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1

Characterization of six textile dyes as fluorescent stains for flow cytometry.  

PubMed

Few fluorescent stains specific for cell constituents other than DNA are available. To assess their potential use as fluorescent stains for flow cytometry, the cell staining specificity of 55 compounds, originally synthesized for use as textile dyes and fluorescent brighteners, was explored and their excitation and emission wavebands determined. From these, six dyes were chosen for more detailed analysis. All six are vital stains, with excitation wavelengths allowing their use with an argon ion laser, and specific for a range of cell structures including mitochondria, Golgi bodies, lipid droplets, nuclear membrane, and endoplasmic reticulum. Concentrations as low as 0.01-0.25 microM were found to be adequate for most purposes, and high background fluorescence was not a problem. Their specificity allows differentiation between non-cycling and cycling cells. The properties of two of the stains allows their combination with propidium iodide or ethidium bromide for simultaneous determination of DNA content profiles. Being vital stains, usable at very low concentrations, and specific for a range of cell organelles, these six stains may be of considerable utility in flow cytofluorometry. We suggest that other textile dyes may be of use in flow cytofluorometry, or that their structures may form a starting point for the synthesis of further fluorescent stains of enhanced specificity. PMID:1688448

Simmons, D M; Mercer, A V; Hallas, G; Dyson, J E

1990-01-01

2

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

PubMed

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

2013-10-01

3

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

2014-01-01

4

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

2013-01-01

5

Candida, fluorescent stain (image)  

MedlinePLUS

This microscopic film shows a fluorescent stain of Candida. Candida is a yeast (fungus) that causes mild disease, but in immunocompromised individuals it may cause life-threatening illness. (Image ...

6

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

7

Infrared fluorescence microscopy of stained tissues: Principles and technic  

Microsoft Academic Search

Infrared photomicrography was used extensively from 1927 to the 1940's, but received little attention during the last decades. However, studies of infrared fluorescence of stained sections could not be found in the accessible literature. Ramsley (1968) published quantitative data on infrared fluorescence of approximately 250 dyes bound to textile fibers. The intensity of infrared fluorescence of many dyes varied widely

Holde Puchtler; Susan N. Meloan; L. D. Paschal

1980-01-01

8

Assessment of FUN-1 vital dye staining: Yeast with a block in the vacuolar sorting pathway have impaired ability to form CIVS when stained with FUN-1 fluorescent dye.  

PubMed

FUN-1 [2-chloro-4-(2,3-dihydro-3-methyl-(benzo-1,3-thiazol-2-yl)-methylidene)-1-phenylquinolinium iodide] is a fluorescent dye used in studies of yeast and other fungi to monitor cell viability in the research lab and to assay for active fungal infection in the clinical setting. When the plasma membrane is intact, fungal cells internalize FUN-1 and the dye is seen as diffuse green cytosolic fluorescence. FUN-1 is then transported to the vacuole in metabolically active wild type cells and subsequently is compacted into fluorescent red cylindrical intravacuolar structures (CIVS) by an unknown transport pathway. This dye is used to determine yeast viability, as only live cells form CIVS. However, in live Saccharomyces cerevisiae with impaired protein sorting to the yeast vacuole, we report decreased to no CIVS formation, depending on the cellular location of the block in the sorting pathway. Cells with a block in vesicle-mediated transport from the Golgi to prevacuolar compartment (PVC) or with a block in recycling from the PVC to the Golgi demonstrate a substantial impairment in CIVS formation. Instead, the FUN-1 dye is seen either in small punctate structures under fluorescence or as diffuse red cytosol under white light. Thus, researchers using FUN-1 should be cognizant of the limitations of this procedure in determining cell viability as there are viable yeast mutants with impaired CIVS formation. PMID:19501122

Essary, Brandin D; Marshall, Pamela A

2009-08-01

9

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2012-04-01

10

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2013-04-01

11

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2014-04-01

12

Chromosome characterization using single fluorescent dye  

DOEpatents

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)

1995-01-01

13

Chromatin fluorescence after carmine staining.  

PubMed

After staining with dilute solutions (0.1 mg/ml in distilled water) of commercial carmine, a strong reddish orange fluorescence was observed in nuclei from cell smears and frozen and paraffin tissue sections. Optimal exciting light was 436 nm (violet-blue) or 450-490 nm (blue). Compact chromatin from interphase nuclei, mitotic and meiotic chromosomes and the kinetoplast of Trypanosoma cruzi showed the highest fluorescence, while the basophilic cytoplasm appeared weakly fluorescent. No emission was observed in cartilage matrix, mast cell granules or goblet cell mucin. This selective method could be valuable in microscopic and cytochemical studies on chromatin because the carmine fluorescence is stable and preparations can be dehydrated and mounted permanently without changes in the fluorescence pattern. PMID:2080525

Stockert, J C; Llorente, A R; Del Castillo, P; Gómez, A

1990-01-01

14

Phenolic acridine orange fluorescent stain for mycobacteria.  

PubMed Central

A new fluorescence acid-fast staining method with acridine orange as the specific stain is presented. Only two reagents are required: the acridine orange-specific stain and a destaining-counterstaining reagent. Compared with auramine fluorescence acid-fast staining, there was less nonspecific staining of non-acid-fast debris which fluoresced a pale green contrasting color to provide a background in which to search for the red-to-orange fluorescing acid-fast bacilli. The results of the study indicate that the acridine orange method is superior to the auramine method in detecting acid-fast bacilli in specimen smears. PMID:8567921

Smithwick, R W; Bigbie, M R; Ferguson, R B; Karlix, M A; Wallis, C K

1995-01-01

15

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.

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

1985-01-01

16

Dyes and stains: from molecular structure to histological application.  

PubMed

In the present review, the chemistry of dyes as well as the interaction mechanisms between tissue and dye has been detailed, and also some of the key factors affecting the selectivity of dyes by certain cellular structures have been mentioned. Moreover, due to the relevance that histological stains have acquired in biomedical research, some of the most common stains have been described, pointing out previous and current applications in basic and applied research. PMID:24389174

Veuthey, Tania; Herrera, Georgina; Dodero, Veronica I

2014-01-01

17

Visualization of mitotic chromosomes in filamentous fungi by fluorescence staining and fluorescence in situ hybridization  

Microsoft Academic Search

Mitotic chromosomes of the plant pathogenic filamentous fungi Botrytis cinerea and Alternaria alternata were observed. Chromosomes prepared by the germ tube burst method were stained with the fluorescent dye 4',6-diamidino-2-phenylindole (DAPI) to yield figures with good resolution. Using this method, component chromosomes were clearly distinguished and the chromosome number could be determined. Fluorescence in situ hybridization (FISH) was also successfully

Masatoki Taga; Minoru Murata

1994-01-01

18

Mercurochrome: a fluorescent and electron opaque dye.  

PubMed

Mercurochrome was applied to tissues and tissue sections in an attempt to examine structural components either in visible light, fluorescence or electron microscopy. Samples of bone marrow from rats were fixed in glutaraldehyde alone, embedded in Durcupan, and studied by using semi-thin and thin sections. After treatment with mercurochrome in acetone before embedding, the eosinophilic granules from leucocytes and chromatin masses showed electron opacity as well as a yellowish green fluorescence under excitation with violet-blue or blue light. An additional treatment of sections with an alkaline hydroalcoholic solution of the dye allowed to visualize these structures under bright-field illumination and to improve the contrast in the electron microscope. This method offers the possibility to examine specific cell components by using a compound which simultaneously possesses staining, fluorescence, and electron microscopic contrasting properties. PMID:6195509

Ferrer, J M; González Garrigues, M; Stockert, J C

1983-05-01

19

Fluorescence efficiency of four infrared polymethine dyes  

Microsoft Academic Search

We report on the fluorescence efficiency of four infrared (IR) polymethine dyes. These figures have been determined using an indirect method based on a fluorescence standard (Rhodamine B in ethanol). The fluorescence decay times have been measured too and their correlation with the quantum efficiency data has been shown. The optical behavior of the IR dyes in three solvents with

M. Casalboni; F. De Matteis; P. Prosposito; A. Quatela; F. Sarcinelli

2003-01-01

20

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

DOEpatents

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)

1996-01-01

21

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

Microsoft Academic Search

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

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

1977-01-01

22

The fluorescence of elastic fibres stained with Eosin and excited by visible light  

Microsoft Academic Search

Synopsis  Fluorescent light of any wavelength, emitted by a microscopical specimen excited with visible light, can be observed using crossed polarizers and a dark-field condenser. The absorbance of Eosin is high in the green portion of the spectrum, so that visible light from a tungsten lamp is highly effective in exciting the fluorescence of this dye.Elastic fibres in routine sections stained

D. J. Goldstein

1969-01-01

23

Visualization of mitotic chromosomes in filamentous fungi by fluorescence staining and fluorescence in situ hybridization.  

PubMed

Mitotic chromosomes of the plant pathogenic filamentous fungi Botrytis cinerea and Alternaria alternata were observed. Chromosomes prepared by the germ tube burst method were stained with the fluorescent dye 4',6-diamidino-2-phenylindole (DAPI) to yield figures with good resolution. Using this method, component chromosomes were clearly distinguished and the chromosome number could be determined. Fluorescence in situ hybridization (FISH) was also successfully applied to the specimens, revealing one ribosomal RNA gene cluster, or nucleolus organizer region (NOR) in the genome of each fungus. A long attenuated chromatid thread expanding from a condensed metaphase chromosome, which had been called a thread-like structure in B. cinerea, was proved to be an NOR. This is the first report of the successful application of FISH to the chromosomes of filamentous fungi. PMID:7859561

Taga, M; Murata, M

1994-10-01

24

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

2005-01-01

25

Use of Fluorescent Dyes for Readily Recognizing Sperm Damage  

PubMed Central

Sperm is produced by the testis and mature in the epididymis. For having a successful conception, the fertilizing sperm should have functional competent membranes, intact acrosome, functional mitochondria and an intact haploid genome. The effects of genetic and environmental factors result in sperm vulnerability to damage in the process of spermatogenesis and maturation. In recent years, the feasibility of detecting sperm damage is enhanced through the advances in technologies like fluoscerent staining techniques assisted with fluorescence microscope, flow cytometry and computer analysis systems. Fluoscerent staining techniques involve the use of fluorescent dyes, either directly or indirectly for binding them with some ingredients of sperm and evaluating the damage of the structure or function of the sperm, i.e. membrane, acrosome, mitochondria, chromosome or DNA. PMID:24163795

Farah, Omar Ibrahim; Cuiling, Li; Jiaojiao, Wang; Huiping, Zhang

2013-01-01

26

Psychosocial Stress of Patients with Port Wine Stains and Expectations of Dye Laser Treatment  

Microsoft Academic Search

Background: Port wine stains can be treated successfully with the dye laser in most cases. The indication for treatment is made on the basis of the emotional stress arising from the port wine stain. Studies of the extent of psychosocial stress to date have led to contradictory results. Objective: To address the question how many patients with port wine stain

M. Augustin; I. Zschocke; K. Wiek; M. Peschen; W. Vanscheidt

1998-01-01

27

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)

1986-01-01

28

FluoroMyelin™ Red is a bright, photostable and non-toxic fluorescent stain for live imaging of myelin  

PubMed Central

FluoroMyelin™ Red is a commercially available water-soluble fluorescent dye that has selectivity for myelin. This dye is marketed for the visualization of myelin in brain cryosections, though it is also used widely to stain myelin in chemically fixed tissue. Here we have investigated the suitability of FluoroMyelin™ Red as a vital stain for live imaging of myelin in myelinating co-cultures of Schwann cells and dorsal root ganglion neurons. We show that addition of FluoroMyelin™ Red to the culture medium results in selective staining of myelin sheaths, with an optimal staining time of 2 hours, and has no apparent adverse effect on the neurons, their axons, or the myelinating cells at the light microscopic level. The fluorescence is bright and photostable, permitting long-term time-lapse imaging. After rinsing the cultures with medium lacking FluoroMyelin™ Red, the dye diffuses out of the myelin with a half life of about 130 minutes resulting in negligible fluorescence remaining after 18–24 hours. In addition, the large Stokes shift exhibited by FluoroMyelin™ Red makes it possible to readily distinguish it from popular and widely used green and red fluorescent probes such as GFP and mCherry. Thus FluoroMyelin™ Red is a useful reagent for live fluorescence imaging studies on myelinated axons. PMID:22743799

Monsma, Paula C.; Brown, Anthony

2012-01-01

29

An ensemble and single-molecule fluorescence microscopy investigation of phase-separated monolayer films stained with Nile Red  

Microsoft Academic Search

Phase-separated Langmuir–Blodgett monolayer films prepared from mixtures of arachidic acid (C19H39COOH) and perfluorotetradecanoic acid (C13F27COOH) were stained via spin-casting with the polarity sensitive phenoxazine dye Nile Red, and characterized using a combination of ensemble and single-molecule fluorescence microscopy measurements. Ensemble fluorescence microscopy and spectromicroscopy showed that Nile Red preferentially associated with the hydrogenated domains of the phase-separated films, and was

Yin Lu; Robyn Porterfield; Terri Thunder; Matthew F. Paige

2011-01-01

30

Fluorescence microplate-based assay for tumor necrosis factor activity using SYTOX Green stain.  

PubMed

We have developed a simple, sensitive, fluorescence microplate-based assay for tumor necrosis factor (TNF) biological activity. The assay employs SYTOX Green nucleic acid stain to detect TNF-induced cell necrosis in actinomycin D sensitized cultured cell lines. SYTOX Green stain is a cationic unsymmetrical cyanine dye that is excluded from live cells but can readily penetrate cells with compromised cell membranes. Upon binding to cellular nucleic acids, the dye exhibits a large enhancement in fluorescence, which is monitored at fluorescein wavelengths. We detected 2.5 pg/mL and quantitated 25-500 pg/mL recombinant murine (rm) and recombinant human (rh) TNF-alpha, using mouse fibroblast-derived WEHI 164, WEHI 13var, and L929 cell lines. The procedure can also be used to detect agents that modulate TNF activity. We demonstrated complete inhibition of rhTNF-alpha using monoclonal anti-human TNF-alpha antibody and determined that approximately 20 ng/mL antibody was sufficient to neutralize 50% of the biological activity of 250 pg/mL rhTNF-alpha in these cell lines. Reagents are added in a single step, followed by a 6- to 8-h incubation period, during which the cytokine exhibits its effects. There are no wash steps, and the assay is readily amenable to automation and high-throughput screening procedures. PMID:11373072

Jones, L J; Singer, V L

2001-06-01

31

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

2008-04-01

32

Facile and eco-friendly synthesis of green fluorescent carbon nanodots for applications in bioimaging, patterning and staining.  

PubMed

We report a facile and eco-friendly strategy for the fabrication of green fluorescent carbon nanodots (CDs), and demonstrate their applications for bio-imaging, patterning, and staining. A one-pot hydrothermal method using various plant petals yields bright green-emitting CDs, providing an easy way for the production of green fluorescent CDs without the need for a tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. The as-prepared CDs show small size distribution and excellent dispersibility. Their strong green fluorescence is observed when the excitation wavelength is between 430 nm and 490 nm. Moreover, they exhibit high tolerance to various external conditions, such as pH values, external cations, and continuous excitation. Due to minimum toxicity as well as good photoluminescence properties, these CDs can be applied to in vitro and in vivo imaging, patterning, and staining. According to confocal fluorescence imaging of human uterine cervical squamous cell carcinoma cells, CDs penetrate into the cell and enter the cytoplasm and the nucleus. More strikingly, carp is directly fed with CDs for in vivo imaging and shows bright green fluorescence at an excitation wavelength of 470 nm. In addition, the obtained CDs are used as fluorescent inks for drawing luminescence patterns. Finally, we also apply the CDs as a fluorescent dye. Interestingly, the absorbent filter paper with staining emits dramatic fluorescence under 470 nm excitation. PMID:25826612

Shi, Lihong; Li, Yanyan; Li, Xiaofeng; Wen, Xiangping; Zhang, Guomei; Yang, Jun; Dong, Chuan; Shuang, Shaomin

2015-04-01

33

Uniform silica nanoparticles encapsulating two-photon absorbing fluorescent dye  

SciTech Connect

We have prepared uniform silica nanoparticles (NPs) doped with a two-photon absorbing zwitterionic hemicyanine dye by reverse microemulsion method. Obvious solvatochromism on the absorption spectra of dye-doped NPs indicates that solvents can partly penetrate into the silica matrix and then affect the ground and excited state of dye molecules. For dye-doped NP suspensions, both one-photon and two-photon excited fluorescence are much stronger and recorded at shorter wavelength compared to those of free dye solutions with comparative overall dye concentration. This behavior is possibly attributed to the restricted twisted intramolecular charge transfer (TICT), which reduces fluorescence quenching when dye molecules are trapped in the silica matrix. Images from two-photon laser scanning fluorescence microscopy demonstrate that the dye-doped silica NPs can be actively uptaken by Hela cells with low cytotoxicity. - Graphical abstract: Water-soluble silica NPs doped with a two-photon absorbing zwitterionic hemicyanine dye were prepared. They were found of enhanced one-photon and two-photon excited fluorescence compared to free dye solutions. Images from two-photon laser scanning fluorescence microscopy demonstrate that the dye-doped silica NPs can be actively uptaken by Hela cells.

Wu Weibing [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); School of Light-Industry Science and Engineering, Nanjing Forestry University, Nanjing 210037 (China); Liu Chang [Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China); Wang Mingliang, E-mail: wangmlchem@263.ne [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Huang Wei [Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China); Zhou Shengrui; Jiang Wei; Sun Yueming [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Cui Yiping; Xu Chunxinag [Advanced Photonics Center, School of Electronic Science and Engineering, Southeast University, Nanjing 210096 (China)

2009-04-15

34

Evaluation of a fluorescent lectin-based staining technique for some acidophilic mining bacteria  

SciTech Connect

A fluorescence-labeled wheat germ agglutinin staining technique was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite and soil particles in the samples did not interfere with the staining procedure.

Fife, D.J.; Bruhn, D.F.; Miller, K.S.; Stoner, D.L.

2000-05-01

35

Van Gieson's picrofuchsin. The staining mechanisms for collagen and cytoplasm, and an examination of the dye diffusion rate model of differential staining  

Microsoft Academic Search

The staining mechanism of van Gieson's picrofuchsin was studied by use of simple protein model systems and tissue sections, and by spectrophotometry and dialysis experiments. At the endpoint of the staining reaction (equilibrium) cytoplasm is yellow. Dye dilution experiments demonstrated that the highest affinity in the tissue section — picrofuchsin system is between binding sites in cytoplasmic protein and acid

Poul Prentø

1993-01-01

36

Some effects of salts on staining: Use of the Donnan Equilibrium to describe staining of tissue sections with acid and basic dyes  

Microsoft Academic Search

Summary  Using a wide variety of acid and basic dyes, and dyebaths of various pH’s and salt contents, it was shown that various effects\\u000a of neutral inorganic salts on the staining of tissue sections could be explained by the Donnan Membrane Equilibrium. Thus\\u000a the simultaneous increases in staining of some tissue components and decreases in staining of others, which occur on

P. J. Bennion; R. W. Horobin

1974-01-01

37

Novel fluorescent dyes for single DNA molecule techniques.  

PubMed

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

2013-01-01

38

Multianalyte microphysiometry reveals changes in cellular bioenergetics upon exposure to fluorescent dyes.  

PubMed

Fluorescent dyes have been designed for internal cellular component specificity and have been used extensively in the scientific community as a means to monitor cell growth, location, morphology, and viability. However, it is possible that the introduction of these dyes influences the basal function of the cell and, in turn, the results of these studies. Electrochemistry provides a noninvasive method for probing the unintended cellular affects of these dyes. The multianalyte microphysiometer (MAMP) is capable of simultaneous electrochemical measurement of extracellular metabolites in real-time. In this study, analytes central to cellular metabolism, glucose, lactate, oxygen, as well as extracellular acidification were monitored to determine the immediate metabolic effects of nuclear stains, including SYTO, DAPI dilactate, Hoechst 33342, and FITC dyes upon the pheochromocytoma PC-12 cells and RAW 264.7 macrophages. The experimental results revealed that the SYTO dye 13 significantly decreased glucose and oxygen consumption and increased extracellular acidification and lactate production in both cell lines, indicating a shift to anaerobic respiration. No other dyes caused significantly definitive changes in cellular metabolism upon exposure. This study shows that fluorescent dyes can have unintended effects on cellular metabolism and care should be taken when using these probes to investigate cellular function and morphology. PMID:24228839

Shinawi, Tesniem F; Kimmel, Danielle W; Cliffel, David E

2013-12-17

39

Pulsed dye laser therapy for port-wine stains in children: psychosocial and ethical issues.  

PubMed

The port-wine stain is a disfiguring vascular birthmark that commonly occurs on the face. Amelioration of this condition in children was difficult or impossible until the introduction of the flashlamp-pumped pulsed dye laser in the late 1980s. This article provides an interdisciplinary social and ethical examination of pulsed dye laser therapy for port-wine stain in childhood. Specific issues raised relate to the management of pain during therapy, rationale for care, expectations of treatment, the high costs of care, equity, marketing pressures, and therapeutic activism. Laser therapy in the dermatologic care of children is an exciting innovation that has transformed clinical practice and raised important social, ethical, and health policy issues. PMID:8463892

Strauss, R P; Resnick, S D

1993-04-01

40

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

2013-02-01

41

Improved detection of amyloid in fat pad aspiration: an evaluation of Congo red stain by fluorescent microscopy.  

PubMed

Amyloid fat pad aspiration specimens for cases with a clinical suspicion of amyloid typically are stained with Congo red and examined by brightfield microscopy. Congophilia with apple-green birefringence by polarization microscopy (PM) is considered diagnostic for amyloid. Examination of Congo red-stained slides by fluorescent microscopy (FM) is considered by some to be a more sensitive detection method. In this study, we assessed the utility of this technique in cytopathology archival slides from abdominal fat pad aspirations previously stained with Congo red dye. Seventy-eight cases of abdominal fat pad aspirations collected during the last 5 yr and stained with the Congo red procedure were obtained from archival files. Additionally, 20 adipose tissue material slides prepared from the surgical pathology specimens were examined as controls. One representative smear was examined in each case using FM equipped with rhodamine excitation/absorption (540/570 nm) filters. Relevant clinical information was obtained in all cases. Twelve cases (15.4%) of the 78 fat pad aspiration cases were reported originally as positive by Congo red stain using polarization and apple-green birefringence as diagnostic criteria. On review, four cases were deemed unsatisfactory. By FM examination 29 of the 74 (39.2%) cases were reclassified as positive for amyloid. The results were confirmed by immunohistochemical stain for amyloid P protein and electron microscopy. A number of similar distinct fluorescence and immunohistochemical patterns were recognized in the positive cases. Minimally weak fluorescence in the adipose tissue was observed in the control cases. The use of FM in Congo red-stained fat pad smears can improve the detection of amyloid in cytology preparations. PMID:15468138

Giorgadze, Tamar A; Shiina, Natsuko; Baloch, Zubair W; Tomaszewski, John E; Gupta, Prabodh K

2004-11-01

42

Blue Fluorescent Dye-Protein Complexes Based on Fluorogenic Cyanine Dyes and Single Chain Antibody Fragments  

PubMed Central

Fluoromodules are complexes formed upon the noncovalent binding of a fluorogenic dye to its cognate biomolecular partner, which significantly enhances the fluorescence quantum yield of the dye. Previously, several single-chain, variable fragment (scFv) antibodies were selected from a yeast cell surface-displayed library that activated fluorescence from a family of unsymmetrical cyanine dyes covering much of the visible and near-IR spectrum. The current work expands our repertoire of genetically encodable scFv-dye pairs by selecting and characterizing a group of scFvs that activate fluorogenic blue-absorbing, blue-fluorescing cyanine dyes, based on oxazole and thiazole heterocycles. The dye binds to both yeast cell surface-displayed and soluble scFvs with low nanomolar Kd values. These dye-protein fluoromodules exhibit high quantum yields, approaching unity for the brightest system. The promiscuity of these scFvs with other fluorogenic cyanine dyes was also examined. Fluorescence microscopy demonstrates that the yeast cell surface-displayed scFvs can be used for multicolor imaging. The prevalence of 405 nm lasers on confocal imaging and flow cytometry systems make these new reagents potentially valuable for cell biological studies. PMID:21180706

Zanotti, Kimberly J.; Silva, Gloria L.; Creeger, Yehuda; Robertson, Kelly L.; Waggoner, Alan S.; Berget, Peter B.; Armitage, Bruce A.

2011-01-01

43

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

2000-01-01

44

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

2014-01-01

45

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

PubMed Central

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

Grecchi, S.; Malatesta, M.

2014-01-01

46

Maximizing dye fluorescence via incorporation of metallic nanoparticles in solution  

NASA Astrophysics Data System (ADS)

Gram-negative bacteria initiate a stress response in which the cells efflux potassium when electrophilic toxins are introduced into their environment. Hence, measurement of K+ concentration in the surrounding water using a fluorescence-based potassium-selective optode has been proposed for environmental and homeland security applications. Unfortunately, the fluorophore commonly used in such an optode is inefficient. Surface enhanced fluorescence (SEF) can be used to increase its fluorescence efficiency, which will improve the sensor's performance. To understand this phenomenon before applying it to the optode system, Rose Bengal (RB), an inexpensive and well characterized dye, in solution with gold and silver nanoparticles was studied. As expected, fluorescence from RB-gold solutions was low since alignment of gold's surface plasmon resonance (SPR) peak and absorption and fluorescence energies in RB favored energy transfer from RB to the gold nanoparticles. The alignment of the silver's SPR peak and the RB transitions favored transfer from silver to RB. SEF was observed in solutions with large dye-to-silver separation. However, little fluorescence was observed when the solution was pumped at the silver's SPR peak. Fluorescence from the dye decreased as dye-to-silver separation decreased. An explanation for these observations is presented; additional research is needed to develop a complete understanding.

Xu, Yang; Lei, Guangyin; Booker, Annette C.; Linares, Katherine A.; Fleming, Dara L.; Meehan, Kathleen; Lu, Guo-Quan; Love, Nancy G.; Love, Brian J.

2004-12-01

47

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

DOEpatents

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)

1998-01-01

48

On the use of fluorescent dyes for concentration measurements in water flows  

Microsoft Academic Search

An experiment was performed to evaluate the characteristics of various fluorescent dyes used as tracers for concentration measurements in water flows, by laser induced fluorescence. Three common fluorescent dyes (fluorescein, rhodamine B and rhodamine 6G) were used, to select the most suitable fluorescent dye and identify its range of linear response. The results showed that, in terms of the stability

C. Arcoumanis; J. J. McGuirk; J. M. L. M. Palma

1990-01-01

49

Argon-pumped tunable dye laser for port-wine stains  

NASA Astrophysics Data System (ADS)

We have been using a continuous dye laser (coherent medical) for more than two years. The wavelength is 585 nm, the power 1.8 W and the fluence 16 - 18 J/cm2. We have treated 364 patients with port-wine stains and 15 children with ulcerated hemangiomas. The results were analyzed using a computer program developed by a team in Lille. The most frequent color was pale pink, followed by deep pink, red and purple. The mean number of laser sessions was 2.3.

Teillac-Hamel, Dominique; de Prost, Yves

1994-12-01

50

Nonlinear emission of quinolizinium-based dyes with application in fluorescence lifetime imaging.  

PubMed

Charged molecules based on the quinolizinum cation have potential applications as labels in fluorescence imaging in biological media under nonlinear excitation. A systematic study of the linear and nonlinear photophysics of derivatives of the quinolizinum cation substituted by either dimethylaniline or methoxyphenyl electron donors is performed. The effects of donor strength, conjugation length, and symmetry in the two-photon emission efficiency are analyzed in detail. The best performing nonlinear fluorophore, with two-photon absorption cross sections of 1140 GM and an emission quantum yield of 0.22, is characterized by a symmetric D-?-A(+)-?-D architecture based on the methoxyphenyl substituent. Application of this molecule as a fluorescent marker in optical microscopy of living cells revealed that, under favorable conditions, the fluorophore can be localized in the cytoplasmatic compartment of the cell, staining vesicular shape organelles. At higher dye concentrations and longer staining times, the fluorophore can also penetrate into the nucleus. The nonlinearly excited fluorescence lifetime imaging shows that the fluorophore lifetime is sensitive to its location in the different cell compartments. Using fluorescence lifetime microscopy, a multicolor map of the cell is drafted with a single dye. PMID:25135761

Marcelo, Gema; Pinto, Sandra; Cañeque, Tatiana; Mariz, Inês F A; Cuadro, Ana M; Vaquero, Juan J; Martinho, José M G; Maçôas, Ermelinda M S

2015-03-19

51

X-34, a fluorescent derivative of Congo red: a novel histochemical stain for Alzheimer's disease pathology.  

PubMed

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 intensely 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 staining. X-34 staining of NFTs correlated closely with anti-TAU antibody staining. A 1:1 correspondence of X-34 and anti-A beta antibody staining of plaques and cerebrovascular amyloid was observed. Both X-34 and thioflavin-S staining were eliminated by formic acid pretreatment, suggesting that beta-sheet secondary protein structure is a necessary determinant of staining. X-34 may be a general amyloid stain, like Congo red, because it also stains systemic amyloid deposits due to lambda-light chain monoclonal gammopathy. In conclusion, X-34 is a highly fluorescent marker for beta-sheet structures and intensely labels amyloid plaques, NFTs, neuropil threads, and vascular amyloid in AD brains. It can be used with both paraffin-embedded and frozen tissues as well as in combination with immunohistochemistry for double labeling. The intensity of staining and the simplicity and reproducibility of the technique suggest that it may be a useful addition to the standard techniques for evaluation of AD neuropathology. (J Histochem Cytochem 48:1223-1232, 2000) PMID:10950879

Styren, S D; Hamilton, R L; Styren, G C; Klunk, W E

2000-09-01

52

Fluorescence and confocal laser scanning microscopy imaging of elastic fibers in hematoxylin-eosin stained sections  

Microsoft Academic Search

We have studied the possibility of associating fluorescence microscopy and hematoxylin-eosin staining for the identification\\u000a of elastic fibers in elastin-rich tissues. Elastic fibers and elastic laminae were consistently identified by the proposed\\u000a procedure, which revealed it-self to be easy and useful for the determination of such structures and their distribution. The\\u000a fluorescence properties of stained elastic fibers are due to

Hernandes Faustino de Carvalho; Sebastião Roberto Taboga

1996-01-01

53

A berberine-aniline blue fluorescent staining procedure for suberin, lignin, and callose in plant tissue  

Microsoft Academic Search

Summary A fluorescent staining procedure to detect suberin, lignin and callose in plants has been developed. This procedure greatly improves on previous methods for visualizing Casparian bands in root exodermal and endodermal cells, and performs equally well on a variety of other plant tissues. Berberine was selected as the most suitable replacement forChelidonium majus root extract after comparing the staining

Mark C. Brundrett; Daryl E. Enstone; Carol A. Peterson

1988-01-01

54

Thioflavin S fluorescent and congo red anisotropic stainings in the histologic demonstration of amyloid  

Microsoft Academic Search

Two methods employed for the histological detection of amyloid, the recently developed Thioflavin S fluorescent microscopic procedure and the Congo red anisotropic staining were compared. It was observed that in senile alterations of the brain, heart, and pancreas and in secondary amyloidosis both methods demonstrate the same structures. Dichroism of Congo red stained structures was also studied and it was

G. Kelényi

1967-01-01

55

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)

2000-01-01

56

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

NASA Astrophysics Data System (ADS)

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

Bhattacharjee, Shubhadeep; Jose, Iven

2011-02-01

57

Electrowetting actuation of a dye-doped fluorescent droplet  

NASA Astrophysics Data System (ADS)

We report tunable color output from a fluorescent dye-doped droplet actuated by electrowetting. The system design, based on a planar electrowetting set-up, is compact and straightforward, with minimal voltage requirements for effective actuation. Fluorescent droplets are sourced from a 1 mM solution of rhodamine 6G in distilled water. Initial contact angle for a dye-doped droplet is 72.1°. At a maximum applied voltage of 20 V, the contact angle decreases to 56.5°. Emission spectra are collected as the droplet fluoresces under UV illumination. Over an electrowetting voltage range of 0 to 20 V, the peak fluorescence wavelength shifts from 568 to 546 nm.

Guerrero, Raphael A.; Mero, Rea Divina C.

2014-11-01

58

Tailor-made dyes for fluorescence correlation spectroscopy (FCS).  

PubMed

Two new fluorescent labels are presented that are optimized for excitation with He/Ne laser and red diode lasers. Application in FCS and labeling of proteins and oligomers are demonstrated. A strong rise of quantum yield and emission life time upon binding to biomolecules are characteristic features of the dyes. PMID:11347900

Czerney, P; Lehmann, F; Wenzel, M; Buschmann, V; Dietrich, A; Mohr, G J

2001-03-01

59

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.

1978-01-01

60

Disposable nitrate-selective optical sensor based on fluorescent dye  

Technology Transfer Automated Retrieval System (TEKTRAN)

A simple, disposable thin-film optical nitrate sensor was developed. The sensor was fabricated by applying a nitrate-selective polymer membrane on the surface of a thin polyester film. The membrane was composed of polyvinylchloride (PVC), plasticizer, fluorescent dye, and nitrate-selective ionophore...

61

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

62

Inhibition of beta-amyloid aggregation by fluorescent dye labels  

SciTech Connect

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

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

2014-02-10

63

Inhibition of beta-amyloid aggregation by fluorescent dye labels  

NASA Astrophysics Data System (ADS)

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

Amaro, Mariana; Wellbrock, Thorben; Birch, David J. S.; Rolinski, Olaf J.

