TY - JOUR. T1 - Engineering ESPT pathways based on structural analysis of LSSmKate red fluorescent proteins with large stokes shift. AU - Piatkevich, Kiryl D.. AU - Malashkevich, Vladimir N.. AU - Almo, Steven C.. AU - Verkhusha, Vladislav. PY - 2010/8/11. Y1 - 2010/8/11. N2 - LSSmKate1 and LSSmKate2 are monomeric red fluorescent proteins (RFPs) with large Stokes shifts (LSSs), which allows for efficient separation of absorbance and emission maxima, as well as for excitation with conventional two-photon laser sources. These LSSmKates differ by a single amino acid substitution at position 160 and exhibit absorbance maxima around 460 nm, corresponding to a neutral DsRed-like chromophore. However, excitation at 460 nm leads to fluorescence emission above 600 nm. Structures of LSSmKate1 and LSSmKate2, determined at resolutions of 2.0 and 1.5, respectively, revealed that the predominant DsRed-chromophore configurations are cis for LSSmKate1 but trans for LSSmKate2. Crystallographic and mutagenesis ...
Nitric Oxide (NO) is a highly-reactive radical gas that can modify a variety of cellular targets in both eukaryotes and bacteria. NO is produced endogenously by a wide variety of organisms: For example, as a cell-signaling molecule in mammals and bacteria via nitric oxide synthase (NOS) enzymes, and as a product of denitrification. As such, it is of great benefit to NO researchers to be able to sensitively detect intracellular NO and stable reactive nitrogen species (RNS) derived from NO. To this end, a protocol for fluorescent detection of intracellular NO/RNS in biofilm cultures of the Gram-positive pathogen Staphylococcus aureus has been optimized using the commercially-available cell-permeable fluorescent stain 4-Amino-5-Methylamino-2,7-Difluorofluorescein Diacetate (DAF-FM diacetate). This compound diffuses into cells and intracellular cleavage by esterase enzymes liberates weakly-fluorescent DAF-FM, which reacts with NO or other specific RNS to become highly fluorescent (Kojima et al., 1999).
Fluorescent Molecular Rotors are sensors of microenvironmental restriction that become fluorescent only if their rotation is constrained. It has been suggested that the change of fluorescence intensity is caused by the restriction of intramolecular rotational relaxation about the donor-acceptor bond of the fluorophores.
Examples of molecular constraint include increased dye (aggregation)1, binding to antibodies2, or being trapped in the polymerization of actin3. There are also studies of membrane fluidity in endothelial cells under fluid shear stress4 where fluorescent molecular rotors are used.

1. Bhattacharyya, A. et al., Indian J. Biochem. Biophys., 32, 442-446 (1995).
2. Iwaki, T. et al., Biochem., 32, 7589-7592 (1993).
3. Sawada, S. et al., Anal. Biochem., 204, 110-117 (1992).
4. Farkas, D.L. and Leif R.C. (ed.), Optical diagnostics of living cells III, Proc SPIE 3291, 101-112 (2000
A red-emitting fluorescent probe was developed for the sensitive and selective detection of H2S. Upon treatment with H2S, this probe exhibited a remarkable fluorescence enhancement (10 fold) with a large Stokes shift (125 nm). The detection limit of this probe was as low as 5.7 nM based on S/N = 3. The appli
We present a technique for observing single fluorophore molecules in solution. A mode-locked laser beam is focused into the solution, thereby defining a two-photon excitation volume localized in three dimensions. Molecules diffusing into and out of this volume produce fluorescence bursts, which are detected with a high signal-to-background ratio. The theoretical foundations for the technique are laid out, including the attendant fluorescence rate distribution, and agree with experimental results obtained for Rhodamine B molecules in water.. © 1995 Optical Society of America. Full Article , PDF Article ...
Studying the implication of hydrogen peroxide in biological processes in plants remains a challenge due to the current shortcomings of H2O2-responsive probes. The use of ContPY1, a new fluorescent probe, which is highly selective and sensitive for H2O2, was investigated. To validate the use of ContPY1 on plants, we have generated protocols employing cells suspensions and leaves, and measured specifically H2O2 production by plants using spectrofluorometry and microscopy. © 2013 Landes Bioscience. ...
ortho-Aminobenzoic acid (Abz) has been used as a convenient fluorescent donor group in internally quenched fluorescent peptides, which are employed as substrates for several proteolytic enzymes. As Abz is usually bound to the N-amino terminal of these peptides, it is of interest to investigate the Abz group fluorescent properties bound to different amino acids. We report in this article the optical absorption and fluorescent properties, in aqueous media, of Abz bound to the alpha-amino group of Ala, Gly, Leu, ne, Val, Pro, Phe, Arg, Glu, Met, Asn, Tyr, and Trp, with monomethyl-amidated alpha-carboxyl group, in order to explore the origin of the drastic reduction of Abz attached to N-alpha amino group of prolyl-peptides, we also examined the fluorescence properties of Abz-NHCH3, Abz-N(CH3)(2), and Abz-pyrrolidine. Molecular dynamics simulation and NMR data indicated a lack of periplanarity of the Abz-dimethylamide, which could be the origin of low fluorescence quantum yield of ...
We have engineered a mutant of HIV Reverse Transcriptase that can be fluorescently labeled by covalent attachment of the environmentally sensitive fluorophore 7-diethylamino-3-((((2-maleimidyl)ethyl)amino)carbonyl)coumarin (MDCC). The result is a polymerase that is kinetically indistinguishable from the wild-type enzyme, but provides a signal to monitor changes in enzyme structure that result from conformational changes induced by substrate binding. Using this system, we have expanded the kinetic model governing nucleotide binding to include an enzymatic isomerization following initial nucleotide binding. In doing so, we define the role of induced-fit in nucleotide specificity and mismatch discrimination. Additionally, we have characterized the kinetics governing the specificity and discrimination of several widely administered Nucleotide Reverse Transcriptase Inhibitors (NRTIs) used to combat HIV infection including 3TC (Lamivudine), FTC (Emtricitabine), and AZT (Zidovudine) for the wild-type ...
