrophilicity of the molecule. N-Nitrosomethylurea (NMU)-induced rat breast carcinomas are clearly demarcated, both immediately and 24 h after intravenous administration of SIDAG, whereas ICG shows a weak tumor contrast under the same conditions. Our findings demonstrate that SIDAG is a high potential contrast agent for optical imaging, which could increase the sensitivity for detection of inflamed regions and tumors.

Ebert, Bernd; Riefke, Björn; Sukowski, Uwe; Licha, Kai



Selective recognition of parallel and anti-parallel thrombin-binding aptamer G-quadruplexes by different fluorescent dyes.  


G-quadruplexes (G4) have been found increasing potential in applications, such as molecular therapeutics, diagnostics and sensing. Both Thio?avin T (ThT) and N-Methyl mesoporphyrin IX (NMM) become fluorescent in the presence of most G4, but thrombin-binding aptamer (TBA) has been reported as the only exception of the known G4-forming oligonucleotides when ThT is used as a high-throughput assay to identify G4 formation. Here, we investigate the interactions between ThT/NMM and TBA through fluorescence spectroscopy, circular dichroism and molecular docking simulation experiments in the absence or presence of cations. The results display that a large ThT ?uorescence enhancement can be observed only when ThT bind to the parallel TBA quadruplex, which is induced to form by ThT in the absence of cations. On the other hand, great promotion in NMM fluorescence can be obtained only in the presence of anti-parallel TBA quadruplex, which is induced to fold by K(+) or thrombin. The highly selective recognition of TBA quadruplex with different topologies by the two probes may be useful to investigate the interactions between conformation-specific G4 and the associated proteins, and could also be applied in label-free fluorescent sensing of other biomolecules. PMID:25245945

Zhao, Dan; Dong, Xiongwei; Jiang, Nan; Zhang, Dan; Liu, Changlin



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


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

Kim, Myun Soo; Kim, Tae Sung



Quirks of dye nomenclature. 1. Evans blue.  


The history, origin, identity, chemistry and use of Evans blue dye are described along with the first application to staining by Herbert McLean Evans in 1914. In the 1930s, the dye was marketed under the name, Evans blue dye, which was profoundly more acceptable than the ponderous chemical name. PMID:23957706

Cooksey, C J



Effects of metabolic inhibitors on vital staining with methylene blue  

Microsoft Academic Search

The peripheral innervation of murine skin was vitally stained with methylene blue and the effects of various metabolic inhibitors on the staining process were investigated. The observed effects suggest that uptake of the dye is dependent on the integrity of a membrane-associated adenosine triphosphatase and an unidentified metallo-enzyme. Glycolysis, the citric acid cycle and the cytochrome system are not necessary

J. A. Kiernan



Application of fluorescence fluctuation spectroscopy to the measurement of the concentration of molecules deposited on solid substrates  

NASA Astrophysics Data System (ADS)

Fluorescence fluctuation spectroscopy is applied to study molecules, passing through a small observation volume, usually subjected to diffusive or convective motion in liquid phase. We suggest that such a technique could be used to measure the areal absolute concentration of fluorophores deposited on a substrate or imbedded in a thin film, with a resolution of a few micrometers. The principle is to translate the solid substrate in front of a confocal fluorescence microscope objective and to record the subsequent fluctuations of the fluorescence intensity. The validity of this concept is investigated on model substrates (fluorescent microspheres), DNA-chips, and dye-stained histidine molecules anchored on silanized glass surfaces.

Derouard, Jacques; Delon, Antoine; Jaffiol, Rodolphe; Vézy, Cyrille



Causes of Bridge Pier Staining.  

National Technical Information Service (NTIS)

Four types of bridge stains exist in Arkansas: Rust stains - those stains directly traceable to rust; red stains - broad stains which are not directly traceable to rust; gray stains - similar to red stains except for color; and graffiti. Bridge stains in ...

S. I. Thornton, C. Springer



Port-wine stain  


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 ...


Introduction of impermeable actin-staining molecules to mammalian cells by optoporation  

PubMed Central

The selective insertion of foreign materials, such as fluorescent markers or plasmids, into living cells has been a challenging problem in cell biology due to the cell membrane's selective permeability. However, it is often necessary that researchers insert such materials into cells for various dynamical and/or drug delivery studies. This problem becomes even more challenging if the study is to be limited to specific cells within a larger population, since other transfection methods, such as viral transfection and lipofection, are not realizable with a high degree of spatial selectivity. Here, we have used a focused femtosecond laser beam to create a small transient hole in the cellular membrane (optoporation) in order to inject nanomolar concentrations of rhodamine phalloidin (an impermeable dye molecule for staining filamentous actin) into targeted living mammalian cells (both HEK and primary cortical neurons). Following optoporation, the dye bound to the intracellular actin network and rise in fluorescence intensity was observed. Theoretical dynamics of the dye's diffusion is discussed, and numerical simulations of diffusion time constants are found to match well with experimental values. PMID:25315642

Dhakal, Kamal; Black, Bryan; Mohanty, Samarendra



Introduction of impermeable actin-staining molecules to mammalian cells by optoporation.  


The selective insertion of foreign materials, such as fluorescent markers or plasmids, into living cells has been a challenging problem in cell biology due to the cell membrane's selective permeability. However, it is often necessary that researchers insert such materials into cells for various dynamical and/or drug delivery studies. This problem becomes even more challenging if the study is to be limited to specific cells within a larger population, since other transfection methods, such as viral transfection and lipofection, are not realizable with a high degree of spatial selectivity. Here, we have used a focused femtosecond laser beam to create a small transient hole in the cellular membrane (optoporation) in order to inject nanomolar concentrations of rhodamine phalloidin (an impermeable dye molecule for staining filamentous actin) into targeted living mammalian cells (both HEK and primary cortical neurons). Following optoporation, the dye bound to the intracellular actin network and rise in fluorescence intensity was observed. Theoretical dynamics of the dye's diffusion is discussed, and numerical simulations of diffusion time constants are found to match well with experimental values. PMID:25315642

Dhakal, Kamal; Black, Bryan; Mohanty, Samarendra



Wright-Giemsa and nonspecific esterase staining of cells.  


This appendix provides two protocols for staining cells. The stains used in the Wright-Giemsa protocol, the Romanowsky stains, are a mixture of methylene blue (and other closely related thiazine dyes) and eosin. The staining protocol is a two-stage method that allows for a more intense staining of the nuclei than would be possible if the Wright and Giemsa stains were mixed together. In the second protocol, nonspecific esterase stain are used to identify cell types containing esterases that have a characteris termediate that can be coupled with a substance, hexazotized pararosaniline, to yield a colored precipitate. Thus, this staining reaction can be used to identify monocytes/macrophages in cell preparations. PMID:18770656

Strober, W



Detection Of Concrete Deterioration By Staining  


A method using concentrated aqueous solutions of sodium cobaltinitrite and a rhodamine dye is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR), and to identify degraded concrete which results in a porous or semi-permeable paste due to carbonation or leaching. These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na--K--Ca--Si gels are identified by yellow staining, and alkali-poor, Ca--Si gels are identified by pink staining.

Guthrie, Jr., George D. (Santa Fe, NM); Carey, J. William (Santa Fe, NM)



High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.  

PubMed Central

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

Bullen, A; Patel, S S; Saggau, P



Spectral characteristics of the mutant form GGBP/H152C of D-glucose/D-galactose-binding protein labeled with fluorescent dye BADAN: influence of external factors  

PubMed Central

The mutant form GGBP/H152C of the D-glucose/D-galactose-binding protein with the solvatochromic dye BADAN linked to cysteine residue Cys 152 can be used as a potential base for a sensitive element of glucose biosensor system. We investigated the influence of various external factors on the physical-chemical properties of GGBP/H152C-BADAN and its complex with glucose. The high affinity (Kd = 8.5 µM) and high binding rate of glucose make GGBP/H152C-BADAN a good candidate to determine the sugar content in biological fluids extracted using transdermal techniques. It was shown that changes in the ionic strength and pH of solution within the physiological range did not have a significant influence on the fluorescent characteristics of GGBP/H152C-BADAN. The mutant form GGBP/H152C has relatively low resistance to denaturation action of GdnHCl and urea. This result emphasizes the need to find more stable proteins for the creation of a sensitive element for a glucose biosensor system. PMID:24711960

Fonin, Alexander V.; Stepanenko, Olga V.; Povarova, Olga I.; Volova, Catherine A.; Philippova, Elizaveta M.; Bublikov, Grigory S.; Kuznetsova, Irina M.; Demchenko, Alexander P.



Development of a fluorescent-intercalating-dye-based reverse transcription loop-mediated isothermal amplification assay for rapid detection of seasonal Japanese B encephalitis outbreaks in pigs.  


The standardization and validation of a one-step, single-tube, accelerated fluorescent-intercalating-dye-based reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the NS3 gene of Japanese B encephalitis virus (JEV) is described for rapid, simple, and high-throughput detection of JEV. The amplification can be completed in 35 min under isothermal conditions at 63°C by employing a set of six primers targeting the NS3 gene of JEV. The RT-LAMP assay described demonstrated high sensitivity for detecting JEV, with a detection limit in swine samples of 8.13 PFU/ml. The specificity of the selected primer sets was established by cross-reactivity studies with pathogens that exhibit similar clinical signs and testing of samples from healthy animals. The clinical applicability of the RT-LAMP assay was validated using either spiked samples or samples from seasonal outbreaks. The comparative evaluation of the RT-LAMP assay revealed 79.59 % concordance with conventional RT-PCR targeting the E gene of JEV. The RT-LAMP assay reported here is a valuable tool for rapid real-time and high-throughput seasonal infection surveillance and quarantine after outbreak through blood sampling by using ordinary real-time PCR thermocyclers without purchasing an expensive Loopamp real-time turbidimeter. PMID:22573187

Tian, C J; Lin, Z X; He, X M; Luo, Q; Luo, C B; Yu, H Q; Chen, R; Wu, X W; Zhu, D Z; Ren, Z J; Bi, Y Z; Ji, J



DNA fragment sizing and sorting by laser-induced fluorescence  

SciTech Connect

A method is provided for obtaining DNA fingerprints using high speed detection systems, such as flow cytometry to determine unique characteristics of DNA pieces from a selected 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 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 directly proportional to the fragment length. Additional dyes can be bound to the DNA piece and DNA fragments to provide information additional to length information. Oligonucleotide specific dyes and/or hybridization probes can be bound to the DNA fragments to provide information on oligonucleotide distribution or probe hybridization to DNA fragments of different sizes.