2014-02-01

64

A comparison of the iodine and fluorescent antibody methods for staining trachoma inclusions in the conjunctiva*  

PubMed Central

In terms of the rate of positive diagnoses the indirect fluorescent antibody (FA) test was rather more effective than iodine for demonstrating trachoma (TRIC) inclusions in conjunctival scrapings, but the degree of advantage was not statistically significant. In duplicate scrapings stained at random by one or the other method, FA staining yielded the higher inclusion count significantly more often than did iodine. Some inclusions that failed to stain with FA were found on subsequent staining with Giemsa. A method is described for improving the post-FA Giemsa staining of conjunctival smears stored at subzero temperatures. Given adequate facilities, the FA stain is preferable to iodine for demonstrating TRIC inclusions in the conjunctiva; but the iodine method, properly used, holds advantages for field use. ImagesPlate 1Plate 1Plate 1Plate 1 PMID:4109203

Sowa, J.; Collier, L. H.; Sowa, Shiona

1971-01-01

65

Near-infrared fluorescence imaging of prostate cancer using heptamethine carbocyanine dyes  

PubMed Central

Near-infrared fluorescence (NIRF) imaging is an attractive novel modality for the detection of cancer. A previous study defined two organic polymethine cyanine dyes as ideal NIRF probes, IR-783 and its derivative MHI-148, which have excellent optical characteristics, superior biocompatibility and cancer targeting abilities. To investigate the feasibility of NIRF dye-mediated prostate cancer imaging, dye uptake and subcellular co-localization were investigated in PC-3, DU-145 and LNCaP human prostate cancer cells and RWPE-1 normal prostate epithelial cells. Different organic anion transporting peptide (OATP) inhibitors were utilized to explore the potential role of the OATP subtype, including the nonspecific OATP inhibitor bromosulfophthalein, the OATP1 inhibitor 17?-estradiol, the selective OATP1B1 inhibitor rifampicin and the selective OATP1B3 inhibitor cholecystokinin octapeptide. NIRF dyes were also used for the simulated detection of circulating tumor cells and the rapid detection of prostate cancer in human prostate cancer tissues and prostate cancer xenografts in mouse models. The results revealed that the cancer-specific uptake of these organic dyes in prostate cancer cells occurred primarily via OATP1B3. A strong NIRF signal was detected in prostate cancer tissues, but not in normal tissues that were stained with IR-783. Prostate cancer cells were recognized with particular NIR fluorescence in isolated mononuclear cell mixtures. The results of the present study demonstrated that NIRF dye-mediated imaging is a feasible and practicable method for prostate cancer detection, although further investigative studies are required before clinical translation. PMID:25354708

YUAN, JIANLIN; YI, XIAOMIN; YAN, FEI; WANG, FULI; QIN, WEIJUN; WU, GUOJUN; YANG, XIAOJIAN; SHAO, CHEN; CHUNG, LELAND W.K.

2015-01-01

66

IR-780 Dye for Near-Infrared Fluorescence Imaging in Prostate Cancer  

PubMed Central

Background The aim of this study was to investigate near-infrared fluorescence (NIRF) imaging as a novel imaging modality that allows for early detection of cancer and real-time monitoring to acquire related information. IR-780 iodide, a lipophilic dye, accumulates selectively in breast cancer cells and drug-resistant human lung cancer cells, with a peak emission at 780 nm that can be easily detected by the NIRF imaging system. The application of IR-780 for prostate cancer imaging was thoroughly investigated to further expand its clinical value. Material/Methods The impact of IR-780 on the survival of prostate cancer cells PC-3 and LNCaP as well as normal prostate epithelial cells RWPE-1 was determined. Duration of IR-780 dye staining was optimized in PC-3 cells. The involvement of specific OATP1B3 inhibitor in the selective accumulation of IR-780 was investigated. IR-780 for prostate cancer imaging was carried out in athymic nude mouse models and, acute toxicity of IR-780 was evaluated. Results IR-780 incubation resulted in a dose-dependent inhibition to cell proliferation. Mean fluorescence intensity of prostate cancer cells peaked at 20-min IR-780 incubation. Specific uptake of IR-780 dye in prostate cancer cells was mainly through the function of OATP1B3. We also demonstrated that NIRF dye effectively identified the subcutaneous prostate cancer xenografts, subsequently confirmed by histological examination. There was no significant impact on the physical activity, weight, and tissue histology of BABL/C mice with 10-fold imaging dose of 1-month IR-780 dye administration. Conclusions NIRF imaging using IR-780 dye is a feasible and practicable method for prostate cancer detection, with potential tumor-killing ability, although more investigations are needed before clinical translation. PMID:25686161

Yi, Xiaomin; Yan, Fei; Wang, Fuli; Qin, Weijun; Wu, Guojun; Yang, Xiaojian; Shao, Chen; Chung, Leland W.K.; Yuan, Jianlin

2015-01-01

67

A new type of two-color fluorescence staining for cytology specimens.  

PubMed

A new two-color fluorescence staining technique for cervical cytology specimens is described. To permit application of this staining in automated cytology, techniques for specimen collection and cell preparation giving a sufficient number of well-separated cells on slides were used. The staining consists of a combination of a modified Feulgen-acriflavine procedure for DNA and a primulin or stilbene isothiocyanate staining for protein. This results in a bright yellow nuclear fluorescence and a blue cytoplasmic fluorescence. The staining procedure can be completed in about 90 min and is therefore suitable for routine application. Sequential inspection of the yellow nuclear and blue cytoplasmic fluorescence can be done with the two-wavelength excitation method used in fluorescence microscopy. For the application of this method, special vertical illuminators are now available. These illuminators are provided with quickly interchangeable filter sets permitting consecutive visualization of, for example, only the nuclei in the first image and the whole cell in the second image. This procedure opens new possibilities for rapid image-analysis systems. PMID:56393

Cornelisse, C J; Ploem, J S

1976-01-01

68

Fluorescence properties of dye doped mesoporous silica  

SciTech Connect

In this paper we present a review of the main results we obtained studying the emission properties of organic-inorganic hybrids obtained combining mesoporous silica and Xantene dyes, in particular the standard reference Rhodamine 6G. The purpose of the review is to show the possibility to efficiently 'dope' the transparent inorganic porous matrix to obtain promising systems for photonic and biomedical applications. The strategies to solve the concentration effect and the leaching phenomenon are discussed within the framework of the single exciton theory.

Carbonaro, Carlo M., E-mail: cm.carbonaro@dsf.unica.it; Corpino, Riccardo, E-mail: cm.carbonaro@dsf.unica.it; Ricci, Pier Carlo, E-mail: cm.carbonaro@dsf.unica.it; Chiriu, Daniele, E-mail: cm.carbonaro@dsf.unica.it [Department of Physics, University of Cagliari, Campus of Monserrato, s.p. no 8, km 0.700, 09042 Monserrato (Italy); Cannas, Carla [Department of Chemical and Geological Sciences, University of Cagliari, Campus of Monserrato, s.p. no 8, km 0.700, 09042 Monserrato (Italy)

2014-10-21

69

Evaluation of Chemical Fluorescent Dyes as a Protein Conjugation Partner for Live Cell Imaging  

PubMed Central

To optimize live cell fluorescence imaging, the choice of fluorescent substrate is a critical factor. Although genetically encoded fluorescent proteins have been used widely, chemical fluorescent dyes are still useful when conjugated to proteins or ligands. However, little information is available for the suitability of different fluorescent dyes for live imaging. We here systematically analyzed the property of a number of commercial fluorescent dyes when conjugated with antigen-binding (Fab) fragments directed against specific histone modifications, in particular, phosphorylated H3S28 (H3S28ph) and acetylated H3K9 (H3K9ac). These Fab fragments were conjugated with a fluorescent dye and loaded into living HeLa cells. H3S28ph-specific Fab fragments were expected to be enriched in condensed chromosomes, as H3S28 is phosphorylated during mitosis. However, the degree of Fab fragment enrichment on mitotic chromosomes varied depending on the conjugated dye. In general, green fluorescent dyes showed higher enrichment, compared to red and far-red fluorescent dyes, even when dye?protein conjugation ratios were similar. These differences are partly explained by an altered affinity of Fab fragment after dye-conjugation; some dyes have less effect on the affinity, while others can affect it more. Moreover, red and far-red fluorescent dyes tended to form aggregates in the cytoplasm. Similar results were observed when H3K9ac-specific Fab fragments were used, suggesting that the properties of each dye affect different Fab fragments similarly. According to our analysis, conjugation with green fluorescent dyes, like Alexa Fluor 488 and Dylight 488, has the least effect on Fab affinity and is the best for live cell imaging, although these dyes are less photostable than red fluorescent dyes. When multicolor imaging is required, we recommend the following dye combinations for optimal results: Alexa Fluor 488 (green), Cy3 (red), and Cy5 or CF640 (far-red). PMID:25184362

Hayashi-Takanaka, Yoko; Stasevich, Timothy J.; Kurumizaka, Hitoshi; Nozaki, Naohito; Kimura, Hiroshi

2014-01-01

70

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

71

Fluorescent labeling of dendritic spines in cell cultures with the carbocyanine dye “DiI”  

PubMed Central

Analyzing cell morphology is a key component to understand neuronal function. Several staining techniques have been developed to facilitate the morphological analysis of neurons, including the use of fluorescent markers, such as DiI (1,1?-dioctadecyl-3,3,3?,3?-tetramethylindocarbocyanine perchlorate). DiI is a carbocyanine membrane dye that exhibits enhanced fluorescence upon insertion of its lipophilic hydrocarbon chains into the lipid membrane of cells. The high photostability and prominent fluorescence of the dye serves as an effective means of illuminating cellular architecture in individual neurons, including detailed dendritic arborizations and spines in cell culture and tissue sections. Here, we specifically optimized a simple and reliable method to fluorescently label and visualize dissociated hippocampal neurons using DiI and high-resolution confocal microscopic imaging. With high efficacy, this method accurately labels neuronal and synaptic morphology to permit quantitative analysis of dendritic spines. Accurate imaging techniques of these fine neuronal specializations are vital to the study of their morphology and can help delineate structure-function relationships in the central nervous system. PMID:24847216

Cheng, Connie; Trzcinski, Olivia; Doering, Laurie C.

2014-01-01

72

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

USGS Publications Warehouse

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

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

2006-01-01

73

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

2002-01-01

74

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

PubMed

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

Fröhlich, J; König, H

1999-03-01

75

Influence of selected fluorescent dyes on small aquatic organisms  

NASA Astrophysics Data System (ADS)

Rhodamine B and Rhodamine WT are fluorescent dyes commonly used as tracers in hydrological investigations. Since introducing intensely red substances into rivers raises understandable doubts of ecological nature, the authors aimed at examining the influence of these dyes on small water fauna using bioindication methods. Quantitative results, calculated with the use of Bliss-Weber probit statistical method, were achieved by means of standardized ecotoxicological tests containing ready-to-hatch resting forms of fairy shrimp ( Thamnocephalus platyurus). Qualitative studies included observation of water flea crustacean ( Daphnia magna) and horned planorbis snail ( Planorbis corneus), both typically present in rivers and representative for temperate climate, as well as guppy fish ( Poecilla reticulata), paramecium protozoan ( Paramaecium caudatum) and the above-mentioned fairy shrimp. The investigation revealed that both dyes in concentrations used for hydrological purposes are low enough to exert almost no toxic impact on water fauna considered.

Rowi?ski, Pawe? M.; Chrzanowski, Marcin M.

2011-02-01

76

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

2009-01-01

77

Coupled oscillators for tuning fluorescence properties of squaraine dyes.  

PubMed

Combining a squaraine (S) and a BODIPY (B) chromophore in a heterodimer (SB) and two heterotrimers (BSB and SBS) by alkyne bridges leads to the formation of coupled oscillators whose fluorescence properties are superior compared to the parent squaraine chromophore. The lowest energy absorption and emission properties of these superchromophores are mainly governed by the squaraine part and are shifted by more than 1000 cm(-1) to the red by excitonic interaction between the squaraine and the BODIPY dye. Employing polarization-dependent transient absorption and fluorescence upconversion measurements, we could prove that the lowest energy absorption in SB and BSB is caused by a single excitonic state but by two for SBS. Despite the spectral red-shift of their lowest absorption band, the fluorescence quantum yields increase for SB and BSB compared to the parent squaraine chromophore SQA. This is caused by intensity borrowing from the BODIPY states, which increases the squared transition moments of the lowest energy band dramatically by 29% for SB and 63% for BSB compared to SQA. Thereby, exciton coupling leads to a substantial enhancement of fluorescence quantum yield by 26% for SB and by 46% for BSB and shifts the emission from the red into the near-infrared. In this way, the BODIPY-squaraine conjugates combine the best properties of each class of dye. Thus, exciton coupling in heterodimers and -trimers is a valuable alternative to tuning fluorescence properties by, e.g., attaching substituents to chromophores. PMID:25738517

Lambert, Christoph; Scherpf, Thorsten; Ceymann, Harald; Schmiedel, Alexander; Holzapfel, Marco

2015-03-18

78

Sensitized Fluorescence of Dichroic Dye in Emissive Type Liquid Crystal Displays  

Microsoft Academic Search

Sensitization effects in a fluorescent nematic liquid crystal display (LCD) have been studied using a fluorescent dichroic dye or a fluorescent liquid crystal as a sensitizer. The sensitized fluorescence intensity can be increased by ten times and a dichroic ratio of the fluorescence is also increased. Moreover, the sensitized fluorescence intensity is controlled by applying the voltage across the cell.

Rumiko Yamaguchi; Hidekazu Nagato; Hasurul Hafiz; Susumu Sato

2004-01-01

79

Fluorescence lifetime imaging with near-infrared dyes  

NASA Astrophysics Data System (ADS)

Near-infrared (NIR) dyes are used as fluorescence markers in small-animal imaging and in diffuse optical tomography of the human brain. In these applications it is important to know whether the dyes bind to proteins or other tissue constituents, and whether their fluorescence lifetimes depend on the targets they are bound to. Unfortunately, neither the lasers nor the detectors of commonly used confocal and multiphoton laser scanning microscopes allow for excitation and detection of NIR fluorescence. We therefore upgraded existing confocal TCSPC FLIM systems with NIR lasers and NIR sensitive detectors. In multiphoton systems we used the Ti:Sa laser as a one-photon excitation source in combination with an NIR-sensitive detector in the confocal beam path. We tested a number of NIR dyes in biological tissue. Some of them showed clear lifetime changes depending on the tissue structures they are bound to. We therefore believe that NIR FLIM can deliver supplementary information on the tissue constitution and on local biochemical parameters.

Becker, Wolfgang; Shcheslavskiy, Vladislav

2013-02-01

80

Sensitive Immunofluorescent Staining of Cells via Generation of Fluorescent Nanoscale Polymer Films in Response to Biorecognition  

PubMed Central

Immunofluorescent staining is central to nearly all cell-based research, yet only a few fluorescent signal amplification approaches for cell staining exist, each with distinct limitations. Here, the authors present a novel, fluorescent polymerization-based amplification (FPBA) method that is shown to enable similar signal intensities as the highly sensitive, enzyme-based tyramide signal amplification (TSA) approach. Being non-enzymatic, FPBA is not expected to suffer from nonspecific staining of endogenous enzymes, as occurs with enzyme-based approaches. FPBA employs probes labeled with photopolymerization initiators, which lead to the controlled formation of fluorescent polymer films only at targeted biorecognition sites. Nuclear pore complex proteins (NPCs; in membranes), vimentin (in filaments), and von Willebrand factor (in granules) were all successfully immunostained by FPBA. Also, FPBA was demonstrated to be capable of multicolor immunostaining of multiple antigens. To assess relative sensitivity, decreasing concentrations of anti-NPC antibody were used, indicating that both FPBA and TSA stained NPC down to a 1:100,000 dilution. Nonspecific, cytoplasmic signal resulting from NPC staining was found to be reduced up to 5.5-fold in FPBA as compared to TSA, demonstrating better signal localization with FPBA. FPBA’s unique approach affords a combination of preferred attributes, including high sensitivity and specificity not otherwise available with current techniques. PMID:21339175

Avens, Heather J.; Berron, Brad J.; May, Allison M.; Voigt, Katerina R.; Seedorf, Gregory J.; Balasubramaniam, Vivek; Bowman, Christopher N.

2011-01-01

81

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

PubMed Central

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

Jahanshahi, Gholamreza; Shirani, Samaneh

2015-01-01

82

Different effects of 33258 Hoechst and DAPI in fluorescent staining of sister chromatids differentially substituted with bromodeoxyuridine  

Microsoft Academic Search

After substitution with 5-bromodeoxyuridine (BrdUrd) for two rounds of replication, chromosomes in cytological preparations stained with 33258 Hoechst show upon epiluminescence an immediate differential sister chromatid fluorescence. When stained with DAPI, however, which has a structural resemblance to part of the 33258 Hoechst molecule, such a differential pattern of fluorescence was only induced after some delay. Upon restaining with the

C. H. C. M. Buys; A. Y. van der Veen

1982-01-01

83

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

PubMed Central

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

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

2014-01-01

84

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

2005-01-01

85

Coomassie blue as a near-infrared fluorescent stain: a systematic comparison with Sypro Ruby for in-gel protein detection.  

PubMed

Quantitative proteome analyses suggest that the well-established stain colloidal Coomassie Blue, when used as an infrared dye, may provide sensitive, post-electrophoretic in-gel protein detection that can rival even Sypro Ruby. Considering the central role of two-dimensional gel electrophoresis in top-down proteomic analyses, a more cost effective alternative such as Coomassie Blue could prove an important tool in ongoing refinements of this important analytical technique. To date, no systematic characterization of Coomassie Blue infrared fluorescence detection relative to detection with SR has been reported. Here, seven commercial Coomassie stain reagents and seven stain formulations described in the literature were systematically compared. The selectivity, threshold sensitivity, inter-protein variability, and linear-dynamic range of Coomassie Blue infrared fluorescence detection were assessed in parallel with Sypro Ruby. Notably, several of the Coomassie stain formulations provided infrared fluorescence detection sensitivity to <1 ng of protein in-gel, slightly exceeding the performance of Sypro Ruby. The linear dynamic range of Coomassie Blue infrared fluorescence detection was found to significantly exceed that of Sypro Ruby. However, in two-dimensional gel analyses, because of a blunted fluorescence response, Sypro Ruby was able to detect a few additional protein spots, amounting to 0.6% of the detected proteome. Thus, although both detection methods have their advantages and disadvantages, differences between the two appear to be small. Coomassie Blue infrared fluorescence detection is thus a viable alternative for gel-based proteomics, offering detection comparable to Sypro Ruby, and more reliable quantitative assessments, but at a fraction of the cost. PMID:24043422

Butt, R Hussain; Coorssen, Jens R

2013-12-01

86

Fluorescence intensity changes associated with contractile activation in frog muscle stained with Nile Blue A.  

PubMed

1. Extrinsic fluorescence intensity changes were studied in frog semitendinosus muscles stained with Nile Blue A in response to electrical stimulation. Muscles were stretched and put into hypertonic solutions to prevent movement. The muscles were illuminated at 90 degrees to their long axis with a narrow beam of light at a central wave-length of 6250 . Fluorescence emission was measured at 90 degrees to the exciting light using a filter which absorbed light of wave-lengths shorter than 6400 . 2. In response to a single stimulus the fluorescence intensity increases briefly. The fluorescence response is propagated at a constant velocity of about 1.5 m/sec. The average ratio of the maximum fluorescence intensity change to the resting fluorescence is 4.5 times 10-3 for supramaximal shocks. The fluorescence intensity change starts early in the falling phase of the action potential. 3. The fluorescence intensity change increases when nitrate replaces chloride and decreases when D2O replaces H2O. The rates of rise and fall of the fluorescence change was unaffected by nitrate replacement of chloride but are slowed where D2O replaces H2O. The rates of rise and fall of the fluorescence change increase with increasing temperature for all solutions used. The peak fluorescence intensity change, however, goes through a maximum at about 17 degrees C for aqueous chloride and nitrate solutions in the range of 10-25 degrees C. With D2O solutions, the peak fluorescence intensity increases monotonically in this range of temperatures. 4. The fluorescence intensity change in response to trains of action potentials are not additive. 5. Depolarization of muscles treated with tetrodotoxin using triangular-shaped fluid electrodes produces an increase in fluorescence at about the same threshold values required to elicit tension in preparations that are not fully stretched. The fluorescence intensity change precedes in time tension development. Near threshold depolarizations, the delay in onset of the fluorescence response can be 80 msec or longer. Byond threshold, delays become shorter and peak responses larger. During maintained depolarization, after the peak response, fluorescence declines to a plateau value. 6. The results suggest that the fluorescence intensity changes are associated with excitation-contraction coupling, possibly with changes in the transmembrane potential of the sarcoplasmic reticulum. PMID:1079536

Bezanilla, F; Horowicz, P

1975-04-01

87

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

PubMed

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

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

2014-09-01

88

Organic fluorescent thermometers based on borylated arylisoquinoline dyes.  

PubMed

Borylated arylisoquinolines with redshifted internal charge-transfer (ICT) emission were prepared and characterized. Upon heating, significant fluorescence quenching was observed, which forms the basis for a molecular thermometer. In the investigated temperature range (283-323?K) an average sensitivity of -1.2 to -1.8%?K(-1) was found for the variations in fluorescence quantum yield and lifetime. In the physiological temperature window (298-318?K) the average sensitivity even reaches values of up to -2.4%?K(-1). The thermometer function is interpreted as the interplay between excited ICT states of different geometry. In addition, the formation of an intramolecular Lewis pair can be followed by (11)B?NMR spectroscopy. This provides a handle to monitor temperature-dependent ground-state geometry changes of the dyes. The role of steric hindrance is addressed by the inclusion of a derivative that lacks the Lewis pair formation. PMID:24861774

Pais, Vânia F; Lassaletta, José M; Fernández, Rosario; El-Sheshtawy, Hamdy S; Ros, Abel; Pischel, Uwe

2014-06-16

89

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

E-print Network

become a reference for in vivo staining of the whole astrocytes population in animal modelsSpecific In Vivo Staining of Astrocytes in the Whole Brain after Intravenous Injection or electroencephalographic recordings in vivo. The high contrast of the staining facilitates the image processing and allows

Paris-Sud XI, Université de

90

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

2013-01-01

91

Squaraine-Derived Rotaxanes: Highly Stable, Fluorescent Near-IR Dyes  

Microsoft Academic Search

Squaraines are fluorescent, near-IR dyes with promising photo- physical properties for biomedical ap- plications. A limitation with these dyes is their inherent reactivity with nucleo- philes, which leads to loss of the chro- mophore. Another drawback is their tendency to form nonfluorescent aggre- gates in water. Both problems can be greatly attenuated by encapsulating the dye inside an amide-containing macro-

Easwaran Arunkumar; Na Fu; Bradley D. Smith

2006-01-01

92

Combined photoacoustic and fluorescent quenching studies on organic dyes  

NASA Astrophysics Data System (ADS)

The development of deconvolution techniques in pulsed-laser, time-resolved photoacoustics has opened the possibility of accurately distinguishing between processes occurring on different time scales, and has given photoacoustics better resolution in determining reaction enthalpies and quantum yields. While fluorescent signals are usually generated by a single de- excitation pathway in the fluorophore, photoacoustic signals usually arise from different sources, such as excited singlet and triplet deactivation, occurring on well-distinguished time scales. The understanding of the effect of quenching on photoacoustic signals therefore requires careful analysis of the data. In this work, a model is developed to describe the effect of fluorescence quenching on photoacoustic signals. The model takes advantage of the time resolution in pulsed-laser photoacoustics. Both static and dynamic quenching are taken into account. Important photophysical parameters (fluorescence and intersystem crossing quantum yields, the bimolecular quenching rate constant, and the volume of the sphere of action) appear in the expressions describing the dependence of photoacoustic signal on quencher concentration. Data from both steady-state fluorescence and time-resolved photoacoustic quenching measurements are analyzed simultaneously using a set of equations containing common parameters. Experimental data on the quenching of organic dyes are presented which support the validity of the model.

Viappiani, Cristiano; Small, Jeanne R.

1992-04-01

93

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

E-print Network

Aerial Imaging of Fluorescent Dye in the Near Shore DAVID B. CLARK Woods Hole Oceanographic) ABSTRACT Aerial images are used to quantify the concentration of fluorescent Rhodamine water tracing (WT of upwelling radiance near the Rhodamine WT excitation and emission peaks varies linearly with the in situ dye

Boss, Emmanuel S.

94

Design and synthesis of polymer-functionalized NIR fluorescent dyes--magnetic nanoparticles for bioimaging.  

PubMed

The fluorescent probes having complete spectral separation between absorption and emission spectra (large Stokes shift) are highly useful for solar concentrators and bioimaging. In bioimaging application, NIR fluorescent dyes have a greater advantage in tissue penetration depth compared to visible-emitting organic dyes or inorganic quantum dots. Here we report the design, synthesis, and characterization of an amphiphilic polymer, poly(isobutylene-alt-maleic anhyride)-functionalized near-infrared (NIR) IR-820 dye and its conjugates with iron oxide (Fe3O4) magnetic nanoparticles (MNPs) for optical and magnetic resonance (MR) imaging. Our results demonstrate that the Stokes shift of unmodified dye can be tuned (from ~106 to 208 nm) by the functionalization of the dye with polymer and MNPs. The fabrication of bimodal probes involves (i) the synthesis of NIR fluorescent dye (IR-820 cyanine) functionalized with ethylenediamine linker in high yield, >90%, (ii) polymer conjugation to the functionalized NIR fluorescent dye, and (iii) grafting the polymer-conjugated dyes on iron oxide MNPs. The resulting uniform, small-sized (ca. 6 nm) NIR fluorescent dye-magnetic hybrid nanoparticles (NPs) exhibit a wider emissive range (800-1000 nm) and minimal cytotoxicity. Our preliminary studies demonstrate the potential utility of these NPs in bioimaging by means of direct labeling of cancerous HeLa cells via NIR fluorescence microscopy and good negative contrast enhancement in T2-weighted MR imaging of a murine model. PMID:23869722

Yen, Swee Kuan; Ja?czewski, Dominik; Lakshmi, Jeeva Lavanya; Dolmanan, Surani Bin; Tripathy, Sudhiranjan; Ho, Vincent H B; Vijayaragavan, Vimalan; Hariharan, Anushya; Padmanabhan, Parasuraman; Bhakoo, Kishore K; Sudhaharan, Thankiah; Ahmed, Sohail; Zhang, Yong; Tamil Selvan, Subramanian

2013-08-27

95

Defining a Polymethine Dye for Fluorescence Anisotropy Applications in the Near-Infrared Spectral Range  

PubMed Central

Fluorescence anisotropy in the near-infrared (NIR) spectral range is challenging because of the lack of appropriate NIR fluorescent labels. We have evaluated polymethine fluorescent dyes to identify a leading candidate for NIR anisotropy applications. The NIR dye LS601 demonstrated low fluorescence anisotropy values (r) as a result of its relatively long fluorescent lifetime 1.3 ns. The r value of LS601 unbound and coupled to biological macromolecules was found to have a sufficient dynamic range from 0.24 to 0.37, demonstrating the feasibility of fluorescence anisotropy in the NIR. The viability of fluorescence anisotropy using a NIR label was demonstrated by characterization of dye-protein conjugates. These results open the door to a number of applications in drug discovery, fluorescence anisotropy imaging and contrast agent development. PMID:22302715

Gustafson, Tiffany P.; Cao, Qian; Achilefu, Samuel

2014-01-01

96

Hollow mesoporous silica nanoparticles for intracellular delivery of fluorescent dye  

PubMed Central

In this study, hollow mesoporous silica nanoparticles (HMSNs) were synthesized using the sol-gel/emulsion approach and its potential application in drug delivery was assessed. The HMSNs were characterized, by transmission electron microscopy (TEM), Scanning Electron Microscopy (SEM), nitrogen adsorption/desorption and Brunauer-Emmett-Teller (BET), to have a mesoporous layer on its surface, with an average pore diameter of about 2 nm and a surface area of 880 m2/g. Fluorescein isothiocyanate (FITC) loaded into these HMSNs was used as a model platform to assess its efficacy as a drug delivery tool. Its release kinetic study revealed a sequential release of FITC from the HMSNs for over a period of one week when soaked in inorganic solution, while a burst release kinetic of the dye was observed just within a few hours of soaking in organic solution. These FITC-loaded HMSNs was also found capable to be internalized by live human cervical cancer cells (HeLa), wherein it was quickly released into the cytoplasm within a short period of time after intracellular uptake. We envision that these HMSNs, with large pores and high efficacy to adsorb chemicals such as the fluorescent dye FITC, could serve as a delivery vehicle for controlled release of chemicals administered into live cells, opening potential to a diverse range of applications including drug storage and release as well as metabolic manipulation of cells. PMID:21208421

2011-01-01

97

An automated cell-counting algorithm for fluorescently-stained cells in migration assays  

PubMed Central

A cell-counting algorithm, developed in Matlab®, was created to efficiently count migrated fluorescently-stained cells on membranes from migration assays. At each concentration of cells used (10,000, and 100,000 cells), images were acquired at 2.5 ×, 5 ×, and 10 × objective magnifications. Automated cell counts strongly correlated to manual counts (r2 = 0.99, P < 0.0001 for a total of 47 images), with no difference in the measurements between methods under all conditions. We conclude that our automated method is accurate, more efficient, and void of variability and potential observer bias normally associated with manual counting. PMID:22011343

2011-01-01

98

Medium effects of fluorescence quantum yields and lifetimes for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

Fluorescence quantum yields and lifetimes for a series of aminocoumarin laser dyes have been measured. The characteristics red shift of fluorescence in polar solvents is accompanied by a marked decrease in emission yield and lifetime for coumarins in which the substituted amine group at the 7 position is free to rotate. Strong emission is maintained in structurally rigid dyes. The non-radiative decay rates for non-rigid dyes which increase in polar solvents are associated with relaxation of emissive planar dye conformations to twisted zwitterionic species.

Jones, G., II; Jackson, W. R.; Halpern, A. M.

1980-01-01

99

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 José; López-Barneo, José; Villadiego, Javier

2013-01-01

100

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

NASA Astrophysics Data System (ADS)

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.; Eltokhy, A.; Harith, M. A.

2011-09-01

101

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)

2011-09-22

102

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

2010-02-01

103

Coherent amplification in fluorescent dye solutions. I. The fluorescence gain spectrum of cresyl violet  

NASA Astrophysics Data System (ADS)

The gain spectrum of cresyl violet has been recorded over the wavelength range 590-650 nm using a synchronously-pumped mode-locked dye laser system. The measured gain spectrum is compared with that calculated using data derived from a conventional absorption spectrum. The value of the polarization techniques developed for measuring orientational and state lifetimes of dye molecules is demonstrated. By locating the probe laser in the spectral region associated with absorption or emission it is shown that it is possible to derive information on the ground or excited electronic states. Fluorescence lifetimes and orientational decay times for cresyl violet in methanol and ethanol are determined for the states S 0 and S 1.

Baran, Jan; Langley, Andrew J.; Jeremy Jones, W.

1984-06-01

104

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

PubMed Central

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 these worms. Deparaffinised rehydrated tissue slides prepared from the pulmonary nodules were stained for one minute in 1% w/v aqueous solutions of TCBS-X or CFW, counterstained, coverslipped, and viewed with a fluorescent microscope. RESULTS--The stains demonstrated the intact worm and worm fragments in 20 cases of pulmonary dirofilariasis collected from hospitals in Houston. The filariae and fragments of filariae stained bright green while the background tissue stained red, delineating the internal structures of the worm. CONCLUSIONS--Dirofilariasis should be included in the differential diagnosis of subpleural masses, and non-specific fluorescent whitening stains can help in the rapid recognition of the fragmented organism in cytological or surgical material. Images PMID:7517073

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

1994-01-01

105

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.

2014-08-01

106

Cytofluorometric Detection of Rodent Malaria Parasites Using Red-Excited Fluorescent Dyes  

PubMed Central

Flow cytometry is a potentially efficient approach for the quantification of parasitemias in experimental malaria infections and drug susceptibility assays using rodent malaria models such as Plasmodium berghei. In this study, we used two red DNA-binding fluorochromes, rhodamine 800 (R800) and LD700, to measure parasitemia levels in whole blood samples from mice infected with P. berghei. Blood samples were treated with RNAse A to eliminate RNA-derived signals. Propidium iodide, which stains both DNA and RNA, was used as a positive control. The parasitemia levels determined by R800 and LD700 were comparable to those calculated by microscopic analysis of blood smears and flow cytometry using Hoechst 33258. RNAse treatment did not affect these measurements. We also used R800 or LD700 to quantify parasitemias in mice infected with a GFP-expressing P. berghei line to correlate the parasitemia levels determined by DNA staining versus parasite numbers using GFP fluorescence as a surrogate measurement. A positive correlation was found between levels determined by flow cytometry using these dyes and those measured by GFP expression. Similar results were obtained when parasitemias determined by flow cytometry were compared to those determined by conventional microscopy. The limit of detection of infected red blood cells using R800 or LD700 staining was 0.1% and 0.15%, respectively. This study demonstrates that red laser-based flow cytometry using R800 or LD700 can be used for effective quantification of parasitemia levels in Plasmodium infected red blood cells. Furthermore, this method has the advantage that it does not require RNAse pretreatment and allows for a greater amount of cells to be analyzed for parasite burden than otherwise measured by conventional microscopy. PMID:22015734

Gerena, Y.; Gonzalez-Pons, M.; Serrano, A. E.