Fluorescent Dyes , Reactive Fluorescent Dyes , HiLyte Fluor 594 hydrazide - TFA Salt; HiLyte Fluor 594, an alternative to Alexa Fluor 594 and DyLight Fluor 594, has spectral characteristics similar to those of Texas Red. The labeling performance and stability are better than those of Texas Red. It has high extinction coefficient (80,000 M-1cm-1), high fluorescence quantum yield (0.9) and low correction factor (0.17). HiLyte FluorTM 594 based Bioconjugates exhibit little spectral overlap with green-fluorescent conjugates, and can be efficiently excited by 568 nm line of Ar-Kr laser and by the 594 nm line of orange He-Ne laser. Extinction Coefficient (M-1cm-1): 80,000 Fluorescence quantum yield: 0.90 Fluorescence Life Time (ns): 4.2; HiLyte Fluor594 hydrazide is a carbonyl-reactive fluorescent labeling dye. It can be used for labeling glycoproteins such as HRP.
ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHORS REQUEST.] The design, synthesis and spectroscopic properties of several long wavelength/NIR fluorescent sensors are discussed. Amongst them, the metal complex-indicator sensors are developed based on the indicator-displacement-assay (IDA) strategy; the other BODIPY derived fluorescent sensors are developed based on the indicator-spacer-receptor (ISR) strategy. For the IDA sensors, one [PBA-Zn receptor + ARS] sensor showed some unique dual wavelength patterns when different sugar analytes were introduced. The [Cu complex + Acid Blue 45] sensors have NIR fluorescent properties and displayed high affinity towards various amino acids and warfarin. For the ISR BODIPY sensors, two of the pH responsive sensors have fluorescent emission at 600nm and displayed appropriate pKas for a physiological environment. One piperazine-BODIPY sensor with a novel structure showed a turn-on NIR fluorescent emission when protonated. One ...
TY - GEN. T1 - Spray pyrolysis synthesis of particles possessing magnetic and fluorescent properties. Application of magnetic/fluorescent particles in immunoassays. AU - Dosev, D.. AU - Nichkova, M.. AU - Dumas, R.. AU - Liu, K.. AU - Kennedy, I. M.. PY - 2005. Y1 - 2005. N2 - Many types of fluorescent nanoparticles have been synthesized as alternatives to organic dyes in biochemistry. Magnetic beads also have a long history of biological applications. In this work we apply flame spray pyrolysis in order to engineer a novel type of particle that has both fluorescent and magnetic properties. The particles have magnetic cores of iron oxide and a fluorescent shell of europium - doped gadolinium oxide (Eu:Gd 2O 3). Measurements on a Vibrating Sample Magnetometer showed an overall paramagnetic response behavior of the composite particles. Fluorescence spectroscopy showed fluorescent spectra typical for the Eu ion in a Gd 2O 3 host with a narrow emission peak centered near 615 nm. Our synthesis method ...
Fluorescent molecular imaging helped surgeons visually identify lung adenocarcinomas during pulmonary resection, according to study results.
Optimized for western blotting with fluorescent-conjugated antibodies. Invitrogen™ iBind™ Fluorescent Detection (FD) Solution Kit is intended for use with the iBind™ Flex Western Device (SLF2000) for use in infrared detection and dual wavelength semi-quantitative analysis. iBind Fluorescent Detection Solution Kit,X1 bottle,X5 buffer, 2 vials X100 additive, 1 vial ...
There is no simple answer to this question as the quantum yield of a fluorescent dye can vary widely, depending on the dyes micro-environment. For example, the quantum yield of a dye attached to a protein may be very different from the quantum yield of the free dye. For dyes attached to a protein, the quantum yield is highly dependent on how many molecules of the dye are attached to the protein (i.e. degree of protein labeling). In general, a higher degree of protein labeling leads to a lower dye quantum yield due to fluorescence quenching via dye-to-dye interaction. For this reason, as the degree of labeling increases, fluorescence intensity of the labeled protein will eventually reach a maximum and start to decline thereafter. In fact, one of the best ways to compare the relative quantum yields of different dyes is to plot the total fluorescence of the labeled proteins as a function of degree of labeling by the dyes as we have done with CF® dyes and other commercial dyes. CF® dyes generally ...
Single-molecule detection has long relied on fluorescent labeling with high quantum-yield fluorophores. Plasmon-enhanced detection circumvents the need for labeling by allowing direct optical detection of weakly emitting and completely nonfluorescent species. This review focuses on recent advances in single molecule detection using plasmonic metal nanostructures as a sensing platform, particularly using a single particle-single molecule approach. In the past decade two mechanisms for plasmon-enhanced single-molecule detection have been demonstrated: (1) by plasmonically enhancing the emission of weakly fluorescent biomolecules, or (2) by monitoring shifts of the plasmon resonance induced by single-molecule interactions. We begin with a motivation regarding the importance of single molecule detection, and advantages plasmonic detection offers. We describe both detection mechanisms and discuss challenges and potential solutions. We finalize by highlighting the exciting possibilities in analytical ...
Real-time PCR was performed using the ABI 7700 Sequence detector (Applied Biosystems) as described previously (Biecker et al., 2004). A dual-labeled fluorogenic probe (labeled with a "reporter" dye at the 5′-end and a second dye, quenching the emission of the "reporter" dye, at the 3′-end) complementary to a sequence within each PCR product was added to the PCR reaction. Cleavage of the probe during elongation by the exonuclease activity of the TaqDNA polymerase separates the reporter from its quencher. Accumulation of PCR products is detected in real time by monitoring the increase in fluorescence of the reporter dye. The PCR reaction was performed in a volume of 25 μl containing 12.5 μl2× TaqMan PCR master mix (Applied Biosystems) as well as 1.2 μl (equivalent to 300 ng of total RNA) of cDNA. The concentrations of the primers and probes are given in Table 1. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) provided as "ready-to-use" primers (100 nM each) and probe (200 nM) by the ...