Jett, J.H.; Hammond, M.L.; Keller, R.A.; Marrone, B.L.; Martin, J.C.



Picrosirius staining plus polarization microscopy, a specific method for collagen detection in tissue sections  

Microsoft Academic Search

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

L. C. U. Junqueira; G. Bignolas; R. R. Brentani



A preservable two color staining procedure to detect toxicant impacts on algae (Selenastrum capricornutum) using flow cytometry  

SciTech Connect

Over the last several years, the use of flow cytometry to assess the impacts of toxicants on algae has increased. Previous studies have tested cell viability using chlorophyll autofluorescence or single stain flow cytometric analysis in fresh algal cultures. A rapid, two-color flow cytometric assay to evaluate viability and cytotoxicity of Selenastrum capricomutum in preserved samples is described. The staining procedure involved fluorescein diacetate, a fluorogenic esterase substrate cleaved in viable cells to fluorescein (green 525 nm) and ethidium homodimer-1 dye which passes through plasma membranes of compromised and dead cells staining DNA (red 620 nm). The auto fluorescence of chlorophyll-a (deep red 675 nm) was used to assess cell viability and examined for use as an internal comparison with the staining procedure. For storage, stained cells were fixed in glutaraldehyde, flash frozen in liquid nitrogen and stored frozen ({minus}20C) for assessment at a later date. Weekly analysis of stored samples showed that the fluorescence of fluorescein diacetate and ethidium homodimer-1 stained cells was stable under these conditions for the 2 months used in this study. A prepared culture of Selenastrum capricomutum containing a 50% (v/v) mixture of live and heat killed cells showed 36.1 % stained live, 13.2% as compromised, 12% unlabeled, and 38.7% dead algal cells. This two-color flow cytometric procedure has proven to be a reliable, sensitive assay to determine viability of Selenastrum capricomutum in preserved samples. The sensitivity of this dual-color assay and the ability to store samples for later analysis are significant improvements over current techniques. This method is being tested for detection of chemical induced algal cytotoxicity and for potential adaptations to field studies.

Faber, M.; Smith, L.; Boermans, H.; Stephenson, G.; Thompson, D.G. [Univ. of Guelph, Ontario (Canada). Dept. of Environmental Biology



Neural stem cell isolation from the whole mouse brain using the novel FABP7-binding fluorescent dye, CDr3.  


Methods for the isolation of live neural stem cells from the brain are limited due to the lack of well-defined cell surface markers and tools to detect intracellular markers. To date most methods depend on the labeling of extracellular markers using antibodies, with intracellular markers remaining inaccessible in live cells. Using a novel intracellular protein FABP7 (Fatty Acid Binding Protein-7) selective fluorescent chemical probe CDr3, we have successfully isolated high FABP7 expressing cells from the embryonic and adult mouse brains. These cells are capable of forming neurospheres in culture, express neural stem cell marker genes and differentiate into neurons, astrocytes and oligodendrocytes. Characterization of cells sorted with Aldefluor or antibodies against CD133 or SSEA-1 showed that the cells isolated by CDr3 exhibit a phenotype distinct from the cells sorted with conventional methods. FABP7 labeling with CDr3 represents a novel method for rapid isolation of neural stem cells based on the expression of a single intracellular marker. PMID:24090932

Leong, Cheryl; Zhai, Duanting; Kim, Beomsue; Yun, Seong-Wook; Chang, Young-Tae



Gram stain of tissue biopsy  


Gram stain of tissue biopsy test involves using crystal violet stain to test a sample of tissue ... a microscope slide. The specimen is stained with crystal violet stain and goes through more processing before ...


Fluorescent visualization of germline apoptosis in living Caenorhabditis elegans.  


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

Lant, Benjamin; Derry, W Brent



Solid acid catalysts: Stain and shine  

NASA Astrophysics Data System (ADS)

Catalyst particles for fluid catalytic cracking are vital for the oil-refinery industry, but their activity is hard to diagnose because of their inter- and intra-particle structural inhomogeneity. With fluorescence confocal microscopy and selective staining, one can now pinpoint the catalytic activity within single catalyst particles from an industrial reactor.

Chen, Peng



Phase synchronization analysis of voltage-sensitive dye imaging during drug-induced epileptic seizures.  

NASA Astrophysics Data System (ADS)

Epileptic seizures are generally held to result from excess and synchronized neural activity. However, recent studies have suggested that this is not necessarily the case. We investigate how the spatiotemporal pattern of synchronization changes during drug-induced in vivo neocortical seizures in rats. Epileptic seizures are caused by the potassium channel blocker 4-aminopyridine, which is often used in experiments to induce epileptic seizures. In our experiments, the neocortex is stained with the voltage-sensitive dye RH-1691. The intensity changes in dye fluorescence are measured by a CCD camera and are consistent with the signal from local field potential recording. We apply phase synchronization analysis to the voltage-sensitive dye signals from pairs of pixels in order to investigate the degree to which synchronization occurs, and how spatial patterns of synchrony may change, during the course of the seizure. Our preliminary results show that two distant pixels are well synchronized during a seizure event.

Takeshita, Daisuke; Tsytsarev, Vassiliy; Bahar, Sonya



Dye filled security seal  


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.

Wilson, Dennis C. W. (Tijeras, NM)



FISH and immunofluorescence staining in Chlamydomonas.  


Here we describe how to use fluorescence in situ hybridization and immunofluorescence staining to determine the in situ distributions of specific mRNAs and proteins in Chlamydomonas reinhardtii. This unicellular eukaryotic green alga is a major model organism in cell biological research. Chlamydomonas is well suited for these approaches because one can determine the cytological location of fluorescence signals within a characteristic cellular anatomy relative to prominent cytological markers. Moreover, FISH and IF staining offer practical alternatives to techniques involving fluorescent proteins, which are difficult to express and detect in Chlamydomonas. The main goal of this review is to describe these powerful tools and to facilitate their routine use in Chlamydomonas research. PMID:21431732

Uniacke, James; Colón-Ramos, Daniel; Zerges, William



Pericardial fluid Gram stain  


... staining a sample of fluid taken from the sac surrounding the heart to diagnose a bacterial infection. ... sample of fluid will be taken from the sac surrounding the heart. Before this is done, some ...


Quick Stain Removal Guide  

E-print Network

paints) rinse garment in warm water. For oil-based paints, apply solvent recommended on paint can or use turpentine. Rinse. Pretreat with prewash stain remover, bar soap or laundry detergent. Rinse and wash. Acne medicine Adhesive tape, chewing gum... paints) rinse garment in warm water. For oil-based paints, apply solvent recommended on paint can or use turpentine. Rinse. Pretreat with prewash stain remover, bar soap or laundry detergent. Rinse and wash. Acne medicine Adhesive tape, chewing gum...

Brown, Pamela J.



Dye Application, Manufacture of Dye Intermediates and Dyes  

NASA Astrophysics Data System (ADS)

It is difficult if not impossible to determine when mankind first systematically applied color to a textile substrate. The first colored fabrics were probably nonwoven felts painted in imitation of animal skins. The first dyeings were probably actually little more than stains from the juice of berries. Ancient Greek writers described painted fabrics worn by the tribes of Asia Minor. But just where did the ancient craft have its origins? Was there one original birthplace or were there a number of simultaneous beginnings around the world?

Freeman, H. S.; Mock, G. N.


Quinone-methide species, a gateway to functional molecular systems: from self-immolative dendrimers to long-wavelength fluorescent dyes.  


Conspectus Over the last 30 years, the quinone-methide elimination has served as a valuable tool for achieving various important molecular functions. Molecular adaptors based on quinone-methide or aza-quinone-methide reactivity have been designed, synthesized, and used in diagnostic probes, molecular amplifiers, drug delivery systems, and self-immolative dendritic/polymeric molecular systems. These unique adaptors function as stable spacers between an enzyme- or reagent-responsive group and a reporter moiety and can undergo 1,4-, 1,6-, or 1,8-type elimination reactions upon cleavage of the triggering group. Such reactivity results in the release of the reporter group through formation of a quinone-methide species. This type of elimination was applied to design distinct molecular adaptors capable of multiple quinone-methide eliminations. Using this chemistry, we have developed unique molecular structures that are known today as self-immolative dendrimers. These dendrimers disassemble upon a single triggering event in a domino-like manner from the focal point to their periphery with the consequent release of multiple end-groups. Such molecular structures are used in self-immolative dendritic prodrugs and in diagnostic probes to obtain a significant amplification effect. To further enhance amplification, we have developed the dendritic chain reaction, which uses simple molecules to achieve functionality of high-generation virtual self-immolative dendrimers. In addition, we harnessed the quinone-methide elimination reactivity to design polymers that disassemble from head-to-tail initiated by an analyte-responsive event. Following this example, other chemical reactivities were demonstrated by scientists to design such polymeric molecules. In a manner analogous to the quinone-methide elimination, electron rearrangement can lead to formation of conjugated quinone-methide-type dyes with long-wavelength emission of fluorescence. We have recently applied an intramolecular charge transfer to form a unique kind of quinone-methide type derivative based on a donor-two-acceptors molecular structure. This intramolecular charge transfer produces a new fluorochrome with an extended conjugation of ?-electron system that is used for the design of long-wavelength fluorogenic probes with a turn-ON option. The rapidly expanding use of quinone-methide species, reflected in the increased number of examples reported in the literature, indicates the importance of this tool in chemistry. These species provide a useful gateway to functional molecular structures with distinct reactivities and spectroscopic characteristics. PMID:25181456

Gnaim, Samer; Shabat, Doron



Staining human lymphocytes and onion root cell nuclei with madder root.  