2011-01-01

107

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

PubMed Central

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

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

2011-01-01

108

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.

2014-04-01

109

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

PubMed

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. PMID:25309455

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

2014-01-01

110

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. PMID:25309455

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

2014-01-01

111

Method and apparatus for staining immobilized nucleic acids  

SciTech Connect

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

Ramsey, J.M.; Foote, R.S.; Jacobson, S.C.

2000-05-02

112

Method and apparatus for staining immobilized nucleic acids  

DOEpatents

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

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

2000-01-01

113

Medium effects on fluorescence quantum yields and lifetimes for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

Fluorescence quantum yields and lifetimes of coumarin dyes are sharply reduced in polar solvents if amine substituent groups are free to rotate. The polar solvent effect is interpreted in terms of relaxation of excited dye from an initial planar conformation to a twisted zwitterionic state.

Jones, Guilford, II; Jackson, William R.; Halpern, Arthur M.

1980-06-01

114

Ultralow detection limits for an organic dye determined by fluorescence spectroscopy with laser diode excitation  

SciTech Connect

Fluorescence of IR-140, a laser dye in methanol solution, is excited by a semiconductor laser diode. Analytical figures of merit are compared for three different instrumental configurations, with the dye measured in a cuvette, a liquid jet, and a compact instrument. The best limit of detection, 46,000 molecules, was achieved with a liquid jet. Linear dynamic range was 6 orders of magnitude. The laser diode operates in the near-infrared region, resulting in low background fluorescence.

Johnson, P.A.; Barber, T.E.; Smith, B.W.; Winefordner, J.D. (Univ. of Florida, Gainesville (USA))

1989-04-15

115

Intercalating Fluorescence Dye YOYO-1 Prevents the Folding Transition in Giant Duplex DNA  

Microsoft Academic Search

Recently, it has become clear that with the addition of polyamines, giant DNA molecules of size greater than 10 kbp exhibit all-or-none switching between elongated coil and folded compact states. Here the effects of the intercalating fluorescent labeling dye, YOYO-1, and the minor-groove binding fluorescent labeling dye, DAPI, on the folding transition of single giant T4 DNA (166 kbp) induced

Natsuhiko Yoshinaga; Tatsuo Akitaya; Kenichi Yoshikawa

2001-01-01

116

FLUORESCENCE SET: XF41 FOR DYES: ECD, CyRO, Carboxy-X-rhodamine,  

E-print Network

nOMEr OPTICAL ® FLUORESCENCE SET: XF41 FOR DYES: ECD, CyRO, Carboxy-X-rhodamine, BODIPY* 581 EMISSION: 610DF20 FLUORESCENCE SET: XF41 FOR DYES: ECD, CyRO, Carbox,-X-rhodamine, BODIPY* 581/591, Calcium.0 650. B 559.8 450.0 >fdry drops nent. ==^8-Z>£ £ °-« 0 " J l " ENTS eswit ·pew mage 2 -D J-S 2 Hi5 O

Kleinfeld, David

117

Phthalocyanine dye as an extremely photostable and highly fluorescent near-infrared labeling reagent  

NASA Astrophysics Data System (ADS)

Current organic fluorophores used as labeling reagents for biomolecule conjugation have significant limitations in photostability. This compromises their performance in applications that require a photostable fluorescent reporting group. For example, in molecular imaging and single molecule microscopy, photostable fluorescent labels are important for observing and tracking individual molecular events over extended period of time. We report in this paper an extremely photostable and highly fluorescent phthalocyanine dye, IRDye TM 700DX, as a near-infrared fluorescence labeling reagent to conjugate with biomolecules. This novel water-soluble silicon phthalocyanine dye has an isomericly pure chemical structure. The dye is about 45 to 128 times more photostable than current near-IR fluorophores, e.g. Alexa Fluor"R"680, Cy TM 5.5, Cy TM 7 and IRDye TM 800CW dyes; and about 27 times more photostable than tetramethylrhodamine (TMR), one of the most photostable organic dyes. This dye also meets all the other stringent requirements as an ideal fluorophore for biomolecules labeling such as excellent water solubility, no aggregation in high ionic strength buffer, large extinction coefficient and high fluorescent quantum yield. Antibodies conjugated with IRDye TM 700DX at high D/P ratio exist as monomeric species in high ionic buffer and have bright fluorescence. The IRDye TM 700DX conjugated antibodies generate sensitive, highly specific detection with very low background in Western blot and cytoblot assays.

Peng, Xinzhan; Draney, Daniel R.; Volcheck, William M.; Bashford, Gregory R.; Lamb, Donald T.; Grone, Daniel L.; Zhang, Yonghong; Johnson, Craig M.

2006-02-01

118

Argon-pumped tunable dye laser therapy for facial port-wine stain hemangiomas in adults--a new technique using small spot size and minimal power  

SciTech Connect

A low power, argon-pumped tunable dye laser was used to deliver yellow light of 577 nm. Individual blood vessels within port-wine stain hemangiomas were treated with a 0.1-mm beam of light using 8 X magnification. This technique permits excellent resolution of facial and nuchal port-wine stain hemangiomas in adults without the adverse complications of textural change, permanent pigmentation abnormality, or hypertrophic scarring.

Scheibner, A.; Wheeland, R.G.

1989-03-01

119

Karyotypic characterization of the great sturgeon, Huso huso, by multiple staining techniques and fluorescent in situ hybridization  

Microsoft Academic Search

A karyotype analysis by several staining techniques was carried out on the great sturgeon, Huso huso (Linnaeus, 1758). The karyotype (2n?=?118?±?2) was composed of 42 pairs of meta-\\/submetacentric chromosomes and 17 pairs of acrocentrics\\/microchromosomes. Constitutive\\u000a heterochromatin was mainly located at the centromeric regions of the acrocentric chromosomes. The biarmed chromosomes showed\\u000a weak C-bands. Fluorescent staining with GC-specific chromomycin A3 showed

F. Fontana; J. Tagliavini; L. Congiu; M. Lanfredi; M. Chicca; C. Laurente; R. Rossi

1998-01-01

120

Monitoring FET flow control and wall adsorption of charged fluorescent dye molecules in nanochannels integrated into a multiple internal reflection  

E-print Network

Monitoring FET flow control and wall adsorption of charged fluorescent dye molecules can be used to monitor the FET flow control of charged, fluorescent dye molecules during fluorescence microscopy is simultaneously used to provide a comparison and verification of the IR analysis

New Mexico, University of

121

Non-invasive Photoacoustic and Fluorescence Sentinel Lymph Node Identification using Dye-loaded Perfluorocarbon Nanoparticles  

PubMed Central

The contrast mechanisms used for photoacoustic tomography (PAT) and fluorescence imaging differ in subtle but significant ways. Design of contrast agents for each or both modalities requires an understanding of the spectral characteristics as well as intra- and intermolecular interactions that occur during formulation. We found that fluorescence quenching that occurs in the formulation of near infrared (NIR) fluorescent dyes in nanoparticles results in enhanced contrast for PAT. The ability of the new PAT method to utilize strongly absorbing chromophores for signal generation allowed us to convert a highly fluorescent dye into an exceptionally high PA contrast material. Spectroscopic characterization of the developed NIR dye-loaded perfluorocarbon-based nanoparticles for combined fluorescence and PA imaging revealed distinct dye-dependent photophysical behavior. We demonstrate that the enhanced contrast allows detection of regional lymph nodes of rats in vivo with time-domain optical and photoacoustic imaging methods. The results further show that the use of fluorescence lifetime (FLT) imaging, which is less dependent on fluorescence intensity, provides a strategic approach to bridge the disparate contrast reporting mechanisms of fluorescence and PA imaging methods. PMID:21171567

Akers, Walter J.; Kim, Chulhong; Berezin, Mikhail; Guo, Kevin; Fuhrhop, Ralph; Lanza, Gregory M.; Fischer, Georg M.; Daltrozzo, Ewald; Zumbusch, Andreas; Cai, Xin; Wang, Lihong V.; Achilefu, Samuel

2010-01-01

122

Temperature distribution measurement on microfabricated thermodevice for single biomolecular observation using fluorescent dye  

Microsoft Academic Search

Precise temperature distribution measurements with high spatial resolution are of great importance in bioassay which uses microfabricated thermodevice, such as single biomolecular observation. We propose a new method to measure the temperature distribution in water with high spatial resolution using the fluorescent dye, Rhodamine B. Since Rhodamine B solution exhibits a strong and reversible temperature-dependent variation in its fluorescent intensity,

Hideyuki F. Arata; Peter Löw; Koji Ishizuka; Christian Bergaud; Beomjoon Kim; Hiroyuki Noji; Hiroyuki Fujita

2006-01-01

123

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

2014-03-01

124

Fluorescence of Dyes in Solutions with High Absorbance. Inner Filter Effect Correction  

PubMed Central

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

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

2014-01-01

125

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

2013-01-01

126

Bacterial Viability and Antibiotic Susceptibility Testing with SYTOX Green Nucleic Acid Stain  

Microsoft Academic Search

A fluorescent nucleic acid stain that does not penetrate living cells was used to assess the integrity of the plasma membranes of bacteria. SYTOX Green nucleic acid stain is an unsymmetrical cyanine dye with three positive charges that is completely excluded from live eukaryotic and prokaryotic cells. Binding of SYTOX Green stain to nucleic acids resulted in a >500-fold enhancement

BRUCE L. ROTH; MARTIN POOT; STEPHEN T. YUE; PAUL J. MILLARD

1997-01-01

127

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

1976-01-01

128

Fluorescent lifetime of near infrared dyes for structural analysis of serum albumin  

NASA Astrophysics Data System (ADS)

Structural alteration of serum albumin, the major extracellular multifunctional protein in mammals, has been linked to a number of diseases. Herein we present a method based on fluorescence lifetime analysis of near-infrared (NIR) probes bound to albumin to interrogate its structural state without prior isolation of the protein. Molecular modeling study revealed that albumin binds polymethine dyes via two binding sites with different sizes and polarities. As a result, a NIR molecular probe typically exhibits two distinct lifetimes with corresponding fractional contributions. The distribution of fractional contributions along with individual fluorescence lifetimes represents unique parameters for characterizing albumin architecture. To evaluate the effect of size and polarity of binding sites on fluorescence lifetime we studied NIR probes in solutions with different viscosity and polarity. We established that viscosity has negligible effect on polymethine dyes lifetime while the change in polarity has a profound impact. We also established a correlation between fluorescence lifetime and solvent polarity function for a number of NIR dyes for quantitative description of binding sites polarity. After screening a library of dyes, we identified a probe with optimal fluorescence lifetime properties to assess structure-related differences of albumins. The results show that changes in the lifetime of NIR dyes reflect the perturbation of albumin's tertiary structures. Because of the reduced absorption of light by blood in the NIR region, the method developed can be used to determine structural changes of albumins in whole blood.

Berezin, Mikhail Y.; Lee, Hyeran; Akers, Walter; Nikiforovich, Gregory; Achilefu, Samuel

2008-02-01

129

Probing endocytosis from the enterocyte brush border using fluorescent lipophilic dyes: lipid sorting at the apical cell surface.  

PubMed

The small intestinal brush border is a specialized cell membrane that needs to withstand the solubilizing effect of bile salts during assimilation of dietary nutrients and to achieve detergent resistance; it is highly enriched in glycolipids organized in lipid raft microdomains. In the present work, the fluorescent lipophilic probes FM 1-43 (N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide), FM 4-64 (N-(3-triethylammoniumpropyl)-4-(6-(4-(diethylamino) phenyl)hexatrienyl)pyridinium dibromide), TMA-DPH (1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene p-toluenesulfonate), and CellMask Orange plasma membrane stain were used to study endocytosis from the enterocyte brush border of organ-cultured porcine mucosal explants. All the dyes readily incorporated into the brush border but were not detectably endocytosed by 5 min, indicating a slow uptake compared with other cell types. At later time points, FM 1-43 clearly appeared in distinct punctae in the terminal web region, previously shown to represent early endosomes (TWEEs). In contrast, the other dyes were relatively "endocytosis resistant" to varying degrees for periods up to 2 h, indicating an active sorting of lipids in the brush border prior to internalization. For some of the dyes, a diphenylhexatriene motif in the lipophilic tail seemed to confer the relative endocytosis resistance. Lipid sorting by selective endocytosis therefore may be a process in the enterocytes aimed to generate and maintain a unique lipid composition in the brush border. PMID:25526697

Danielsen, E Michael

2015-05-01

130

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

PubMed

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

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

2015-03-01

131

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

132

Diketopyrrolopyrrole: brilliant red pigment dye-based fluorescent probes and their applications.  

PubMed

The development of fluorescent probes for the detection of biologically relevant species is a burgeoning topic in the field of supramolecular chemistry. A number of available dyes such as rhodamine, coumarin, fluorescein, and cyanine have been employed in the design and synthesis of new fluorescent probes. However, diketopyrrolopyrrole (DPP) and its derivatives have a distinguished role in supramolecular chemistry for the design of fluorescent dyes. DPP dyes offer distinctive advantages relative to other organic dyes, including high fluorescence quantum yields and good light and thermal stability. Significant advancements have been made in the development of new fluorescent probes based on DPP in recent years as a result of tireless research efforts by the chemistry scientific community. In this tutorial review, we highlight the recent progress in the development of DPP-based fluorescent probes for the period spanning 2009 to the present time and the applications of these probes to recognition of biologically relevant species including anions, cations, reactive oxygen species, thiols, gases and other miscellaneous applications. This review is targeted toward providing the readers with deeper understanding for the future design of DPP-based fluorogenic probes for chemical and biological applications. PMID:25186723

Kaur, Matinder; Choi, Dong Hoon

2015-01-01

133

Room temperature single-photon Source:Single-dye molecule fluorescence in Liquid Crystal host  

Microsoft Academic Search

We report on new approaches toward an implementation of an efficient, room temperature, deterministically polarized, single-photon source (SPS) on demand-a key hardware element for quantum information and quantum communication. Operation of a room temperature SPS is demonstrated via photon antibunching in the fluorescence from single terrylene-dye molecules embedded in a cholesteric liquid crystal host. Using oxygen-depleted liquid crystal hosts, dye-bleaching

Svetlana G. Lukishova; Ansgar W. Schmid; Andrew J. McNamara; Robert W. Boyd; Carlos R. Stroud

2003-01-01

134

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

PubMed

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

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

2014-11-17

135

Tracer studies of transport processes in the tidal Hudson River: A comparison of SF6 and a fluorescent dye  

Microsoft Academic Search

Fluorescent dyes have frequently been used to study transport processes such as net advection and longitudinal dispersion in rivers. Recently, it has been shown that sulfur hexafluoride (SF6) is a viable alternative to dyes, while offering many advantages. For example, SF6 is less expensive than dye, and has a greater dynamic range. As a result, experiments can be conducted on

D. T. Ho; P. Schlosser; R. Houghton; T. Caplow

2004-01-01

136

Improved DNA Sequencing Accuracy and Detection of Heterozygous Alleles Using Manganese Citrate and Different Fluorescent Dye Terminators  

PubMed Central

The use of dideoxynucleotide triphosphates labeled with different fluorescent dyes (dye terminators) is the most versatile method for automated DNA sequencing. However, variation in peak heights reduces base-calling accuracy and limits heterozygous allele detection, favoring use of dye-labeled primers for this purpose. We have discovered that the addition of a manganese salt to the PE Applied Biosystems dye-terminator sequencing kits overcomes these limitations for the older rhodamine dyes as well as the more recent dichloro-rhodamine dyes (dRhodamine and BigDyes). Addition of manganese to reactions containing dRhodamine-based dye terminators produced the highest base-calling accuracy. This combination resulted in the most uniform electropherogram profiles, superior to those produced by BigDye terminators and published for dye primers, and facilitated detection of heterozygous alleles. PMID:10400927

Korch, Christopher; Drabkin, Harry

1999-01-01

137

Spectrofluorimetric techniques in the study of the interaction between fluorescent dyes and proteins or nuclear acids.  

PubMed

After a review of the applications of spectrofluorimetric techniques to the study of ligand--biological substrate interactions, mention is made of the main fluorescent dyes used for the demonstration of structural characteristics and conformational alterations in proteins, nucleic acids, etc. The possibilities of using new compounds recommended in the literature (fluorescamine, fluoropa, a.o.) for the identification and study of proteins are analysed and original investigations with newly synthesized fluorescent compounds (anthraquinone dyes, anhydrides of peridicarboxylic acids, Tb3+ and Sm3+ complexes of the pyridine -2,6-dicarboxylic acid) are presented. PMID:749334

Zaharia, C N; T?r?b??anu-Mih?il?, C

1978-01-01

138

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

PubMed Central

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

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

2014-01-01

139

Photosensitive fluorescent dye contributes to phototoxicity and inflammatory responses of dye-doped silica NPs in cells and mice.  

PubMed

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

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

2014-01-01

140

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.

141

DBD dyes as fluorescence lifetime probes to study conformational changes in proteins.  

PubMed

Previously, [1,3]dioxolo[4,5-f][1,3]benzodioxole (DBD)-based fluorophores used as highly sensitive fluorescence lifetime probes reporting on their microenvironmental polarity have been described. Now, a new generation of DBD dyes has been developed. Although they are still sensitive to polarity, in contrast to the former DBD dyes, they have extraordinary spectroscopic properties even in aqueous surroundings. They are characterized by long fluorescence lifetimes (10-20 ns), large Stokes shifts (?100 nm), high photostabilities, and high quantum yields (>0.56). Here, the spectroscopic properties and synthesis of functionalized derivatives for labeling biological targets are described. Furthermore, thio-reactive maleimido derivatives of both DBD generations show strong intramolecular fluorescence quenching. This mechanism has been investigated and is found to undergo a photoelectron transfer (PET) process. After reaction with a thiol group, this fluorescence quenching is prevented, indicating successful bonding. Being sensitive to their environmental polarity, these compounds have been used as powerful fluorescence lifetime probes for the investigation of conformational changes in the maltose ATP-binding cassette transporter through fluorescence lifetime spectroscopy. The differing tendencies of the fluorescence lifetime change for both DBD dye generations promote their combination as a powerful toolkit for studying microenvironments in proteins. PMID:24214850

Wawrzinek, Robert; Ziomkowska, Joanna; Heuveling, Johanna; Mertens, Monique; Herrmann, Andreas; Schneider, Erwin; Wessig, Pablo

2013-12-16

142

Acid-fast stain  

MedlinePLUS

The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body ... dye. The slide is then washed with an acid solution and a different stain is applied. Bacteria ...

143

Application of thiazole dyes to amyloid under conditions of direct cotton dyeing: Correlation of histochemical and chemical data  

Microsoft Academic Search

The fluorescent brightening agent Phorwhite (Blankophor) BBU imparts intense selective fluorescence to amyloid, but this modern reagent is no longer readily available on the biological dye market. Conventional Thioflavine S and T stains require differentiation and are not specific. To improve selectivity, direct and cationic thiazole dyes were substituted in the alkaline Congo Red and the Phorwhite BBU procedure. With

H. Puchtler; F. Sweat Waldropl; S. N. Meloan

1983-01-01

144

Testing the Fraunhofer line discriminator by sensing fluorescent dye  

NASA Technical Reports Server (NTRS)

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

Stoertz, G. E.

1969-01-01

145

The mutual influence of two different dyes on their sensitized fluorescence (cofluorescence) in nanoparticles from complexes  

NASA Astrophysics Data System (ADS)

We have studied the fluorescence sensitization and quenching for pairs of different dyes simultaneously incorporated into nanoparticles from complexes M(diketone)3phen, where M(III) is La(III), Lu(III), or Sc(III); diketone is p-phenylbenzoyltrifluoroacetone (PhBTA) or naphthoyltrifluoroacetone (NTA); and phen is 1,10-phenanthroline. We have shown that, upon formation of nanoparticles in the solution in the presence of two dyes the concentrations of which are either comparable with or lower than the concentration of nanoparticles (<20 nM), the intensities of the sensitized fluorescence of dyes in nanoparticles in binary solutions and in solutions of either of the dyes coincide. We have found that the intensity of sensitized fluorescence of small (<20 nM) concentrations of rhodamine 6G (R6G) or Nile blue (NB) increases by an order of magnitude upon simultaneous introduction into nanoparticles of 1 ?M of coumarin 30 (C30), while the intensity of fluorescence of C30 sensitized by complexes decreases by an order of magnitude. The same effect is observed as 1 ?M of R6G are introduced into nanoparticles with NB ([NB] ? 20 nM). The increase in the fluorescence of dye molecules upon their incorporation from the solution into nanoparticles from complexes is noticeably lower than that expected from the proposed ratio of concentrations of complexes and dyes in nanoparticles. Analysis of the obtained data indicates that the introduction of large concentrations of C30 or R6G dyes into nanoparticles makes it possible to prevent large energy losses due to impurities or upon transition to a triplet state that arises during the migration of the excitation energy over S 1 levels of complexes. Energy accumulated by these dyes is efficiently transferred to another dye that is present in the solution at lower concentrations and that has a lower-lying S 1 level, which makes it possible to increase its fluorescence by an order of magnitude upon its incorporation into nanoparticles.

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

2013-10-01

146

Interactions of cyanine dyes with nucleic acids. XXIV. Aggregation of monomethine cyanine dyes in presence of DNA and its manifestation in absorption and fluorescence spectra  

Microsoft Academic Search

Absorption, fluorescence emission and excitation spectra of benzothiazole cyanine dyes — thiazole orange (TO) and 7-methyl-6-(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidenmethyl) [1,3] dioxolo [4?,5?:4,5] benzo [d] [1,3] thiazolium methylmethosulfate (Cyan 13) — were investigated over a wide concentration range. The dyes form aggregates with a ‘sandwich’-like structure in water solution. At low dye to DNA concentrations ratios, Cyan 13 and TO monomers appear to interact

T. Yu Ogul'chansky; M. Yu Losytskyy; V. B Kovalska; V. M Yashchuk; S. M Yarmoluk

2001-01-01

147

Fluorescence decay dynamics of organic dye molecules in solution  

NASA Astrophysics Data System (ADS)

A picosecond laser system consisting of two tuneable dye lasers pumped synchronously by a mode locked argon-ion laser has been used for studying the relaxation of the S 1 excited states of dye molecules Nile Blue and Oxazine 720. The dependence of the excited state lifetimes on the solvent and on the temperature are discussed. Both intramolecular and intermolecular decay channels contribute to the radiationaless de-excitation. The mechanism of intramolecular decay is different, while that of intermolecular decay is very similar for the two molecules.

Grofcsik, A.; Kubinyi, M.; Jones, W. J.

1995-03-01

148

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.

2008-01-01

149

Labeling Stem Cells with Fluorescent Dyes for non-invasive Detection with Optical Imaging  

PubMed Central

Optical imaging (OI) is an easy, fast and inexpensive tool for in vivo monitoring of new stem cell based therapies. The technique is based on ex vivo labeling of stem cells with a fluorescent dye, subsequent intravenous injection of the labeled cells and visualization of their accumulation in specific target organs or pathologies. The presented technique demonstrates how we label human mesenchymal stem cells (hMSC) by simple incubation with the lipophilic fluorescent dye DiD (C67H103CIN2O3S) and how we label human embryonic stem cells (hESC) with the FDA approved fluorescent dye Indocyanine Green (ICG). The uptake mechanism is via adherence and diffusion of the lypophilic dye across the phospholipid cell membrane bilayer. The labeling efficiency is usually improved if the cells are incubated with the dye in serum-free media as opposed to incubation in serum-containing media. Furthermore, the addition of the transfection agent Protamine Sulfate significantly improves contrast agent uptake. PMID:19066580

Boddington, Sophie; Henning, Tobias D.; Sutton, Elizabeth J.; Daldrup-Link, Heike E.

2008-01-01

150

Picosecond fluorescence lifetime measurements on dyes adsorbed at semiconductor and insulator surfaces  

SciTech Connect

Fluorescence lifetimes in the 50 to 60-ps range were measured for rhodamine B and eosin adsorbed on tin oxide and indium oxide surfaces. Somewhat shorter lifetimes were obtained for rhodamine B adsorbed on plain glass. Implications these results have for models of the dye-sensitized photoinjection into semiconductors are discussed.

Liang, Y. (Temple Univ., Philadelphia, PA); Ponte Goncalves, A.M.; Negus, D.K.

1983-01-06

151

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

PubMed Central

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

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

1974-01-01

152

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.

2004-01-01

153

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

PubMed Central

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

Tabery, H M

1992-01-01

154

Multifunctional particles: Magnetic nanocrystals and gold nanorods coated with fluorescent dye-doped silica shells  

SciTech Connect

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 Stoeber 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. - Graphical abstract: Colloidal gold nanorods and iron platinum and iron oxide nanocrystals were encapsulated with fluorescent dye-doped silica shells using a generic coating strategy. These heterostructures are promising contrast agents for dual-mode medical imaging. Their optical and magnetic properties were studied and are reported here.

Heitsch, Andrew T.; Smith, Danielle K.; Patel, Reken N. [Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, TX 78712-1062 (United States); Ress, David [Imaging Research Center, University of Texas at Austin, Austin, TX 78759-5316 (United States); Korgel, Brian A. [Department of Chemical Engineering, Texas Materials Institute, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, TX 78712-1062 (United States)], E-mail: korgel@che.utexas.edu

2008-07-15

155

Dynamic staining of bacteria at a single-cell level  

NASA Astrophysics Data System (ADS)

Bacterial infectious diseases remain one of the major health hazards nation- and worldwide. The expedience of detection and identification of bacterial pathogens determines how early the diagnosis is, and hence, what the treatment and the outcome of the illness would be. As we have previously reported, the dynamics of fluorescence staining provides venues for the development of expedient assays for detection and identification of bacterial species[1]. We measured the kinetics of bacterial staining with cyanine and thioflavin dyes and investigated their photophysical properties. We demonstrated that the pseudo first-order kinetic constants of the fluorescence staining processes have species specificity without contrition dependence. Combining the dynamics of staining with real-time fluorescence microscopy we characterized the fluorescence staining process at the single-cell level with improved sensitivity and contrast.

Nuñez, Vicente; Upadhyayula, Srigokul; Lin, Adam; Chau, Kenny; Vullev, Valentine I.

2011-05-01

156

Groove-binding unsymmetrical cyanine dyes for staining of DNA: dissociation rates in free solution and electrophoresis gels  

Microsoft Academic Search

The rates of dissociation of three non-intercalative unsymmetrical cyanine dyes, BEBO, BETO and BOXTO from mixed-sequence DNA have been studied with the DNA either free in solution or in confining porous agarose gels. The properties of the new dyes were compared to the related inter- calating dyes BO, BO-PRO, TO-PRO and YO-PRO. With DNA in solution, BEBO dissociates more slowly

Maja Eriksson; H. Jonas Karlsson; Gunnar Westman; Bjorn Akerman

2003-01-01

157

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

158

Synchronous fluorescence spectroscopic study of solvatochromic curcumin dye  

NASA Astrophysics Data System (ADS)

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

Patra, Digambara; Barakat, Christelle

2011-09-01

159

A new polymerizable fluorescent PET chemosensor of fluoride (F-) based on naphthalimide-thiourea dye  

NASA Astrophysics Data System (ADS)

A novel N-allyl-4-amino-substituted 1,8-naphthalimide dye, containing thiourea functional group with intense yellow-green fluorescence was successfully synthesized. Copolymerization was done with styrene. The photophysical characteristics of dye and its copolymer in solution and solid film were investigated in the presence of halide ions. The results reveal that the fluorescence emissions of the monomer dye and also its polymer were 'switched off' in the presence of fluoride ions. The dye showed spectral shifts and intensity changes in the presence of more fluoride ions which lead to detect certain fluoride concentrations of 10-150 mM at visible wavelengths. By adding the fluoride ions, green-yellow to purple color changes occurs and the green fluorescence emission quenches, all of which easily observed by naked eyes. These phenomena are essential for producing a dual responsive chemosensor for fluoride ions. The polymeric sensor, in the film state exhibited a fast response to the fluoride ions.

Alaei, Parvaneh; Rouhani, Shohre; Gharanjig, Kamaladin; Ghasemi, Jahanbakhsh

2012-05-01

160

Cross-shore Exchange on a Rip-channeled Beach Using Fluorescent Dye  

NASA Astrophysics Data System (ADS)

The cross-shore exchange of material between the surf zone and inner-shelf was examined during seven fluorescent dye tracer deployments. Field observations were obtained at a beach in Sand City, Monterey Bay, CA, which is comprised of shore-connected shoals with incised, quasi-periodic, O(125m), rip channels, during June, 2010. Typical deployment conditions consisted of low tides and offshore waves with Hs of 0.6 to 1.8m, Tmo of 8.1 to 9.4s, and approaching the shore with normal incidence, resulting in persistent rip current events. Fluorescent Rhodamine dye was released at a point inside the surf zone and the distribution over time and space was observed. An array of stationary fluorometers was deployed at the offshore edge of the surf zone and at the lateral boundaries encompassing two rip current systems. Persons equipped with a fluorometer and GPS walked around in the surf zone study region to increase the spatial coverage. Near-surface dye concentration was also measured using fluorometers mounted on three moving, GPS-equipped vessels outside of the surf zone to examine the distribution and offshore extent of the dye plumes. Surfzone drifters were deployed simultaneously during each dye deployment to spatially map the flow field. In order to examine the vertical structure of the cross-shore exchange, multiple vertical casts of co-located fluorometer and CTD measurements were conducted in dye plumes outside of the surf zone. Qualitative results give spatial estimates of the particle pathways and show alongshore variability of the dye expulsions, with dye exiting the surf zone as plumes through the rip currents only, and extending up to three surfzone widths offshore. Dye plumes outside of the surf zone were found to be coincident with the thermocline, and were depth-uniform and encompassed greater than half, or all, of the water column. Quantitative measures of the decay rate of the dye in the surf zone will provide an estimate of the surf zone flushing time. This effort was supported by the National Science Foundation and the Office of Naval Research.

Brown, J.; Macmahan, J. H.; Reniers, A. J.

2010-12-01

161

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

162

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)

1994-12-31

163

Benchtop Antigen Detection Technique using Nanofiltration and Fluorescent Dyes  

NASA Technical Reports Server (NTRS)

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

Scardelletti, Maximilian C.; Varaljay, Vanessa

2009-01-01

164

Fluorescence Dynamics of Dye Probes in Micelles Nakul C. Maiti, M. M. G. Krishna, P. J. Britto, and N. Periasamy*  

E-print Network

depolarization dynamics of organic fluorescent dye probes (nile red, cresyl violet, DODCI, rhodamine B, and rhodamine DPPE) were studied in cationic, anionic, and neutral micelles by picosecond time-resolved single

Mallela, Krishna M. G.

165

Demonstration of Actinomyces and Arachnia species in cervicovaginal smears by direct staining with species-specific fluorescent-antibody conjugate.  

PubMed Central

For direct observation of microaerophilic actinomycetes by fluorescent antibody, a procedure was developed in which pepsin treatment and rhodamine conjugate of normal serum were used to reduce nonspecific staining in cervicovaginal smears. Actinomyces israelii, Actinomyces naeslundii, and Arachnia propionica were observed in cervicovaginal smears from women who did use and who did not use an intrauterine contraceptive device. A. israelii was found more commonly in women with an intrauterine contraceptive device, but no evidence was obtained that the use of an intrauterine contraceptive device influenced the presence of either A. propionica or A. naeslundii. PMID:6161943

Pine, L; Malcolm, G B; Curtis, E M; Brown, J M

1981-01-01

166

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

PubMed Central

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

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

2008-01-01

167

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

1994-01-01

168

DO-sensing based on enhancement of cladding fluorescence in dye-doped plastic fiber  

NASA Astrophysics Data System (ADS)

A new technique for the optical sensing of dissolved oxygen (DO) is proposed here. It is based on the enhancement in fluorescence yield of TPP dye at (lambda) equals 656 nm, when excited by He-Cd blue laser of (lambda) equals 441 nm in the presence of dissolved oxygen. The sensor head was fabricated by cladding the ARTON fiber core with the poly-4-methyl-1- pentene polymer matrix suitably doped with Tetraphenylporphine dye. This sensor head, when placed in a test chamber and end-pumped by He-Cd laser, generates the intense fluorescence at 656 nm. Its intensity was noticed to increase with increasing the amount of DO. A theoretical model of the sensor response was designed and is also discussed.

Vishnoi, Gargi; Morisawa, Masayuki; Muto, Shinzo

1998-09-01

169

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

PubMed

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

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

2015-03-17

170

Native and fluorescent dye-dependent single-DNA molecule microchip dynamics as measured by differential interference contrast microscopy.  

PubMed

In a free solution of 10.0 mM Gly-Gly (pH 8.2), the flow directions of native-DNA and DNA molecules intercalated with the fluorescent dye YOYO-1 were reversed in the microchip channel. These results clearly showed that in a confined space and under specific environmental conditions, the fluorescent dye modified the original properties and behavior of the native-DNA molecule. PMID:21750823

Oh, Doori; Lee, Seungah; Kang, Seong Ho

2011-08-28

171

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

PubMed

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

Gromova, Yulia A; Orlova, Anna O; Maslov, Vladimir G; Fedorov, Anatoly V; Baranov, Alexander V

2013-01-01

172

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

2014-12-01

173

Metal-enhanced fluorescence of dye-doped silica nano particles.  