A high dynamic range apparatus for separation and detection of polynucleotide fragments has a housing adapted to receive an electrophoresis gel holder containing an electrophoresis gel loaded with fluorophore-labeled samples; one or more laser diodes for providing radiation of a frequency suitable for excitation of the fluorophore which irradiates a an array of excitation/detection sites on the electrophoresis gel; an array of detectors aligned with the excitation/detection sites for collecting fluorescent emissions; and one or more components for increasing the dynamic range of the instrument by at least an order of magnitude. These components, which can be used individually or in combination include detectors that are connected to a signal processing system that modulates the period of signal integration employed so that large signals are totaled at short time intervals and smaller signals are totaled at longer time intervals; the use of a beam splitter to produces a high intensity beam of emitted
Quinoxalinones are widely exploited for their biological activities, but more rarely for their fluorescence behavior, partly due to a lack of data. Herein, we investigated the photophysical properties of selected 3-benzoylquinoxalin-2-ones and their NaBH4-reduced products, obtained by the rearrangement of be
A unique DNA-binding dye with features ideal for both qPCR and High Resolution Melting® (HRM) analysis*. EvaGreen® dye binds to dsDNA via a novel "release-on-demand" mechanism, which permits the use of a relatively high dye concentration in qPCR without PCR inhibition (Ref. 1).. A unique feature of EvaGreen® dye is its safety. DNA-binding dyes are inherently dangerous due to their potential to cause mutation. With this in mind, Biotiums scientists designed EvaGreen® dye such that it cannot cross cell membranes, thus preventing the dye from being in contact with genomic DNA in live cells. All other commercial PCR dyes enter into cells in a matter of minutes. SYBR® Green I, for example, has been shown to be environmentally more toxic than ethidium bromide, a well-known mutagen (Ref. 2). Independent labs have confirmed that EvaGreen dye is nonmutagenic, noncytotoxic and safe to aquatic life for direct disposal in the drain. For details, download the EvaGreen® Dye Safety Report.. An added ...
To overcome this issue of reduced resolution in STED imaging due to photodegradation, ITbMs team led by Principal Investigators Shigehiro Yamaguchi, a synthetic chemist and Tetsuya Higashiyama, a plant biologist have developed a new fluorescent dye, C-Naphox that has enhanced photostability relative to conventional dyes. C-Naphox has demonstrated to be extremely photoresistant with almost no degradation of fluorescence even after prolonged STED imaging in live cells.. C-Naphox (diarylmethylene-bridged naphthophosphole P-oxide) consists of an aromatic framework with an amino moiety incorporated for its electron-donating properties and phosphorus oxide for its electron-accepting properties, leading to intense fluorescence emissions.. "Although the previously synthesized molecules in the Yamaguchi group have also led to high fluorescence intensity, it is the carbon-bridged structure in C-Naphox that is the key to its extremely high resistance to high intensity light," says Aiko Fukazawa, an ...
PTI RatioMaster is a monochromator-based wide-field microscope system for measuring ratio-fluorescence or fluorescence dye intensity of labeled proteins in nanomolar concentrations. Ratio-fluorescence microscopy is the ultimate tool to study dynamic events in live cells and cellular structures. Unlike conventional intensity based fluorescence microscopy, ratio-fluorescence eliminates the effects of photo-bleaching, cell path length variation, non-uniformity of dye loading, non-uniform field of view, making ratio-fluorescence the most accurate method to determine intracellular ion concentrations. More importantly, PTI RatioMaster is fast enough to provide essential dynamic information about ion concentrations and interactions with other molecules, drugs or added reagents. The PTI RatioMaster is capable of dynamic ratio fluorescence measurements on a millisecond timescale. A xenon arc lamp provides high intensity, continuous broadband illumination. Alternating excitation wavelengths are selected ...
Description DNA Dye Non-Toxic products from Biocrede represent a new and safe class of nucleic acid stains for the visualization of double-stranded DNA, singl
Fluorescence microscopy is ideal for intracellular ion measurements and the most common of these measurements is intracellular calcium imaging measurements. Two of the most popular dyes for calcium imaging are Fura-2 and Indo-1. PTI EasyRatioPro is a monochromator-based wide-field microscope system for measuring ratio-fluorescence or fluorescence dye intensity of labeled proteins in nanomolar concentrations. Ratio-fluorescence microscopy is the ultimate tool to study dynamic events in live cells and cellular structures. Unlike conventional intensity based fluorescence microscopy, ratio-fluorescence eliminates the effects of photo-bleaching, cell path length variation, non-uniformity of dye loading, non-uniform field of view, making ratio-fluorescence the most accurate method to determine intracellular ion concentrations. More importantly, PTI EasyRatioPro is fast enough to provide essential dynamic information about ion concentrations and interactions with other molecules, drugs or added ...
IHC staining was visualized with a fluorescent microscope (Olympus BX51), and images were taken with a digital camera (Olympus DP30BW) using appropriate filters for different fluorophores or bright-field illumination for DAB stain. Identical images were taken for double IHC, overlaid, and pseudocolored using Olympus Software and Adobe Photoshop (Adobe Systems). Contrast and brightness were adjusted for fluorescent signals with Adobe Photoshop (Adobe Systems) for better visualization of neurons.. For Ad-iZ/EGFPf tracing from LepRb neurons in the DMH, we analyzed four mice with correct injections into the DMH and showed representative images of projection sites in the mPOA, DMH, PVN, and rRPa in Figure 4.. For FG tracing experiments, we focused our analysis on the mPOA and DMH/DHA to investigate colocalization of LepRb neurons with FG-traced neurons from the RMR/rRPa (n = 4), DMH/DHA (n = 3), or PVN (n = 2). Representative images were shown for the DMH/DHA and mPOA, and, in some cases, we ...
Dual-channel fluorometer for personal quantitation workflow. Designed to provide highly sensitive fluorescent detection when quantifying nucleic acids, the compact instrument is simple to operate. The Quantus Fluorometer is optimized with preprogrammed settings for Promega QuantiFluor™ Dye Systems to quantitate nucleic acids and offers the flexibility to create customized methods and quantitation settings for other fluorescent dyes. ...