We performed staining experiments on cells using natural dyes and different mordants using techniques that are used for wool and silk dyeing. The natural dye sources were madder root, daisy, corn cockle and yellow weed. Ferrous sulfate, copper sulfate, potassium tartrate, urea, potassium aluminum sulfate and potassium dichromate were used as mordants. Distilled water, distilled water plus ethanol, heptane, and distilled water plus methanol were used as solvents. All dye-mordant-solvent combinations were studied at pH 2.4, 3.2 and 4.2. The generic staining procedure was to boil 5-10 onion roots or stimulated human lymphocyte (SHL) preparations in a dye bath on a hot plate. Cells were examined at every half hour. For multicolor staining, madder-dyed lymphocytes were decolorized, then stained with Giemsa. The AgNOR technique was performed following the decolorization of Giemsa stained lymphocytes. Good results were obtained for both onion root cells and lymphocytes that were boiled for 3 h in a dye bath that included 4 g madder root, 4 g ferrous sulfate as mordant in 50 ml of 1:1 (v/v) methanol:distilled water. The pH was adjusted to 4.2 with 6 ml acetic acid. We conclude that madder root has potential as an alternative dye for staining biological materials. PMID:15804822

Cücer, N; Guler, N; Demirtas, H; Imamo?lu, N



Novel Near Infrared Fluorescent Dyes.  

National Technical Information Service (NTIS)

The overall objective of this program is to produce new fluorophores suitable for biosensor signal transduction with excitation wavelengths greater than 665 nm and having electrophilic functionalities for covalent attachment to proteins and nucleic acids....

S. M. Fernandez, E. F. Guignon



Stain Removal Guide  

NSDL National Science Digital Library

Recently retired from "the most successful contract manufacturing Detergent and Sanitiser company in New Zealand," Allan Campbell, PhC MPS, has decided to share his knowledge of detergent chemistry with the world. And what better source for fabric stain tips than a chemist? Visitors can browse the guide, which covers everything from acids to wood saps (including cod liver oil, soy sauce, and chutney), via a frame on the left-hand side of their browsers, Removal tips are listed on the right. A handy site, especially for users facing an ever-spiralling variety of stains in their youngsters's frocks.


Mechanism of the membrane potential sensitivity of the fluorescent membrane probe merocyanine 540.  


The fluorescence and optical absorption of the membrane-staining dye merocyanine 540 (M-540) have been widely used to measure cellular transmembrane potentials. We have studied the molecular mechanisms of these optical changes by measuring the fluorescence polarization of M-540 and its response to membrane potential changes in hemispherical lipid bilayer membranes. The fluorescence responds to a potential step in two distinct time scales: a fast response with a rise time less than the instrumental capability of 6 micromilligram and a slow response with a time constant around 10(-1) s. Both response amplitudes are proportional to the amplitude of the membrane potential change and both require an asymmetrical distribution of M-540 across the membrane. The slow response is ascribed to a net change of the dye concentration in the membrane. The fast response appears to be dominated by a change in the distribution of orientations of the dye molecules in the membrane, with a concomitant perturbation of a monomer-dimer equilibrium, due to interaction of the applied electric field with the permanent molecular dipol moment of M-540. The amplitude of the fast fluorescence response is concentration dependent and can be modeled by including membrane saturation effects and the presence of a nonfluorescent dimer species in the membrane at high dye concentrations. Absorbance changes reported by other investigators are consistent with this model mechanism. PMID:728397

Dragsten, P R; Webb, W W



Preparation of 6-hydroxyindolines and their use for preparation of novel laser dyes  


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.

Field, G.F.; Hammond, P.R.



Preparation of 6-hydroxyindolines and their use for preparation of novel laser dyes  


A novel method 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.

Field, George F. (Danville, CA); Hammond, Peter R. (Livermore, CA)



Dye Painting!  

ERIC Educational Resources Information Center

This resource provides practical instructions for applying color and design directly to fabric. Basic information about the dye painting process is given. The guide addresses the technical aspects of fabric dye and color use and offers suggestions for fabric manipulation and dye application in order to achieve various design effects. This…

Johnston, Ann


Preoperative methylene blue staining of galactographically suspicious breast lesions.  


Microdochectomy is the standard treatment of galactographically suspicious breast lesions. Precise preoperative marking of the suspicious duct and intraductal lesions facilitates selective minimal-volume microdochectomy. Methylene blue dye staining fulfills this criterion. A retrospective review of our experience of preoperative methylene blue staining in 30 patients with unilateral spontaneous nonlactiferous single duct nipple discharge operated on during 1986-1995 in the Oulu University Hospital for galactographically suspicious breast lesions. Galactography was successful in 29 out of 30 (93.3%) cases. Preoperative methylene blue staining was attempted in all cases on the day of surgery and it was successful in 22 (73.3%) cases making subsequent selective minimal-volume microdochectomy easy to perform. The failure of methylene blue staining led to quadrantectomy in 4 cases and smaller breast resections in the remaining 4 cases. Preoperative methylene blue dye staining crucially facilitates selective minimal-volume microdochectomy. An interval between primary galactography and later methylene blue staining leads to failures in approximately one quarter of the cases. A higher success rate would necessitate scheduling the microdochectomy on the same day as the primary galactography (and the subsequent methylene blue staining in suspicious cases). PMID:9412841

Saarela, A O; Kiviniemi, H O; Rissanen, T J



Novel Process for Laser Stain Removal from Archaeological Oil Paintings  

NASA Astrophysics Data System (ADS)

Some samples of oil paintings (5 × 5 cm) were prepared on wooden panel with four types of fungi commonly encountered on oil paintings were selected for this study. Each of the fungi is associated with different colored stains. Fungus Alternaria tenuis is associated by a dense black stain, Chetomium globosum by a brownish gray stain, Aspergillus flavus by a yellowish stain, and Fusaruim oxysporum by a pinkish stain. Fungi growing on oil paintings affect the surface characteristics by forming a variety of colored patches typically composed of many complex chemical substances that are produced during metabolic processes. These colored stains may be encrusted in spores, present in mycelium or secreted to a substance such as oil paintings surfaces. While the fungal stains can sometimes be extracted with appropriate solvents, there are some stains that resist solvent extraction entirely. Developing new solvent system that might attack the paint structure, and is time consuming and requires a great deal of trial and error. Mechanical stain removal is also problematic in that it often produces abrasion of the surface, markedly deteriorating the artwork, and is extra ordinarily fine and tedious. For these reasons, we decided to examine an alternative physical technique as a new approach to deal with stain removal. Since the stains are due to the existence of fungi, we thought it a good idea to remove them by singlet oxygen. We applied the photo dynamic process through which the fungi stains were covered with organic dye derivatives in solution under controlled illumination in the lab. The samples were then irradiated by low power Laser light from a He-Ne laser, the dye will be photodecomposed and produce singlet oxygen. We report in this work the results obtained as a function of: - The concentration and types of the organic dye in solution, - The presence of certain amounts of liquids added to the solution, - The scanning speed of the laser beam on the sample surface, - The irradiation time. For each case fresh samples were used and photographed before and after the treatment. The results obtained will be speculated and discussed. This procedure was applied to the cleaning of archaeological oil paintings for the first time to our knowledge. The method could well be considered as a new field of combined science and technology applied to laser stain removal and represents a significant addition to the techniques available to art conservation.

El-Nadi, Lotfia; El-Feky, Osama; Abdellatif, Galila; Darwish, Sawsan



A comparative study of quantitative stains for DNA in image cytometry.  


In this study we examined the reproducibility of several stains used to measure nuclear DNA by image cytometry. The specimens were touch preparations of liver and testis from mouse and liver, intestine and brain from rat, fixed in either neutral formalin or Carnoy's solution. The tested stains included four Feulgen methods (pararosaniline, azure-A, thionin and acriflavine), the gallocyanine-chromalum stain and two fluorescent stains (acridine orange and propidium iodide). Absorbance measurements employed a video image analysis system; fluorescence measurements were from a scanning microspectrophotometer. The acriflavine-Feulgen stain was analyzed for both absorbance and fluorescence. All seven stains were quantitative for DNA and gave reproducible results. The absorbance measurements had a lower coefficient of variation (CV) than the fluorescence values. In a nested analysis of variance of the pararosaniline Feulgen stains, cell-to-cell variability accounted for 67% of the total variance; slide-to-slide, 9%; and batch-to-batch, 24%. These values did not change significantly when the staining was performed in an automatic staining machine. For DNA analysis using image cytometry, we conclude that the Feulgen staining technique is the most useful. In particular, acriflavine-Feulgen-stained cells fixed in Carnoy's fluid give the least variation between measurement values and the most accurate ratios between the separate ploidy groups. For fluorescence cytometry we recommend Carnoy's fixation and the acriflavine-Feulgen stain because of its narrow CV as compared to acridine orange and propidium iodide. PMID:1718295

Mikel, U V; Becker, R L



Fluorometric procedures for dye tracing  

USGS Publications Warehouse

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)

Wilson, James E., Jr.; Cobb, E. D.; Kilpatrick, F. A.