PubMed

Recent advancements in metal-enhanced fluorescence (MEF) suggest that it can be a promising tool for detecting molecules at very low concentrations when a fluorophore is fixed near the surface of metal nanoparticles. We report a simple method for aggregating multiple gold nanoparticles (GNPs) on Rhodamine B (RhB)-doped silica nanoparticles (SiNPs) utilizing dithiocarbamate (DTC) chemistry to produce MEF in solution. Dye was covalently incorporated into the growing silica framework via co-condensation of a 3-aminopropyltriethoxysilane (APTES) coupled RhB precursor using the Stöber method. Electron microscopy imaging revealed that these mainly non-spherical particles were relatively large (80 nm on average) and not well defined. Spherical core-shell particles were prepared by physisorbing a layer of RhB around a small spherical silica particle (13 nm) before condensing an outer layer of silica onto the surface. The core-shell method produced nanospheres (~30 nm) that were well defined and monodispersed. Both dye-doped SiNPs were functionalized with pendant amines that readily reacted with carbon disulfide (CS2) under basic conditions to produce DTC ligands that have exhibited a high affinity for gold surfaces. GNPs were produced via citrate reduction method and the resulting 13 nm gold nanospheres were then recoated with an ether-terminated alkanethiol to provide stability in ethanol. Fluorescent enhancement was observed when excess GNPs were added to DTC coated dye-doped SiNPs to form nanoparticle aggregates. Optimization of this system gave a fluorescence brightness enhancement of over 200 fold. Samples that gave fluorescence enhancement were characterized through Transmission Emission Micrograph (TEM) to reveal a pattern of multiple aggregation of GNPs on the dye-doped SiNPs. PMID:25627927

Gunawardana, Kalani B; Green, Nathaniel S; Bumm, Lloyd A; Halterman, Ronald L

2015-03-01

174

Oligonucleotide assisted light-emitting Alq3 microrods: energy transfer effect with fluorescent dyes.  

PubMed

Oligonucleotide assisted tri(8-hydroxyquinoline) aluminium (Alq3) microrods were prepared for the first time. When hybridized with oligonucleotide labeled by Cy3 fluorescent dye, a significant photoluminescence variation of the Alq3 microrods was observed due to Förster resonance energy transfer, unlike when Cy5-oligonucleotide was used. Versatile nucleotide manipulation would open up wider applications of Alq3-based materials, based on this fundamental observation. PMID:23535632

Cui, Chunzhi; Park, Dong Hyuk; Kim, Jeongyong; Joo, Jinsoo; Ahn, Dong June

2013-06-14

175

Fluorescence quenching of dyes covalently attached to single-walled carbon nanotubes.  

PubMed

The development of chromophore-carbon nanotube hybrids requires efficient and accurate methods to investigate their photophysical properties. Using the ability of the fluorescence labeling of surface species (FLOSS) technique to determine the density of covalently attached dyes to the surface of single-walled carbon nanotubes (SWCNTs), the luminescence of dye-SWCNT hybrids was quantitatively studied with two chromophores: dansyl hydrazine (DH) and panacyl bromide (PB). The fluorescence intensity of PB-SWCNT hybrids was reduced by 20-80% compared to that of free PB. A strong positive correlation between the degree of quenching and the residual metal impurity content in the SWCNT sample suggests that quenching of fluorescence of PB in PB-SWCNTs may be caused by the metal impurities and not by SWCNTs. On the contrary, the intensity of fluorescence of DH-SWCNT hybrids was reduced by almost 2 orders of magnitude compared to free DH, independent of the residual metal content in the SWCNT sample, suggesting that quenching of fluorescence in DH-SWCNT hybrids might occur via charge transfer from DH chromophores to SWCNTs, and revealing the potential of DH-SWCNT hybrids for solar light harvesting applications. PMID:21766814

Chiu, Cheuk Fai; Dementev, Nikolay; Borguet, Eric

2011-09-01

176

Flow cytometric discrimination of bacterial populations in seawater based on SYTO 13 staining of nucleic acids  

Microsoft Academic Search

Flow cytometric (FCM) counts of bacteria stained with SYTO 13, a cyanine dye, were highly correlated with DAPI epifluorescence microscopic counts in coastal seawater samples. Fluorescence intensity of stained cells appeared to depend on nucleic acid content and on the polarization of cell membranes. Right angle light scatter values of bacterial populations were clearly related to cell size. By FCM

Marc Troussellier; Claude Courties; Philippe Lebaron; Pierre Servais

1999-01-01

177

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

NASA Astrophysics Data System (ADS)

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

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

2015-03-01

178

Optical properties of some novel 2,5-disubstituted 1,3,4-oxadiazole derivatives and their application as an efficient cell staining azo dyes.  

PubMed

A series of six 2,5-disubstituted 1,3,4-oxadiazole derivatives with various length of conjugation have been synthesized and their optical properties including UV-visible absorption spectra, fluorescence emission spectra, molar absorption co-efficient, Stokes shift and the relative fluorescence quantum yield were measured in a variety of organic solvents. Correlation of the absorption spectra and fluorescence emission response of the 2,5-disubstituted 1,3,4-oxadiazole derivatives with the substituent effect revealed that the optical response can easily be tuned toward red shift by increasing conjugation length. The synthesized compounds were further employed in bioimaging assay in order to investigate their potential as an efficient cell staining agent using L-929 cells under confocal fluorescence microscope which showed scrupulous cell permeability and no toxicity as assessed by MTT assay. PMID:25245061

Saleem, Muhammad; Ali, Anser; Park, Bong Joo; Choi, Eun Ha; Lee, Ki Hwan

2014-11-01

179

Fluorescence staining of yeast cells permeabilized by killer toxin K1: Determination of optimum conditions  

Microsoft Academic Search

Optimal assay conditions were established for the previously described method used to determine the activity ofSaccharomyces cerevisiae pore-forming killer toxin K1. The method is based on cell staining with bromocresol purple. Sensitive cells ofS. cerevisiae from the early exponential phase under nongrowth conditions and in the presence of glucose were the most convenient for determining the killer toxin activity. Maximum

Helena Kurzweilová; Karel Sigler

1993-01-01

180

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

PubMed

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

Graham, E T; Trentham, W R

1998-07-01

181

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.

2014-02-01

182

Self-quenching DNA probes based on aggregation of fluorescent dyes  

NASA Astrophysics Data System (ADS)

Here we present a novel class of self-quenching, double-labeled DNA probes based on the formation of non fluorescent H-type dye dimers. We therefore investigated the aggregation behavior of the red-absorbing oxazine derivative MR121 and found a dimerization constant of about 3000 M-1. This dye was successfully used to develop hairpin-structured as well as linear self-quenching DNA probes that report the presence of the target DNA by an increase of the fluorescence intensity by a factor of 3 to 12. Generally fluorescence quenching of the hairpin-structure probes is more efficient compared to the linear probes, whereas the kinetic of the fluorescence increase is significantly slower. The new probes were used for the identification of different mycobacteria and their antibiotic resistant species. As a test system a probe for the identification of a DNA sequence specific for the Mycobacterium xenopi was synthesized differing from the sequence of the Mycobacterium fortuitum by 6 nucleotides. Furthermore we developed a method for the discrimination between the sequences of the wild type and an antibiotic resistant species of Mycobacterium tuberculosis. Both sequences differ by just 2 nucleotides and were detected specifically by the use of competing olignonucleotides.

Schafer, Gabriela; Muller, Matthias; Hafner, Bernhard; Habl, Gregor; Nolte, Oliver; Marme, Nicole; Knemeyer, Jens-Peter

2005-04-01

183

Detection of acid moisture in photovoltaic modules using a dual wavelength pH-sensitive fluorescent dye  

NASA Astrophysics Data System (ADS)

The formation of acetic acid via the penetration of moisture into ethylene vinyl acetate (EVA) in photovoltaic (PV) modules is cited as the main reason for PV modules’ degradation. Currently, there is no effective method for detecting acetic moisture in PV modules. We proposed a simple method for detecting acid moisture in PV modules using a dual-wavelength pH-sensitive dye that measures pH by the ratio of the intensities of two peaks in the fluorescence spectra of the dye. We detected the pH change caused by acetic acid with the change in the intensity ratio of the fluorescence spectra of the dried dye. Furthermore, we observed that the dry fluorescent dye is heat resistant to withstand the lamination process for the manufacturing of PV modules, and has good long-term durability.

Asaka, Takashi; Iwami, Kentaro; Taguchi, Atsushi; Umeda, Norihiro; Masuda, Atsushi

2014-01-01

184

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

Microsoft Academic Search

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)

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

1997-01-01

185

Critical tonicity determination of sperm using fluorescent staining and flow cytometry  

SciTech Connect

The use of cryopreserved, rather than fresh, mammalian semen for artificial insemination confers several important medical and/or economic advantages. However, current methods for cryopreservation of both human and bovine spermatozoa result in approximately only a 50% survival rate with thawing, obviously reducing the fertilizing capacity of the semen. A primary consideration during the cooling process is to avoid intracellular ice crystal formation with its lethal consequences to the cell. Current techniques achieve this by controlling the cooling rate. Computation of the time necessary for this dehydration, and hence, the cooling rate, is dependent upon knowledge of the water permeability coefficient (L{sub {rho}}) and its activation energy. The fluorophore, 6-carboxyfluoroscein diacetate (CFDA), which is nonfluorescent, readily crosses the intact plasma membrane. Intracellular esterases hydrolyze CFDA to 6-carboxyfluoroscein, a fluorescent, membrane-impermeable fluorophore. Consequently, spermatozoa with intact plasma membranes fluoresce bright green (Garner et. al., 1986), but those with disrupted membranes do not. Therefore, the purpose of this study was to use loss of CFDA fluorescence to determine the osmolality at which 50% of the spermatozoa will swell and lyse (critical tonicity, CT). These data will then be used to determine the L{sub {rho}} and its activation energy for sperm, thus increasing the knowledge available in cellular cryopreservation. 15 refs., 3 figs.

Noiles, E.E.; Ruffing, N.A.; Kleinhans, F.W.; Mark, L.A.; Watson, P.F.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA)); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine); Mazur, P. (Oak Ridge National Lab., TN (USA))

1990-01-01

186

Large improvement of photon capture for a dye-sensitized solar cell integrated with a fluorescent layer  

NASA Astrophysics Data System (ADS)

An integrated design of dye-sensitized solar cell with fluorescent layer is realized. A fluorescent layer is deposited on a fluorine-doped tin oxide (FTO) glass with a blank right above a N719 dye-sensitized TiO2 coating which is printed on the central area of the conductive face of the FTO glass. Current density-voltage characteristic measurement indicates that our integrated system largely enhances photon harvesting by 44% compared with a cell without a fluorescent layer, which is attributed to the improvement of photon harvesting from the spectrum range and the space area.

Li, Da; Ding, Cairong; Shen, Hui; Liu, Yong; Zhang, Yueli; Li, Ming; Yan, Jin

2010-01-01

187

Use of the Dye Stain Assay and Ultraviolet Light Test for Assessing Vaginal Insertion of Placebo-filled Applicators Before and After Sex  

PubMed Central

Background Applicator dye staining and ultraviolet (UV) light have been used in trials to measure adherence, but not in the setting of before and after sex gel dosing (BAT-24). This study was designed to determine if semen or pre-sex gel dosing impacts the sensitivity and specificity of a dye stain assay (DSA) for measuring vaginal insertion of placebo-filled applicators with BAT-24 dosing. Methods Healthy monogamous couples received Microlax®-type applicators filled with hydroxyethylcelluose placebo gel. Women were instructed to vaginally insert one dose of gel before and a second dose after sex and to return applicators within 48 hours after sex. Applicators were stained to detect semen followed by UV then DSA and scored by two readers. Positive and negative controls were randomly included in applicator batches. Results Fifteen couples completed the study. Each female returned at least six applicators over a 30-day period. The sensitivity for insertion of post-sex applicators was higher for UV (97%) compared to DSA (90%) and the specificity was similar (?96%). For pre-sex applicators, the sensitivity and specificity were higher for DSA (100%) compared to UV testing (87% sensitivity, 96% specificity). Among returned post-sex applicators, 95% tested positive by UV compared to 87% by DSA. Agreement between readers was significantly better on the pre-sex applicators for DSA than for UV and for post-sex readings agreement was less than half that for UV, although the results were not statistically significant. Conclusions Applicator tests are feasible for measuring adherence in trials with gel dosing before and after sex. PMID:24220355

Keller, Marla J.; Buckley, Niall; Katzen, Lauren L.; Walsh, Jennifer; Friedland, Barbara; Littlefield, Sarah; Lin, Juan; Xue, Xiaonan; Cornelison, Terri; Herold, Betsy C.; Einstein, Mark H.

2014-01-01

188

Picosecond laser studies of the solvent-dependent nonradiative pathways in near-IR fluorescent dyes: implications on their use in ultrasensitive analysis  

Microsoft Academic Search

Photophysical investigations using steady-state and picosecond, time-resolved fluorescence techniques on several NIR polymethine dyes were performed in order to elucidate solvent- dependent nonradiative pathways.

Steven A. Soper; Quincy L. Mattingly; Benjamin L. Legendre

1994-01-01

189

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

PubMed Central

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 interactions in vitro between a class of spinal cord neurons, sympathetic preganglionic neurons, and their normal target, neurons from the sympathetic chain. Here, we describe how we use two highly fluorescent carbocyanine dyes, which differ in color but are otherwise similar, to identify neurons in culture. The long carbon chain carbocyanine dyes we use are lipid-soluble and so become incorporated into the plasma membrane. Neurons can be labeled either retrogradely or during dissociation. Some of the labeled membrane gradually becomes internalized and retains its fluorescence, allowing identification of cells for several weeks in culture. These dyes do not affect the survival, development, or basic physiological properties of neurons and do not spread detectably from labeled to unlabeled neurons. It seems likely that cells become retrogradely labeled mainly by lateral diffusion of dye in the plane of the membrane. If so, carbocyanine dyes may be most useful for retrograde labeling over relatively short distances. An additional feature of carbocyanine labeling is that neuronal processes are brightly fluorescent for the first few days in culture, presumably because dye rapidly diffuses into newly inserted membrane. We have used carbocyanine dyes to identify sympathetic preganglionic neurons in culture. Our results indicate that preganglionic neurons can survive in the absence of their target cells and that several aspects of their differentiation in the absence of target appear normal. PMID:2424918

1986-01-01

190

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

PubMed

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

2014-12-01

191

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

2010-01-01

192

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

PubMed

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

2010-04-01

193

Orderly arranged fluorescence dyes as a highly efficient chemiluminescence resonance energy transfer probe for peroxynitrite.  

PubMed

Chemiluminescence (CL) probes for reactive oxygen species (ROS) are commonly based on a redox reaction between a CL reagent and ROS, leading to poor selectivity toward a specific ROS. The energy-matching rules in the chemiluminescence resonance energy transfer (CRET) process between a specific ROS donor and a suitable fluorescence dye acceptor is a promising method for the selective detection of ROS. Nevertheless, higher concentrations of fluorescence dyes can lead to the intractable aggregation-caused quenching effect, decreasing the CRET efficiency. In this report, we fabricated an orderly arranged structure of calcein-sodium dodecyl sulfate (SDS) molecules to improve the CRET efficiency between ONOOH* donor and calcein acceptor. Such orderly arranged calcein-SDS composites can distinguish peroxynitrite (ONOO(-)) from a variety of other ROS owing to the energy matching in the CRET process between ONOOH* donor and calcein acceptor. Under the optimal experimental conditions, ONOO(-) could be assayed in the range of 1.0-20.0 ?M, and the detection limit for ONOO(-) [signal-to-noise ratio (S/N) = 3] was 0.3 ?M. The proposed strategy has been successfully applied in both detecting ONOO(-) in cancer mouse plasma samples and monitoring the generation of ONOO(-) from 3-morpholinosydnonimine (SIN-1). Recoveries from cancer mouse plasma samples were in the range of 96-105%. The success of this work provides a unique opportunity to develop a CL tool to monitor ONOO(-) with high selectivity in a specific manner. Improvement of selectivity and sensitivity of CL probes holds great promise as a strategy for developing a wide range of probes for various ROS by tuning the types of fluorescence dyes. PMID:25693881

Wang, Zhihua; Teng, Xu; Lu, Chao

2015-03-17

194

In vivo effects of focused shock waves on tumor tissue visualized by fluorescence staining techniques.  

PubMed

Shock waves can cause significant cytotoxic effects in tumor cells and tissues both in vitro and in vivo. However, understanding the mechanisms of shock wave interaction with tissues is limited. We have studied in vivo effects of focused shock waves induced in the syngeneic sarcoma tumor model using the TUNEL assay, immunohistochemical detection of caspase-3 and hematoxylin-eosin staining. Shock waves were produced by a multichannel pulsed-electrohydraulic discharge generator with a cylindrical ceramic-coated electrode. In tumors treated with shock waves, a large area of damaged tissue was detected which was clearly differentiated from intact tissue. Localization and a cone-shaped region of tissue damage visualized by TUNEL reaction apparently correlated with the conical shape and direction of shock wave propagation determined by high-speed shadowgraphy. A strong TUNEL reaction of nuclei and nucleus fragments in tissue exposed to shock waves suggested apoptosis in this destroyed tumor area. However, specificity of the TUNEL technique to apoptotic cells is ambiguous and other apoptotic markers (caspase-3) that we used in our study did not confirmed this observation. Thus, the generated fragments of nuclei gave rise to a false TUNEL reaction not associated with apoptosis. Mechanical stress from high overpressure shock wave was likely the dominant pathway of tumor damage. PMID:25200989

Lukes, Petr; Zeman, Jan; Horak, Vratislav; Hoffer, Petr; Pouckova, Pavla; Holubova, Monika; Hosseini, S Hamid R; Akiyama, Hidenori; Sunka, Pavel; Benes, Jiri

2015-06-01

195

Hybridization chain reaction-based fluorescence immunoassay using DNA intercalating dye for signal readout.  

PubMed

A novel format of fluorescence immunosorbent assay based on the hybridization chain reaction (HCR) using a DNA intercalating dye for signal readout was constructed for the sensitive detection of targets, both in competitive and sandwich modes. In this platform, the capture and recognition processes are based on immunoreactions and the signal amplification depends on the enzyme-free, isothermal HCR-induced labelling event. After a competitive or a sandwich immunoreaction, a biotinylated capture DNA was bound to a biotinylated signal antibody through avidin, and triggered the HCR by two specific hairpins into a nicked double helix. Gene Finder (GF), a fluorescent probe for double-strand DNA, was intercalated in situ into the amplified chain to produce the fluorescence signal. The limit of detection (LOD) for rabbit IgG in competitive mode by HCR/GF immunoassay was improved at least 100-fold compared with the traditional fluorescence immunoassay using the fluorescein isothiocyanate-labelled-streptavidin or fluorescein isothiocyanate-labelled second antibody as the signal readout. The proposed fluorescence immunoassay was also demonstrated by using ?-fetoprotein as the model target in sandwich mode, and showed a wide linear range from 28 ng mL(-1) to 20 ?g mL(-1) with a LOD of 6.0 ng mL(-1). This method also showed satisfactory analysis in spiked human serum, which suggested that it might have great potential for versatile applications in life science and point-of-care diagnostics. PMID:24828400

Deng, Yan; Nie, Ji; Zhang, Xiao-hui; Zhao, Ming-Zhe; Zhou, Ying-Lin; Zhang, Xin-Xiang

2014-07-01

196

Apparatus for eliminating background interference in fluorescence measurements  

DOEpatents

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

1986-01-01

197

Apparatus for eliminating background interference in fluorescence measurements  

DOEpatents

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.

1986-03-04

198

Live cell cycle analysis of Drosophila tissues using the Attune Acoustic Focusing Cytometer and Vybrant DyeCycle violet DNA stain.  

PubMed

Flow cytometry has been widely used to obtain information about DNA content in a population of cells, to infer relative percentages in different cell cycle phases. This technique has been successfully extended to the mitotic tissues of the model organism Drosophila melanogaster for genetic studies of cell cycle regulation in vivo. When coupled with cell-type specific fluorescent protein expression and genetic manipulations, one can obtain detailed information about effects on cell number, cell size and cell cycle phasing in vivo. However this live-cell method has relied on the use of the cell permeable Hoechst 33342 DNA-intercalating dye, limiting users to flow cytometers equipped with a UV laser. We have modified this protocol to use a newer live-cell DNA dye, Vybrant DyeCycle Violet, compatible with the more common violet 405nm laser. The protocol presented here allows for efficient cell cycle analysis coupled with cell type, relative cell size and cell number information, in a variety of Drosophila tissues. This protocol extends the useful cell cycle analysis technique for live Drosophila tissues to a small benchtop analyzer, the Attune Acoustic Focusing Cytometer, which can be run and maintained on a single-lab scale. PMID:23712023

Flegel, Kerry; Sun, Dan; Grushko, Olga; Ma, Yiqin; Buttitta, Laura

2013-01-01

199

Comparison between Sulphorhodamine-B dye staining and 51Cr-release method in cytotoxicity assay of endodontic sealers.  

PubMed

The aim of this study was to evaluate Sulphorhodamine-B (SRB) staining against 51Cr-release in cytotoxicity tests of six endodontic sealers, namely, MU sealer (Mahidol University) ROCANAL 2, ROCANAL 3, Apexit, Endomethasone, and AH-26. Monolayers (5 x 10(5) cells/ml) of the mouse cell line Mu-mu-1 were used as test cells. Following incubation at 37 degrees C in 5% CO2 for 24 h in the presence of each sealer, cells were stained with 0.4% SRB and the absorbance at 540 nm determined as measure of cell viability. For 51Cr-release assay, cells were labelled with 51Cr before testing with sealers, and radioactivity in the supernatant was measured in a liquid scintillation counter. Both techniques indicated that Apexit was the least toxic sealer. In view of the ease of conducting SRB staining for tests of cell viability, this may be the method of choice over 51Cr-release assay in the evaluation of endodontic sealer cytotoxicity. PMID:9545942

Vajrabhaya, L; Sithisarn, P; Wilairat, P; Leelaphiwat, S

1997-06-01

200

Modification of the BrdU\\/H33258 technique for flow cytometry based on the pH-dependence of the fluorescence of H33258 stained DNA  

Microsoft Academic Search

A simple analytical method is described for the evaluation of cell cycle progression data by modification of the BrdU\\/H33258 technique for flow cytometry. This procedure allows to obtain quenched and unquenched DNA-histograms of cells containing BrdU-substituted DNA by staining with one dye only, namely H33258. Quenched histograms are obtained at pH=7 and give information about how far cells have passed

W. Kroll; Philipps-Universitfit Marburg

1984-01-01

201

Diffusion controlled reactions: Fluorescence quenching of cationic dyes by charged quenchers  

NASA Astrophysics Data System (ADS)

Rate coefficients of diffusion-limited fast reactions of charged reactants are predicted to be time dependent or time independent in different theoretical approaches to solve the Debye-Smoluchowski equation. Different rate coefficient expressions are also predicted in different time domains. Fluorescence quenching experiments using two cationic dyes (rhodamine B and cresyl violet) and four efficient ionic quenchers (iron complexes) in aqueous solutions were carried out to verify the theoretical prediction. A detailed data analysis of the quenched fluorescence decay over a range of concentration of the quenchers supports the prediction that the ``long'' time rate coefficient is k(t)˜a+bt-1/2. Exact agreement with the theoretical predictions is not obtained in any of the fluorophore-quencher systems described in this work. Cresyl violet-ferrocyanide and cresyl violet-ferricyanide are two systems for which the experimental values of diffusion coefficient D and distance parameter RHN are justifiably close to theoretical expectation.

Periasamy, N.; Doraiswamy, S.; Maiya, G. B.; Venkataraman, B.

1988-02-01

202

Radical C?H Arylation of the BODIPY Core with Aryldiazonium Salts: Synthesis of Highly Fluorescent Red-Shifted Dyes.  

PubMed

We describe herein the first radical C?H arylation of BODIPY dyes. This novel, general, one-step synthetic procedure uses ferrocene to generate aryl radical species from aryldiazonium salts and allows the straightforward synthesis of brightly fluorescent (?>0.85) 3,5-diarylated and 3-monoarylated boron dipyrrins in up to 86?% yield for a broad range of aryl substituents. In this way, new and complex dyes with red-shifted spectra can be easily prepared. PMID:25689682

Verbelen, Bram; Boodts, Stijn; Hofkens, Johan; Boens, Noël; Dehaen, Wim

2015-04-01

203

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. PMID:25435859

Popenko, Oleksandr

2014-01-01

204

Steady-state and time-resolved fluorescence study of some dyes in polymer microspheres showing morphology dependent resonances  

NASA Astrophysics Data System (ADS)

Fluorescence emission spectra of N,N'-bis(2,5-di-tert-butylphenyl)-3,4:9,10- Perylenebis(dicarboximide) (DBPI), rhodamine 6G (R6G), and cresyl violet (CV) in spherical polymer beads of less than 20 ?m diameter show sharp ripple structures. The observed peak positions and the intervals of the structures are consistent with the calculations of the morphology dependent resonances (MDR). Observed intensities of the MDR in the fluorescence emission spectra are found to show excitation energy dependence. The fluorescence spectra have also been measured as a function of the refractive indexes of the medium and the bead. These MDR in the beads up to 4 ?m diameter do not appear to affect the fluorescence decay of the dyes, since the fluorescence lifetime remains constant irrespective of the size of the bead and the refractive index of a surrounding medium. Simulations based on the Lorentz-Mie theory for the microspheres of different refractive indexes have been used to quantify the observed effect on the basis of the available data on the homogeneous widths of the dye molecules. A fluorescence study of microcrystals of DBPI is also presented here from the point of view of comparison with fluorescence decay of dye impregnated beads. The microcrystals exhibit a size effect in the fluorescence decay which has been attributed mainly to the self-absorption effect.

Bisht, Prem B.; Fukuda, Kazuhiro; Hirayama, Satoshi

1996-11-01

205

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

206

Micelles assembled with carbocyanine dyes for theranostic near-infrared fluorescent cancer imaging and photothermal therapy.  

PubMed

It is an emerging focus to explore a theranostic nanocarrier for simultaneous cancer imaging and therapy. Herein, we demonstrate a theranostic micelle system for cancer near infrared fluorescent (NIRF) imaging with enhanced signal to noise ratio and superior photothermal therapy. The copolymers consisting of monomethoxy poly(ethylene glycol) and alkylamine-grafted poly(L-aspartic acid) are assembled with carbocyanine dyes into theranostic micelles, which exhibit small size, high loading capacity, good stability, sustained release behavior, and enhanced cellular uptake. The micelles achieve the preferable biodistribution and long-term retention of carbocyanine dyes at tumor, which result in enhanced NIRF imaging by generating stable retention of NIRF signals at both hypervascular and hypovascular tumors during a long-term imaging period of up to 8 day, accompanying with negligible noise at normal tissues. The photostability of carbocyanine dye (Cypate) plays an important role for long-term cancer imaging with enhanced SNR. Moreover, the micelles exhibit severe photothermal damage on cancer cells via the destabilization of subcellular organelles upon photoirradiation, causing superior photothermal tumor regress. The micelles act as a powerful theranostic nanocarrier for simultaneous cancer imaging with high contrast and superior photothermal therapy. PMID:24008037

Yang, Hong; Mao, Huajian; Wan, Zhihui; Zhu, Aijun; Guo, Miao; Li, Yanli; Li, Xinming; Wan, Jiangling; Yang, Xiangliang; Shuai, Xintao; Chen, Huabing

2013-12-01

207

Energy transfer processes in dye-doped nanostructures yield cooperative and versatile fluorescent probes  

NASA Astrophysics Data System (ADS)

Fast and efficient energy transfer among dyes confined in nanocontainers provides the basis of outstanding functionalities in new-generation luminescent probes. This feature article provides an overview of recent research achievements on luminescent Pluronic-Silica NanoParticles (PluS NPs), a class of extremely monodisperse core-shell nanoparticles whose design can be easily tuned to match specific needs for diverse applications based on luminescence, and that have already been successfully tested in in vivo imaging. An outline of their outstanding properties, such as tuneability, bright and photoswitchable fluorescence and electrochemiluminescence, will be supported by a critical discussion of our recent works in this field. Furthermore, novel data and simulations will be presented to (i) thoroughly examine common issues arising from the inclusion of multiple dyes in a small silica core, and (ii) show the emergence of a cooperative behaviour among embedded dyes. Such cooperative behaviour provides a handle for fine control of brightness, emission colour and self-quenching phenomena in PluS NPs, leading to significantly enhanced signal to noise ratios.

Genovese, Damiano; Rampazzo, Enrico; Bonacchi, Sara; Montalti, Marco; Zaccheroni, Nelsi; Prodi, Luca

2014-02-01

208

Probing quenched dye fluorescence of Cy3-DNA-Au-nanoparticle hybrid conjugates using solution and array platforms.  

PubMed

Tuning the luminescence intensity of fluorophores using nanoparticles has shown great potential for the detection of inorganic metal ions, viruses, and proteins. The enhancement or quenching of a dye's fluorescence intensity is strongly dependent on the spatial separation of the dye from the nanoparticle surface. To extend luminescence probing from the solution platform to the solid-state platform, we explored and performed dye quenching assessment using an array format in this study. We report the distance-dependent fluorescence behavior of Au-DNA conjugates prepared by equilibrating phosphine-stabilized gold nanoparticles (AuNPs) of 10-nm size with the designed spacer ds-DNA consisting of thiol-modified target and Cy3-labeled complementary probe of different lengths (5-20 nm). The Cy3-labeled products were immobilized onto MPTMS (3-mercaptopropyltrimethoxysilane)-modified glass substrates and then excited with a 532-nm laser source. Quenching efficiency of AuNPs with increasing Au-to-dye distance was assessed using ligand exchange of the thiolated oligonucleotide by 2-mercaptoethanol (ME) to obtain free Cy3-DNA probe, thus eliminating nanoparticle effect on the dye's luminescence intensity. Effective exchange, revealed by UV-vis absorption and fluorescence profiles, was achieved in a few minutes. It was observed that fluorescence quenching of Au-DNA-Cy3 assessed using the array format was consistent with the result in solution phase for the conjugates with up to 10-nm Au-to-Cy3 separation distance. PMID:22305419

Obliosca, Judy M; Wang, Pen-Cheng; Tseng, Fan-Gang

2012-04-01

209

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

PubMed

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

2014-10-23

210

Preparation and properties of nanosized fluorescent solid films based on a polyelectrolyte-surfactant complex with organic dyes  

NASA Astrophysics Data System (ADS)

A procedure for preparing an organosoluble stoichiometric complex based on a cationic polyelectrolyte and an anionic surfactant is described. A method is proposed for forming monolayers at the water-air interface, along with conditions for preparing fluorescent nanosized solid films based on polyelectrolyte complex and organic dyes using the Langmuir-Blodgett (LB) method. The spectral and luminescent properties of the obtained films are investigated. It is established from the absorption and fluorescence spectra of LB films that electrostatic interaction between the molecules of polyelectrolyte complex and oxazine dyes results in dimer formation.

Seliverstova, E. V.; Ibrayev, N. Kh.; Kudaibergenov, S. E.

2013-05-01

211

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

ADLER, LYNN S.; IRWIN, REBECCA E.

2006-01-01

212

DNA Sequence-Enabled Reassembly of the Green Fluorescent Protein Cliff I. Stains, Jason R. Porter, Aik T. Ooi, David J. Segal,*, and Indraneel Ghosh*,  

E-print Network

DNA Sequence-Enabled Reassembly of the Green Fluorescent Protein Cliff I. Stains, Jason R. Porter only in the presence of a specific DNA sequence (Figure 1) to allow for direct detection of DNA availability of DNA binding Cys2-His2 zinc finger motifs3 for targeting desired sequences of double

Ghosh, Indraneel

213

Use of fluorescent-antibody staining of cytocentrifuge-prepared smears in combination with cell culture for direct detection of respiratory viruses.  

PubMed

Over a 3-year period, 1,003 respiratory samples were collected and examined for selected respiratory viruses with cytocentrifuged prepared smears stained with fluorescently labeled antibodies (IFA) in conjunction with cell culture. IFA results were compared with results obtained by cell culture. Viruses were isolated or detected by direct means in 401 samples. Agreement between culture and IFA was 90%. PMID:9650977

Doing, K M; Jerkofsky, M A; Dow, E G; Jellison, J A

1998-07-01

214

Improvement of ciliate identification and quantification: a new protocol for fluorescence in situ hybridization (FISH) in combination with silver stain techniques.  