Method for rapid-base sequencing in DNA and RNA with two-base labeling and employing fluorescent detection of single molecules at two wavelengths. Bases modified to accept fluorescent labels are used
Chromeo 505 is a bright green fluorescent dye that replaces fluorescein, FITC, Alexa 500, Dylight 505 or other dyes that are excitable at 488 nm. Chromeo 505 and its conjugates are bright, photostable and compatible with standard fluorescent microscopes.
Solon, Ohio (PRWEB) May 06, 2013 -- DNA quantitation is crucial to experimental design and interpretation of results, especially in sensitive molecular biology
Chromeo 642 is a bright dark-red fluorescent dye that replaces Cy5, Alexa 647, DyLight 649 or other dyes that are excitable from 630 nm-650 nm. Chromeo 642 and its conjugates are bright, photostable and compatible with standard fluorescent microscopes.
Contrast agents play an important role in the study of biological tissues and whole organisms, since they enable visualization of functional structures. Fluorescent contrast agents also enable specific targeting in therapeutic approaches. Developing optimized contrast agents is central to optimizing the performance of both imaging and therapy. The ideal contrast agent for optical microscopy combines high resolution, specific targeting of functional groups, 3D imaging (depth resolution), low toxicity, low bleaching (long observation time at high signal), and high signal to noise (low background). Traditional organic dyes and fluorescent proteins are excited in the ultraviolet (UV) or blue spectral region, and emit at a longer-wavelength that is Stokes-shifted. The use of the short-wavelength excitation leads to a short penetration depth of the excitation light and give rise to autofluorescence, photobleaching and photodamage to biological specimens. It is thus primarily suited to pathological and ...
A toxin is used to introduce an otherwise cell-impermeant fluorophore-antibody (or some thing which is equally specific) to bind to an intracellular protein which allows for super resolution imaging and single particle tracking inside the living cell.
Current techniques for observing the cytoskeleton can be difficult to get into living cells, can be toxic, and are usually limited in resolution and duration, since the signal wears off over time. A common technique is fluorescence microscopy, where fluorescent molecules (probes) are attached to cell structures and then lit up against a dark background.. The team of Kai Johnsson at EPFL has developed novel fluorescent probes that can easily enter live cells, are non-toxic, have long-lasting signals, and most importantly, offer unprecedented image resolution. In 2013, the researchers developed a fluorescent molecule called silicon-rhodamine (SiR), which switches on only when it binds to the charged surface of a protein like the ones found on the cytoskeleton. When SiR switches on, it emits light at far-red wavelengths.. The challenge was getting SiR to bind specifically to the cytoskeletons proteins, actin and tubulin. To achieve this, the scientists fused SiR molecules with compounds ...
MilliporeSigma offers a versatile range of dyes for microscopy, including high-quality Certistain® dyes, fluorescence dyes, dry dyes and dye mixtures.
Abnormal concentrations of ATP are associated with many diseases and cancers, and quantitative detection of ATP is thus of great importance for disease diagnosis and prognosis. In the present work, we report a new dual recycling amplification sensor integrated with catalytic hairpin assembly (CHA) to achieve high sensitivity for fluorescent detection of ATP. The association of the target ATP with the aptamer beacons causes the allosteric structure switching of the aptamer beacons to expose the toehold regions, which hybridize with and unfold the fluorescently quenched hairpin signal probes (HP1) to recycle the target ATP and to trigger CHA between HP1 and the secondary hairpin probes (HP2) to form HP1/HP2 duplexes ...
Designed as an automated assay on the Leica Biosystems BOND RX Research Advanced Staining System, this new assay enables single-molecule detection of up to four RNA targets simultaneously. Ideal for co-localization and co-expression studies, the assay and RNAscope® LS 2.5 Probes are available for application in your own lab and via ACDs Pharma Assay Services.
We are interested in designing and building small molecules to measure or manipulate biological systems. Our laboratory synthesizes bright fluorescent labels that enable the imaging of individual molecules in living cells. We also develop fluorogenic probes where the chemical and photophysical properties can be masked by assorted molecular functionalities and then unmasked by a user-designated process involving light, enzymatic activity, or environmental changes. This chemical masking suppresses unwanted fluorescence signals, thereby functioning as a filter for bioimaging and other experiments. Combining these novel compounds with advances in instrumentation, protein engineering, and genetic manipulation allows us to devise sophisticated ways to illuminate complex biological systems.. ...
Fluorescent Dyes , Reactive Fluorescent Dyes , HiLyte Fluor 647 amine; HiLyte Fluor 647 amine is a carbonyl-reactive fluorescent labeling dye that generates the conjugates that are slightly red-shifted compared to those of Cy5 dyes, resulting in an optimal match to filters designed for Cy5 dye. Its conjugate may have better performance than Cy5 for fluorescence polarization-based assays. Extinction Coefficient (M-1cm-1): 250,000 Fluorescence quantum yield: 0.33 Fluorescence Life Time (ns): 1.0
This application note describes a Multicolour Fluorescent Western Blot allowing the detection of multiple proteins on the same blot, without stripping and reprobing, with final quantative, straightforward and accurate analysis. The FluorChem Q, a CCD-based detection platform is able to rapidly and easily perform traditional chemiluminescent and multicolour fluorescent detection.
Each microsphere is dyed with three different fluorescent dyes with excitation maxima of 377, 517 and 588nm, and emission maxima of 479, 546 and 612nm.
Except values of excitation and emission maxima, solubility in water and values of quantum yield of fluorescent label, photostability of both indicator alone and its conjugates and minimal effect of indicator during fragmentation analysis of biomolecules are also important for its practical use. With respect to these facts, labels based on BODIPY excel, because they exhibit better photostability then fluorescein and have minimal effect on mobility of fragments during DNA sequencing. We have developed conjugate of BODIPY with dibenzazocine molecule which is able to bind spontaneously to proteins or nucleic acids bearing azido group and formed covalently labelled molecules. Designed system then can be used for monitoring of proteosynthesis or synthesis of oligonucleotides as key factors of correct function of cells, enzymes or processes such as proliferation and apoptosis. By this way it can be possible to indicate various pathological changes. For this reason, the mentioned system can be used for ...