Effectiveness of photosensitive dye during uptake and redistribution  

NASA Astrophysics Data System (ADS)

The location of photosensitive dye within a cell will affect the efficacy of photodynamic therapy (PDT). This report demonstrates that during the first 3 hours of dye (Photofrin porfimer) uptake from a liquid medium, the dye is diffusely distributed within the cell. After 24 hours of dye uptake, the dye is localized in specific sites within the cell. Fluorescence spectroscopy demonstrated that the 3-hour dye's emission peak near 635 nm was slightly blue shifted for the localized 24-hour dye. This paper demonstrates that the diffuse dye (at 3 hours) is more effective for PDT than the localized dye (at 24 hours). The amount of diffuse dye within the cell that is required to achieve an LD50 (50% lethal dose) is 1.5-fold to 4.5- fold less than the amount of localized dye required, using the same light exposure. The range of 1.5 - 4.5-fold refers to the results for four cell lines.

He, Xiao-Yan; Jacques, Steven L.; Gofstein, Gary



Fluorescence imaging of microbe-containing particles shot from a two-stage Light-gas gun into an aerogel.  


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

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



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...


Hair Dyes  

Microsoft Academic Search

\\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

David Basketter; Jeanne Duus Johansen; John McFadden; Heidi Søsted


Environmentally safe removal\\/disposal of Coomassie Brilliant Blue from gel destain and used gel stain  

Microsoft Academic Search

Gel destaining following Coomassie Brilliant Blue (CBB) staining involves the use of toxic reagents. Here we demonstrate the efficacy of various paper adsorbents in adsorbing CBB. Kimwipes adsorbed the best, followed by Teri towels, multifold towels, and Whatman numbers 1 and 3 filter papers. Three Kimwipes completely adsorbed the dye released from a CBB-stained mini-gel. Nonradioactive destain solution can, therefore,

Yaser Dorri; Biji T. Kurien



Length of stain dosimeter  

NASA Technical Reports Server (NTRS)

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.

Lueck, Dale E. (inventor)



Fluorescence Microscopy Methods for Determining the Viability of Bacteria in Association with Mammalian Cells  

PubMed Central

Central to the field of bacterial pathogenesis is the ability to define if and how microbes survive after exposure to eukaryotic cells. Current protocols to address these questions include colony count assays, gentamicin protection assays, and electron microscopy. Colony count and gentamicin protection assays only assess the viability of the entire bacterial population and are unable to determine individual bacterial viability. Electron microscopy can be used to determine the viability of individual bacteria and provide information regarding their localization in host cells. However, bacteria often display a range of electron densities, making assessment of viability difficult. This article outlines protocols for the use of fluorescent dyes that reveal the viability of individual bacteria inside and associated with host cells. These assays were developed originally to assess survival of Neisseria gonorrhoeae in primary human neutrophils, but should be applicable to any bacterium-host cell interaction. These protocols combine membrane-permeable fluorescent dyes (SYTO9 and 4',6-diamidino-2-phenylindole [DAPI]), which stain all bacteria, with membrane-impermeable fluorescent dyes (propidium iodide and SYTOX Green), which are only accessible to nonviable bacteria. Prior to eukaryotic cell permeabilization, an antibody or fluorescent reagent is added to identify extracellular bacteria. Thus these assays discriminate the viability of bacteria adherent to and inside eukaryotic cells. A protocol is also provided for using the viability dyes in combination with fluorescent antibodies to eukaryotic cell markers, in order to determine the subcellular localization of individual bacteria. The bacterial viability dyes discussed in this article are a sensitive complement and/or alternative to traditional microbiology techniques to evaluate the viability of individual bacteria and provide information regarding where bacteria survive in host cells. PMID:24056524

Johnson, M. Brittany; Criss, Alison K.



Gram stain of skin lesion  


Skin lesion gram stain ... a glass slide. A series of different colored stains is applied to the sample. A laboratory team ... test. For information on risks related to the removal of a skin sample, see skin lesion biopsy .


A unique charge-coupled device/xenon arc lamp based imaging system for the accurate detection and quantitation of multicolour fluorescence.  


In recent years the use of fluorescent dyes in biological applications has dramatically increased. The continual improvement in the capabilities of these fluorescent dyes demands increasingly sensitive detection systems that provide accurate quantitation over a wide linear dynamic range. In the field of proteomics, the detection, quantitation and identification of very low abundance proteins are of extreme importance in understanding cellular processes. Therefore, the instrumentation used to acquire an image of such samples, for spot picking and identification by mass spectrometry, must be sensitive enough to be able, not only, to maximise the sensitivity and dynamic range of the staining dyes but, as importantly, adapt to the ever changing portfolio of fluorescent dyes as they become available. Just as the available fluorescent probes are improving and evolving so are the users application requirements. Therefore, the instrumentation chosen must be flexible to address and adapt to those changing needs. As a result, a highly competitive market for the supply and production of such dyes and the instrumentation for their detection and quantitation have emerged. The instrumentation currently available is based on either laser/photomultiplier tube (PMT) scanning or lamp/charge-coupled device (CCD) based mechanisms. This review briefly discusses the advantages and disadvantages of both System types for fluorescence imaging, gives a technical overview of CCD technology and describes in detail a unique xenon/are lamp CCD based instrument, from PerkinElmer Life Sciences. The Wallac-1442 ARTHUR is unique in its ability to scan both large areas at high resolution and give accurate selectable excitation over the whole of the UV/visible range. It operates by filtering both the excitation and emission wavelengths, providing optimal and accurate measurement and quantitation of virtually any available dye and allows excellent spectral resolution between different fluorophores. This flexibility and excitation accuracy is key to multicolour applications and future adaptation of the instrument to address the application requirements and newly emerging dyes. PMID:11332749

Spibey, C A; Jackson, P; Herick, K



Differential giemsa staining of sister chromatids and the study of sister chromatid exchanges without autoradiography  

Microsoft Academic Search

Chinese hamster ovary cells grown for two rounds of DNA replication in the presence of BrdUrd contain sister chromatids that fluoresce differentially when stained with Hoechst 33258. If such fluorescent treatments are followed by incubation in 2 X SSC or water at 62° C and staining in 3% Giemsa, the chromosomes now contain one dark (unifilarly substituted) chromatid and one

Sheldon Wolff; Paul Perry



Use of fluorescent DNA-intercalating dyes in the analysis of DNA via ion-pair reversed-phase denaturing high-performance liquid chromatography  

Microsoft Academic Search

SYBR Green 1 is an asymmetrical cyanine DNA-binding dye that provides an opportunity for increasing the sensitivity of nucleic acid detection when used in conjunction with gel electrophoresis. In this paper, we summarize the general properties and specific uses of SYBR green 1 in ion-pair reversed-phase denaturing high-performance liquid chromatography (IP DHPLC). We describe several applications for the WAVE DHPLC

Ahmad R Bahrami; Mark J Dickman; Maryam M Matin; John R Ashby; Paul E Brown; Matthew J Conroy; Gregory J. S Fowler; James P Rose; Qaiser I Sheikh; Anthony T Yeung; David P Hornby



Radiation Dosimetry via Automated Fluorescence Microscopy  

NASA Technical Reports Server (NTRS)

A developmental instrument for assessment of radiation-induced damage in human lymphocytes includes an automated fluorescence microscope equipped with a one or more chargecoupled- device (CCD) video camera(s) and circuitry to digitize the video output. The microscope is also equipped with a three-axis translation stage that includes a rotation stage, and a rotary tray that holds as many as thirty specimen slides. The figure depicts one version of the instrument. Once the slides have been prepared and loaded into the tray, the instrument can operate unattended. A computer controls the operation of the stage, tray, and microscope, and processes the digital fluorescence-image data to recognize and count chromosomes that have been broken, presumably by radiation. The design and method of operation of the instrument exploit fluorescence in situ hybridization (FISH) of metaphase chromosome spreads, which is a technique that has been found to be valuable for monitoring the radiation dose to circulating lymphocytes. In the specific FISH protocol used to prepare specimens for this instrument, metaphase lymphocyte cultures are chosen for high mitotic index and highly condensed chromosomes, then several of the largest chromosomes are labeled with three of four differently colored whole-chromosome-staining dyes. The three dyes, which are used both individually and in various combinations, are fluorescein isothiocyanate (FITC), Texas Red (or equivalent), and Cy5 (or equivalent); The fourth dye 4',6-diamidino- 2-phenylindole (DAPI) is used as a counterstain. Under control by the computer, the microscope is automatically focused on the cells and each slide is scanned while the computer analyzes the DAPI-fluorescence images to find the metaphases. Each metaphase field is recentered in the field of view and refocused. Then a four-color image (more precisely, a set of images of the same view in the fluorescent colors of the four dyes) is acquired. By use of pattern-recognition software developed specifically for this instrument, the images in the various colors are processed to recognize the metaphases and count the chromosome fragments of each color within the metaphases. The intermediate results are then further processed to estimate the proportion of cells that have suffered genetic damage. The prototype instrument scans at an average areal rate of 4.7 mm2/h in unattended operation, finding about 14 metaphases per hour. The false-alarm rate is typically less than 3 percent, and the metaphase-miss rate has been estimated to be less than 5 percent. The counts of chromosomes and fragments thereof are 50 to 70 percent accurate.

Castleman, Kenneth R.; Schulze, Mark



Squaraine-Derived Rotaxanes: Sterically Protected Fluorescent Near-IR Dyes Easwaran Arunkumar, Christopher C. Forbes, Bruce C. Noll, and Bradley D. Smith*  

E-print Network

, Christopher C. Forbes, Bruce C. Noll, and Bradley D. Smith* Department of Chemistry and Biochemistry, UniVersity of Notre Dame, Notre Dame, Indiana 46556 Received December 17, 2004; E-mail: Fluorescent

Smith, Bradley D.