PubMed

A new protocol for taxon specific probe based fluorescent in situ hybridization was developed for the identification and quantification of ciliates in microbial communities. Various fixatives and experimental parameters were evaluated and optimized with respect to cell permeability and morphological preservation. Optimum results were adaption by obatined of a modified fixation method using Bouin's solution. Furthermore, conventional staining procedures such as different Protargol stain techniques and a silver nitrate impregnation method were modified and can now be applied in combination with fluorescence in situ hybridization. The new protocol allows a rapid and reliable identification as well as quantification of ciliates based upon classical morphological aspects and rRNA based phylogenetic relationships performed in one experiment. Furthermore, a set of specific probes targeting different regions of the 18S rRNA was designed for Glaucoma scintillans Ehrenberg, 1830 and tested by applying this new approach of combining in situ cell hybridization with conventional staining techniques. PMID:12583717

Fried, Johannes; Ludwig, Wolfgang; Psenner, Roland; Schleifer, Karl Heinz

2002-12-01

215

Single-lane single-fluor sequencing using dideoxy-labeled, heavy-atom-modified near-IR fluorescent dyes  

Microsoft Academic Search

Using a near-IR (NIR) fluorescence detection system and labels synthesized in our laboratories, electropherograms of oligonucleotides separated by capillary gel electrophoresis and detected using NIR fluorescence will be presented. The sequence of nucleotide bases was determined using a single-lane, single-dye technique. The molar concentrations of the ddNTP's used during extension reactions were varied in order to achieve a ratio of

Daryl C. Williams; James H. Flanagan; Benjamin L. Legendre; Robert P. Hammer; Steven A. Soper

1995-01-01

216

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

SciTech Connect

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{sub 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{sup 2}/g) with 3.40 nm pore diameter and a high fluorescence in the near infrared region at {lambda}=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 {mu}m/s under the influence of a magnetic field, hence demonstrating the multifunctionality and potential for biomedical applications in targeting and imaging. - Graphical Abstract: Hydrophobic fluorescent Ruthenium complex has been loaded into the mesopores as a surrogate drug to simulate drug delivery and to enhance the multifunctionality of the magnetic NIR emitting particles. Highlights: > Monodisperse magnetic mesoporous silica particles emitting in the near infrared region are obtained in one-pot synthesis. > We prove the capacity of such particles to uptake hydrophobic dye to mimic drug loading. > Loaded fluorescent particles can be moved under a magnetic field in a microfluidic device.

Le Guevel, Xavier, E-mail: xavier.leguevel@dcu.ie [Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Nooney, Robert; McDonagh, Colette; MacCraith, Brian D. [Biomedical Diagnostics Institute, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland)

2011-06-15

217

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

2012-01-01

218

Fluorescent viability stains to probe the metabolic status of aflatoxigenic fungus in dual culture of Aspergillus flavus and Pichia anomala  

Technology Transfer Automated Retrieval System (TEKTRAN)

The metabolic activity of aflatoxigenic fungus, Aspergillus flavus co-cultured with a biocontrol yeast, Pichia anomala was examined using several vital stains. Both the FUN-1 stain and the combined use of DiBAC4(5) with CDFA-AM stains demonstrated that P. anomala inactivated the ATP generating syst...

219

Enhancement of the molecular hyperpolarizability by a supramolecular amylose dye inclusion complex, studied by hyper-Rayleigh scattering with fluorescence suppression  

NASA Astrophysics Data System (ADS)

The first hyperpolarizability ? of a free hemicyanine dye and a homologue dye included in a supramolecular complex have been determined by hyper-Rayleigh scattering. Since the inclusion complex is fluorescent, high-frequency demodulation of the time-delayed multiphoton fluorescence has been used to retrieve a fluorescence-free inherent value for its first hyperpolarizability. The free dye does not exhibit fluorescence; the inclusion induces fluorescence with a lifetime of 4.8±0.1 ns; and the inclusion complex has a fluorescence-free value for its dispersion-free first hyperpolarizability ?0 of approximately twice that for the free dye ((200±5)×10 -30 vs. (100±10)×10 -30 esu)). The enhanced polar orientation of this complex in thin films, and better thermal and mechanical stability, together with this increase in molecular nonlinearity confirm inclusion as a way to engineer efficient macroscopic arrangements for nonlinear optics.

Clays, Koen; Olbrechts, Geert; Munters, Tom; Persoons, André; Kim, Oh-Kil; Choi, Ling-Siu

1998-09-01

220

Photochemistry and Photobiology, 2004, 79(5): 440446 The Complex of Apomyoglobin with the Fluorescent Dye Coumarin 153{  

E-print Network

with the Fluorescent Dye Coumarin 153{ P. K. Chowdhury1 , M. Halder1 , L. Sanders1 , R. A. Arnold1 , Y. Liu1 , D. W is provided by the complex of coumarin 153 (C153) with apomyoglobin (ApoMb). C153 has been exhaustively

Song, Xueyu

221

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

EPA Science Inventory

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

222

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

Microsoft Academic Search

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

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

1997-01-01

223

dsDNA-specific fluorescent copper nanoparticles as a "green" nano-dye for polymerization-mediated biochemical analysis.  

PubMed

Here we exploit dsDNA-specific fluorescent copper nanoparticles (CuNPs) as a "green" nano-dye for polymerization-mediated biochemical analysis. Good feasibility and universality are demonstrated through detecting three model targets (polymerase, mercury ion and nucleic acid). PMID:25204899

Qing, Zhihe; Qing, Taiping; Mao, Zhengui; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui; He, Dinggeng

2014-10-28

224

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.

2011-06-01

225

Gram stain  

MedlinePLUS

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

226

Thiophene-based dyes for probing membranes.  

PubMed

We report the synthesis of four new cationic dipolar push-pull dyes, together with an evaluation of their photophysical and photobiological characteristics pertinent to imaging membranes by fluorescence and second harmonic generation (SHG). All four dyes consist of an N,N-diethylaniline electron-donor conjugated to a pyridinium electron-acceptor via a thiophene bridge, with either vinylene (-CH[double bond, length as m-dash]CH-) or ethynylene (-C[triple bond, length as m-dash]C-) linking groups, and with either singly-charged or doubly-charged pyridinium terminals. The absorption and fluorescence behavior of these dyes were compared to a commercially available fluorescent membrane stain, the styryl dye FM4-64. The hyperpolarizabilities of all dyes were compared using hyper-Rayleigh scattering at 800 nm. Cellular uptake, localization, toxicity and phototoxicity were evaluated using tissue cell cultures (HeLa, SK-OV-3 and MDA-231). Replacing the central alkene bridge of FM4-64 with a thiophene does not substantially change the absorption, fluorescence or hyperpolarizability, whereas changing the vinylene-links to ethynylenes shifts the absorption and fluorescence to shorter wavelengths, and reduces the hyperpolarizability by about a factor of two. SHG and fluorescence imaging experiments in live cells showed that the doubly-charged thiophene dyes localize in plasma membranes, and exhibit lower internalization rates compared to FM4-64, resulting in less signal from the cell cytosol. At a typical imaging concentration of 1 ?M, the doubly-charged dyes showed no significant light or dark toxicity, whereas the singly-charged dyes are phototoxic even at 0.5 ?M. The doubly-charged dyes showed phototoxicity at concentrations greater than 10 ?M, although they do not generate singlet oxygen, indicating that the phototoxicity is type I rather than type II. The doubly-charged thiophene dyes are more effective than FM4-64 as SHG dyes for live cells. PMID:25703541

López-Duarte, Ismael; Chairatana, Phoom; Wu, Yilei; Pérez-Moreno, Javier; Bennett, Philip M; Reeve, James E; Boczarow, Igor; Kaluza, Wojciech; Hosny, Neveen A; Stranks, Samuel D; Nicholas, Robin J; Clays, Koen; Kuimova, Marina K; Anderson, Harry L

2015-03-11

227

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.

2013-03-01

228

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

229

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

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

230

Wood stains  

MedlinePLUS

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.

231

Comparing mono- and divalent DNA groove binding cyanine dyes -- binding geometries, dissociation rates, and fluorescence properties.  

PubMed

The unsymmetrical cyanine dyes BOXTO-PRO and BOXTO-MEE were derived from the DNA groove binder BOXTO, by adding a positively charged or a non-ionic hydrophilic tail to BOXTO, respectively. The main objective was to obtain more efficient DNA probes, for instance in electrophoresis and microscopy, by slowing down the dissociation of BOXTO from DNA. The interactions with mixed sequence DNA was studied with fluorescence and absorbance spectroscopy, stopped-flow dissociation and gel electrophoresis. Both the derivatives are groove bound as BOXTO, and have similar fluorescence properties when bound to mixed sequence DNA in free solution. BOXTO-PRO exhibits a slower dissociation than BOXTO from DNA, whereas the dissociation rate for BOXTO-MEE is faster and, unexpectedly independent of the ionic strength. During gel electrophoresis both BOXTO-PRO and BOXTO-MEE exhibit a faster dissociation rate than BOXTO. Still, BOXTO-PRO seems to be a good alternative as DNA probe, especially for applications in free solution where the dissociation is slower than for the corresponding intercalator TOPRO-1. PMID:16624475

Eriksson, Maja; Westerlund, Fredrik; Mehmedovic, Merima; Lincoln, Per; Westman, Gunnar; Larsson, Anette; Akerman, Björn

2006-08-01

232

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

PubMed Central

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

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

2014-01-01

233

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

Microsoft Academic Search

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

P. Del Castillo; A. R. Llorente; A. Gomez; J. Gosalvez; V. J. Goyanes; J. C. Stockert

1990-01-01

234

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

2014-01-01

235

SELECTIVITY AND SPECIFICITY OF SMALL MOLECULE FLUORESCENT DYES/PROBES USED FOR THE DETECTION OF Zn2+ AND Ca2+ IN CELLS  

PubMed Central

Fluorescent dyes are widely used in the detection of labile (free or exchangeable) Zn2+ and Ca2+ in living cells. However, their specificity over other cations and selectivity for detection of labile vs. protein-bound metal in cells remains unclear. We characterized these important properties for commonly used Zn2+ and Ca2+ dyes in a cellular environment. By tracing the fluorescence emission signal along with UV-Vis and size exclusion chromatography-inductively coupled plasma mass spectrometry (SEC-ICP-MS) in tandem, we demonstrated that among the dyes used for Zn2+, Zinpyr-1 fluoresces in the low molecular mass (LMM) region containing labile Zn2+, but also fluoresces in different molecular mass regions where zinc ion is detected. However, FluoZin™-3 AM, Newport Green™ DCF and Zinquin ethyl ester display weak fluorescence, lack of metal specificity and respond strongly in the high molecular mass (HMM) region. Four Ca2+ dyes were studied in an unperturbed cellular environment, and two of these were tested for binding behavior under an intracellular Ca2+ release stimulus. A majority of Ca2+ was in the labile form as tested by SEC-ICP-MS, but the fluorescence from Calcium Green-1™ AM, Oregon Green® 488 BAPTA-1, Fura red™ AM and Fluo-4 NW dyes in cells did not correspond to free Ca2+ detection. Instead, the dyes showed non-specific fluorescence in the mid- and high-molecular mass regions containing Zn, Fe and Cu. Proteomic analysis of one of the commonly seen fluorescing regions showed the possibility for some dyes to recognize Zn and Cu bound to metallothionein-2. These studies indicate that Zn2+ and Ca2+ binding dyes manifest fluorescence responses that are not unique to recognition of labile metals and bind other metals, leading to suboptimal specificity and selectivity. PMID:24356796

Landero-Figueroa, Julio A.; Vignesh, Kavitha Subramanian; Deepe, George; Caruso, Joseph

2014-01-01

236

Handling and detection of 25 amol of near-infrared dye deoxynucleotide conjugates by capillary electrophoresis with laser-induced fluorescence detection  

Microsoft Academic Search

Near-infrared dyes are attractive as labeling reagents to enhance sensitivity in trace analysis largely because background fluorescence is low in this spectral region. Here we demonstrate, towards a goal of detecting DNA adducts in small biological samples, that some near-infrared (IR) dye-labeled deoxynucleotides can be separated and detected with high sensitivity by capillary electrophoresis (CE)–laser-induced fluorescence detection (LIF) in a

Guodong Li; Jianxin Gao; Xiaojuan Zhou; Olga Shimelis; Roger W. Giese

2003-01-01

237

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

2014-10-01

238

Treatment of port wine stains with pulsed dye laser: a retrospective study of 848 cases in Shandong Province, People’s Republic of China  

PubMed Central

Background Currently, 595 nm pulsed dye laser (PDL) therapy is offered as one of the effective treatments of port wine stains (PWSs). However, the efficacy of PDL differs in different populations. Objective The purpose of the study was to investigate the efficacy, and related factors, of 595 nm PDL in the treatment of PWSs in Chinese patients with skin type III to IV. Methods A total of 848 cases that were treated with PDL were enrolled and analyzed in this study. An independent dermatologist evaluated these lesions according to the before and after photographs. Results The response rate (RR) of all the 848 PWS patients was 69.9%, within which the cure rate was 6.3%. The patients aged ?1 year had the highest RR (93.9%), whereas those treated after age 50 reacted the worst (RR =25%). We analyzed the anatomical distribution of the lesion and found that the temporal region had the highest lesion clearance (RR =75.3%), while the extremities had the lowest clearance (RR =44.5%). Compared with the patients whose lesion size was larger than 80 cm2, the patients with small lesion size, of 0–20 cm2, had better clinical effect (RR =73.8% vs 53.2%). The reactions of the patients with hyperplastic lesion were worse than those with red patches (RR =36.4% vs 71.7%). As well, increasing treatment numbers could achieve higher clearance rates (P=0.005). Conclusion The PDL had a relatively high RR but a low clearance rate in Chinese patients with PWS, although the earlier the intervention, the better was the efficacy. The response of PDL was, not only related to the anatomical area, but also, to the lesion size, type of lesion (ie, the presence of existing hyperplastic lesions), and the number of treatment, all of which are essential for the evaluation of therapeutic effect and acquisition of patients consent before treatment. PMID:25548515

Shi, Wenhao; Wang, Jinliang; Lin, Yan; Geng, Jianhui; Wang, Haixia; Gong, Yueqin; Liu, Huaxu; Zhang, Furen

2014-01-01

239

DFT/TDDFT investigation on the UV-vis absorption and fluorescence properties of alizarin dye.  

PubMed

The photophysical and photochemical properties of alizarin, a fluorescent organic red dye of the family of the anthraquinones, have been theoretically investigated by focusing our attention on its emission properties in relation to an excited-state internal proton transfers from the phenolic hydroxyl group to the carbonyl oxygen. The potential energy curve of the proton transfer in the first excited state has been computed in solvents of different polarity and the emission spectra of both tautomers simulated, including the vibronic effects, using the Franck-Condon approximation. Calculations performed by equilibrating the solvent with the excited-state geometry and electron density using a self-consistent procedure have led to interesting differences with respect to their linear response counterpart. The results obtained point out that, while the emission energy of alizarin is sensitive to solvent polarity, that of the proton-transfer tautomer is computed at similar wavelengths independently of the solvent. Comparison between computed and experimental data has allowed us to rationalize the alizarin double emission measured in non-polar solvents. PMID:25651191

Amat, Anna; Miliani, Costanza; Romani, Aldo; Fantacci, Simona

2015-02-18

240

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.

2013-10-01

241

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

PubMed

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. PMID:24056530

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

2013-11-01

242

Biological staining: mechanisms and theory.  

PubMed

New staining techniques continue to be introduced, and older ones continue to be used and improved. Several factors control specificity, selectivity and visibility of the end product in any procedure using dyes, fluorochromes, inorganic reagents or histochemical reactions applied to sections or similar preparations. Local concentration of the tissue target often determines the intensity of the observed color, as does the fine structure within the object being stained, which may facilitate or impede diffusion of dyes and other reagents. Several contributions to affinity control the specificity of staining. These include electrical forces, which result in accumulation of dye ions in regions of oppositely charged tissue polyions. Weaker short-range attractions (hydrogen bonding, van der Waals forces or hydrophobic bonding, depending on the solvent) hold dyes ions and histochemical end products in contact with their macromolecular substrates. Nonionic forces can also increase visibility of stained sites by causing aggregation of dye molecules. Covalent bonds between dye and tissue result in the strongest binding, such as in methods using Schiff's reagent and possibly also some mordant dyes. The rate at which a reagent gains access to or is removed from targets in a section or other specimen affect what is stained, especially when more then one dye is used, together or sequentially. Rate-controlled staining is greatly influenced by the presence and type of embedding medium, such as a resin, that infiltrates the tissue. The rates of chemical reactions are major determinants of outcome in many histochemical techniques. Selective staining of different organelles within living cells is accomplished mainly with fluorochromes and is controlled by mechanisms different from those that apply to fixed tissues. Quantitative structure-activity relations (QSAR) of such reagents can be derived from such molecular properties as hydrophilic-hydrophobic balance, extent of conjugated bond systems, acid-base properties and ionic charge. The QSAR correlates with staining of endoplasmic reticulum, lysosomes, mitochondria, DNA, or the plasma membranes of living cells. PMID:11991329

Horobin, R W

2002-01-01

243

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

PubMed

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

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

2015-01-14

244

Simultaneous optical coherence tomography-Indocyanine Green dye fluorescence imaging system for investigations of the eye's fundus  

NASA Astrophysics Data System (ADS)

We have developed a dual-channel optical coherence tomography-Indocyanine Green dye (OCT-ICG) fluorescence system based on a previously reported ophthalmic OCT confocal imaging system. The confocal channel is tuned to the fluorescence wavelength range of the ICG, and light from the same optical source is used to generate the OCT image and to excite the ICG fluorescence. The system enables the clinician to visualize simultaneously en face OCT slices and corresponding ICG angiograms of the ocular fundus, displayed side by side. C-scan (constant depth) and B-scan (cross section) images are collected by a fast en face scan (T scan). The pixel-to-pixel correspondence between the OCT and angiography images allows the user to capture OCT Bscans precisely at selected points on the ICG confocal images.

Dobre, George M.; Podoleanu, Adrian Gh.; Rosen, Richard B.

2005-01-01

245

In vivo fluorescence imaging of lysosomes: a potential technique to follow dye accumulation in the context of PDT?  

NASA Astrophysics Data System (ADS)

Lysosomes and intracellular acidic compartments seem to play an important role in the context of PDT. Some photosensitizers are localized in the lysosomes of tumor-associated macrophages. Liposomes, which are lysosomotropic drug carriers, are used to deliver photosensitizers in tumors. Liposomes are taken up by the liver cells after intravenous injection. Intracellular pathway and liposomes localization in the different liver cells require sacrifice of the animals, cell separation, and observation by electronic microscopy. Little is known about liposomes kinetic uptake by the acidic intracellular compartments in vivo. We propose in this study a new method to follow liposomes uptake in the liver in vivo using a fluorescent pH-sensitive probe. We have already demonstrated the ability of fluorescence spectroscopy and imaging using a pH-dependent probe to monitor pH in living tissues. As pH of lysosome is very low, the kinetic of liposome uptake in this intracellular acidic compartment is followed by monitoring the pH of the whole liver in vivo and ex vivo. Liposomes-encapsulated carboxyfluorescein are prepared by the sonication procedure. Carboxyfluorescein is used at high concentration (100 mM) in order to quench its fluorescence. Liposomes are injected to Wistar rats into the peinil vein. After laparotomy, fluorescence spectra and images are recorded during two hours. Results show a rapid fluorescence increase followed by a slow phase of fluorescence decrease. pH decreases from physiological value to 6.0. After sacrifice and flush with cold saline solution, pH of liver ex vivo is found to be 5.0 - 5.5. These data show a rapid clearance of released dye and an uptake of liposomes by the liver cells and, as liposomes penetrate in the acidic compartment, dye is released from liposomes and is delivered in lysosomes leading to the decrease of pH.

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

1995-03-01

246

Bulk and single-molecule fluorescence studies of the saturation of the DNA double helix using YOYO-3 intercalator dye.  

PubMed

We report a thorough photophysical characterization of the interactions between double-stranded DNA (dsDNA) and the trimethine cyanine homodimer dye YOYO-3. The fluorescence emission of this dye is enhanced by intercalation within the DNA double helix. We have explored the saturation of the dsDNA by bound YOYO-3 at the single-molecule level by studying the single-pair Förster resonance energy transfer (FRET) from an energy donor, Alexa Fluor 488, tagged at the 5' end of the double helix and the energy acceptor, YOYO-3, bound to the same DNA molecule. The spontaneous binding of YOYO-3 gives rise to an effective distribution of different FRET efficiencies and, therefore, donor-acceptor (D-A) distances. These distributions reveal the existence of multiple states of YOYO-3. Steady-state and time-resolved fluorescence and circular dichroism confirmed the presence of a DNA-bound aggregate of YOYO-3, conspicuous at high dye/base pair ratios. The spectral features of the aggregate suggest that it may have the structure of a parallel H-aggregate. PMID:22947035

Lopez, Sergio G; Ruedas-Rama, Maria J; Casares, Salvador; Alvarez-Pez, Jose M; Orte, Angel

2012-09-27

247

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

PubMed Central

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

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

2015-01-01

248

Solvent influence on absorption and fluorescence spectra of merocyanine dyes: a theoretical and experimental study  

NASA Astrophysics Data System (ADS)

The solvaton-CS INDO model, previously successfully used to describe the solvatochromic properties of merocyanines, has been extended to the study of the solvent influence on the fluorescence spectra (fluorosolvatochromism) of these dyes. A ketocyanine (M1) and a stilbazolium betaine (M2) were chosen as representatives of positively and negatively solvatochromic behaviours, respectively. The gap of experimental knowledge concerning the emission properties of M2 was filled by a spectrofluorometric analysis in a set of solvents covering a large range of the ET(30) scale. Solvato- and fluorosolvatochromism were described by calculating the S 0(eq.)?S 1(Franck-Condon) and S 1(eq.)?S 0(Franck-Condon) transition energies as a function of a polarity factor related to the static dielectric constant of the solvent, and ranging from 0 to 1. The absorbing S 0(eq.) and emitting S 1(eq.) units (solute molecule + solvent cage) were approximated using the S 0 and S 1 geometries of the unsolvated molecule and the respective charge distributions fitted to the current value of k( ?). The calculation results fully confirm that S 0 and S 1 states of merocyanines can be viewed as a mixture of a neutral and a zwitterionic structure whose composition is controlled by the solvent polarity. The plots of the calculated spectral data (absorption and emission maxima and corresponding Stokes shifts) vs k( ?) are in fairly good agreement with those of the experimental data over almost the entire range of the normalized ETN values, thus showing that specific solvent interactions are at least partly simulated within the solvaton-CS INDO scheme. The methodological prerequisites for a correct prediction of solvatochromic shifts are recalled with reference to previous conflicting theoretical interpretations.

Baraldi, I.; Brancolini, G.; Momicchioli, F.; Ponterini, G.; Vanossi, D.

2003-03-01

249

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

PubMed

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

2014-05-01

250

Modulating Fluorescence Anisotropy of Terminally Labeled Double-Stranded DNA via the Interaction between Dye and Nucleotides for Rational Design of DNA Recognition Based Applications.  

PubMed

Effective signal enhancement for fluorescence anisotropy in a simple manner is most desirable for fluorescence anisotropy method development. This work aimed to provide insights into the fluorescence anisotropy of terminally labeled double-stranded DNA (dsDNA) to facilitate a facile and universal design strategy for DNA recognition based applications. We demonstrated that fluorescence anisotropy of dsDNA could be regulated by the nature of dyes, the molecular volume, and the end structure of dsDNA. Fluorescence anisotropy ascended with the increased number of base pairs up to 18 bp and leveled off thereafter, indicating the molecular volume was not the only factor responsible for fluorescence anisotropy. By choosing dyes with the positively charged center, high fluorescence anisotropy signal was obtained due to the confinement of the segmental motion of dyes through the electrostatic interaction. By properly designing the end structure of dsDNA, fluorescence anisotropy could be further improved by enlarging the effective overall rotational volume, as supported by two-dimensional (2D) (1)H-(1)H nuclear Overhauser enhancement spectroscopy (NOESY). With the successful enhancement of the fluorescence anisotropy for terminally labeled dsDNA, simple and universal designs were demonstrated by sensing of major classes of analytes from macromolecules (DNA and protein) to small molecules (cocaine). PMID:25671552

Huang, Hongduan; Wei, Hejia; Zou, Mingjian; Xu, Xiao; Xia, Bin; Liu, Feng; Li, Na

2015-03-01

251

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. PMID:25349674

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

2014-01-01

252

Measurement of Bluetongue Virus Binding to a Mammalian Cell Surface Receptor by an In Situ Immune Fluorescent Staining Technique  

Technology Transfer Automated Retrieval System (TEKTRAN)

A quantifiable in situ immune fluorescent assay (IFA) was developed to measure bluetongue virus (BTV) binding to mammalian cells. The utility of the assay was demonstrated with both Chinese hamster ovary (CHO) and bovine pulmonary artery endothelial (CPAE) cells. Since heparin sulfate (HS) has been ...

253

In Situ Immune Infrared Fluorescent Staining for Detection and Quantification of Bluetongue Virus in Cullicoides Insect Cell Culture  

Technology Transfer Automated Retrieval System (TEKTRAN)

Bluetongue virus (BTV) is transmitted to sheep, cattle and other ruminants by Culicoides spp. of biting midges. Cell lines have been developed from C. sonorensis; however, techniques for directly detecting and quantifying virus in these insect cells are lacking. In situ immune infrared fluorescent s...

254

A long-wavelength fluorescent squarylium cyanine dye possessing boronic acid for sensing monosaccharides and glycoproteins with high enhancement in aqueous solution.  

PubMed

Fluorescence sensing of saccharides and glycoproteins using a boronic acid functionalized squarylium cyanine dye ("SQ-BA") is characterized in terms of synthetic, fluorometric, thermodynamic and kinetic parameters. In our previous work, this newly synthesized dye was successfully applied to the separation and quantification of Gram-positive bacteria by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF); however, the fundamental properties of the dye and its saccharide complexes still required elucidation, as presented in this paper. The dye itself forms nonemissive, soluble aggregates in aqueous solution. With the addition of a monosaccharide, the dye aggregate dissociates to form an emissive monomer accompanied by the formation of a cyclic cis-diol ester with long-wavelength emission (?(ex) = 630 nm, ?(em) = 660 nm). A very large fluorescence enhancement factor of 18× was observed for the sensing dye as a fructose complex at pH 10, yielding a limit of detection of 10 ?M fructose. The relative order of fluorescence enhancement of SQ-BA with other monosaccharides was found to be: fructose > ribose > arabinose ? galactose > xylose > mannose > rhamnose > fucose ? glucose; and apparent affinity constants of 10(2.80), 10(2.08) and 10(0.86) M(-1) were determined for fructose, ribose and glucose, respectively. Formation of the emissive complexes occurred within minutes, proving the kinetics of the sugar-dye interactions to be suitable for on-column labeling methods in CE-LIF. Furthermore, the sensing dye was successfully applied to glycoproteins, mucin type I-S and type III, which were detected with high sensitivity in batch aqueous solution as a result of the sugar-selective boronic acid-diol esterification as well as hydrophobic interactions. PMID:22778592

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

2012-01-01

255

DNA complexes with dyes designed for energy transfer as fluorescent markers  

DOEpatents

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

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

1995-03-28

256

Highly Photostable Near-Infrared Fluorescent pH Indicators and Sensors Based on BF2-Chelated Tetraarylazadipyrromethene Dyes  

PubMed Central

In this study, a series of new BF2-chelated tetraarylazadipyrromethane dyes are synthesized and are shown to be suitable for the preparation of on/off photoinduced electron transfer modulated fluorescent sensors. The new indicators are noncovalently entrapped in polyurethane hydrogel D4 and feature absorption maxima in the range 660–710 nm and fluorescence emission maxima at 680–740 nm. Indicators have high molar absorption coefficients of ?80?000 M–1 cm–1, good quantum yields (up to 20%), excellent photostability and low cross-sensitivity to the ionic strength. pKa values of indicators are determined from absorbance and fluorescence measurements and range from 7 to 11, depending on the substitution pattern of electron-donating and -withdrawing functionalities. Therefore, the new indicators are suitable for exploitation and adaptation in a diverse range of analytical applications. Apparent pKa values in sensor films derived from fluorescence data show 0.5–1 pH units lower values in comparison with those derived from the absorption data due to Förster resonance energy transfer from protonated to deprotonated form. A dual-lifetime referenced sensor is prepared, and application for monitoring of pH in corals is demonstrated. PMID:22738322

2012-01-01

257

Ultrasound-guided fine-needle aspiration of a posterior neck dedifferentiated liposarcoma with MDM2 fluorescence in situ hybridization performed on a Pap-stained smear.  

PubMed

Head and neck liposarcomas, while rare, tend to be subcutaneous and well-differentiated. Dedifferentiated liposarcomas of the head and neck are exceedingly rare in the literature. We present a case of a dedifferentiated liposarcoma arising in the soft tissue of the posterior neck of an 86-year-old man and diagnosed by fine-needle aspiration. Aspirate smears showed a dual population of atypical lipomatous and spindled cells. MDM2 (murine double minute 2) amplification was demonstrated on a Pap-stained smear using fluorescence in situ hybridization (FISH). To the best of our knowledge, this is the first report of MDM2 FISH amplification in a liposarcoma performed on an aspirate smear. Diagn. Cytopathol. 2015;43:320-324. © 2014 Wiley Periodicals, Inc. PMID:25132684

Zreik, Riyam; Soyalp, Krystal; Ruiz, Steve; Ward, Russell; Dobin, Sheila; Chen, Xiangbai; Liu, Lina; Rao, Arundhati

2015-04-01

258

In vivo tumor-targeted dual-modal fluorescence/CT imaging using a nanoprobe co-loaded with an aggregation-induced emission dye and gold nanoparticles.  

PubMed

As an intensely studied computed tomography (CT) contrast agent, gold nanoparticle has been suggested to be combined with fluorescence imaging modality to offset the low sensitivity of CT. However, the strong quenching of gold nanoparticle on fluorescent dyes requires complicated design and shielding to overcome. Herein, we report a unique nanoprobe (M-NPAPF-Au) co-loading an aggregation-induced emission (AIE) red dye and gold nanoparticles into DSPE-PEG(2000) micelles for dual-modal fluorescence/CT imaging. The nanoprobe was prepared based on a facile method of "one-pot ultrasonic emulsification". Surprisingly, in the micelles system, fluorescence dye (NPAPF) efficiently overcame the strong fluorescence quenching of shielding-free gold nanoparticles and retained the crucial AIE feature. In vivo studies demonstrated the nanoprobe had superior tumor-targeting ability, excellent fluorescence and CT imaging effects. The totality of present studies clearly indicates the significant potential application of M-NPAPF-Au as a dual-modal non-invasive fluorescence/X-ray CT nanoprobe for in vivo tumor-targeted imaging and diagnosis. PMID:25542798

Zhang, Jimei; Li, Chan; Zhang, Xu; Huo, Shuaidong; Jin, Shubin; An, Fei-Fei; Wang, Xiaodan; Xue, Xiangdong; Okeke, C I; Duan, Guiyun; Guo, Fengguang; Zhang, Xiaohong; Hao, Jifu; Wang, Paul C; Zhang, Jinchao; Liang, Xing-Jie

2015-02-01

259

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

2009-01-01

260

Fully Automated Fluorescent in situ Hybridization (FISH) Staining and Digital Analysis of HER2 in Breast Cancer: A Validation Study  

PubMed Central

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

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

2015-01-01

261

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.

Julie Yu

2010-01-01

262

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

2007-01-01

263

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

NASA Astrophysics Data System (ADS)

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

Acikgoz, Sabriye

2015-02-01

264

Monitoring of the prostate tumour cells redox state and real-time proliferation by novel biophysical techniques and fluorescent staining.  

PubMed

The present paper is focused on zinc(ii) treatment effects on prostatic cell lines PC-3 (tumour) and PNT1A (non-tumour). Oxidative status of cells was monitored by evaluation of expression of metallothionein (MT) isoforms 1A and 2A at the mRNA and protein level, glutathione (oxidised and reduced), and intracellular zinc(ii) after exposition to zinc(ii) treatment at concentrations of 0-150 ?M using electrochemical methods, western blotting and fluorescent microscopy. A novel real-time impedance-based growth monitoring system was compared with widely used end-point MTT assay. Impedance-based IC(50) for zinc(ii) is 55.5 and 150.8 ?M for PC-3 and PNT1A, respectively. MTT-determined IC(50) are >1.3-fold higher. Impedance-based viability correlates with viable count (r > 0.92; p < 0.03), not with MTT. Two-fold lower intracellular zinc(ii) in the tumour PC-3 cell line was found. After zinc(ii) treatment >2.6-fold increase of intracellular zinc(ii) was observed in non-tumour PNT1A and in tumour PC-3 cells. In PC-3 cells, free and bound zinc(ii) levels were enhanced more markedly as compared to PNT1A. PNT1A produced 4.2-fold less MT compared to PC3. PNT1A cells showed a 4.8-fold increase trend (r = 0.94; p = 0.005); PC-3 did show a significant trend at MT1 and MT2 protein levels (r = 0.93; p = 0.02) with nearly ten-fold increase after 100 ?M zinc(ii) treatment. In terms of redox state, PNT1A had a predominance of reduced GSH forms (GSH?:?GSSG ratio > 1), when exposed to zinc(ii) compared to PC3, where predominance of oxidised forms remains at all concentrations. IC(50) differs significantly when determined by MTT and real-time impedance-based assays due to dependence of impedance on cell morphology and adhesion. When real-time growth monitoring, precise electrochemical methods and fluorescent microscopy are performed together, accurate information for metal fluxes, their buffering by thiol compounds and monitoring of the redox state become a powerful tool for understanding the role of oxidative stress in carcinogenesis. PMID:22592803

Masarik, Michal; Gumulec, Jaromir; Hlavna, Marian; Sztalmachova, Marketa; Babula, Petr; Raudenska, Martina; Pavkova-Goldbergova, Monika; Cernei, Natalia; Sochor, Jiri; Zitka, Ondrej; Ruttkay-Nedecky, Branislav; Krizkova, Sona; Adam, Vojtech; Kizek, Rene

2012-06-01

265

High resolution multicolor fluorescence in situ hybridization using cyanine and fluorescein dyes: rapid chromosome identification by directly fluorescently labeled alphoid DNA probes.  