Overwhelmed with complicated flow cytometry panel design? Learn how you can simplify your panel design by incorporating new dyes.
Main Page , Multiple Labeling. It is often useful to be able to stain for two or more antigens in one common tissue section. This can be achieved by immunofluorescence method using different fluorescent dyes. Multiple staining can also be done with peroxidase conjugated antibodies developed with different chromogen substrates to produce the end products of different colors. There are three basic approaches in planning multiple staining: parallel, sequential and adjacent. In addition, the antibody dilution and condition are also important factors to be considered. Finally, appropriate color combination is also crucial since improper color combination may produce poor result and fail to demonstrate multiple antigens in the same section. For best result, the careful design and test of multiple staining protocols are necessary.. ...
Various liposome products are available for bioscience research and drug delivery. The liposome products include various liposome research tools and liposomes encapsulated with drugs, fluorescence dyes and biomolecules.
A standard material that is used for judging an abnormal portion in a particle analyzer is described. The standard material comprises first standard particles to be fluorescence-stained by a fluorescence-staining treatment and second standard particles that have preliminarily contained a fluorescence dye.A method and an analyzer that can judge an abnormal portion in a particle analyzer by using such a standard material are also described.
TECHNOLOGY (INVENTION) DESCRIPTION: We introduce an expanding family of non-planar (3D structured) cationic dyes with interesting fluorescent properties that are markedly environment sensitive (e.g. DNA, proteins, heparin, membranes). Our library of 1500 dyes is based on 19 skeletal structures, which are easily modified by standard commercially available chemicals to achieve favourable properties. Our compounds are being screened in various applications such as flow cytometry and microscopy. Strong non-linear optical properties of dyes and their applications in microscopy or spectroscopy are under investigation.. ...
Dear all, in the light of on-going conversation about compensation I would also like to ask a theoretical, but very confusing question. Please accept my apologies for a long text, I really dont know how to explain my question shortly. I wonder how computer calculates proper compensation in a situation when particle is stained with two fluorochromes A and B and both fluorochromes send their signal into two channels (like FITC & PE combination)? On my opinion to calculate proper compensation the one must know true (it means already compensated) number in a first place. Ill try to explain what I mean. Assume that you have a particle stained with fluorochromes A and B. After doing compensation controls with only one dye at a time you find out that A spills over into B for 20% and B spills over into A for 10%. After running double positive (AB positive) particle through flow cytometer youll get a non-compensated data where A signal equals to 3000 and B signal equals to 10000. ...
The Muse® Count & Viability Kit 200X - 100 Tests (Part Number: MCH100104) was developed for absolute cell count and viability determination of difficult cell samples. It is designed to address the need for a compatible reagent for non-mammalian cell lines, such as SF-9 insect cells. These cells prefer significantly lower pH and higher osmolarity than mammalian cells for optimal viability. The reagent contains the same fluorescent DNA-binding dyes used in the Muse Count & Viability Kit, but in a highly concentrated formulation. These dyes have differential permeability to viable and non-viable cells, and provide absolute cell count and viability data on cell suspensions from a variety of cultured cell lines. Both viable and non-viable cells are differentially stained based on their permeability to the DNA-binding dyes in the reagent. Data generated using the Guava® Muse® Cell Analyzer with the Muse Software provides:. ...
On 21 Nov 2006 10:42:15 -0800, Lechu ,lech_kaczmarczyk At yahoo.com, wrote: , What you would reccommed as an alternative to ECL systems + standard , autoradiography film? I start to find film developing pretty boring , and time-consuming, and I always have problems with the right , adjustment of exposure time to get reproducible results. Lifetime of , luminescence is also pretty short. Any suggestions as for reasonable , alternatives? Maybe some fluorescence-based methods? you could use regular substrate-enzyme colour developing methods... (please check up the substrates for alkaline phosphatase and HRP in Molecular Cloning by Sambrook and Maniatis; I dont remember it on the top of my head ...been a while since I used them.)....they work well, if you have high specificity antibodies. Alternatively, you could use the Licor machine, if you have access to it, which uses some special IR tagged secondaries.... I have seen a demo of it, and havent really used it myself to particularly know how ...
Novel Peptide Sequence -IQ-tag- with High Affinity for NIR Fluorochromes Allows Protein and Cell Specific Labeling for In Vivo Imaging. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
BioLegend's LEGENDScreen™ products are lyophilized, fluorophore-conjugated antibodies provided in 96-well plates for the purpose of screening cell surface molecules on your cells of interest. Kits are provided with lyophilized antibodies in 96-well plates at optimal concentrations, cell staining buffer, fixation buffer, and plate sealers. BioLegend develops and manufactures world-class, cutting-edge immunological reagents for biomedical research, offered at an outstanding value.
Confocal microscopy with optical sectioning has revolutionized biological studies by providing sharper images than conventional optical microscopy. Here, we introduce a fluorescence imaging method with enhanced resolution and imaging contrast, which can be implemented using a commercial confocal microscope setup. This approach, called the reversibly switchable photo-imprint microscopy (rsPIM), is based on the switching dynamics of reversibly switchable fluorophores. When the fluorophores are switched from the bright (ON) state to the dark (OFF) state, their switching rate carries the information about the local excitation light intensity. In rsPIM, a polynomial function is used to fit the fluorescence signal decay during the transition. The extracted high-order coefficient highlights the signal contribution from the center of the excitation volume, and thus sharpens the resolution in all dimensions. In particular, out-of-focus signals are greatly blocked for large targets, and thus the image ...
|p|Helix NP™ Blue is a blue-emitting nucleic acid stain. It is impermeant to live cells and thus can be used for the discrimination of live and dead cells. In fixed and permeabilized cells, it can be used to assess cell cycle status.  In immunofluorescence microscopy, it can be used as a n
Recipient of ASLMS Funding in 2009 and 2010 ~. "Novel Optical Probes for Image-Guided Tumor Resection and Photodynamic Therapy Based on Glucose Transporters". Tumors often present a shift in metabolism to a less efficient glycolysis. This has been employed diagnostically, using Fluorodeoxy-D-Glucose Positron Emission Tomography (FDG-PET). We propose to synthesize fluorescently-labeled deoxyglucose analogues (F*-DG), whose potential usefulness is 2-fold. Firstly, they could provide high contrast for fluorescence imaging, in particular to improve fluorescence image guided resection (FGR) of tumors. FGR effectively extends the surgeons vision, so that small amounts of residual tumor that are not normally visible can be detected and removed. We will develop this initially for brain tumors, building on previous work, but the concept is widely applicable to any solid tumor that invades the normal host tissue, such as oral tumors that will be a second target. Secondly, we will test the performance ...