Metal-enhanced fluorescence from paper substrates: Modified spectral properties of dyes for potential high-throughput surface analysis and assays and as an anti-counterfeiting technology  

Microsoft Academic Search

In this paper, we report the first observation of metal-enhanced fluorescence emission of fluorophores from paper substrates. The fluorescence intensity is ?5- and ?9-fold brighter from Rose Bengal (RB) and Pt(II) octaethylporphine (PtOEP), respectively, on silver colloid-deposited paper as compared to uncoated paper. In addition, a reduced lifetime of RB near to silver particles (0.77ns) was observed as compared to

Yongxia Zhang; Kadir Aslan; Michael J. R. Previte; Chris D. Geddes



Use of the vital stain FUN-1 indicates viability of Phytophthora capsici propagules and can be used to predict maximum zoospore production.  


The fluorescent vital dye FUN®-1 (2-chloro-4-[2,3-dihydro-3-methyl-{benzo-1,3-thiazol-2-yl}-methylidene]-1-phenylquinolinium iodide) was evaluated as a tool to assess Phytophthora capsici sporangia and zoospore metabolic activity and viability. Under aerobic conditions, mycelia, sporangia and zoospores cultured on agar medium and stained with FUN-1 exhibited red fluorescent cylindrical intravacuolar structures (CIVS) that were clearly visible at 100× magnification. Encysted zoospores did not exhibit CIVS after exposure to FUN-1 dye. Over 7 d there was a significant reduction in the percent of sporangia containing CIVS, which corresponded with a significant increase in zoospore formation and release. The decline in the percentage of metabolically active sporangia and increase in the number of zoospores fit both a linear and log regression model. The FUN-1 dye was suitable for distinguishing between live and dead sporangia and effective in monitoring the change in metabolic activity of sporangia over time. It will be useful in determining parameters, including P. capsici culture age, that maximize production of zoospores in vitro. PMID:24782503

Lewis Ivey, Melanie L; Miller, Sally A



Digitization of stained glass  

NASA Astrophysics Data System (ADS)

Digital photography was applied to the capture of images of the stained glass windows in the historic parish church in Fairford, Gloucestershire, England. Because of their size, the windows had to be photographed in 45 separate sections in order to capture all the detail present in the painting on the glass. The digital images of each section, approximately 3000 by 2300 pixels, were then mosaiced together in order to construct the very high resolution image needed for the complete window. A special backlight panel was constructed for the purpose, and techniques developed for minimizing the effects of reflected light and for calibrating the color of the images. Improvements in the technology for mounting and positioning the camera were identified as the most significant factors currently preventing the widespread adoption of this technology for virtual heritage applications.

MacDonald, Lindsay W.



21 CFR 866.3460 - Rabiesvirus immuno-fluorescent reagents.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Rabiesvirus immuno-fluorescent reagents. 866.3460 Section 866... § 866.3460 Rabiesvirus immuno-fluorescent reagents. (a) Identification...rabiesvirus antisera conjugated with a fluorescent dye used to identify...



21 CFR 866.3460 - Rabiesvirus immuno-fluorescent reagents.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Rabiesvirus immuno-fluorescent reagents. 866.3460 Section 866... § 866.3460 Rabiesvirus immuno-fluorescent reagents. (a) Identification...rabiesvirus antisera conjugated with a fluorescent dye used to identify...



Feasibility of digitally stained multimodal confocal mosaics to simulate histopathology  

NASA Astrophysics Data System (ADS)

Fluorescence confocal mosaicing microscopy of tissue biopsies stained with acridine orange has been shown to accurately identify tumors and with an overall sensitivity of 96.6% and specificity of 89.2%. However, fluorescence shows only nuclear detail similar to hematoxylin in histopathology and does not show collagen or cytoplasm, which may provide necessary negative contrast information similar to eosin used in histopathology. Reflectance mode contrast is sensitive to collagen and cytoplasm without staining. To further improve sensitivity and specificity, digitally stained confocal mosaics combine confocal fluorescence and reflectance images in a multimodal pseudo-color image to mimic the appearance of histopathology with hematoxylin and eosin and facilitate the introduction of confocal microscopy into the clinical realm.

Gareau, Daniel S.



Feasibility of digitally stained multimodal confocal mosaics to simulate histopathology.  


Fluorescence confocal mosaicing microscopy of tissue biopsies stained with acridine orange has been shown to accurately identify tumors and with an overall sensitivity of 96.6% and specificity of 89.2%. However, fluorescence shows only nuclear detail similar to hematoxylin in histopathology and does not show collagen or cytoplasm, which may provide necessary negative contrast information similar to eosin used in histopathology. Reflectance mode contrast is sensitive to collagen and cytoplasm without staining. To further improve sensitivity and specificity, digitally stained confocal mosaics combine confocal fluorescence and reflectance images in a multimodal pseudo-color image to mimic the appearance of histopathology with hematoxylin and eosin and facilitate the introduction of confocal microscopy into the clinical realm. PMID:19566342

Gareau, Daniel S



Detecting freeze injury and seasonal cold-hardening of cells and tissues in the gall fly larvae, Eurosta solidaginis (Diptera: Tephritidae) using fluorescent vital dyes  

Microsoft Academic Search

This study identified a hierarchy in levels of cold tolerance for diverse tissues from larvae of Eurosta solidaginis. Following freezing at ?80 °C, larval survival and the viability of specific tissues were assessed using membrane-permeant DNA stain (SYBY-14) and propidium iodide.Integumentary muscle, hemocytes, tracheae, and the crystal-containing portion of the Malpighian tubules were most susceptible to freezing injury. A second

Shu-Xia Yi; Richard E Lee



Chemical aspects of santalin as a histological stain.  


Recent research on the chemical nature of the red dyes isolated from Pterocarpus santalinus and certain West African plants, viz., Baphia nitida, Pterocarpus osun and Pterocarpus soyauxii, have been reviewed. P. santalinus contains santalins A, B and C, but no santarubin. Santalins and santarubins have been found in P. osun, P. soyauxii and B. nitida. The structural formulae of the santalins are presented and their differences from santarubins indicated. Santalins A and B have some similarities in structure with hematein. This is probably responsible for their staining properties; the possible mechanism of staining is discussed. PMID:6166100

Banerjee, A; Mukherjee, A K



Spectroscopic studies, fluorescence quenching by molecular oxygen and amplified spontaneous emission of 1,4-bis [2-(2-pyridyl) vinyl] benzene (P2VB) diolefinic laser dye  

NASA Astrophysics Data System (ADS)

The UV-visible electronic absorption spectra, molar absorptivity, fluorescence spectra, fluorescence quantum yield and excited state lifetime of 1,4-bis [2-(2-pyridyl) vinyl] benzene P2VB were measured in different solvents. The fluorescence quenching of P2VB by molecular oxygen was also studied using lifetime measurements. A 2 × 10-4 mol dm-3 solution of P2VB in dimethyl formamide (DMF) gave amplified spontaneous emission (ASE) in blue spectral region with emission maximum at 420 nm upon pumping by 337.1 nitrogen laser pulse. The photochemical quantum yields (?c) of trans-cis photoisomerization of P2VB were calculated in different organic solvents. The photoreactivity of P2VB are also studied PMMA matrix.

El-Daly, Samy A.; Ebeid, E. M.



Quantification of dye-mediated photodamage during single-molecule DNA imaging.  


Single-molecule fluorescence imaging of DNA-binding proteins has enabled detailed investigations of their interactions. However, the intercalating dyes used to visually locate DNA molecules have the undesirable effect of photochemically damaging the DNA through radical intermediaries. Unfortunately, this damage occurs as single-strand breaks (SSBs), which are visually undetectable but can heavily influence protein behavior. We investigated the formation of SSBs on DNA molecules by the dye YOYO-1 using complementary single-molecule imaging and gel electrophoresis-based damage assays. The single-molecule assay imaged hydrodynamically elongated lambda DNA, enabling the real-time detection of double-strand breaks (DSBs). The gel assay, which used supercoiled plasmid DNA, was sensitive to both SSBs and DSBs. This enabled the quantification of SSBs that precede DSB formation. Using the parameters determined from the gel damage assay, we applied a model of stochastic DNA damage to the time-resolved DNA breakage data, extracting the rates of single-strand breakage at two dye staining ratios and measuring the damage reduction from the radical scavengers ascorbic acid and ?-mercaptoethanol. These results enable the estimation of the number of SSBs that occur during imaging and are scalable over a wide range of laser intensities used in fluorescence microscopy. PMID:22484041

Tycon, Michael A; Dial, Catherine F; Faison, Keia; Melvin, Whitney; Fecko, Christopher J



Multicolor staining of root systems in pot culture  

Microsoft Academic Search

We have developed a method for staining the root systems of neighboring plants distinguishably in pot culture to facilitate studies of the interactions between plants. Pot soil was desiccated until the plant wilted, and then the shoot was cut and a dye solution (Fantasy) was pressure-injected into the roots at 0.05 MPa (gauge). All the roots, including fine roots of double-planted

Toshifumi Murakami; Satoshi Shimano; Satoshi Kaneda; Miyuki Nakajima; Yasufumi Urashima; Norikazu Miyoshi



Fluorescence characteristics of 5-carboxytetramethylrhodamine linked covalently to the 5' end of oligonucleotides: multiple conformers of single-stranded and double-stranded dye-DNA complexes.  