PubMed

We tested DNA probes directly labeled by fluorescently labeled nucleotides (Cy3-dCTP, Cy5-dCTP, FluorX-dCTP) for high resolution uni- and multicolor detection of human chromosomes and analysis of centromeric DNA organization by in situ hybridization. Alpha-satellite DNA probes specific to chromosomes 1, 2, 3, 4 + 9, 5 + 19, 6, 7, 8, 10, 11, 13 + 21, 14 + 22, 15, 16, 17, 18, 20, 22, X and Y were suitable for the accurate identification of human chromosomes in metaphase and interphase cells. Cy3-labeled probes had several advantages: (1) a high level of fluorescence (5-10 times more compared with fluorescein-labeled probes); (2) a low level of fluorescence in solution, allowing the detection of target chromosomes in situ during hybridization without the washing of slides; and (3) high resistance to photobleaching during prolonged (1-2 h) exposure to strong light, thus allowing the use of a high energy mercury lamp or a long integration time during image acquisition in digital imaging microscopy for the determination of weak signals. For di- and multicolor fluorescence in situ hybridization (FISH), we successfully used different combinations of directly fluorophorated probes with preservation of images by conventional microscopy or by digital imaging microscopy. FluorX and Cy3 dyes allowed the use of cosmid probes for mapping in a one-step hybridization experiment. Cyanine-labeled fluorophorated DNA probes offer additional possibilities for rapid chromosome detection during a simple 15-min FISH procedure, and can be recommended for basic research and clinical studies, utilizing FISH. PMID:8786090

Yurov, Y B; Soloviev, I V; Vorsanova, S G; Marcais, B; Roizes, G; Lewis, R

1996-03-01

266

Development of indirect competitive fluorescence immunoassay for 2,2',4,4'-tetrabromodiphenyl ether using DNA/dye conjugate as antibody multiple labels  

Technology Transfer Automated Retrieval System (TEKTRAN)

An indirect competitive fluorescence immunoassay using DNA/dye conjugate as antibody multiple labels was developed on 96-well plates for the identification and quantification of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in aqueous samples. A hapten, 2,4,2'-tribromodiphenyl ether-4’-aldehyde was sy...

267

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

PubMed Central

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

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

2015-01-01

268

A multifunctional magnetic nanocarrier bearing fluorescent dye for targeted drug delivery by enhanced two-photon triggered release.  

PubMed

We report a novel nanoformulation for targeted drug delivery which utilizes nanophotonics through the fusion of nanotechnology with biomedical application. The approach involves an energy-transferring magnetic nanoscopic co-assembly fabricated of rhodamine B (RDB) fluorescent dye grafted gum arabic modified Fe(3)O(4) magnetic nanoparticle and photosensitive linker by which dexamethasone drug is conjugated to the magnetic nano-assembly. The advantage offered by this nanoformulation is the indirect photo-triggered-on-demand drug release by efficient up-converting energy of the near-IR (NIR) light to higher energy and intraparticle energy transfer from the dye grafted magnetic nanoparticle to the linker for drug release by cleavage. The synthesized nanoparticles were found to be of ultra-small size (13.33 nm) and are monodispersed in an aqueous suspension. Dexamethasone (Dexa) drug conjugated to RDB-GAMNP by photosensitive linker showed appreciable release of Dexa by photo-triggered response on exposure to radiation having a wavelength in the NIR region whereas no detectable release was observed in the dark. Photo-triggered response for the nanoformulation not bearing the rhodamine B dye was drastically less as less Dexa was released on exposure to NIR radiation which suggest that the photo-cleavage of linker and release of Dexa mainly originated from the indirect excitation through the uphill energy conversions based on donor-acceptor model FRET. The promising pathway of nanophotonics for the on-demand release of the drug makes this nanocarrier very promising for applications in nanomedicine. PMID:19420604

Banerjee, Shashwat S; Chen, Dong-Hwang

2009-05-01

269

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

PubMed

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

2013-04-19

270

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

PubMed

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

2012-08-21

271

Conditions for dye-filling of sensory neurons in Caenorhabditis elegans.  

PubMed

Dye-filling is a common method used to stain Caenorhabditis elegans sensory neurons in vivo. While the amphids and phasmids are easy to stain, a subset of sensory neurons, the IL2 neurons, are difficult to stain reproducibly. Here we examined the conditions under which the IL2 neurons take up the lipophilic fluorescent dye DiI. We find that IL2 dye-filling depends on salt concentration, but not osmolarity. Low salt prior and during incubation is important for efficient dye uptake. Additional parameters that affect dye-filling are the speed of shaking during incubation and the addition of detergents. Our modified dye-filling procedure provides a reliable method to distinguish mutant alleles that stain amphids and phasmids, IL2 neurons, or both. An additional benefit is that it can also stain the excretory duct. The method allows genetic screens to be performed to identify mutants that selectively affect only one of the sensory structures or the excretory duct. PMID:20149821

Tong, Yong-Guang; Bürglin, Thomas R

2010-04-30

272

Assessment of SYBR Green I Dye-Based Fluorescence Assay for Screening Antimalarial Activity of Cationic Peptides and DNA Intercalating Agents.  

PubMed

The SYBR green I (SG) dye-based fluorescence assay for screening antimalarial compounds is based on direct quantitation of parasite DNA. We show that DNA-interacting cationic cell-penetrating peptides (CPPs) and intercalating agents compete with SG dye to bind to DNA. Therefore, readouts of this assay, unlike those of the [(3)H]hypoxanthine incorporation assay, for the antimalarial activity of the above DNA binding agents may be erroneous. In the case of CPPs, false readouts can be improved by the removal of excess peptides. PMID:25691642

Bhatia, Rakesh; Gautam, Ankur; Gautam, Shailendra K; Mehta, Divya; Kumar, Vinod; Raghava, Gajendra P S; Varshney, Grish C

2015-05-01

273

Electronic energy transfer between fluorescent dyes with inter- and intramicellar interactions  

NASA Astrophysics Data System (ADS)

Energy transfer by dipole-dipole interaction between cationic dyes solubilized in micelles of sodium dodecyl sulfate (SDS) in aqueous solution was studied in the particular case where donor-acceptor Förster critical radius ( R0) is larger than the micelle diameter ( dm). Using the donor-acceptor dye pairs acridine/Nile blue ( R 0=68 Å), and 9-aminoacridine/Nile blue ( R 0=36 Å), long range interaction allows energy transfer from a survival isolated excited donor to an acceptor solubilized in a neighboring micelle. The efficiency of intramicellar energy transfer in steady-state measurements was proportional to the product of micelle concentration and average acceptor occupancy, being more pronounced in the case of the pair with large R0 value. In these situations with R0> dm, the distribution analysis of decay times recovers two well separated contributions where the short-lived components are related to fast intramicellar quenching, and the long-lived components are ascribed to long range intermicellar energy transfer.

de Oliveira, Hueder P. M.; Gehlen, Marcelo H.

2003-05-01

274

Fluorescent Dye-doped Sol-gel Sensor for Highly Sensitive Carbon Dioxide Gas Detection below Atmospheric Concentrations  

SciTech Connect

Optical fluorescence sol-gel sensors have been developed for the detection of carbon dioxide gas in the 0.03?30% range with a detection limit of 0.008% (or 80 ppm) and a quantitation limit of 0.02% (or 200 ppm) CO{sub 2}. Sol?gels were spin-coated on glass slides to create an organically modified silica-doped matrix with the 1-hydroxypyrene-3,6,8-trisulfonate (HPTS) fluorescent indicator. The luminescence intensity of the HPTS indicator (513 nm) is quenched by CO{sub 2}, which protonates the anionic form of HPTS. An ion pair technique was used to incorporate the lipophilic dye into the hydrophilic sol?gel matrix. TiO{sub 2} particles (<5 {mu}m diameter) were added to induce Mie scattering and increase the incident light interaction with the sensing film, thus increasing the signal-to-noise ratio. Moisture-proof overcoatings have been used to maintain a constant level of water inside the sensor films. The optical sensors are inexpensive to prepare and can be easily coupled to fiber optics for remote sensing capabilities. A fiber-optic bundle was used for the gas detection and shown to work as part of a multianalyte platform for simultaneous detection of multiple analytes. The studies reported here resulted in the development of sol?gel optical fluorescent sensors for CO{sub 2} gas with sensitivity below that in the atmosphere (ca. 387 ppm). These sensors are a complementary approach to current FT-IR measurements for real-time carbon dioxide detection in environmental applications.

Dansby-Sparks, Royce N. [University of Tennessee, Knoxville (UTK); Jin, Jun [University of Tennessee, Knoxville (UTK); Mechery, Shelly J [ORNL; Sampathkumaran, Uma [InnoSense Incorporates; Owens, Thomas W [ORNL; Yu, Bi Dan [InnoSense Incorporates; Goswami, Kisholoy [InnoSense Incorporates; Hong, Kunlun [ORNL; Grant, Joseph [NASA Stennis Space Center; Xue, Ziling {nmn} [ORNL

2009-01-01

275

Sodium hydroxide-induced conformational change in schizophyllan detected by the fluorescence dye, aniline blue  

Microsoft Academic Search

Molecular conformation is considered to be an important factor in determining the biological activity of glucans; however, a simple method to detect the conformation change for glucans in solution has not been developed. We found that the fluorescence intensity of aniline blue bound to schizophyllan (SPG) can be used to estimate the relative amount of single helix converting to triple

Shih-Houng Young; Robert R Jacobs

1998-01-01

276

Gram Stain  

MedlinePLUS

... may be present are categorized by color and shape during the microscopic evaluation: Color — typically bacteria may be either "Gram positive" (purple) ... cells (intracellular) are also noted. The Gram stain color and the bacterial shape give clues as to what bacteria might be ...

277

A novel method for determination of inorganic polyphosphates using the fluorescent dye fura-2.  

PubMed

A method for determining inorganic polyphosphate, which is based on the Mn(2+)-induced quenching of the fluorescence of the calcium indicator fura-2, is described. The effect of Mn2+ ions on fura-2 fluorescence is gradually abolished in the presence of increasing concentrations of polyphosphate; this allows the quantification both of synthetic polyphosphates and of the naturally occurring polymer isolated from tissues or cells. The described method has some advantages compared to conventional procedures for detection of polyphosphates based on the metachromatic effect on toluidine blue. It can be applied for the determination of pyrophosphate, tripolyphosphate and other short-chain polyphosphates not detectable by toluidine blue and it can be used for measurement both of pyrophosphatase and exopolyphosphatase activity. PMID:9073354

Lorenz, B; Münkner, J; Oliveira, M P; Leitão, J M; Müller, W E; Schröder, H C

1997-03-15

278

Characterization of core-shell lattices by near-IR fluorescent cyanine dyes  

Microsoft Academic Search

Cyanine-based near-IR fluorescent probes have been applied as labels to determine aldehyde-groups in polymeric materials. The advantage of such probes is that they can be applied to polymers which are autofluorescent or strongly colored or to strongly scattering polymer emissions. The example which is discussed in this paper is the labelling of a polymeric core-shell latex, comprising a polystyrene core

Johannes W. Hofstraat; Gerrit D. van Houwelingen; Marcel J. Nuijens; Cees Gooijer; Nel H. Velthorst

1997-01-01

279

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

PubMed Central

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

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

2009-01-01

280

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

NASA Astrophysics Data System (ADS)

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

Yates, Emma

2012-02-01

281

Label-free and sensitive fluorescence detection of nucleic acid, based on combination of a graphene oxid /SYBR green I dye platform and polymerase assisted signal amplification  

NASA Astrophysics Data System (ADS)

A new label-free isothermal fluorescence amplification detection for nucleic acid has been developed. In this paper, we first developed a novel sensitive and specific detection platform with an unmodified hairpin probe (HP) combination of the graphene oxid (GO)/ SYBR green I dye (SG), which was relied on the selective principle of adsorption and the high quenching efficiency of GO. Then for the application of this new strategy, we used Mirco RNA-21 (Mir-21) as the target to evaluate this working principle of our design. When the target was hybridizing with the HP and inducing its conformation of change, an efficient isothermal circular strand-displacement polymerization reaction was activating to assist the first signal amplification. In this format, the formed complex conformation of DNA would interact with its high affinity dye, then detached from the surface of GO after incubating with the platform of GO/intercalating dye. This reaction would accompany with obvious fluorescence recovery, and accomplish farther signal enhancement by a mass of intercalating dye inserting into the minor groove of the long duplex replication product. By taking advantage of the multiple amplification of signal, this method exerted substantial enhancement in sensitivity and could be used for rapid and selective detection of Mir-21 with attomole range. It is expected that this cost-effective GO based sensor might hold considerable potential to apply in bioanalysis studies.

Zhu, Xiao; Xing, Da

2012-12-01

282

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

PubMed

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

2014-08-01

283

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; Gabbaï, François P.; Conti, Peter S.

2013-01-01

284

Frontier molecular orbital analysis of dual fluorescent dyes: predicting two-color emission in N-aryl-1,8-naphthalimides.  

PubMed

A 3 x 3 matrix of disubstituted N-aryl-1,8-naphthalimides was synthesized for the evaluation and discovery of dual fluorescence (DF). The matrix elements included for this study were based on a predictive model that is proposed as a seesaw balanced photophysical model. This model serves as a guide to optimize the dual fluorescence emission from N-phenyl-1,8-naphthalimides by appropriate placement of substituent groups at both the 4-position of the N-arene as well as the 4'-position of the naphthalene ring. Steady-state fluorescence studies under a variety of solvents indicate that four of the nine dyes in the matrix are dual fluorescent. To provide a more quantitative description of the model, cyclic voltammetry experiments were used to calculate HOMO/LUMO energies of the aromatic components that comprise these DF dyes and give evidence in support for potential mixing of S1 and S2 excited states. Given the difficulties in predicting excited state properties such as molecular fluorescence, this ratio of four out of nine "hits" for discovering DF signifies proof of principle for this proposed model and should provide a rational basis for the synthesis of future DF 1,8-naphthalimide systems. PMID:20626080

Nandhikonda, Premchendar; Begaye, Michael P; Cao, Zhi; Heagy, Michael D

2010-07-21

285

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

Microsoft Academic Search

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

Kan-Yi Pu; Bin Liu

286

Fluorescence ratiometric properties induced by nanoparticle plasmonics and nanoscale dye dynamics.  

PubMed

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

Hakonen, Aron

2013-01-01

287

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  

PubMed Central

Abstract. 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. PMID:24356647

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

2013-01-01

288

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

2013-12-01

289

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

1976-01-01

290

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.

1966-01-01

291

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

PubMed

A three-laser flow cytometer for quantitative analysis and sorting of cells and microscopic particles has been developed and evaluated using argon- and krypton-ion lasers as excitation sources. Cells stained with three fluorescent dyes having different excitation spectra enter a flow chamber where they first pass through an electronic volume sensor and then intersect three spatially separated laser beams for fluorescence excitation of bound dyes and light scatter measurements. Separate pairs of beam-shaping optics independently position and focus each beam onto the cell stream thus permitting cells to be sequentially illuminated. Fluorescence is measured by a detector that employs a single collecting lens for single or multilaser excitation experiments. Fluorescence signals are processed and displayed as frequency distribution histograms using an LSI-11 computer. This instrument is described in detail with illustrative examples using cells stained for DNA content, protein, and cell surface antigens and cells that have phagocytized fluorescent microspheres. PMID:7056131

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

1982-01-01

292

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.

2011-01-01

293

Whitening of Polymer Light-Emitting Diodes by Dispersing Vapor of an Orange Fluorescent Dye into a Blue-Emitting Polymer Film  

NASA Astrophysics Data System (ADS)

Whitening of polymer light-emitting diodes (PLEDs) based on the blue-emitting poly(9,9-dioctylfluorene) (PDOF) films was possible by dispersing vapor of an orange fluorescent dye 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) into the film by means of the solution-free vapor transportation method (VTM). Devices prepared with this method showed good color stability with bias voltage increase, while those formed with conventional spin-coating, where dyes and polymers were mixed in a solution (solution-mixed), showed color change from yellow to white-yellow. The maximum luminance of the PLED formed by the VTM was higher than that formed by conventional spin-coating process.

Mizokuro, Toshiko; Heck, Claire; Tanigaki, Nobutaka; Hiraga, Takashi; Tanaka, Norio

2008-02-01

294

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  

PubMed Central

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 (D4.3) 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. PMID:24936156

2014-01-01

295

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

2014-05-01

296

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

2007-09-01

297

Charge-trapping effect of doped fluorescent dye on the electroluminescent processes and its performance in polymer light-emitting diodes  

Microsoft Academic Search

We have measured the temperature dependence of the steady-state current-voltage (I–V) characteristics and the transient electroluminescent (EL) characteristics in 4-(dicyanomethylene)-2-t-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped polyfluorene devices to study the charge-trapping effect of DCJTB fluorescent dye on luminescence processes and on device performance. Physical and chemical analyses prove that DCJTB molecules serve both as electron and hole traps, and the charge-trapping effect is

Tengling Ye; Zhenyu Chen; Jiangshan Chen; Dongge Ma

2010-01-01

298

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

PubMed

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

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

2015-01-01

299

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

EPA Science Inventory

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

300

Characterization of Chiral H and J Aggregates of Cyanine Dyes Formed by DNA Templating Using Stark and Fluorescence Spectroscopies  

E-print Network

aggregates are important to materials science, chemistry,1 and light-harvesting biological systems.2 Dye ag- gregates bound by noncovalent interactions are frequently used as photographic sensitizers3

Chowdhury, Arindam

301

A novel, simple and efficient dye laser with low amplified spontaneous emission background for analytical fluorescence and ionization spectroscopy  

SciTech Connect

A new, simple, compact and efficient, grazing- incidence type of dye laser is suggested which has a low level of Amplified Spontaneous Emission. By using a Coumarin dye (LD 5000) pumped with a 20 mJ XeCl excimer laser, and a diffraction grating with 3000 grooves/mm, an efficiency of 11%, a spectral bandwidth of 0.6 cm{sup -1} and a tuning range from 458 to 517 nm have been obtained.

Matveev, Oleg I.; Omenetto, Nicolo' [EC, Joint Research Centre, Environment Institute, 21020 Ispra, Varese (Italy)

1995-04-01

302

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.

2007-01-01

303

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

PubMed Central

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

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

2015-01-01

304

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

305

Organic fluorescent dyes supported on activated boron nitride: a promising blue light excited phosphors for high-performance white light-emitting diodes.  

PubMed

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

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

2015-01-01

306

A ‘Magnetic’ Gram Stain for Bacterial Detection  

PubMed Central

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

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

2012-01-01

307

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

2012-01-01

308

Ruthenium red colorimetric and birefringent staining of amyloid-? aggregates in vitro and in Tg2576 mice.  

PubMed

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

Cook, Nathan P; Archer, Clarissa M; Fawver, Janelle N; Schall, Hayley E; Rodriguez-Rivera, Jennifer; Dineley, Kelly T; Martí, Angel A; Murray, Ian V J

2013-03-20

309

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

PubMed

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

2013-12-01

310

Fluorescence rejection in Raman spectroscopy using a synchronously pumped, cavity-dumped dye laser and gated photon counting  

Microsoft Academic Search

The application of a picosecond-pulsed laser system, in conjunction with a time-to-amplitude converter, to the suppression of fluorescence noise in Raman spectra is described. Enhancements of 14.6 (Raman signal\\/fluorescence background) and 2.8 (Raman signal\\/fluorescence noise) were obtained for a solution of benzene doped with a fluorophore with lifetime tau f=11.8 ns, while corresponding improvements of 5.5 and 2.0 were observed

J. Howard; N. J. Everall; R. W. Jackson; K. Hutchinson

1986-01-01

311

DNA fragment sizing and sorting by laser-induced fluorescence  

DOEpatents

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)

1996-01-01

312

Karyotyping of barley chromosomes by a new fluorescence banding technique combined with scanning probe microscopy.  

PubMed

Fluorescence banding has been used to classify chromosomes, except those of barley. Four of the seven barley chromosomes are indistinguishable by length or arm ratio. C-banding has been used for classification; however, it requires a long aging period. Here, we describe a new fluorescence banding method for barley. The chromosomes are treated with warm acetate followed by staining with a fluorescent dye, YOYO-1. Using this method, all seven barley chromosomes can be clearly distinguished. Atomic force microscopy and scanning near-field microscopy analyses revealed that the surfaces of the banded chromosomes were flat, indicating that the fluorescence intensity reflected the internal DNA density or condensation of chromatin. PMID:22058025

Sugiyama, Shigeru; Yoshino, Tomoyuki; Hirose, Tamaki; Ohtani, Toshio

2012-01-01

313

Accomplishments of the Trustees and laboratory staff of the Biological Stain Commission, 2002-2013.  

PubMed

During the 12 years from 2002 to 2013, the Trustees and laboratory personnel of the Biological Stain Commission (BSC) can claim many accomplishments. These accomplishments are itemized under 11 categories: continuous publication of the official journal, Biotechnic & Histochemistry; production of four special issues of Biotechnic & Histochemistry devoted to specific dyes or stains; standardization of staining and dye purity; mechanisms of staining and prediction of dye behavior; publication of books or book chapters; effects of fixation and processing on staining; cancer research; immunohistochemistry; BSC Laboratory activities; miscellaneous publications; and administrative accomplishments. PMID:24665939

Dapson, R W

2014-08-01

314

Ionic and non-ionic bonds in staining, with special reference to the action of urea and sodium chloride on the staining of elastic fibres and glycogen  

Microsoft Academic Search

Summary 1. A powerful hydrogen bonding agent such as urea may affect staining in several ways: (a) by competing for hydrogen bonding sites in the tissue or on the dye particle, it may inhibit staining in which the dye-substrate link is a hydrogen bond; (6) because it is a dipole, urea may have some affinity for charged sites in the

S. Africa

315

Solvent effects on the absorption and fluorescence spectra of some laser dyes: Estimation of ground and excited-state dipole moments  

NASA Astrophysics Data System (ADS)

The absorption and fluorescence spectra of three extensively used laser dyes namely 1,1,4,4-tetraphenyl-1,3-butadiene (TPB), 2-(4'- t-butylphenyl)-5-(4?-biphenylyl)-1-oxa-3,4-diazole (BPBD), 1,4-bis[2-(2-methylphenyl)ethenyl]-benzene (Bis-MSB) have been recorded at room temperature (300 K) in solvents of different polarities. The effects of the solvents upon the spectral properties are discussed. The ground-state dipole moments ( ?g) were determined experimentally by Guggenheim and Higasi method separately and were compared with theoretical values obtained using quantum chemical method. The ground-state dipole moments obtained by using Guggenheim method were then used in the estimation of excited-state dipole moments ( ?e) by using Lippert's, Bakhshiev's and Kawski-Chamma-Viallet's equations. In all the above three equations the variation of the Stokes shift with the solvent dielectric constant and refractive index was made use of. It was observed that dipole moments of excited state were higher than those of the ground state for all the dyes.

Thipperudrappa, J.; Biradar, D. S.; Manohara, S. R.; Hanagodimath, S. M.; Inamadar, S. R.; Manekutla, R. J.

2008-03-01

316

The antioxidant glutathione in the fish cell lines EPC and BCF-2: response to model pro-oxidants as measured by three different fluorescent dyes.  

PubMed

Reduced glutathione (GSH) protects cells against injury by oxidative stress and maintains a range of vital functions. In vitro cell cultures have been used as experimental models to study the role of GSH in chemical toxicity in mammals; however, this approach has been rarely used with fish cells to date. The present study aimed to evaluate sensitivity and specificity of three fluorescent dyes for measuring pro-oxidant-induced changes of GSH contents in fish cell lines: monochlorobimane (mBCl), 5-chloromethylfluorescein diacetate (CMFDA) and 7-amino-4-chloromethylcoumarin (CMAC-blue). Two cell lines were studied, the EPC line established from a skin tumour of carp Cyprinus carpio, and BF-2 cells established from fins of bluegill sunfish Lepomis macrochirus. The cells were exposed for 6 and 24 h to low cytotoxic concentrations of pro-oxidants including hydrogen peroxide, paraquat (PQ), copper and the GSH synthesis inhibitor, L-buthionine-SR-sulfoximine (BSO). The results indicate moderate differences in the GSH response between EPC and BF-2 cells, but distinct differences in the magnitude of the GSH response for the four pro-oxidants. Further, the choice of GSH dye can critically affect the results, with CMFDA appearing to be less specific for GSH than mBCl and CMAC-blue. PMID:19444932

Jos, A; Cameán, A M; Pflugmacher, S; Segner, H

2009-04-01

317

Comparison of fluorescence in situ hybridisation using peptide nucleic acid probes, Gram stain/acridine orange leukocyte cytospin and differential time to positivity methods for detection of catheter-related bloodstream infection in patients after haematopoietic stem cell transplantation.  

PubMed

In 46 febrile neutropenic patients who had undergone haematopoietic stem cell transplantation, the fluorescence in situ hybridisation using peptide nucleic acid probes (PNA FISH), Gram stain/acridine orange leukocyte cytospin (Gram/AOLC), and differential time to positivity (DTP) methods were performed for detection of catheter-related bloodstream infections (CRBSIs). As compared with the DTP method (which detected 11 patients with CRBSI), the PNA FISH and the Gram/AOLC methods detected ten of 11 CRBSI patients, resulting in a sensitivity, specificity, negative predictive value and positive predictive value of 91%, 100%, 97% and 100%, respectively, for the PNA FISH method as well as for the Gram/AOLC method. PMID:20041887

Krause, R; Salzer, H F; Hönigl, M; Valentin, T; Auner, H W; Zollner-Schwetz, I

2010-10-01

318

MDPF Staining of Proteins on Western Blots  

Microsoft Academic Search

\\u000a We describe a method for the detection of total protein patterns on polyvinylidene difluoride (PVDF) membranes using the fluorogenic\\u000a dye 2-methoxy-2,4-diphenyl3(2H)-furanone (MDPF) (1). This method is based on the fluorescent properties of this dye (2). As can be seen in Fig. 1, MDPF (A) and the hydrolysis product (C) are nonfluorescent; only the adduct B formed with the proteins is

F. Javier Alba; Joan-Ramon Daban

319

Synthesis of a polymer bearing several coumarin dyes along the side chain and study of its fluorescence in pure and binary solvent mixtures as well as aqueous surfactant solutions.  

PubMed

A copolymer bearing several pendent dyes (coumarin derivatives) along the side chain has been synthesized, and its fluorescence parameters have been monitored in pure solvents and also as a function of composition of binary solvent mixtures. Fluorescence parameters (the maximum energy of fluorescence, quantum yield, and rate constant for the decay of the excited state) of the free fluorophore show significant dependence on the nature of the immediate environment around it. The value of a parameter measured in neat solvent for the fluorophore covalently bound to the polymer is different from that of the free fluorophore, indicating that the polymer chain influences the spectroscopic properties of the dye. Whereas the energy of maximum fluorescence of the free fluorophore shows a nonlinear correlation with the solvent composition of solvent mixtures, an almost linear correlation has been observed for the polymer. A significant variation of photophysical parameters of the dye dissolved in binary solvent mixtures, which is different from that of the free fluorophore, has been observed. Thus, the free fluorophore and the fluorophore bound to the polymer sense different environments in binary solvent mixtures. A dramatic variation of fluorescence intensity of the fluorophore bound to the polymer has been observed when sodium dodecyl sulfate (SDS) is added to an aqueous solution of the polymer. The results have been explained in terms of the existence of different species (polymer, polymer-SDS aggregates, micelles) in equilibrium in solution. PMID:24712342

Kedia, Niraja; Roy, Saswati Ghosh; De, Priyadarsi; Bagchi, Sanjib

2014-05-01

320

Locked-flavylium fluorescent dyes with tunable emission wavelengths based on intramolecular charge transfer for multi-color ratiometric fluorescence imaging.  

PubMed

A new class of locked-flavylium fluorophores with tunable emission wavelengths based on intramolecular charge transfer were designed, synthesized, and evaluated. The optical studies indicate that sensor LF3 can display an intriguing character, fluorescence ratiometric response in three channels by tuning the ICT efficiencies. PMID:25797486

Chen, Hua; Lin, Weiying; Jiang, Wenqing; Dong, Baoli; Cui, Haijun; Tang, Yonghe

2015-04-25

321

Construction of a Selective Fluorescent Probe for GSH Based on a Chloro-Functionalized Coumarin-enone Dye Platform.  

PubMed

Glutathione (GSH), the most abundant intracellular biothiol, protects cellular components from damage caused by free radicals and reactive oxygen species (ROS), and plays a crucial role in human pathologies. A fluorescent probe that can selectively sense intracellular GSH would be very valuable for understanding of its biological functions and mechanisms of diseases. In this work, a 3,4-dimethoxythiophenol-substituted coumarin-enone was exploited as a reaction-type fluorescent probe for GSH based on a chloro-functionalized coumarin-enone platform. In the probe, the 3,4-dimethoxythiophenol group functions not only as a fluorescence quencher through photoinduced electron transfer (PET) to ensure a low background fluorescence, but also as a reactive site for biothiols. The probe displays a dramatic fluorescence turn-on response toward GSH with the long-wavelength emission (600?nm) and significant Stokes shift (100?nm). The selectivity of the probe toward GSH over cysteine (Cys), homocysteine (Hcy), and other amino acids was demonstrated. Assisted by laser-scanning confocal microscopy, we have demonstrated that the probe could specifically sense GSH over Cys/Hcy in human renal cell carcinoma SiHa cells. PMID:25652957

Liu, Yawei; Lv, Xin; Liu, Jing; Sun, Yuan-Qiang; Guo, Wei

2015-03-16

322

Cellular uptake of modified oligonucleotides: fluorescence approach  

NASA Astrophysics Data System (ADS)

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

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

2005-06-01

323

pH-induced vesicle-to-micelle transition in amphiphilic diblock copolymer: investigation by energy transfer between in situ formed polymer embedded gold nanoparticles and fluorescent dye.  

PubMed

The ability to regulate the formation of nanostructures through self-assembly of amphiphilic block copolymers is of immense significance in the field of biology and medicine. In this work, a new block copolymer synthesized by using reversible addition-fragmentation chain transfer (RAFT) polymerization technique from poly(ethylene glycol) monomethyl ether acrylate (PEGMA) and Boc-l-tryptophan acryloyloxyethyl ester (Boc-l-trp-HEA) was found to spontaneously form pH-responsive water-soluble nanostructures after removal of the Boc group. While polymer vesicles or polymerosomes were formed at physiological pH, the micelles were formed at acidic pH (< 5.2), and this facilitated a pH-induced reversible vesicle-to-micelle transition. Formation of these nanostructures was confirmed by different characterization techniques, viz. transmission electron microscopy, dynamic light scattering, and steady-state fluorescence measurements. Further, these vesicles were successfully utilized to reduce HAuCl4 and stabilize the resulting gold nanoparticles (AuNPs). These AuNPs, confined within the hydrophobic shell of the vesicles, could participate in energy transfer process with fluorescent dye molecules encapsulated in the core of the vesicles, thus forming a nanometal surface energy transfer (NSET) pair. Subsequently, following the efficiency of energy transfer between this pair, it was possible to monitor the process of transition from vesicles to micelles. Thus, in this work, we have successfully demonstrated that NSET can be used to follow the transition between nanostructures formed by amphiphilic block copolymers. PMID:25494810

Maiti, Chiranjit; Banerjee, Rakesh; Maiti, Saikat; Dhara, Dibakar

2015-01-13

324

Immunofluorescence analysis of cytokeratin 8/18 staining is a sensitive assay for the detection of cell apoptosis  

PubMed Central

Apoptosis is one of the major types of programmed cell death. During this process, cells experience a series of morphological and biochemical changes. Flow cytometric analysis of Annexin V staining of cell surface phosphatidylserine, in combination with a DNA-staining dye to probe the permeability of the cell membrane, is an established method for detecting apoptosis. The present study aimed to show that the immunofluorescence analysis of cytokeratin (CK) 8/18 staining may provide a new and sensitive assay for the detection of apoptotic cells. Tumor cells were treated with 20 ?M cisplatin to induce apoptosis. Following 12 and 24 h of cisplatin treatment, cells were collected and stained with 4?,6-diamidine-2?-phenylindole dihydrochloride (DAPI) and fluorescein-labeled anti-CK8/18 antibody. The apoptotic cells were subsequently examined by fluorescence microscopy. Annexin V-fluorescein isothiocyanate/propidium iodide staining followed by flow cytometric analysis confirmed that cisplatin was able to induce apoptosis in tumor cells. Immunofluorescence analysis demonstrated that apoptotic cells had a distinct CK8/18 staining pattern. In living cells, CK8/18 was uniformly distributed in the cytoplasm and cytosol; however in the apoptotic cells with a condensed and/or fragmented apoptotic nucleus (as identified by DAPI staining), fluorescein-labeled anti-CK8/18 antibody exhibited unusual punctate and/or bubbly staining in the cytosol. In the apoptotic cells that could not be identified by DAPI staining, fluorescein-labeled CK8/18 displayed polarized aggregated staining in the cytosol. These results indicate that fluorescein-conjugated CK8/18 may be a useful and sensitive indicator of cell apoptosis. PMID:25663887

DONG, QIAO-MEI; LING, CHUN; ZHAO, LI

2015-01-01

325

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.

2007-01-01

326

Acri-2,7-Py, a bright red-emitting DNA probe identified through screening of a distyryl dye library.  