Quanterixs Simoa single-molecule detection method combined with high-affinity antibodies detected minute levels of problematic interferon alpha proteins, a study said.
CF dyes are highly water soluble, small organic dyes designed by scientists at Biotium for labeling proteins and nucleic acids. With a series of over 20 colors (and growing), many of our CF dyes are brighter and more photostable than competing dyes. For more information please see the product flyers for individual CF dyes, the CF Dye Selection Guide, and our CF Dye FAQs , http://www.interchim.eu/forum/cf-dyes-faq-f44.html ...
Fluorescent dye derived from dipyrrometheneboron difluoride. Water insoluble and forms stable amide bond with primary amines via carbodiimide activation. (U0129) - Products - Abnova
Fluorescent dye derived from dipyrrometheneboron difluoride. Water insoluble and forms disulfides with thiol bonds. (U0132) - Products - Abnova
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Links to Timelapse Sequences Related to Figures. Figure 3. Images of a deep neural-over-mesoderm explant show F-spondin expression.. (2.1 Mb timelapse). Figure 4. Images of a deep neural-over-mesoderm explant show Shh expression (top), fluorescent cells videorecorded from stages 13 to 13.5 (middle), and an overlay of the two (bottom).. (2.3 Mb timelapse). Figure 5. Images of a deep neural-over-mesoderm explant at stage 13 (A) show Shh expression (top), fluorescently-labeled cells within the medial domain (middle), and an overlay of the two (bottom).. (1.9 Mb timelapse). Figure 7. In a deep neural-over-mesoderm explant videorecorded from stage 11.5 to stage 15, cell intercalation develops in an anterior-to-posterior and lateral-to-medial progression and is conservative (A).. (4.9 Mb timelapse). Figure 8. In a deep neural explant videorecorded from stage 11.5 to stage 15, mediolateral cell intercalation is promiscuous (A).. (6.2 Mb timelapse). Figure 11. In deep neural-over-mesoderm explants, ...
We have vast experience in synthesis of fluorescence & dye labeled peptides, e.g. w. Abz, Mca, Amc, FAM, FITC, Tamra, Cy3, Cy5, Alexa, Dylight, Atto & more
This interactive fluorescent dye chart helps you select your preferred fluorescent label from our whole portfolio of dyes and reactive groups.
A simple essay on computer viruses Could have added more examplesViruses: Complex Molecules or Simple Life Forms?Viruses have been defined as entities whose genomes are elementsof nucleic acid that replicate inside living cells using the cellularsynth...
Daily News How Gaining and Losing Weight Affects the Body Millions of measurements from 23 people who consumed extra calories every day for a month reveal changes in proteins, metabolites, and gut microbiota that accompany shifts in body mass.. ...
Advances in single-cell technologies have revealed vast differences between cells once thought to be in the same category, calling into question how we define cell type in the first place ...
Here, I wanted to briefly discuss other applications of fluorescent molecules in biology, other than microscopy. One simple use for fluorescent molecules is measuring the amount of emitted light by a fluorimeter. This can be used with different florescent dyes that respond to different biological aspects (e.g. calcium levels, cell viability, mitochondrial function, DNA replication,…
Diverse types of probes have been employed to image cell death, in order to determine the immune mediated damage of transplanted organs, the extent of ischemia...
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... is a very sensitive and versatile method used to label specific molecular targets within cells and tissues through combined use of specific antibodies and chemical fluorescent tags
Laser scanning microscopes (LSMs) have proven extremely flexible in 3D imaging in a non-destructive manner. Most difficulties encountered in biological imaging are caused by intrinsic sample characteristics that compromise 3D imaging by limiting penetration depth and cause image distortions. Discriminating fluorescent labels from autofluorescence is another common challenge in plant and animal tissue samples. this application note describes how these problems can be overcome using Zeiss
... fluorochrome is a high quality APC-cyanine tandem for the red diode-laser designed to achieve the best performance for all the available conjugated antibodies. This fluorochrome is compatible with any flow cytometer equipped with a red diode-laser and the appropriate filters and detectors for the infrared signal. Cytognos offers a wide portfolio of APC-C750 conjugates as well as a custom-conjugation service ...
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荧光信号 在 预防医学与卫生学 分类中 的翻译结果:fluorescent signals||双语例句|英文例句|相关文摘
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Currently there are no approved biomarkers for the pre-symptomatic diagnosis of Alzheimers disease (AD). Cathepsin-D (Cat-D) is a lysosomal protease that is present at elevated levels in amyloid plaques and neurons in patients with AD and is also elevated in some cancers. We have developed a magnetic resonance imaging (MRI)/fluorescent contrast agent to detect Cat-D enzymatic activity. The purpose of this study was to investigate the cellular and tissue uptake of this MRI/fluorescent contrast agent. The agent consists of an MRI probe [DOTA-caged metal ion (Gd3+ or Tm3+)] and a fluorescent probe coupled to a cell-penetrating-peptide sequence by a Cat-D recognition site. The relaxivity of Gd3+-DOTA-CAT(cleaved) was measured in 10% heat-treated bovine serum albumin (BSA) phantoms to assess contrast efficacy at magnetic fields ranging from 0.24 mT to 9.4 T. In vitro, Tm3+-DOTA-CAT was added to neuronal SN56 cells over-expressing Cat-D and live-cell confocal microscropy was performed at 30 min. ...