PubMed Central

Fluorescence steady-state and lifetime experiments have been carried out on duplex and single-stranded DNA molecules labeled at the 5' ends with 5-carboxytetramethylrhodamine (TMRh). The temperature and ionic strength of the solutions were varied over large ranges. The results reveal at least three well-defined states of the TMRh-DNA molecules for the single-stranded as well as for the double-stranded DNA molecules. Two states are fluorescent, with lifetimes in the range of 0.5-1 ns and 2.5-3 ns. A third state of TMRh-DNA does not fluoresce (a dark species of TMRh-DNA). The distribution of the TMRh-DNA molecules among these three states is strongly temperature and ionic strength dependent. Estimates are made of some reaction parameters of the multistate model. The results are discussed in terms of the photophysics of TMRh, and consequences of the multiple conformers of TMRh-DNA for studies involving fluorescence studies with TMRh-labeled DNA are considered. PMID:8842236

Vamosi, G; Gohlke, C; Clegg, R M



Pyrrolo-dC oligonucleotides bearing alkynyl side chains with terminal triple bonds: synthesis, base pairing and fluorescent dye conjugates prepared by the azide-alkyne "click" reaction.  


5-(Octa-1,7-diynyl)-2'-deoxyuridine was converted into the furano-dU derivative 7 by copper-catalyzed cyclization; the pyrolodC-derivative 3 was formed upon ammonolysis. The bicyclic nucleosides 3 and 7 as well as the corresponding non-cyclic precursors 4 and 6 all containing terminal C[triple bond]C bonds were conjugated with the non-fluorescent 3-azido-7-hydroxycoumarin 5 employing the copper(I)-catalyzed Huisgen-Sharpless-Meldal cycloaddition "click reaction". Strongly fluorescent 1H-1,2,3-triazole conjugates (30-33) are formed incorporating two fluorescent reporters-the pyrdC nucleoside and the coumarin moiety. Oligonucleotides incorporating 6-alkynyl and 6-alkyl 7H-pyrrolo[2,3-d]pyrimidin-2(3H)-one nucleosides (3 and 2f) have been prepared by solid-phase synthesis using the phosphoramidite building blocks 10 and 13 ; the pyrrolo-dC oligonucleotides are formed during ammonia treatment. The duplex stability of oligonucleotides containing 3 and related derivatives was studied. Oligonucleotides with terminal triple bonded nucleosides such as 3 are more stabilizing than those lacking a side chain with terminal unsaturation; open-chain derivatives (4) are even more efficient. The click reaction was also performed on oligonucleotides containing the pyrdC-derivative and the fluorescence properties of nucleosides, oligonucleotides and their coumarin conjugates were studied. PMID:18421402

Seela, Frank; Sirivolu, Venkata Ramana



Environmentally safe removal/disposal of Coomassie Brilliant Blue from gel destain and used gel stain.  


Gel destaining following Coomassie Brilliant Blue (CBB) staining involves the use of toxic reagents. Here we demonstrate the efficacy of various paper adsorbents in adsorbing CBB. Kimwipes adsorbed the best, followed by Teri towels, multifold towels, and Whatman numbers 1 and 3 filter papers. Three Kimwipes completely adsorbed the dye released from a CBB-stained mini-gel. Nonradioactive destain solution can, therefore, be recycled for destaining CBB-stained gels. Stain removal with Kimwipes helps in reducing destain use and in reducing organic liquid waste, and it is 7.5-fold cheaper compared with an available method for CBB disposal. Following this, we determined the suitability of this procedure to remove the dye from a used CBB staining solution awaiting proper disposal by our Institutional Safety Office. The dye from a 0.05% CBB staining solution could be removed in 5 to 10 min using 75 Kimwipes. The CBB-adsorbed Kimwipes did not release the stain when squeezed dry even after incubation in various salts over 1week and in water for 5 weeks. The CBB removed allows its easy disposal as solid waste and will not leach out from solid landfills. Thus, stain removal with Kimwipes helps in disposing CBB in an environmentally friendly manner and allows recycling of destaining solution. PMID:20507825

Dorri, Yaser; Kurien, Biji T



Brilliant Blue FCF as a Dye Tracer for Solute Transport Studies—A Toxicological Overview  

Microsoft Academic Search

Brilliant Blue FCF (C.I. 42090) was found to be a useful dye tracer to stain the flow paths of water in soil media. Being neutral or anionic, it is not strongly adsorbed by negatively charged soil constituents. The dye is used in food because its general toxicity is low. However, to stain the flow paths of water in soil, fairly

Markus Flury; Hannes Fltihler



Dye Painting with Fiber Reactive Dyes  

ERIC Educational Resources Information Center

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…

Benjamin-Murray, Betsy



Bispectral Photometric Stereo based on Fluorescence National Institute of Informatics  

E-print Network

natural gems and corals, to fluorescent dyes used in clothing. One of the important characteristics phenomenon oc- curring in many objects from natural gems and corals, to fluorescent dyes used for clothing), fluorescent-only image observed in the red channel (mid- dle), and reflective-component-only images observed

Tokyo, University of


Measurement of Mitochondrial Membrane Potential Using Fluorescent Rhodamine Derivatives  

Microsoft Academic Search

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

Russell C. Scaduto; Lee W. Grotyohann




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...


Fluorescence incoherent color holography.  


We present a new imaging method to record multicolor digital holograms from objects emitting fluorescent light. The fluorescent light specific to the emission wavelength of various fluorescent dyes after excitation of three dimensional (3D) objects is recorded on a digital monochrome camera after reflection from a diffractive optical element (DOE). For each wavelength of fluorescent emission, the camera sequentially records three holograms reflected from the DOE, each with a different phase factor of the DOE's function. The three holograms are superposed in a computer to create a complex valued Fresnel hologram of each fluorescent emission. The holograms for each fluorescent color are further combined in a computer to produce a multicolored fluorescence hologram and 3D color image. PMID:19532459

Rosen, Joseph; Brooker, Gary



Confusion over live/dead stainings for the detection of vital microorganisms in oral biofilms - which stain is suitable?  

PubMed Central

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



Molecular cytogenetics using fluorescence in situ hybridization  

SciTech Connect

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.

Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.



Staining is complete in less than three hours The procedure includes only three steps --fixation, oxidation and staining  

E-print Network

standard UV illumination Compatible with SYPRO Ruby protein gel stain for detection of protein contaminants green fluorescence that is easy to visualize using a simple UV transilluminator. Contaminating proteins. They play a large role in protecting the bacterium from host defense mechanisms and antibiotics and trigger

Lebendiker, Mario


Hybrid nanoparticles for drug delivery and bioimaging: mesoporous silica nanoparticles functionalized with carboxyl groups and a near-infrared fluorescent dye.  


The development of a drug delivery system with fluorescent biolabels is important in anti-cancer drug delivery application due to the potential for simultaneous diagnosis and treatment of diseases. Here, we reported the synthesis and multiple functionalization of mesoporous silica nanoparticle (MSN) for bioimaging and controlled drug release. After the functionalization with carboxyl group, the nanoparticles exhibited much better dispersity and stability in aqueous solution than MSN. Furthermore, a substantial doxorubicin (DOX) loading level was achieved and DOX-loaded nanoparticles exhibited noticeable pH-sensitive behavior with accelerated release of DOX in acidic environment. Compared with native DOX-MSN, DOX-MSN/COOH-Cy5 exhibited enhanced intracellular uptake efficacy and stronger effect on killing tumor cells. Meanwhile, it was observed that the MSN/COOH-Cy5 was able to locate in the cytoplasm of MCF-7 cells and could accumulate in tumor tissues for a long period of time. Overall, the functional nanoparticle could potentially be used for simultaneous controlled drug release and near-infrared fluorescent bioimaging. PMID:23394807

Xie, Meng; Shi, Hui; Ma, Kun; Shen, Haijun; Li, Bo; Shen, Song; Wang, Xinshi; Jin, Yi



Exogenous fluorescent tracer agents based on pegylated pyrazine dyes for real-time point-of-care measurement of glomerular filtration rate.  


Novel pyrazine carboxamides bearing hydrophilic poly(ethylene glycol) (PEG) moieties were designed, synthesized, and evaluated for use as fluorescent glomerular filtration rate (GFR) tracer agents. Among these, compounds 4d and 5c that contain about 48 ethylene oxide units in the PEG chain exhibited the most favorable physicochemical and renal clearance properties. In vitro studies show that these two compounds have low plasma protein binding, a necessary condition for renal excretion. In vivo animal model results show that 4d and 5c have a higher urine recovery of the injected dose than iothalamate (a commonly considered gold standard GFR agent). Pharmacokinetic studies show that these two compounds exhibit a plasma clearance equivalent to iothalamate, but with a faster (i.e. lower) terminal half-life than iothalamate (possibly from restricted distribution into the extracellular space due to large molecular size and hydrodynamic volume). Furthermore, the plasma clearance of 4d and 5c remained unchanged upon blockage of the tubular secretion pathway with probenecid, a necessary condition for establishment of clearance via glomerular filtration exclusively. Finally, noninvasive real-time monitoring of this class of compounds was demonstrated by pharmacokinetic clearance of 5c by optical measurements in rat model, which correlates strongly with plasma concentration of the tracer. Hence, 4d and 5c are promising candidates for translation to the clinic as exogenous fluorescent tracer agents in real-time point-of-care monitoring of GFR. PMID:22459210

Poreddy, Amruta R; Neumann, William L; Freskos, John N; Rajagopalan, Raghavan; Asmelash, Bethel; Gaston, Kimberly R; Fitch, Richard M; Galen, Karen P; Shieh, Jeng-Jong; Dorshow, Richard B



Biomat flow: fluorescent dye field experiments, pore-scale modeling of flow and transport properties, and field-scale flow models  

NASA Astrophysics Data System (ADS)