PubMed

The identification of DNA sensors is still a challenge since no DNA probe possesses all the photophysical properties required for live-cell imaging: high fluorescence yield, red emission, permeability, no photobleaching and no cytotoxicity. We describe the preparation of a distyryl dye library and its evaluation on a panel of nucleic acids with various structures (duplex DNA, quadruplex DNA and RNA). The screening involved measuring the modification of the fluorescence properties of the dyes with or without nucleic acids on a microplate reader, and allowed the identification of selective quadruplex DNA ligands with good affinities. Using this screening method we discovered a new bright red-emitting DNA stain, Acri-2,7-Py, for fixed cells. In living cells, the staining was not nuclear and photodamage generated through illumination induced cellular death. These processes require further studies to determine the relevance of Acri-2,7-Py in photodynamic therapy. PMID:24323895

Naud-Martin, Delphine; Martin-Benlloch, Xavier; Poyer, Florent; Mahuteau-Betzer, Florence; Teulade-Fichou, Marie-Paule

2014-02-01

327

The development of simple and sensitive small-molecule fluorescent probes for the detection of serum proteins after native polyacrylamide gel electrophoresis.  

PubMed

In this paper, a simple and sensitive small-molecule fluorescent probe, 2,5-dihydroxy-4'-dimethylaminochalcone (DHDMAC), was designed and synthesized for the detection of human serum proteins via hydrophobic interactions after polyacrylamide gel electrophoresis (PAGE). This probe produced lower fluorescence emission in the absence of proteins, and the emission intensity was significantly increased after the interaction with serum proteins. To demonstrate the imaging performance of this probe as a fluorescent dye, a series of experiments was conducted that included sensitivity comparison and 2D-PAGE. The results indicated that the sensitivity of DHDMAC staining is comparable to that of the most widely used fluorescent dye, SYPRO Ruby, and more protein spots (including thyroxine-binding globulin, angiotensinogen, afamin, zinc-?-2-glycoprotein and ?-1-antichymotrypsin) were detected after 2D-PAGE. Therefore, DHDMAC is a good protein reporter due to its fast staining procedure, low detection limits and high resolution. PMID:22475746

Wang, Fangfang; Huang, Lingyun; Na, Na; He, Dacheng; Sun, Dezhi; Ouyang, Jin

2012-05-21

328

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

PubMed Central

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

2014-01-01

329

Coumarin 545: an emission reference dye with a record-low temperature coefficient for ratiometric fluorescence based temperature measurements.  

PubMed

The emission intensities of coumarin 545 solution exhibit a low temperature dependence, with a record-low temperature coefficient of only ?0.025% per °C. This monomer-aggregate coupled fluorescence system can be used for ratiometric temperature measurements with high spatial and temporal resolutions; three different working modes have been demonstrated. PMID:25563387

Mao, Deqi; Liu, Xiaogang; Qiao, Qinglong; Yin, Wenting; Zhao, Miao; Cole, Jacqueline M; Cui, Jingnan; Xu, Zhaochao

2015-02-01

330

4,4'-Diarylsulfanyl-2,2',5,5'-tetraoxybiaryl derivatives as a water-soluble fluorescent dye.  

PubMed

4,4'-Disulfanyl-2,2',5,5'-tetrahydrobiaryl (5,5'-disulfanyl hydroquinone dimer) derivatives were readily synthesized from benzoquinone and thiols via an oxidative coupling reaction. The hydroquinone dimers showed strong fluorescence upon excitation at 330 nm, and it was observed that the presence of the sulfanyl groups at the C4 and C4' positions is important for achieving strong photoluminescence. The tetrapotassium salts of the hydroquinone dimers also showed good water solubility, but the fluorescence disappeared rapidly on dissolution in water. 2,2'- and 5,5'-protected biaryls were synthesized. The dipotassium salt of the 5,5'-dimethoxy-2,2'-dihydroxy derivative was observed to show good and stable fluorescence in water, while the dipotassium salt of the 2,2'-dimethoxy-5,5'-dihydroxy derivative showed less water solubility. Introduction of propargyl groups was demonstrated to provide a convenient method for installing amino acids derivatives. This derivatization afforded potentially useful compounds for attaching the biologically active fragment to the fluorescent unit. PMID:24400983

Kamimura, Akio; Nokubi, Tomomi; Watanabe, Ryusuke; Ishikawa, Mari; Nasu, Kotaro; Uno, Hidemitsu; Sumimoto, Michinori

2014-02-01

331

Improved signal-to-noise in fluorescence scattering by means of nonlinear pumping with a frequency modulated dye laser  

Microsoft Academic Search

Laser-induced fluorescence (LIF) is a well established technique used to determine the neutral hydrogen density in fusion plasmas. There is a requirement to extend these measurements to the Divertor section of large plasma devices, but this is problematical due to the high levels of stray laser light and background plasma emission. Here we describe a method, based on harmonic saturated

M. J. Forrest; R. J. Winfield

1992-01-01

332

Sensitive immunoassay detection of multiple environmental chemicals on protein microarrays using DNA/dye conjugate as a fluorescent label  

Technology Transfer Automated Retrieval System (TEKTRAN)

Indirect competitive immunoassays were developed on protein microarrays for the sensitive and simultaneous detection of multiple environmental chemicals in one sample. In this assay, a DNA/SYTOX Orange conjugate was employed as antibody labels to increase the fluorescence signal and sensitivity. Ep...

333

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

PubMed

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

2014-01-01

334

Micromanipulation and physiological monitoring of cells using two-photon excited fluorescence in cw laser tweezers  

NASA Astrophysics Data System (ADS)

We report the observation of two-photon fluorescence excitation and cell confinement, simultaneously, in a continuous-wave (cw) single-beam gradient force optical trap, and demonstrate its use as an in-situ probe to study the physiological state of an optically confined cell sample. At the wavelength of 1064 nm, a single focused gaussian laser beam is used to simultaneously confine, and excite visible fluorescence from, a human sperm cell that has been tagged with propidium iodide, a exogenous fluorescent dye that functions as a viability assay of cellular physiological state. The intensity at the dye peak emission wavelength of 620 nm exhibits a near-square-law dependence on incident trapping beam photon laser power, a behavior consistent with a two-photon absorption process. In addition, for a sperm cell held stationary in the optical tweezers for a period of several minutes at a constant trapping power, red fluorescence emission was observed to increase the time, indicating that the cell has gradually transitioned between a live and dead state. Two-photon excited fluorescence was also observed in chinese hamster ovary cells that were confined by cw laser tweezers and stained with either propidium iodide or Snarf, a pH-sensitive dye probe. These results suggest that, for samples suitably tagged with fluorescent probes and vital stains, optical tweezers can be used to generate their own in-situ diagnostic optical probes of cellular viability or induced photodamage, via two-photon processes.

Sonek, Gregory J.; Liu, Yagang; Berns, Michael W.; Tromberg, Bruce J.

1996-05-01

335

Clinical staining of the ocular surface: mechanisms and interpretations.  

PubMed

In this article we review the mechanism of ocular surface staining. Water-soluble dyes are excluded from the normal epithelium by tight junctions, the plasma membranes and the surface glycocalyx. Shed cells can take up dye. A proportion of normal corneas show sparse, scattered time-dependent, punctate fluorescein uptake, which, we hypothesise, is due to a graded loss of the glycocalyx barrier, permitting transcellular entry into pre-shed cells. In pathological staining, there is little evidence of 'micropooling' at sites of shedding and the term 'punctate erosion' may be a misnomer. It is more likely that the initial event involves transcellular dye entry and, in addition, diffusion across defective tight junctions. Different dye-staining characteristics probably reflect differences in molecular size and other physical properties of each dye, coupled with differences in visibility under the conditions of illumination used. This is most relevant to the rapid epithelial spread of fluorescein from sites of punctate staining, compared to the apparent confinement of dyes to staining cells with dyes such as lissamine green and rose bengal. We assume that fluorescein, with its lower molecular weight, spreads initially by a paracellular route and then by transcellular diffusion. Solution-Induced Corneal Staining (SICS), related to the use of certain contact lens care solutions, may have a different basis, involving the non-pathological uptake of cationic preservatives, such as biguanides, into epithelial membranes and secondary binding of the fluorescein anion. It is transient and may not imply corneal toxicity. Understanding the mechanism of staining is relevant to the standardisation of grading, to monitoring disease and to the conduct of clinical trials. PMID:25461622

Bron, A J; Argüeso, P; Irkec, M; Bright, F V

2015-01-01

336

Cyanine dye fluorescence used to measure membrane potential changes due to the assembly of complement proteins C5b-9  

Microsoft Academic Search

Summary The fluorescent potentiometric indicator diS-C3-(5) has been used to investigate changes in membrane potential due to assembly of the C5b-9 membrane attack complex of the complement system. EAC1-7 human red blood cells and resealed erythrocyte ghosts—bearing membrane-assembled C5b67 complexes—were generated by immune activation in C8-deficient human serum. Studies performed with these cellular intermediates revealed that the membrane potential of

Therese Wiedmer; Peter J. Sims

1985-01-01

337

Detection of chloroform in water using an azo dye-modified ?-cyclodextrin - Epichlorohydrin copolymer as a fluorescent probe  

NASA Astrophysics Data System (ADS)

Chlorination disinfection by-products (DBPs) in water pose a health threat to humans and the aquatic environment. Their detection in water sources is therefore vital. Herein we present the detection of chloroform, a DBP, using a molecular fluorescent probe. The detection was based on the quenching of fluorescence of the probe by chloroform due to host-guest complex formation between ?-cyclodextrin in the probe and the chloroform molecule. The stability constant for the host-guest complex was high at 3.825 × 104 M-1. Chloroform quenched the fluorescence of the copolymer the most compared to the other small chlorinated compounds studied, suggesting that the probe was more sensitive to chloroform, with a sensing factor of 0.35 compared to as low as 0.0073 for dichloromethane. There was no interference from other chloroalkanes on the quenching efficiency of chloroform. The probe was used to detect chloroform in dam water as well as in bottled water. Detection of chloroform in both water samples using the probe was possible without chemically treating the water samples which may introduce other pollutants.

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

338

Laser treatment of port-wine stains  

PubMed Central

Port-wine stains are a type of capillary malformation affecting 0.3% to 0.5% of the population. Port-wine stains present at birth as pink to erythematous patches on the skin and/or mucosa. Without treatment, the patches typically darken with age and may eventually develop nodular thickening or associated pyogenic granuloma. Laser and light treatments provide improvement through selective destruction of vasculature. A variety of vascular-selective lasers may be employed, with the pulsed dye laser being the most common and well studied. Early treatment produces more optimal results. Advances in imaging and laser treatment technologies demonstrate potential to further improve clinical outcomes. PMID:25624768

Brightman, Lori A; Geronemus, Roy G; Reddy, Kavitha K

2015-01-01

339

Detection Of Concrete Deterioration By Staining  

DOEpatents

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)

1999-09-21

340

Dye-coated europium monosulfide  

SciTech Connect

Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

Kar, Srotoswini [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States); Dollahon, Norman R. [Department of Biology, Villanova University, Villanova, PA 19085 (United States); Stoll, Sarah L., E-mail: sls55@georgetown.ed [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States)

2011-05-15

341

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

1979-01-01

342

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

1995-12-31

343

Mapping live cell viscosity with an aggregation-induced emission fluorogen by means of two-photon fluorescence lifetime imaging.  

PubMed

Intracellular viscosity is a crucial parameter that indicates the functioning of cells. In this work, we demonstrate the utility of TPE-Cy, a cell-permeable dye with aggregation-induced emission (AIE) property, in mapping the viscosity inside live cells. Owing to the AIE characteristics, both the fluorescence intensity and lifetime of this dye are increased along with an increase in viscosity. Fluorescence lifetime imaging of live cells stained with TPE-Cy reveals that the lifetime in lipid droplets is much shorter than that from the general cytoplasmic region. The loose packing of the lipids in a lipid droplet results in low viscosity and thus shorter lifetime of TPE-Cy in this region. It demonstrates that the AIE dye could provide good resolution in intracellular viscosity sensing. This is also the first work in which AIE molecules are applied in fluorescence lifetime imaging and intracellular viscosity sensing. PMID:25645956

Chen, Sijie; Hong, Yuning; Zeng, Yan; Sun, Qiqi; Liu, Yang; Zhao, Engui; Bai, Gongxun; Qu, Jianan; Hao, Jianhua; Tang, Ben Zhong

2015-03-01

344

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.

1992-12-31

345

Labeling of capsid proteins and genomic RNA of human rhinovirus with two different fluorescent dyes for selective detection by capillary electrophoresis.  

PubMed

During uncoating of human rhinoviruses, the innermost capsid protein VP4 and the genomic RNA are released from the viral protein shell. This process gives rise to subviral particles that are composed of the remaining three capsid proteins VP1, VP2, and VP3. The process is believed to take place in a sequential manner in that first VP4 is expelled resulting in A-particles sedimenting at 135S followed by the RNA resulting in B-particles sedimenting at 80S. Aiming at ultimately analyzing this process in vivo, we introduced two different fluorophores into the RNA and the viral capsid proteins, respectively. Incubation of the virus with RiboGreen resulted in formation of a RNA-dye complex with lambda(ex)/lambda(em) = 500/525 nm, whereas subsequent derivatization of the viral protein shell in the same sample with AMCA-S introduced a label with lambda(ex)/lambda(em) = 345-350/440-460 nm. In this way, both viral components could be selectively detected via fluorescence in a capillary electrophoresis system. The intact virus delivers two superimposed signals in the electropherogram. Derivatization of the free amino groups of the capsid proteins partially preserved the bioaffinity of the virus toward a synthetic receptor fragment, an artificial recombinant concatemer of repeat number 3 of the very low density lipoprotein receptor. Between 10 and 20% of the infectivity were recovered after labeling when compared to native virus. In addition to analysis of factors influencing the stability of the virus by CE, double-labeled virions might be useful for the investigation of the uncoating process by real-time confocal fluorescence microscopy. PMID:15595880

Kremser, Leopold; Petsch, Martina; Blaas, Dieter; Kenndler, Ernst

2004-12-15

346

The Chemically Synthesized Ageladine A-Derivative LysoGlow84 Stains Lysosomes in Viable Mammalian Brain Cells and Specific Structures in the Marine Flatworm Macrostomum lignano.  

PubMed

Based on the chemical structure and the known chemical synthesis of the marine sponge alkaloid ageladine A, we synthesized the ageladine A-derivative 4-(naphthalene-2-yl)-1H-imidazo[4,5-c]pyridine trifluoroacetate (LysoGlow84). The two-step synthesis started with the Pictet-Spengler reaction of histamine and naphthalene-2-carbaldehyde to a tetrahydropyridine intermediate, which was dehydrogenated with activated manganese (IV) oxide to LysoGlow84. Structure and purity of the synthesized LysoGlow84 were confirmed by NMR spectroscopy and mass spectrometry. The fluorescence intensity emitted by LysoGlow84 depended strongly on the pH of the solvent with highest fluorescence intensity recorded at pH 4. The fluorescence maximum (at 315 nm excitation) was observed at 440 nm. Biocompatibility of LysoGlow84 was investigated using cultured rat brain astrocytes and the marine flatworm Macrostomum lignano. Exposure of the astrocytes for up to 6 h to micromolar concentrations of LysoGlow84 did not compromise cell viability, as demonstrated by several viability assays, but revealed a promising property of this compound for staining of cellular vesicles. Conventional fluorescence microscopy as well as confocal scanning microscopy of LysoGlow84-treated astrocytes revealed co-localization of LysoGlow84 fluorescence with that of LysoTracker® Red DND-99. LysoGlow84 stained unclear structures in Macrostomum lignano, which were identified as lysosomes by co-staining with LysoTracker. Strong fluorescence staining by LysoGlow84 was further observed around the worms' anterior gut and the female genital pore which were not counterstained by LysoTracker Red. Thus, LysoGlow84 is a new promising dye that stains lysosomes and other acidic compartments in cultured cells and in worms. PMID:25679913

Mordhorst, Thorsten; Awal, Sushil; Jordan, Sebastian; Petters, Charlotte; Sartoris, Linda; Dringen, Ralf; Bickmeyer, Ulf

2015-01-01

347

The Chemically Synthesized Ageladine A-Derivative LysoGlow84 Stains Lysosomes in Viable Mammalian Brain Cells and Specific Structures in the Marine Flatworm Macrostomum lignano  

PubMed Central

Based on the chemical structure and the known chemical synthesis of the marine sponge alkaloid ageladine A, we synthesized the ageladine A-derivative 4-(naphthalene-2-yl)-1H-imidazo[4,5-c]pyridine trifluoroacetate (LysoGlow84). The two-step synthesis started with the Pictet-Spengler reaction of histamine and naphthalene-2-carbaldehyde to a tetrahydropyridine intermediate, which was dehydrogenated with activated manganese (IV) oxide to LysoGlow84. Structure and purity of the synthesized LysoGlow84 were confirmed by NMR spectroscopy and mass spectrometry. The fluorescence intensity emitted by LysoGlow84 depended strongly on the pH of the solvent with highest fluorescence intensity recorded at pH 4. The fluorescence maximum (at 315 nm excitation) was observed at 440 nm. Biocompatibility of LysoGlow84 was investigated using cultured rat brain astrocytes and the marine flatworm Macrostomum lignano. Exposure of the astrocytes for up to 6 h to micromolar concentrations of LysoGlow84 did not compromise cell viability, as demonstrated by several viability assays, but revealed a promising property of this compound for staining of cellular vesicles. Conventional fluorescence microscopy as well as confocal scanning microscopy of LysoGlow84-treated astrocytes revealed co-localization of LysoGlow84 fluorescence with that of LysoTracker® Red DND-99. LysoGlow84 stained unclear structures in Macrostomum lignano, which were identified as lysosomes by co-staining with LysoTracker. Strong fluorescence staining by LysoGlow84 was further observed around the worms’ anterior gut and the female genital pore which were not counterstained by LysoTracker Red. Thus, LysoGlow84 is a new promising dye that stains lysosomes and other acidic compartments in cultured cells and in worms. PMID:25679913

Mordhorst, Thorsten; Awal, Sushil; Jordan, Sebastian; Petters, Charlotte; Sartoris, Linda; Dringen, Ralf; Bickmeyer, Ulf

2015-01-01

348

A Loop-Mediated Isothermal Amplification (LAMP) Assay for Strongyloides stercoralis in Stool That Uses a Visual Detection Method with SYTO-82 Fluorescent Dye  

PubMed Central

An assay to detect Strongyloides stercoralis in stool specimens was developed using the loop-mediated isothermal amplification (LAMP) method. Primers were based on the 28S ribosomal subunit gene. The reaction conditions were optimized and SYTO-82 fluorescent dye was used to allow real-time and visual detection of the product. The product identity was confirmed with restriction enzyme digestion, cloning, and sequence analysis. The assay was specific when tested against DNA from bacteria, fungi and parasites, and 30 normal stool samples. Analytical sensitivity was to < 10 copies of target sequence in a plasmid and up to a 10-2 dilution of DNA extracted from a Strongyloides ratti larva spiked into stool. Sensitivity was increased when further dilutions were made in water, indicative of reduced reaction inhibition. Twenty-seven of 28 stool samples microscopy and polymerase chain reaction positive for S. stercoralis were positive with the LAMP method. On the basis of these findings, the assay warrants further clinical validation. PMID:24323513

Watts, Matthew R.; James, Gregory; Sultana, Yasmin; Ginn, Andrew N.; Outhred, Alexander C.; Kong, Fanrong; Verweij, Jaco J.; Iredell, Jonathan R.; Chen, Sharon C-A.; Lee, Rogan

2014-01-01

349

REDUCING INCIDENTAL FLUORESCENCE IN LIVE CELL IMAGING A. Altinok 1  

E-print Network

of California Santa Barbara, Santa Barbara, CA 93106 ABSTRACT Fluorescence staining is the prevailing image stained cell structures. Generic image processing algorithms address the problem indirectly Fluorescence staining is the main live cell imaging method in biological research [1]. Developments

California at Santa Barbara, University of

350

A modular fiber optic system for intramural functional fluorescence measurement  

NASA Astrophysics Data System (ADS)

Fluorescence imaging techniques have been central to much biomedical science research over the past two decades. In particular, functional imaging has provided important new information about processes that occur at cellular and sub-cellular levels. With this approach, living tissues are stained with dyes whose emission is modulated by changes in the environment to which the dye is exposed. The fluorescence imaging systems used within this context typically incorporate relatively complex free space optical assemblies and a stable platform is necessary to maintain appropriate alignment of their components. Because of the poor efficiency of these systems, it is necessary to use powerful light sources and sensitive photo-detectors. We have developed a novel fluorescence imaging system in which free-space optics are replaced by optical fibers, passive optical splitters and associated components. Solid state lasers are used as the excitation light source. A variety of detection systems have been utilized including a spectrometer. The feasibility of the approach has been established using a rat heart preparation stained with the membrane potential-sensitive dye, di-4-ANEPPS. Detailed emission spectra for this dye, at different levels of resting membrane potential, are presented here for 532 nm and 488 nm excitation. Cardiac action potentials obtained with the modular fiber optic system correspond closely to intracellular potentials acquired at adjacent sites in the isolated rat heart preparation. Our modular fiber optic system is cheaper, more efficient, more flexible and more robust than conventional fluorescence imaging systems. Using a high-speed spectrometer for photodetection, it is possible to implement the signal processing required for multi-line or ratiometric imaging in software, which further enhances the efficiency and flexibility of the system. We believe that this approach has wide potential applications for biomedical fluorescence imaging.

Tai, Dean C.; Rutherford, Sally; Caldwell, Bryan J.; LeGrice, Ian J.; Harvey, John D.; Smaill, Bruce H.

2005-04-01

351

Dye filled security seal  

DOEpatents

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)

1982-04-27

352

Nanoparticle Stained Glass  

NSDL National Science Digital Library

In this activity/demo, learners are introduced to the connection between medieval stained glass artisans and nanotechnology. Learners discover that the red and yellow colors in stained glass windows come from nanoparticles of gold and silver embedded in the glass. This activity/demo consists of two hands-on activities: making a collaborative stained glass window with pre-made nanoparticle solutions containing silver or gold and making a take-away card that contains a small piece of nanoparticle stained “glass."

2014-06-18

353

APPLICATION OF A TWO-COLOR LASER INDUCED FLUORESCENCE (LIF) TECHNIQUE FOR TEMPERATURE MAPPING  

E-print Network

fluorescence dyes with different emission characteristics - one is the temperature sensitive dye (Rhodamine-B) and the other is the temperature insensitive dye (Rhodamine-110). The ratio of the two fluorescence emission

Kihm, IconKenneth David

354

Twisted Cyanines: A Non-Planar Fluorogenic Dye with Superior Photostability and its Use in a Protein-Based Fluoromodule  

PubMed Central

The cyanine dye thiazole orange (TO) is a well-known fluorogenic stain for DNA and RNA, but this property precludes its use as an intracellular fluorescent probe for non-nucleic acid biomolecules. Further, as is the case with many cyanines, the dye suffers from low photostability. Here we report the synthesis of a bridge-substituted version of TO named ?-CN-TO, where the central methine hydrogen of TO is replaced by an electron withdrawing cyano group, which was expected to decrease the susceptibility of the dye toward singlet oxygen-mediated degradation. An X-ray crystal structure shows that ?-CN-TO is twisted drastically out of plane, in contrast to TO, which crystallizes in the planar conformation. ?-CN-TO retains the fluorogenic behavior of the parent dye TO in viscous glycerol/water solvent, but direct irradiation and indirect bleaching studies showed that ?-CN-TO is essentially inert to visible light and singlet oxygen. In addition, the twisted conformation of ?-CN-TO mitigates non-specific binding and fluorescence activation by DNA and a previously selected TO-binding protein and exhibits low background fluorescence in HeLa cell culture. ?-CN-TO was then used to select a new protein that binds and activates fluorescence from the dye. The new ?-CN-TO/protein fluoromodule exhibits superior photostability to an analogous TO/protein fluoromodule. These properties indicate that ?-CN-TO will be a useful fluorogenic dye in combination with specific RNA and protein binding partners for both in vitro and cell-based applications. More broadly, structural features that promote nonplanar conformations can provide an effective method for reducing nonspecific binding of cationic dyes to nucleic acids and other biomolecules. PMID:23252842

Shank, Nathaniel I.; Pham, Ha; Waggoner, Alan S.; Armitage, Bruce A.

2013-01-01

355

Twisted cyanines: a non-planar fluorogenic dye with superior photostability and its use in a protein-based fluoromodule.  

PubMed

The cyanine dye thiazole orange (TO) is a well-known fluorogenic stain for DNA and RNA, but this property precludes its use as an intracellular fluorescent probe for non-nucleic acid biomolecules. Further, as is the case with many cyanines, the dye suffers from low photostability. Here, we report the synthesis of a bridge-substituted version of TO named ?-CN-TO, where the central methine hydrogen of TO is replaced by an electron withdrawing cyano group, which was expected to decrease the susceptibility of the dye toward singlet oxygen-mediated degradation. An X-ray crystal structure shows that ?-CN-TO is twisted drastically out of plane, in contrast to TO, which crystallizes in the planar conformation. ?-CN-TO retains the fluorogenic behavior of the parent dye TO in viscous glycerol/water solvent, but direct irradiation and indirect bleaching studies showed that ?-CN-TO is essentially inert to visible light and singlet oxygen. In addition, the twisted conformation of ?-CN-TO mitigates nonspecific binding and fluorescence activation by DNA and a previously selected TO-binding protein and exhibits low background fluorescence in HeLa cell culture. ?-CN-TO was then used to select a new protein that binds and activates fluorescence from the dye. The new ?-CN-TO/protein fluoromodule exhibits superior photostability to an analogous TO/protein fluoromodule. These properties indicate that ?-CN-TO will be a useful fluorogenic dye in combination with specific RNA and protein binding partners for both in vitro and cell-based applications. More broadly, structural features that promote nonplanar conformations can provide an effective method for reducing nonspecific binding of cationic dyes to nucleic acids and other biomolecules. PMID:23252842

Shank, Nathaniel I; Pham, Ha H; Waggoner, Alan S; Armitage, Bruce A

2013-01-01

356

Tracking antigen-driven responses by flow cytometry: monitoring proliferation by dye dilution.  

PubMed

Cell-tracking reagents such as the green-fluorescent protein labeling dye CFSE and the red-fluorescent lipophilic membrane dye PKH26 are commonly used to monitor cell proliferation by flow cytometry in heterogeneous cell populations responding to immune stimuli. Both reagents stain cells with a bright homogeneous fluorescence, which is partitioned between daughter cells during each cell division. Because daughter cell fluorescence intensities are approximately halved after each division, the intensity of a cell relative to its intensity at the time of staining provides information about how many divisions it has undergone. Knowing how many rounds of division have occurred and the relative number of cells in each daughter generation, one can back-calculate the number of cells in the original population (i.e., cells present at the time of stimulus) that went on to respond by proliferating. Using this information, the precursor cell frequencies and extent of expansion to a specific antigen or mitogen of interest can be calculated. Concurrently, the phenotype of the cells can be determined, as well as their ability to bind antigen or synthesize cytokines, providing more detailed characterization of all cells responding to the antigen, not just effector cells. In multiparameter flow cytometric experiments to simultaneously analyze antigen-specific tetramer binding, cytokine production and T-cell proliferation, we found that only approximately half of the cells that exhibited specific binding to influenza tetramer also proliferated, as measured by dye dilution, and synthesized IFNgamma in response to antigen. We expect the advent of new cell tracking dyes emitting from the violet to the near infrared combined with the increasing number of lasers and detectors on contemporary flow cytometers to further expand the usefulness of this approach to characterization of complex antigen-driven immunological responses. PMID:18785636

Wallace, Paul K; Tario, Joseph D; Fisher, Jan L; Wallace, Stephen S; Ernstoff, Marc S; Muirhead, Katharine A

2008-11-01

357

Shedding light on the photostability of two intermolecular charge-transfer complexes between highly fluorescent bis-1,8-naphthalimide dyes and some ?-acceptors: a spectroscopic study in solution and solid states.  

PubMed

Given the great importance of the various uses of 1,8-naphthalimides in the trends of biology, medicine and industry, the current study focused on extending the scope of these dyes by introducing some of their charge-transfer (CT) complexes. For this purpose, two highly fluorescent bis-1,8-naphthalimide dyes and their complexes with some ?-acceptors have been synthesized and characterized spectroscopically. The ?-acceptors include picric acid (PA), chloranilic acid (CLA), tetracyanoquinodimethane (TCNQ) and dichlorodicyanobenzoquinone (DDQ). The molecular structure, spectroscopic and fluorescence properties as well as the binding modes were deduced from IR, UV-vis and (1)H NMR spectral studies. The binding ratio of complexation was determined to be 1:1 according to the elemental analyses and photometric titrations. It has been found that the order of acceptance ability for the different acceptors is TCNQ>DDQ>CLA>PA. The photostability of 1,8-naphthalimide dye as a donor and its charge-transfer complex doped in polymethyl methacrylate/PMMA were exposed to UV-Vis radiation and the change in the absorption spectra was achieved at different times during irradiation period. PMID:25022501

Refat, Moamen S; Ismail, Lamia A; Adam, Abdel Majid A

2015-01-01

358

A near-infrared phthalocyanine dye-labeled agent for integrin ?v?6-targeted theranostics of pancreatic cancer.  

PubMed

Integrin ?v?6 is widely upregulated in variant malignant cancers but is undetectable in normal organs, making it a promising target for cancer diagnostic imaging and therapy. Using streptavidin-biotin chemistry, we synthesized an integrin ?v?6-targeted near-infrared phthalocyanine dye-labeled agent, termed Dye-SA-B-HK, and investigated whether it could be used for cancer imaging, optical imaging-guided surgery, and phototherapy in pancreatic cancer mouse models. Dye-SA-B-HK specifically bound to integrin ?v?6 in vitro and in vivo with high receptor binding affinity. Using small-animal optical imaging, we detected subcutaneous and orthotopic BxPC-3 human pancreatic cancer xenografts in vivo. Upon optical image-guidance, the orthotopically growing pancreatic cancer lesions could be successfully removed by surgery. Using light irradiation, Dye-SA-B-HK manifested remarkable antitumor effects both in vitro and in vivo. (18)F-FDG positron emission tomography (PET) imaging and ex vivo fluorescence staining validated the observed decrease in proliferation of treated tumors by Dye-DA-B-HK phototherapy. Tissue microarray results revealed overexpression of integrin ?v?6 in over 95% cases of human pancreatic cancer, indicating that theranostic application of Dye-DA-B-HK has clear translational potential. Overall, the results of this study demonstrated that integrin ?v?6-specific Dye-SA-B-HK is a promising theranostic agent for the management of pancreatic cancer. PMID:25890722

Gao, Duo; Gao, Liquan; Zhang, Chenran; Liu, Hao; Jia, Bing; Zhu, Zhaohui; Wang, Fan; Liu, Zhaofei

2015-06-01

359

Apparatus Would Stain Microscope Slides  

NASA Technical Reports Server (NTRS)

Proposed apparatus meters specific amounts of fluid out of containers at specific times to stain microscope slides. Intended specifically for semiautomated staining of microbiological and hematological samples in microgravity, leakproof apparatus used in other environments in which technicians have little time to allocate to staining procedures and/or exposure to toxic staining agents or to micro-organisms to be stained hazardous. Apparatus adapted to perform almost any staining procedure and accommodates multiple staining reagents, useful for small or remote clinical laboratories.

Breeding, James D.

1993-01-01

360

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

E-print Network

dyes that absorb near-IR radiation have an increasing number of applications in materials science this capping strategy may also work with squaraines, we were attracted to an alternative approach, name- ly, a hydrogen bond directed clipping reaction around the core of a dumbell-shaped squaraine dye.7 The structure

Smith, Bradley D.

361

Gram-Stained Fusobacterium  

NSDL National Science Digital Library

A gram-negative stained Fusobacterium spp. with spindle-shaped morphology. This bacterium may be spindle shaped or coccobacilli; it is often pleomorphic. Without spindle shapes, it is often difficult to differentiate from other nonmotile anaerobe

American Society For Microbiology

2006-06-30

362

Port-Wine Stain  

MedlinePLUS

... limb. The syndrome is most frequently diagnosed in infancy or early childhood. Who's At Risk Port-wine ... difference between a port-wine stain and other birthmarks, such as a salmon patch or a hemangioma, ...

363

Port-Wine Stains  

MedlinePLUS

... their own, they can be treated. In fact, laser therapies can make many port-wine stains much ... mark might be. The good news is that lasers (highly concentrated light energy) can make many kids' ...

364

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

365

A low-toxic artificial fluorescent glycoprotein can serve as an efficient cytoplasmic labeling in living cell.  