TY - JOUR. T1 - Myosin V walks hand-over-hand. T2 - Single fluorophore imaging with 1.5-nm localization. AU - Yildiz, Ahmet. AU - Forkey, Joseph N.. AU - McKinney, Sean A.. AU - Ha, Taekjip. AU - Goldman, Yale E.. AU - Selvin, Paul R.. PY - 2003/6/27. Y1 - 2003/6/27. N2 - Myosin V is a dimeric molecular motor that moves processively on actin, with the center of mass moving ±37 nanometers for each adenosine triphosphate hydrolyzed. We have labeled myosin V with a single fluorophore at different positions in the light-chain domain and measured the step size with a standard deviation of ,1.5 nanometers, with 0.5-second temporal resolution, and observation times of minutes. The step size alternates between 37 + 2x nm and 37 - 2x, where x is the distance along the direction of motion between the dye and the midpoint between the two heads. These results strongly support a hand-over-hand model of motility, not an inchworm model.. AB - Myosin V is a dimeric molecular motor that moves processively on ...
TMA-DPH (1-(4-trimethylammonium)-6-phenyl-1,3,5-hexatriene), a hydrophobic fluorescent membrane probe, interacts with living cells by instantaneous incorporation into the plasma membrane, where it becomes fluorescent. It then follows the intracellular constitutive membrane traffic and acts as a bulk membrane marker of the endocytic pathway (Illinger, D., P. Poindron, P. Fonteneau, M. Modolell, and J. G. Kuhry. 1990. Biochim. Biophys. Acta. 1030:73-81; Illinger, D., P. Poindron, and J. G. Kuhry. 1991. Biol. Cell. 73:131-138). As such, TMA-DPH displays particular properties mainly due to partition between membranes and aqueous media. From these properties, original arguments can be inferred in favor of the maturation model for the endocytic pathway, against that of pre-existing compartments, in L929 cultured mouse fibroblasts. (a) TMA-DPH labeling is seen to progress from the cell periphery to perinuclear regions during endocytosis without any noticeable loss in fluorescence intensity; with a ...
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Development of Functional Fluorescent Molecular Probes for the Detection of Biological Substances. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Calcium ions play an important role in cell function, acting as effectors and/or signaling molecules for a variety of cellular biochemical and physiological processes. The development of a variety of Ca2+-sensitive fluorescent indicators and advancements in imaging technology have enhanced the ability to follow both global and localized changes in intracellular Ca2+ at ever improving temporal and spatial resolution. Ratiometric Ca2+ indicators like fura-2 permit the measurement of intracellular Ca2+ concentration (Grynkiewicz et al., 1985). But, they tend to have a limited dynamic range and a significant fluorescence background, which reduce their sensitivity to small local increases in Ca2+. On the other hand, certain nonratiometric Ca2+ indicators, such as fluo-3, although not able to give a dynamic direct read-out of the Ca2+ concentration, have very low fluorescence when not bound to Ca2+ and have a significant increase in fluorescence intensity upon binding Ca2+ (e.g., ∼200 times for ...
N-Alkylation of a novel pyridine sensor results in pyridinium salts whose conformations are stabilised by pyridinium cation-π interactions resulting in a fluorescent response that can be used to sense the presence of alkylating agents in solution at low concentration.. ...
노인성 치매에서 가장 많은 비율을 차지하는 알츠하이머병 (Alzheimers disease) 환자의 뇌에는 이 질병의 핵심 표지자로 알려져 있는 아밀로이드 단백질 (amyloid β protein)이 쌓여있으며, 이 단백질이 질병의 발달과 연관성에 대한 많은 연구가 있다. 아밀로이드 단백질 연구에 있어서 조직염색 (tissue staining)을 통한 공초점 (confocal microscope) 그리고 이광자 현미경 (two-photon microscope) 촬영이 큰 역할을 하고 있으며, 이에 아밀로이드 단백질 특이한 형광염료 (fluorescence dye)의 중요성이 부각되었다. 본 연구에서는 기존의 아밀로이드 단백질 형광염료와는 다른 새로운 형광염료를 개발하였다. 형광염료내의 전자기부자 (donor)와 수락자 (acceptor)사이의 종류 그리고 두 분자 사이의 거리를 조절함으로써 조직염색 시 더 적은 자가형광을 내며, 더 특이적으로 아밀로이드 ...
I used single molecule fluorescence and fluorescence lifetime measurements of fluorescent dyes conjugated to DNA to better understand the photophysical and photochemical interactions between organic dye molecules and DNA. This process is important, because fluorescent dyes are frequently used as labels for DNA, but interactions with specific DNA bases can significantly affect the fluorescent properties of the dyes, leading from chromatic shifts all the way to fluorescence quenching. Thus, it is very important to obtain a full understanding of the photophysics of these interactions if cDNA or siRNAs are used as molecular probes. I studied DNA hairpins that were labeled with different numbers of red-emitting Atto655 dyes. I investigated three different samples: a DNA hairpin labeled with three dyes, one with two dyes, and one with only one dye attached to specific bases and well-known spatial separations. Sample preparation consisted of denaturing and annealing the short synthesized single strands ...
The use of labelling or staining agents has greatly assisted the study of complex biological interactions in the field of biology. In particular, fluorescent labelling of biomolecules has been demonstrated as an indispensable tool in many biological studies. Types of fluorescent labelling agents that are commonly used include conventional classes of organic fluorophores such as fluorescein and cyanine dyes, as well as newer types of inorganic nanoparticles such as QDs, and novel fluorescent latex/silica nanobeads. The newer classes of fluorescent labels are gaining increasing popularity in place of their predecessors due to their better optical properties such as possessing an enhanced photostability and a larger Stokes shift over conventional organic fluorophores, for example. This paper gives an overview of the recent advances on these luminescent nanomaterials with emphases on their optical characteristics that are crucial in fluorescence microscopy, both advantages and limitations in their ...