Recent studies highlight the important role that the upper litter layer in forest soils (biomat) plays in hillslope and catchment runoff generation. This biomat layer is a very loose material with high porosity and organic content. Direct sampling is usually problematic due to limited layer thickness. Conventional laboratory measurements can mobilize solids or even cause structure failure of the sample thus making measurements unreliable. It is also difficult to assess local variation in soil properties and transition zones using these methods; thus, they may not be applicable to biomat studies. However, if the physics of flow through this layer needs to be quantified and incorporated into a model, a detailed study of hydraulic properties is necessary. Herein we show the significance of biomat flow by staining experiments in the field, study its structure and transition to mineral soil layer using X-ray micro-tomography, assess hydraulic properties and structure differences using a pore-scale modeling approach, and, finally, use conventional variably-saturated flow modeling based on Richards equation to simulate flow in the hillslope. Using staining tracers we show that biomat flow in forested hillslopes can extend long distances (lateral displacement was about 1.2 times larger than for subsurface lateral flow) before infiltration occurs into deeper layers. The three-dimensional structure of an undisturbed sample (4 x 3 x 2.5 cm) of both biomat and deeper consolidated soil was obtained using an X-ray micro-tomography device with a resolution of 15 um. Local hydraulic properties (e.g., permeability and water retention curve) for numerous layers (e.g., transition zones, biomat, mineral soil) were calculated using Stokes flow FDM solution and pore-network modeling. Anisotropy, structure differences, and property fluctuations of different layers were quantified using local porosity analysis and correlation functions. Current results support the hypothesis that small-scale structural differences alone can explain the lateral transport observed in field. Possible water repellent behaviour at the biomat-mineral soil interface may also be contributing to extended surface flow. Based on conventional modeling with HYDRUS-2D we show how pore-scale modelling-derived hydraulic properties can improve large scale simulations and clarify how local heterogeneities in wetting and hydraulic properties affect infiltration into deeper soils and likely magnify preferential flow. This work was partially supported by RFBR grants 12-05-33089, 12-04-32264, 13-04-00409, 13-05-01176 and 12-05-01130.

Gerke, K.; Sidle, R. C.; Mallants, D.; Vasilyev, R.; Karsanina, M.; Skvortsova, E. B.; Korost, D. V.



Measurement of time of travel in streams by dye tracing  

USGS Publications Warehouse

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.

Kilpatrick, F. A.; Wilson, James F.



Monofunctional Carbocyanine Dyes for Bio- and Bioorthogonal Conjugation  

PubMed Central

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

Shao, Fangwei; Weissleder, Ralph; Hilderbrand, Scott A



Fluorescence Quantum Efficiency Of Flat Panel Luminescence Solar Concentrator Material  

NASA Astrophysics Data System (ADS)

The relaxation of a few typical orange and red absorbing dyes in PMMA ( polymethylmetacrylate ) is studied by compensation photocalorimetry and picosecond fluorescence spectroscopy. At ambient temperature the orange dyes have a fluorescence quantum efficiency of close to unity and they decay monoexponentially. The red dyes have lower efficiencies and their decay can be described by two exponentials. This decay kinetic is not in agreement with the model of dipol-dipol mediated intramolecular fluorescence quenching.

Strauss, E.; Seelert, W.; Keller, W.; Dammaschke, M.



Wide-field and two-photon imaging of brain activity with voltage- and calcium-sensitive dyes  

PubMed Central

This review presents three examples of using voltage- or calcium-sensitive dyes to image the activity of the brain. Our aim is to discuss the advantages and disadvantages of each method with particular reference to its application to the study of the brainstem. Two of the examples use wide-field (one-photon) imaging; the third uses two-photon scanning microscopy. Because the measurements have limited signal-to-noise ratio, the paper also discusses the methodological aspects that are critical for optimizing the signal. The three examples are the following. (i) An intracellularly injected voltage-sensitive dye was used to monitor membrane potential in the dendrites of neurons in in vitro preparations. These experiments were directed at understanding how individual neurons convert complex synaptic inputs into the output spike train. (ii) An extracellular, bath application of a voltage-sensitive dye was used to monitor population signals from different parts of the dorsal brainstem. We describe recordings made during respiratory activity. The population signals indicated four different regions with distinct activity correlated with inspiration. (iii) Calcium-sensitive dyes can be used to label many individual cells in the mammalian brain. This approach, combined with two-photon microscopy, made it possible to follow the spike activity in an in vitro brainstem preparation during fictive respiratory rhythms. The organic voltage- and ion-sensitive dyes used today indiscriminatively stain all of the cell types in the preparation. A major effort is underway to develop fluorescent protein sensors of activity for selectively staining individual cell types. PMID:19651647

Homma, Ryota; Baker, Bradley J.; Jin, Lei; Garaschuk, Olga; Konnerth, Arthur; Cohen, Lawrence B.; Zecevic, Dejan



Quirks of dye nomenclature. 3. Trypan blue.  


Abstract Trypan blue is colorant from the 19(th) century that has an association with Africa as a chemotherapeutic agent against protozoan (Trypanosomal) infections, which cause sleeping sickness. The dye still is used for staining biopsies, living cells and organisms, and it also has been used as a colorant for textiles. PMID:24867494

Cooksey, Cj



Colloidal chitin stained with Remazol Brilliant Blue R®, a useful substrate to select chitinolytic microorganisms and to evaluate chitinases  

Microsoft Academic Search

A simple and sensitive method based on the use of colloidal chitin stained with Remazol Brilliant Blue R® (RBB) is proposed to evaluate chitinase activity. If this colloidal-stained substrate is included as a carbon source in a liquid medium, this technique allows the selection or the comparison of chitinolytic microorganisms. The colloidal substrate is proportionally solubilized and the dye released

M Gómez Ram??rez; L. I Rojas Avelizapa; N. G Rojas Avelizapa; R Cruz Camarillo



Detecting freeze injury and seasonal cold-hardening of cells and tissues in the gall fly larvae, Eurosta solidaginis (Diptera: Tephritidae) using fluorescent vital dyes.  


This study identified a hierarchy in levels of cold tolerance for diverse tissues from larvae of Eurosta solidaginis. Following freezing at -80 degrees C, larval survival and the viability of specific tissues were assessed using membrane-permeant DNA stain (SYBY-14) and propidium iodide. Integumentary muscle, hemocytes, tracheae, and the crystal-containing portion of the Malpighian tubules were most susceptible to freezing injury. A second group consisting of fat body, salivary glands, and the proximal region of the Malpighian tubules were intermediate in their susceptibility, while the foregut, midgut, and hindgut were the most resistant to freezing injury. Seasonal increases in larval cold tolerance were closely matched by changes in the cold tolerance of individual tissues. Compared to larvae collected in September, the survival rates for each of the six tissues tested from October-collected larvae increased by 20-30%. The survival rate in all tissues was notably higher than that of whole animals, indicating that larval death could not be explained by the mortality in any of the tissues we tested. This method will be useful for assessing the nature of chilling/freezing injury, the role cryoprotectants, and cellular changes promoting cold tolerance. PMID:14568577

Yi, Shu-Xia; Lee, Richard E



Spore Stain of Bacillus cereus  

NSDL National Science Digital Library

This strain of Bacillus cereus was isolated from a sample of gasoline-contaminated soil and cultured on blood agar. This picture allows students to see spores utilizing a simple, reliable method of staining.

American Society For Microbiology;



Sensing with fluorescent nanoparticles  

NASA Astrophysics Data System (ADS)

Fluorescent chemosensors are chemical systems that can detect and signal the presence of selected analytes through variations in their fluorescence emission. Their peculiar properties make them arguably one of the most useful tools that chemistry has provided to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In its simplest design, a fluorescent chemosensor is composed of a fluorescent dye and a receptor, with a built-in transduction mechanism that converts recognition events into variations of the emission properties of the fluorescent dye. As soon as fluorescent nanoparticles became available, several applications in the field of sensing were explored. Nanoparticles have been used not only as better-performing substitutes of traditional dyes but also as multivalent scaffolds for the realization of supramolecular assemblies, while their high surface to volume ratio allows for distinct spatial domains (bulk, external surface, pores and shells) to be functionalized to a comparable extent with different organic species. Over the last few years, nanoparticles proved to be versatile synthetic platforms for the implementation of new sensing schemes.

Baù, Luca; Tecilla, Paolo; Mancin, Fabrizio



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.  


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

Viehweger, Katrin; Barbaro, Lisa; García, Karina Pombo; Joshi, Tanmaya; Geipel, Gerhard; Steinbach, Jörg; Stephan, Holger; Spiccia, Leone; Graham, Bim



Under-air staining of the anterior capsule using Trypan blue with a 30 G needle  

PubMed Central

The original technique of staining the anterior capsule of the lens with Trypan blue involves the injection of an air bubble in the anterior chamber. A drawback of this technique is the possible instability of the anterior chamber caused by the sudden exit of air when the dye is injected with the cannula through the side-port incision. Other staining techniques that use viscoelastic substances to increase the stability of the anterior chamber and to dose the injected dye have been described. The authors present an under-air staining technique of the anterior capsule using one drop of Trypan blue injected with a 30 G needle through the peripheral cornea. This procedure prevents the air bubble from escaping the anterior chamber and allows fast and selective staining of the capsule. PMID:23386783

Giammaria, Daniele; Giannotti, Michele; Scopelliti, Angelo; Pellegrini, Giacomo; Giannotti, Bruno



A new panoptic stain for developmental biology--the mouse placenta paradigm.  