PubMed

To maintain the virtue of good optical property and discard the dross of conventional fluorescent staining dyes, we provide a strategy for designing new fluorescent scaffolds. In this study, a novel fluorescent labeling glycoprotein (chitosan-poly-L-cysteine, CPC) was synthesized through graft copolymerization. CPC gives emission peak at 465-470 nm when excited at 386 nm. The submicro-scale CPC microspheres could be localized and persisted specifically in the cytoplasm of living cells, with strong blue fluorescence. Moreover, CPC was highly resistant to photo bleaching, the fluorescence was remained stable for up to 72 h as the cells grew and developed. The glycoprotein CPC was bio-compatible and in zero grade cytotoxicity as quantified by MTT assay. The fluorescent labeling process with our newly designed glycoprotein CPC is exceptionally efficient. PMID:25498627

Si, Jiangju; Liang, Dawei; Kong, Dan; Wu, Sufang; Yuan, Lan; Xiang, Yan; Jiang, Lei

2015-03-01

366

Identification of small-scale low and high permeability layers using single well forced-gradient tracer tests: Fluorescent dye imaging and modelling at the laboratory-scale  

NASA Astrophysics Data System (ADS)

Heterogeneity in aquifer permeability, which creates paths of varying mass flux and spatially complex contaminant plumes, can complicate the interpretation of contaminant fate and transport in groundwater. Identifying the location of high mass flux paths is critical for the reliable estimation of solute transport parameters and design of groundwater remediation schemes. Dipole flow tracer tests (DFTTs) and push-pull tests (PPTs) are single well forced-gradient tests which have been used at field-scale to estimate aquifer hydraulic and transport properties. In this study, the potential for PPTs and DFTTs to resolve the location of layered high- and low-permeability layers in granular porous media was investigated with a pseudo 2-D bench-scale aquifer model. Finite element fate and transport modelling was also undertaken to identify appropriate set-ups for in situ tests to determine the type, magnitude, location and extent of such layered permeability contrasts at the field-scale. The characteristics of flow patterns created during experiments were evaluated using fluorescent dye imaging and compared with the breakthrough behaviour of an inorganic conservative tracer. The experimental results show that tracer breakthrough during PPTs is not sensitive to minor permeability contrasts for conditions where there is no hydraulic gradient. In contrast, DFTTs are sensitive to the type and location of permeability contrasts in the host media and could potentially be used to establish the presence and location of high or low mass flux paths. Numerical modelling shows that the tracer peak breakthrough time and concentration in a DFTT is sensitive to the magnitude of the permeability contrast (defined as the permeability of the layer over the permeability of the bulk media) between values of 0.01-20. DFTTs are shown to be more sensitive to deducing variations in the contrast, location and size of aquifer layered permeability contrasts when a shorter central packer is used. However, larger packer sizes are more likely to be practical for field-scale applications, with fewer tests required to characterise a given aquifer section. The sensitivity of DFTTs to identify layered permeability contrasts was not affected by test flow rate.

Barns, Gareth L.; Thornton, Steven F.; Wilson, Ryan D.

2015-01-01

367

Automated four color CD4/CD8 analysis of leukocytes by scanning fluorescence microscopy using Quantum dots  

NASA Astrophysics Data System (ADS)

Scanning Fluorescence Microscope (SFM) is a new technique for automated motorized microscopes to measure multiple fluorochrome labeled cells (Bocsi et al. Cytometry 2004, 61A:1). The ratio of CD4+/CD8+ cells is an important in immune diagnostics in immunodeficiency and HIV. Therefor a four-color staining protocol (DNA, CD3, CD4 and CD8) for automated SFM analysis of lymphocytes was developed. EDTA uncoagulated blood was stained with organic and inorganic (Quantum dots) fluorochromes in different combinations. Aliquots of samples were measured by Flow Cytometry (FCM) and SFM. By SFM specimens were scanned and digitized using four fluorescence filter sets. Automated cell detection (based on Hoechst 33342 fluorescence), CD3, CD4 and CD8 detection were performed, CD4/CD8 ratio was calculated. Fluorescence signals were well separable on SFM and FCM. Passing and Bablok regression of all CD4/CD8 ratios obtained by FCM and SFM (F(X)=0.0577+0.9378x) are in the 95% confidence interval. Cusum test did not show significant deviation from linearity (P>0.10). This comparison indicates that there is no systemic bias between the two different methods. In SFM analyses the inorganic Quantum dot staining was very stable in PBS in contrast to the organic fluorescent dyes, but bleached shortly after mounting with antioxidant and free radical scavenger mounting media. This shows the difficulty of combinations of organic dyes and Quantum dots. Slide based multi-fluorescence labeling system and automated SFM are applicable tools for the CD4/CD8 ratio determination in peripheral blood samples. Quantum Dots are stable inorganic fluorescence labels that may be used as reliable high resolution dyes for cell labeling.

Bocsi, Jozsef; Mittag, Anja; Varga, Viktor S.; Molnar, Bela; Tulassay, Zsolt; Sack, Ulrich; Lenz, Dominik; Tarnok, Attila

2006-02-01

368

Bichromophoric dyes for wavelength shifting of dye-protein fluoromodules.  

PubMed

Dye-protein fluoromodules consist of fluorogenic dyes and single chain antibody fragments that form brightly fluorescent noncovalent complexes. This report describes two new bichromophoric dyes that extend the range of wavelengths of excitation or emission of existing fluoromodules. In one case, a fluorogenic thiazole orange (TO) was attached to an energy acceptor dye, Cy5. Upon binding to a protein that recognizes TO, red emission due to efficient energy transfer from TO to Cy5 replaces the green emission observed for monochromophoric TO bound to the same protein. Separately, TO was attached to a coumarin that serves as an energy donor. The same green emission is observed for coumarin-TO and TO bound to a protein, but efficient energy transfer allows violet excitation of coumarin-TO, versus longer wavelength, blue excitation of monochromophoric TO. Both bichromophores exhibit low nanomolar KD values for their respective proteins, >95% energy transfer efficiency and high fluorescence quantum yields. PMID:25679477

Pham, Ha H; Szent-Gyorgyi, Christopher; Brotherton, Wendy L; Schmidt, Brigitte F; Zanotti, Kimberly J; Waggoner, Alan S; Armitage, Bruce A

2015-03-11

369

Epiluminescence Microscopy for Port-Wine Stains: Pretreatment Evaluation  

Microsoft Academic Search

Background: Port-wine stains (PWSs) are characterized by an increased number of ectatic vessels. The treatment of choice is the use of some lasers such as pulsed dye lasers. However, some lesions are nonresponsive to laser treatment. Perhaps the vessels’ depth and diameter and the thickness of the vessel wall are important factors influencing the effectiveness of the laser treatment. Methods:

Enrico Maria Procaccini; Giuseppe Argenziano; Stefania Staibano; Gerardo Ferrara; Giuseppe Monfrecola

2001-01-01

370

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.

371

Are picro-dye reactions for collagens quantitative?  

Microsoft Academic Search

Previous studies of picro-dye reactions demonstrated wide variations in the binding of different dyes. Picro-Sirius Red F3BA was recommended because it colors all collagens intensely and is suitable for polarization microscopy. Recent publications on quantitative uses of this stain were surprising. To obtain further information on the chemical mechanisms of dye binding by proteins, 94 sulfonated azo dyes were tested

H. Puchtler; S. N. Meloan; F. S. Waldrop

1988-01-01

372

Time-resolved multicolor two-photon excitation fluorescence microscopy of cells and tissues  

NASA Astrophysics Data System (ADS)

Multilabeling which maps the distribution of different targets is an indispensable technique in many biochemical and biophysical studies. Two-photon excitation fluorescence (TPEF) microscopy of endogenous fluorophores combining with conventional fluorescence labeling techniques such as genetically encoded fluorescent protein (FP) and fluorescent dyes staining could be a powerful tool for imaging living cells. However, the challenge is that the excitation and emission wavelength of these endogenous fluorophores and fluorescent labels are very different. A multi-color ultrafast source is required for the excitation of multiple fluorescence molecules. In this study, we developed a two-photon imaging system with excitations from the pump femtosecond laser and the selected supercontinuum generated from a photonic crystal fiber (PCF). Multiple endogenous fluorophores, fluorescent proteins and fluorescent dyes were excited in their optimal wavelengths simultaneously. A time- and spectral-resolved detection system was used to record the TPEF signals. This detection technique separated the TPEF signals from multiple sources in time and wavelength domains. Cellular organelles such as nucleus, mitochondria, microtubule and endoplasmic reticulum, were clearly revealed in the TPEF images. The simultaneous imaging of multiple fluorophores of cells will greatly aid the study of sub-cellular compartments and protein localization.

Zheng, Wei

2014-11-01

373

Probing and fluorescence enhanc with single gold nanorods  

E-print Network

antenna and can enhance fluorescence of a weak dye (crystal violet) by 1000-fold. The enhancement fac antenna and can enhance fluorescence of a weak dye (crystal violet) fold. The enhancement factor strongly is an efficient antenna and can enhance fluorescence of a weak dye (crystal violet) tor strongly depends

Shyamasundar, R.K.

374

Stained-Glass Pastels  

ERIC Educational Resources Information Center

The author has always liked the look of stained-glass windows. Usually the designs are simplified and the shapes are easier for younger students to draw. This technique seemed to be the perfect place for her fifth-graders to try their hand at color mixing. The smaller spaces and simple shapes were just what she needed for this group. Her students…

Laird, Shirley

2009-01-01

375

Stained Glass Glue  

NSDL National Science Digital Library

In this activity on page 6 of the PDF, learners use glue instead of glass to create artwork that can be hung in a window. Discover how the chemicals in various materials mix together to make a colorful, translucent "stained glass" creation.

American Chemical Society

2001-01-01

376

"Stained Glass" Landscape Windows  

ERIC Educational Resources Information Center

Both adults and children alike marvel at the grand vivid stained-glass windows created by American artist Louis Comfort Tiffany. Today he is commonly recognized as one of America's most influential designers and artists throughout the last nineteenth and early twentieth century. In the lesson described in this article, students created their own…

Vannata, Janine

2008-01-01

377

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

2013-03-01

378

Differential staining of acid glycosaminoglycans (mucopolysaccharides) by Alcian blue in salt solutions  

Microsoft Academic Search

The application of the “critical electrolyte concentration” (CEC) concept to the differentiation of acidic glycosaminglycans (mucopolysaccharides) is described. Alcian Blue 8GX stains with increasing selectivity as increasing amounts of magnesium chloride are incorporated into the dye solution. Model experiments with pure polyanions, or artifically carboxylated, phosphorylated and sulphated liver sections, showed that binding of dye to carboxylate or phosphate groups

J. E. Scott; J. Dorling

1965-01-01

379

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

NASA Astrophysics Data System (ADS)

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.

Kawaguchi, Yuko; Sugino, Tomohiro; Tabata, Makoto; Okudaira, Kyoko; Imai, Eichi; Yano, Hajime; Hasegawa, Sunao; Hashimoto, Hirofumi; Yabuta, Hikaru; Kobayashi, Kensei; Kawai, Hideyuki; Mita, Hajime; Yokobori, Shin-ichi; Yamagishi, Akihiko

2014-08-01

380

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

PubMed

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

2014-02-01

381

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

NASA Astrophysics Data System (ADS)

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.

Kawaguchi, Yuko; Sugino, Tomohiro; Tabata, Makoto; Okudaira, Kyoko; Imai, Eichi; Yano, Hajime; Hasegawa, Sunao; Hashimoto, Hirofumi; Yabuta, Hikaru; Kobayashi, Kensei; Kawai, Hideyuki; Mita, Hajime; Yokobori, Shin-ichi; Yamagishi, Akihiko

2014-02-01

382

Fluorescence-detected DNA sequencing  

SciTech Connect

Our research effort funded by this grant primarily focused on development of suitable fluorescent dyes for DNA sequencing studies. Prior to our efforts, the dyes being sued in commercial DNA sequencers were various versions of fluorescein dyes for the shorter wavelengths and of rhodamine dyes for the longer wavelengths. Our initial goal was to synthesize a set of four dyes that could all be excited by the 488 and 514 nm line of the argon laser lines and that have emission spectra that minimize spectral overlap. The specific result sought was higher fluorescent intensity, particularly of the longest wavelength dyes than was available using existing dyes. Another important property of the desired set of dyes was uniform ionic charge in order to have minimum interference on the electrophoretic mobility during the sequencing. During the period of this grant we prepared and characterized four types of dyes: fluorescent bifluorophores, derivatives of rhodamine dyes, derivatives of rhodol dyes and derivatives of boron dipyrromethene difluoride (BODIPY{trademark}) dyes.

Haugland, R.P.

1990-01-01

383

Enhancing analysis of cells and proteins by fluorescence imaging on silk-based biomaterials: modulating the autofluorescence of silk.  

PubMed

Silk is a versatile and established biomaterial for various tissue engineering purposes. However, it also exhibits strong autofluorescence signals-thereby hindering fluorescence imaging analysis of cells and proteins on silk-derived biomaterials. Sudan Black B (SB) is a lysochrome dye commonly used to stain lipids in histology. It has also been reported to be able to quench autofluorescence of tissues in histology and has been tested on artificial biomedical polymers in recent years. It was hypothesized that SB would exert similar quenching effects on silk, modulating the autofluorescence signals, and thereby enabling improved imaging analysis of cells and molecules of interests. The quenching effect of SB on the intrinsic fluorescence properties of silk and on commercial fluorescent dyes were first investigated in this study. SB was then incorporated into typical fluorescence-based staining protocols to study its effectiveness in improving fluorescence-based imaging of the cells and proteins residing with the silk-based biomaterials. Silk processed into various forms of biomaterials (e.g., films, sponges, fibers, and electrospun mats) was seeded with cells and cultured in vitro. At sacrificial time points, specimens were harvested, fixed, and prepared for fluorescence staining. SB, available commercially as a powder, was dissolved in 70% ethanol (0.3% [w/v]) to form staining solutions. SB treatment was introduced at the last step of typical immunofluorescence staining protocols for 15-120?min. For actin staining protocols by phalloidin toxin, SB staining solutions were added before and after permeabilization with Triton-X for 15-30?min. Results showed that ideal SB treatment duration is about 15?min. Apart from being able to suppress the autofluorescence of silk, this treatment duration was also not too long to adversely affect the fluorescent labeling probes used. The relative improvement brought about by SB treatment was most evident in the blue and green emission wavelengths compared with the red emission wavelength. This study has showed that the use of SB is a cost and time effective approach to enhance fluorescence-based imaging analyses of cell-seeded silk biomaterials, which otherwise would have been hindered by the unmodulated autofluorescence signals. PMID:25050876

Neo, Puay Yong; Tan, Daryl Jian-An; Shi, Pujiang; Toh, Siew Lok; Goh, James Cho-Hong

2015-02-01

384

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

1974-01-01

385

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

PubMed

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

2001-03-01

386

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...

387

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.

2013-01-01

388

Application of stains-all staining to the analysis of axonemal tubulins: identification of beta-tubulin and beta-isotubulins.  

PubMed

The cationic dye, Stains-all, is known to stain brain beta-tubulin blue and alpha-tubulin red (Serrano, L. et al. (1986) J. Biochem. Biophys. Methods 12, 281-287; Serrano, L. et al. (1989) Biochem. Int., 19, 235-246). The present experiments show that this stain can also be applied to detect beta-tubulin in axonemal tubulins from various sources such as cilia of protozoa, sperm flagella of echinoderm, and sperm flagella of mollusc. Furthermore, these experiments showed that it selectively stains isoforms of axonemal beta-tubulin blue following isoelectric focusing, whereas those of alpha-tubulin are stained red. These results indicate that Stains-all staining is a useful tool for electrophoretic analysis of axonemal tubulins. PMID:1704028

Nakamura, K; Masuyama, E; Wada, S; Okuno, M

1990-01-01

389

Enhanced Fluorescence Cell Imaging with Metal-Coated Slides  

PubMed Central

Fluorescence labeling is the prevailing imaging technique in cell biology research. When they involve statistical investigations on a large number of cells, experimental studies require both low magnification to get a reliable statistical population and high contrast to achieve accurate diagnosis on the nature of the cells' perturbation. Because microscope objectives of low magnification generally yield low collection efficiency, such studies are limited by the fluorescence signal weakness. To overcome this technological bottleneck, we proposed a new method based on metal-coated substrates that enhance the fluorescence process and improve collection efficiency in epifluorescence observation and that can be directly used with a common microscope setup. We developed a model based on the dipole approximation with the aim of simulating the optical behavior of a fluorophore on such a substrate and revealing the different mechanisms responsible for fluorescence enhancement. The presence of a reflective surface modifies both excitation and emission processes and additionally reshapes fluorescence emission lobes. From both theoretical and experimental results, we found the fluorescence signal emitted by a molecular cyanine 3 dye layer to be amplified by a factor ?30 when fluorophores are separated by a proper distance from the substrate. We then adapted our model to the case of homogeneously stained micrometer-sized objects and demonstrated mean signal amplification by a factor ?4. Finally, we applied our method to fluorescence imaging of dog kidney cells and verified experimentally the simulated results. PMID:17172306

Moal, E. Le; Fort, E.; Lévêque-Fort, S.; Cordelières, F. P.; Fontaine-Aupart, M.-P.; Ricolleau, C.

2007-01-01

390

A time differential staining technique coupled with full bilateral gill denervation to study ionocytes in fish.  

PubMed

Branchial ionocytes (ICs) are the functional units for ionic regulation in fish. In adults, they are found on the filamental and lamellar epithelia of the gill where they transport ions such as Na(+), Cl(-) and Ca(2+) via a variety of ion channels, pumps and exchangers. The teleost gill is extrinsically innervated by the facial (VI), glossopharyngeal (IX) and vagus (X) nerves. The IX and X nerves are also the extrinsic source of branchial IC innervation. Here, two techniques used to study the innervation, proliferation and distribution of ICs are described: a time differential staining technique and a full bilateral gill denervation technique. Briefly, goldfish are exposed to a vital mitochondrion-specific dye (e.g., MitoTracker Red) which labels (red fluorescence) pre-existing ICs. Fish were either allowed to recover for 3 - 5 days or immediately underwent a full bilateral gill denervation. After 3 - 5 days of recovery, the gills are harvested and fixed for immunohistochemistry. The tissue is then stained with an ?-5 primary antibody (targets Na(+)/K(+) ATPase containing cells) in conjunction with a secondary antibody that labels all (both new and pre-existing) ICs green. Using confocal imaging, it was demonstrated that pre-existing ICs appear yellow (labelled with both a viable mitochondrion-specific dye and ?-5) and new ICs appear green (labelled with ?-5 only). Both techniques used in tandem can be applied to study the innervation, proliferation and distribution of ICs on the gill filament when fish are exposed to environmental challenges. PMID:25868043

Tzaneva, Velislava; Perry, Steve F

2015-01-01

391

A Time Differential Staining Technique Coupled with Full Bilateral Gill Denervation to Study Ionocytes in Fish  

PubMed Central

Branchial ionocytes (ICs) are the functional units for ionic regulation in fish. In adults, they are found on the filamental and lamellar epithelia of the gill where they transport ions such as Na+, Cl- and Ca2+ via a variety of ion channels, pumps and exchangers. The teleost gill is extrinsically innervated by the facial (VI), glossopharyngeal (IX) and vagus (X) nerves. The IX and X nerves are also the extrinsic source of branchial IC innervation. Here, two techniques used to study the innervation, proliferation and distribution of ICs are described: a time differential staining technique and a full bilateral gill denervation technique. Briefly, goldfish are exposed to a vital mitochondrion-specific dye (e.g., MitoTracker Red) which labels (red fluorescence) pre-existing ICs. Fish were either allowed to recover for 3 - 5 days or immediately underwent a full bilateral gill denervation. After 3 - 5 days of recovery, the gills are harvested and fixed for immunohistochemistry. The tissue is then stained with an ?-5 primary antibody (targets Na+/K+ ATPase containing cells) in conjunction with a secondary antibody that labels all (both new and pre-existing) ICs green. Using confocal imaging, it was demonstrated that pre-existing ICs appear yellow (labelled with both a viable mitochondrion-specific dye and ?-5) and new ICs appear green (labelled with ?-5 only). Both techniques used in tandem can be applied to study the innervation, proliferation and distribution of ICs on the gill filament when fish are exposed to environmental challenges. PMID:25868043

Tzaneva, Velislava; Perry, Steve F.

2015-01-01

392

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)

1994-01-01

393

Application of surface-enhanced Raman scattering (SERS) for the identification of anthraquinone dyes used in works of art  

Microsoft Academic Search

Surface-enhanced Raman scattering (SERS) was investigated for applications in the analysis of anthraquinone dyes used in works of art. Two SERS procedures were developed and evaluated with three frequently used anthraquinone dyes, alizarin, carminic acid and lac dye. The first procedure involves coating a layer of silver nanoparticles directly on pieces of filter paper stained with the dyes of interest

Kui Chen; Marco Leona; Kim-Chi Vo-Dinh; Fei Yan; Musundi B. Wabuyele; Tuan Vo-Dinh

2006-01-01

394

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.

2009-05-01

395

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

PubMed

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

2012-07-01

396

Planar laser induced fluorescence in aqueous flows  

Microsoft Academic Search

Planar laser-induced fluorescence (PLIF) is a non-intrusive technique for measuring scalar concentrations in fluid flows.\\u000a A fluorescent dye is used as a scalar proxy, and local fluorescence caused by excitation from a thin laser sheet can be related\\u000a to dye concentration. This review covers quantitative PLIF in aqueous flows, with discussions of fluorescence theory, experimental\\u000a methods and equipment, image processing

J. P. Crimaldi

2008-01-01

397

Development of novel fluorescent probe- protein protected gold nanoclusters for biomedical applications  

NASA Astrophysics Data System (ADS)

This dissertation explores photo-physics, fluorescence polarization properties; resonance energy transfer (RET) probes, and cellular imaging applications for novel fluorescent probe BSA Au clusters By Rayleigh scattering subtraction from extinction spectrum, we found that BSA Au clusters shows peak absorption around 360 nm and shoulder near 500 nm. Peak fluorescence emission lies around 650nm. The fluorescence quantum yield was determined to be 0.06%, while it displayed long fluorescence lifetime of 1.8 mus. BSA Au clusters show stable fluorescence properties and resistance to unfolding and quenching with varying pH, temperature, quencher and denaturant concentration. Moreover, BSA Au clusters shows distinct fluorescence polarization behavior as measured in solvents of different viscosity. The BSA Au cluster, due to long lifetime and high polarization, can potentially be used in studying large macromolecules such as protein complexes with large molecular weight and developing fluorescence polarization immunoassays. BSA Au clusters suffer from several disadvantages such as low quantum efficiency (typically near 6%) and broad emission spectrum (540nm to 800nm). We describe an approach by developing RET probes to enhance the apparent brightness more than 2 fold of BSA Au clusters by linking it with high extinction donor organic dye pacific blue (PB). Moreover, we prepared another conjugate of BSA Au clusters with the near infra-red (NIR) dye Dylight 750 (Dy750), where BSA Au cluster act as a donor to Dy750, showing 46% transfer efficiency to the NIR dye Dy750 with long lifetime component in acceptor decay through RET. Transferring energy from BSA Au cluster to Dy750 will have a RET probe with narrow emission spectrum and long lifetime component which can be explored in imaging applications. Furthermore, herein I describe the use of these long lived BSA Au clusters in cellular and tissue imaging applications. In first approach, I have shown its utility as FLIM probe as well as a time gated intensity imaging probe. In second approach we have shown the one can increase the intensity of long lived BSA Au cluster in cells without increasing the short lived auto-fluorescence background thereby increasing signal to noise ratio at least by 15 times. Furthermore, by applying gated detection strategy to multipulse excitation imaging experiment we increased the signal to noise ratio to 30, a dramatic improvement in contrast for low fluorescence quantum yield dye. In summary, BSA Au clusters can be used as a fluorescent cellular stain advancing the bioimaging technology via their long fluorescence lifetime.

Rostamzadeh Renani, Fatemeh

398

[Ultrahigh magnifying endoscopy: development of CM double staining for endocytoscopy and its safety].  

PubMed

Endocytoscopy is ultrahigh magnifying endoscopy which enables in vivo cellular imaging of gastrointestinal mucosa. Double staining using both 0.05% crystal violet and 0.1% methylene blue (CM double staining) was developed as this was anticipated to produce similar results to conventional haematoxylin-eosin staining in histology. Endocytoscopy with CM staining enables us to evaluate tissue atypia by approximating the tip of the endoscope onto the mucosal surface. Our initial clinical experience of 152 patients who underwent endocytoscopic examination did not identify any patients with clinically evident side effects. The safety of staining methods has recently been questioned in the literature and in order to clarify this further, a literature review was undertaken. There are only a few reports warning against the use of dye, due to toxicity. This was particularly apparent in animal studies with increased risk of carcinogenesis after one year of daily dye administration. Single administration of dye, however, does not seem to cause severe side effects especially at the low concentrations used during endoscopy. Olliver et al. described one case of genetic injury secondary to dye administration, but carcinogenesis after routine chromoendoscopy has not been verified. Although there is not sufficient evidence to support that genetic injury results in carcinogenesis, we advocate measures during endoscopy to reduce the volume and concentration of dye solution in contact with the gastrointestinal mucosa. Therefore, regularly suctioning and irrigation should be routinely performed as a precautionary measure. PMID:20662202

Inoue, Haruhiro; Yokoyama, Akira; Kudo, Shin-ei

2010-07-01

399

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.

2014-04-01

400

Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging  

SciTech Connect

Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

Bwambok, David [Louisiana State University; El-Zahab, Bilal [Lousianna State University; Challa, Santhosh [Louisiana State University; Li, Min [Lousianna State University; Chandler, Lin [Horiba Jobin Yvon Inc.; Baker, Gary A [ORNL; Warner, Isiah M [ORNL

2009-01-01

401

Submicrosecond Imaging Under A Pulsed-Laser Fluorescence Microscope  

NASA Astrophysics Data System (ADS)

A microscope system has been constructed that enables digital imaging of a fluorescent cell under pulsed illumination. Each image is produced by a single laser pulse of duration less than 0.3 11 s. With this system, microsecond responses of a single cell to an externally applied electric field have been resolved temporally and spatially. The cell membrane was stained with a voltage-sensitive fluorescent dye. The induction of transsmembrane potential by the applied field, and the perforation (electroporation) of the cell membrane under an intense field, were seen as successive images. The major finding was a transient increase, at the moment of perforation, in the membrane permeability to an enormous level in localized regions of the cell membrane. Possible roles in cell technology, as well as other applications of the microscope system, are discussed.

Kinosita, Kazuhiko; Ashikawa, Ikuo; Hibino, Masahiro; Shigemori, Masaya; Yoshim ura, Hideyuki; Itoh, Hiroyasu; Nagayama, Kuniaki; lkegami, Akira

1988-06-01

402

Near Infrared Fluorescent NanoGUMBOS for Biomedical Imaging  

PubMed Central

Herein, we report on near infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 °C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS. PMID:19928781

Bwambok, David K.; El-Zahab, Bilal; Challa, Santhosh K.; Li, Min; Chandler, Lin; Baker, Gary A.; Warner, Isiah M.

2009-01-01

403

Flashlamp-excited dye laser therapy for treatment of cutaneous vascular lesions  

NASA Astrophysics Data System (ADS)

Flashlamp excited dye laser therapy represents an exciting new advance in the treatment of a variety of cutaneous vascular lesions. Portwine stains, angiomas and telangiectases can be treated in all age groups with this laser system. This paper will review the physics of flashlamp dye laser photothermolysis. The differences between argon laser photocoagulation and flashlamp excited dye laser therapy will be reviewed.

Goldberg, David J.

1990-06-01

404

Removing Stains from Washable Fabrics.  

E-print Network

I UUL. Z TA24S.7 8873 NO.1616 B.1616 / Texas Agricultural Extension Service LIBRARY FEB 0 1 1989 Texas A&M University Removing Stains from Washable Fabrics Ann Vanderpoorten 8eard* Most spots and stains can be removed by prompt... warded by extending the life of your clothing and other textile products. Guidelines for Removing Stains ? Know as much about the fabric as possible. Read the care label to determine safe procedures, and re member that the procedures described...

Beard, Ann Vanderpoorten

1988-01-01

405

A fluorescent redox dye. Influence of several substrates and electron carriers on the tetrazolium salt—formazan reaction of Ehrlich ascites tumour cells  

Microsoft Academic Search

Summary  This study was performed to elaborate the best conditions for measuring the redox activity of Ehrlich ascites tumour cells by using a new tetrazolium salt, cyantolyl tetrazolium chloride (CTC). This tetrazolium salt forms a fluorescent water-insoluble formazan on reduction on the surface of intact vital cells. The influences of fixation and of various substrates and electron carriers on the cellular

J. Stellmach; E. Severin

1987-01-01

406

[Identification of catecholamines in the rat brain and mollusk tissues using semithin slices and retrograde staining].  

PubMed

The suggested technique allows revealing the transport-specific dye (primulin) and catecholamine fluorescence simultaneously in the same cell of brain. Intense fluorescence is observed when brain tissue is quickly dehydrated and embedded in the epoxy resin. The same method is suggested for the identification of catecholamines in the embryonal and juvenile tissues of gastropod Lymnaea stagnalis (Mollusca Pulmonata) without using of primulin dye. PMID:2482195

Prudnikov, I M; Ma?ski?, V A; Chepera, E N

1989-01-01

407

Treatment of port-wine stains: analysis  

SciTech Connect

Port-wine stains (PWS) are bluish red skin stains that are caused by enlarged, ectatic blood vessels in the dermis. Laser treatment of PWS is analyzed from computation of the spatial distribution of heat production by direct absorption of the laser light and subsequent heat conduction. The absorption and scattering caused by oxyhemoglobin, epidermis, and dermis as a function of wavelength are utilized in this analysis. Ideal treatment is defined as coagulating the ectatic blood vessels without irreversible damage to the epidermis and dermis. The analysis shows that a millisecond pulsed, yellow dye laser at 577 nm (one of the large absorption bands in blood) is the laser of choice to treat PWS, offering as close to the ''ideal treatment'' as possible. The blue-green argon laser, which is currently the most frequently used laser for this purpose, is strongly recommended with irradiation times in milliseconds. Other lasers that are in clinical use, such as the red ruby and near-infrared Nd-YAG lasers, can provide selective treatment only when the epidermis is cooled concurrently. The CO/sub 2/ laser, on the other hand, can coagulate the blood vessels only through heat conduction from the hot epidermis; hence, it has neither the treatment selectivity nor any other physical option to force this selectivity.

van Gemert, M.J.; Welch, A.J.

1987-08-01

408

Fluorescence quenching in oligonucleotides containing 7-substituted 7-deazaguanine bases prepared by the nicking enzyme amplification reaction.  

PubMed

Recently, we reported the use of the Nicking Enzyme Amplification Reaction (NEAR) for the enzymatic synthesis of short oligonucleotides (ONs) containing 5-substituted pyrimidine or 7-substituted 7-deazaadenine nucleotides. Since no oligonucleotide products were visible on agarose gels stained by an intercalating dye (GelRed), we assumed that the method did not work for 7-substituted 7-deazaguanine deoxyribonucleoside triphosphates. We revisited the work and found that the NEAR method works for 7-deazaguanine nucleotides as well but that the resulting modified ONs quench the fluorescence of DNA intercalators, rendering them invisible on gel electrophoresis stained by them. Here, we report on the modified methodology for the NEAR synthesis and analysis of G-modified ONs and on quantification of the fluorescence quenching. PMID:25599383

Ménová, Petra; Dziuba, Dmytro; Güixens-Gallardo, Pedro; Jurkiewicz, Piotr; Hof, Martin; Hocek, Michal

2015-02-18

409

Direct observation method of individual single-stranded DNA molecules using fluorescent replication protein A.  

PubMed

Direct observation studies of single molecules have revealed molecular behaviors usually hidden in the ensemble and time-averaging of bulk experiments. Direct single DNA molecule analysis of DNA metabolism reactions such as DNA replication, repair, and recombination is necessary to fully understand these essential processes. Intercalation of fluorescent dyes such as YOYO-1 and SYTOX Orange has been the standard method for observing single molecules of double-stranded DNA (dsDNA), but effective fluorescent dyes for observing single molecules of single-stranded DNA (ssDNA) have not been found. To facilitate direct single-molecule observations of DNA metabolism reactions, it is necessary to establish methods for discriminating ssDNA and dsDNA. To observe ssDNA directly, we prepared a fusion protein consisting of the 70 kDa DNA-binding domain of replication protein A and enhanced yellow fluorescent protein (RPA-YFP). This fusion protein had ssDNA-binding activity. In our experiments, dsDNA was stained by SYTOX Orange and ssDNA by RPA-YFP, and we succeeded in staining ssDNA and dsDNA by using RPA-YFP and SYTOX Orange simultaneously. PMID:21225324

Oshige, Masahiko; Kawasaki, Shohei; Takano, Hiroki; Yamaguchi, Kouji; Kurita, Hirofumi; Mizuno, Takeshi; Matsuura, Shun-ichi; Mizuno, Akira; Katsura, Shinji

2011-05-01

410

[Study of the secondary and tertiary structure of phage MS2 RNA using nucleases and fluorescent dyes specific for secondary structure].  

PubMed

The binding of ethidium bromide (EtBr) and acridine orange (AO) to RNA in native state or after hydrolysis by S1 and SV nucleases that specifically split single-stranded and double-stranded segments was studied. Nuclease S1 hydrolysis of RNA does not increase the number of EtBr strong binding sites, Tm and hyperchromic effect being also unchanged. Hydrolysis by double-stranded segments accessible to EtBr is followed by the diminishing of Tm and hyperchromism. A supposition is put forward that the main role in stabilization of the RNA tertiary structure is played by double-stranded segments arranged so that some of them are hidden and do not interact with dyes. One of the possible models may be parallel oriented intramolecular "hair-pins" forming compact "rod-like" structures. PMID:6097815

Borisova, O F; Grechko, V V; Aleshkina, L A; Kuznetsova, N V

1984-01-01

411

Effect of molecular-level insulation on the performance of a dye-sensitized solar cell: fluorescence studies in solid state.  

PubMed

The performance of a dye-sensitized solar cell (DSSC) that is based on the host-guest encapsulation of 5-[4-diphenylamino)phenyl]thiophene-2-cyanoacrylic acid (L1) inside ?-cyclodextrin hosts has been tested. The formation of the complex in the solid state and when adsorbed on TiO(2) was characterized using steady and picosecond time-resolved emission techniques, as well as time dependent DFT calculations. The molecular-level insulation has led to a small enhancement in the energy-conversion performance of the fabricated DSSC with the best results being an increase in the open circuit voltage (Voc) from 0.7 to 0.8 V. The importance of th