The RNAscope® Multiplex Fluorescent assays provide the same exceptional sensitivity as our singleplex assays, allowing single-molecule detection of up to four RNA targets simultaneously. The RNAscope® Multiplex Fluorescent assays are ideal for co-localization studies of any genes in nearly any tissue type using fluorescent labels. Advanced Cell Diagnostics offers two types of multiplex fluorescent assays. RNAscope® Fluorescent Assay, our first generation assay, is an all in one kit, ideal for fresh or fixed frozen tissues.
This application note describes the use of the SPECTRAmax GEMINI XS fluorescence microplate reader, which helps in studying the changes in levels of intracellular cAMP.
With respect to cellular analysis, the underlying principle of flow cytometry is that a cell suspension is focused into a single cell stream, which passes through a light source (typically a laser beam). The scattered and emitted fluorescent light (if the cells are fluorescently labeled) is subsequently measured using a range of detectors and these measurements are used to generate multi-parameter data sets that describe the physical characteristics of the cells and their fluorescent properties. The size and granularity of cells can be identified on the basis of their forward and side light scatter characteristics (FSc and SSc respectively). Their characteristics and/or expression of different proteins can be further defined by pre-staining with fluorescently-labeled antibodies or molecules that identify cellular components and / or integrity (viability) or, indeed, fluorescently-labeled proteins.. Flow cytometers can evaluate cells at an extremely rapid rate (up to several tens of thousands of ...
Fluorescein is unionised at acidic pH and the fluorescence intensity changes with pH [19, 20]. As expected, our results clearly demonstrate this effect on fluorescence levels using a FRET pair and a quencher pair with FAM. By use of the ATTO495-ATTO647N FRET pair for Hoogsteen-based parallel triplex formation, a robust and reliably LightCycler method was established. This novel FRET pair is well-suited for Tm and ΔTm determinations over a broad pH range of parallel triplex formations.. Furthermore, this FRET pair clearly demonstrates the pH independence from pH 5.5 to 7.5 of antiparallel duplex Tm determinations in contrast to the pH dependent Tm determination of parallel triplex formation from pH 4.5 to 6.0. An interesting feature of this is the negative correlation between pH and fluorescence intensity as pH increases from 4.5 to 6.0 for parallel triplex formation (Figure 3c). This is in concordance with the expected lower efficacy of parallel triplex formation due to the lack of protonated ...
Widefield fluorescent image of epithelial cells (nuclei stained with DAPI, yellow; and filamentous actin stained with Alexa Fluor 488 phalloidin, magenta )
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On the substrate carrying a sub-wavelength grating covered with a thin metal layer, a fluorescent dye-labeled cell was observed by fluorescence microscope. The fluorescence intensity was more than 20 times greater than that on an optically flat glass substrate. Such a great fluorescence enhancement from labeled cells bound to the grating substrate was due to the excitation by grating coupled surface plasmon resonance. The application of a grating substrate to two-dimensional detection and fluorescence microscopy appears to offer a promising method of taking highly sensitive fluorescence images.. ©2008 Optical Society of America. Full Article , PDF Article ...
These can be very useful. Most allow you to plot out the excitation and emission curves of a number of fluorescent dyes. Some allow the user to add filter sets and excitation sources to see how well they work with the dyes being considered. Noteworthy examples include: an extensive database of single and 2-photon dye spectra assembled here at the University of Arizona (Utzinger & Boswell), Thermo-Fishers Fluorescence spectraviewer, Semrocks searchlight, Fluorophores.org, Chromas spectra viewer, Biolegends viewer, Leicas Fluoscout, Omega Opticals curvomatic, and Zeiss Fluorescence Dye and Filter Database ...
Single-molecule fluorescence spectroscopy and super-resolution microscopy are important elements of the ongoing technical revolution to reveal biochemical and cellular processes in unprecedented clarity and precision. Demands placed on the photophysical properties of the fluorophores are stringent a …
The rhodamine labeled f-actin did not appear in the composite image of the three different fluorophores due to the intensity of the fluorescence being too low to register. This could be due to photobleaching that had previously occurred in this specific area of the sample, or if the sample was not labeled adequately with enough fluorescent dye. Time-lapse data for all three fluorophores under the same condition revealed discrepancies in rate of decay and initial intensity for each fluorophore. A relative high initial intensity for DAPI labeled dsDNA can be explained by the relative high net local concentration of bright fluorophores. Each nucleus contains a high concentration of dsDNA, which when stained with DAPI, creates a large solid fluorescent region with overlapping fluorophores. This differs from both tubulin and f-actin, which are of tube like nature, and appear as porous regions of interest where background light can seep through and be analyzed, making the initial brightness in the ...
We recently finished our Ask the Expert discussion on Improving Live Cell Fluorescence Imaging. This week we had several interesting questions focused on combating the negative effects of imaging on cell health and viability including looking at media options as a possible solution.
A new fluorescent Zn2+ chemosensor (P1) based on a functionalized porphyrin was synthesized and characterized. P1 displayed dramatic ratiometric variations in absorption and fluorescent emission spectra upon exposure to Zn2+ due to the formation of a 1:1 Zn2+/P1 complex. The sensor also exhibited high selectivity and sensitivity toward Zn2+ over other common metal ions in the physiological pH range with a detection limit of 1.8 mM. The sensor showed fast response times and excellent reproducibility, thus confirming its potential applicability as a fluorescent sensor for Zn2+ sensing.
A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with several π bonds. Fluorophores are sometimes used alone, as a tracer in fluids, as a dye for staining of certain structures, as a substrate of enzymes, or as a probe or indicator (when its fluorescence is affected by environmental aspects such as polarity or ions). More generally they are covalently bonded to a macromolecule, serving as a marker (or dye, or tag, or reporter) for affine or bioactive reagents (antibodies, peptides, nucleic acids). Fluorophores are notably used to stain tissues, cells, or materials in a variety of analytical methods, i.e., fluorescent imaging and spectroscopy. Fluorescein, by its amine reactive isothiocyanate derivative FITC, has been one of the most popular fluorophores. From antibody labeling, the applications have spread to ...