A panoptic histological stain, PHTA, is introduced for routine use in developmental biology. The protocol is based on three dyes, hematoxylin and, after tannic acid treatment, phloxine B and azure B. It was optimized for differential staining of extracellular matrix, cytoplasm and chromatin. The method is quick, inexpensive and well-reproducible. The mouse placenta is used here to demonstrate the excellent suitability of PHTA for routine morphology. PMID:11677809

Kurz, H; Wittekind, D



BODIPY Dyes In Photodynamic Therapy  

PubMed Central

BODIPY dyes tends to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with 3O2. In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas. PMID:23014776

Kamkaew, Anyanee; Lim, Siang Hui; Lee, Hong Boon; Kiew, Lik Voon; Chung, Lip Yong



The use of a caries detector dye in cavity preparation.  


The aim of this study was to compare the conventional visual and tactile method of detecting carious dentine during cavity preparation using a mirror, probe and excavator with a visual method enhanced by a dye. The dye, 1% acid red in propylene glycol, was used on 100 cavities prepared by dental students and passed as clinically satisfactory by their teachers. Results showed dye stain at the enamel-dentine junction in 57 cavities (57%) which had been assessed as caries-free in this area using conventional visual and tactile means. Subsequent laboratory work on extracted carious teeth confirmed histologically that the dye stains demineralised dentine. If clinicians consider it important to render the enamel-dentine junction caries-free, it might be prudent to use the dye as an aid to diagnosis in this area. PMID:2789871

Kidd, E A; Joyston-Bechal, S; Smith, M M; Allan, R; Howe, L; Smith, S R



Centromere and cytoplasmic staining pattern recognition: a local approach.  


Autoimmune diseases are very serious and also invalidating illnesses. The benchmark procedure for their diagnosis is the indirect immunofluorescence (IIF) assay performed on the HEp-2 substrate. Medical doctors first determine the fluorescence intensity exhibited by HEp-2 wells and then report the staining pattern. Despite its pivotal role, IIF is affected by inter- and intra-laboratory variabilities demanding for the development of computer-aided-diagnosis tools supporting medical doctor decisions. With reference to staining pattern recognition, state-of-the-art approaches recognize five main patterns characterized by well-defined cell edges. These approaches are based on cell segmentation, a task that recent work suggests to be harder than the classification itself. In this paper, we extend the panel of detectable HEp-2 staining patterns, introducing the recognition of centromere and cytoplasmic patterns, which have a high specific match with certain autoimmune diseases, from other stainings. Since image segmentation algorithms fail on these samples, we developed a classification system integrating local descriptors and the bag of visual word approach, which represents image contents without the burden of segmentation. We tested our approach on a large dataset of HEp-2 images with high variability in both fluorescence intensity and staining patterns correctly recognizing the 97.12 % of samples. The system has also been validated in a daily routine fashion on 108 consecutive IIF analyses of hospital outpatients and inpatients, achieving an accuracy rate of 97.22 %. PMID:23877232

Iannello, Giulio; Onofri, Leonardo; Soda, Paolo



Fluorescence properties of organic dyes: quantum chemical studies on the green/blue neutral and protonated DMA-DPH emitters in polymer matrices.  


The absorption and fluorescence spectra of the green emitter DMA-DPH {1-[4-(dimethylamino)phenyl]-6-phenylhexa-1,3,5-triene} and its protonated blue-emitter form have been studied theoretically through time-dependent density functional theory (TD-DFT) and resolution-of-identity 2nd order perturbative coupled cluster (RI-CC2) calculations with basis sets up to augmented triple-? quality, in the gas phase and in solvents of different polarity. These systems dispersed in a polymer matrix are of interest for applications in organic light emitting diode devices (OLEDs). Calculations show that the observed absorption and emission spectra correspond to transitions between the S(0) and S(1) states, in both systems. The nature and characteristics of these transitions are discussed. Excellent agreement with experimental data is obtained, both for absorption and emission, provided that the state-specific polarized continuum model (SS-PCM) method is employed for the inclusion of the solvent. PMID:22025129

Kerkines, Ioannis S K; Petsalakis, Ioannis D; Argitis, Panagiotis; Theodorakopoulos, Giannoula



Polypeptide micelles with dual pH activatable dyes for sensing cells and cancer imaging  

NASA Astrophysics Data System (ADS)

pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment.pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00519h

Gong, Ping; Yang, Yueting; Yi, Huqiang; Fang, Shengtao; Zhang, Pengfei; Sheng, Zonghai; Gao, Guanhui; Gao, Duyang; Cai, Lintao



Ultrasensitive fluorescence detection of DNA sequencing gels  

SciTech Connect

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.

Mathies, R.A.



Ultrafast tissue staining with chemical tags  

PubMed Central

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

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.



Lenticular mitoprotection. Part A: Monitoring mitochondrial depolarization with JC-1 and artifactual fluorescence by the glycogen synthase kinase-3? inhibitor, SB216763  

PubMed Central

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

Brooks, Morgan M.; Neelam, Sudha; Fudala, Rafal; Gryczynski, Ignacy



Dye laser amplifier  


An improved dye laser amplifier is disclosed. The efficiency of the dye lr amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant.

Moses, Edward I. (Livermore, CA)



Researchers Synthesize Brightest Fluorescent Particles Ever  

E-print Network

it flows to or tracking sources of air pollution. "You could spray these particles Original story at wwwResearchers Synthesize Brightest Fluorescent Particles Ever Fluorescent image of a physical mixture of fluorescent silica particles of different shapes with different dyes. Credit: Clarkson University Clarkson

Sokolov, Igor


Automated single-slide staining system  

NASA Technical Reports Server (NTRS)

Apparatus developed to Gram-stain single slides automatically is flexible enough to accommodate other types of staining procedures. Method frees operator and eliminates necessity for subjective evaluations as to length of staining or decolorizing time.

Mills, S. M.; Wilkins, J. R.



TSQ, a Common Fluorescent Sensor for Cellular Zinc, Images Zinc Proteins  

PubMed Central

Zn2+ is a necessary cofactor for thousands of mammalian proteins. Research has suggested that transient fluxes of cellular Zn2+ are also involved in processes such as apoptosis. Observations of Zn2+ trafficking have been collected using Zn2+ responsive fluorescent dyes. A commonly used Zn2+ fluorophore is TSQ. The chemical species responsible for TSQ's observed fluorescence in resting or activated cells have not been characterized. Parallel fluorescence microscopy and spectrofluorometry of LLC-PK1 cells incubated with TSQ demonstrated punctate staining that concentrated around the nucleus and was characterized by an emission maximum near 470 nm. Addition of cell permeable Zn-pyrithione resulted in greatly increased, diffuse fluorescence that shifted the emission peak to 490 nm, indicative of the formation of Zn(TSQ)2. TPEN, a cell permeant Zn2+ chelator, largely quenched TSQ fluorescence returning the residual fluorescence to the 470 nm emission maximum. Gel filtration chromatography of cell supernatant from LLC-PK1 cells treated with TSQ revealed that TSQ fluorescence (470 nm emission) eluted with the proteome fractions. Similarly, addition of TSQ to proteome prior to chromatography resulted in 470 nm fluorescence emission that was not observed in smaller molecular weight fractions. It is hypothesized that Zn-TSQ fluorescence, blue-shifted from the 490 nm emission maximum of Zn(TSQ)2, results from ternary complex, TSQ-Zn-protein formation. As an example, Zn-carbonic anhydrase formed a ternary adduct with TSQ characterized by a fluorescence emission maximum of 470 nm and a dissociation constant of 1.55 × 10-7 M. Quantification of TSQ-Zn-proteome fluorescence indicated that approximately 8% of cellular Zn2+ was imaged by TSQ. These results were generalized to other cell types and model Zn-proteins. PMID:21774459

Meeusen, Jeffrey W.; Tomasiewicz, Henry; Nowakowski, Andrew; Petering, David H.



New tetrachromic VOF stain (Type III-G.S) for normal and pathological fish tissues.  


A new VOF Type III-G.S stain was applied to histological sections of different organs and tissues of healthy and pathological larvae, juvenile and adult fish species (Solea senegalensis; Sparus aurata; Diplodus sargo; Pagrus auriga; Argyrosomus regius and Halobatrachus didactylus). In comparison to the original Gutiérrez VOF stain, more acid dyes of contrasting colours and polychromatic/metachromatic properties were incorporated as essential constituents of the tetrachromic VOF stain. This facilitates the selective staining of different basic tissues and improves the morphological analysis of histochemical approaches of the cell components. The VOF Type III -6.5 stain is composed of a mixture of several dyes of varying size and molecular weight (Orange Gstained. Muscle fibers, collagen, reticulin and elastin fibers, erythrocytes, cartilage, bone, mucous cells, oocytes and larvae were selectively stained and differentiated. Dyes with small size and molecular weight (i.e Orange G), penetrate all tissue structures rapidly, but are only tightly retained in densely textured tissues (i.e erythrocytes). Methyl Blue is an interesting triarylmethane dye (large size and molecular weight), which is incorporated in this new VOF tetrachrome stain, and acquires histochemical significance when used at acid pH (2.8) because collagen and reticulin fibers, as well basophilic and metachromatic substances (strongly ionized sulphated glycoconjugates) can be identified. Muscle tissues show an evident green colour (Fast Green or Light Green affinities), even those isolated and/or diffuse muscle fibers present in the digestive submucosa layer. Connective tissues showed a specific and strong blue colour (Methyl Blue affinity) or mixed blue-red staining (Methyl Blue and Acid Fucshin affinities). Very noticeable is the staining of the mucous cells, as well as the hyaline capsule of the viral lymphocystic cells, which were stained blue-purple (carboxylated and/or strongly ionized sulphated groups). Cartilaginous tissues showed a blue or purple (Methyl Blue affinity) staining, and a specific red colour (Acid Fucshin affinity) was evident during calcification or in b