BAVILI TABRIZI, Ahad y DEHGHANI TEYMURLOUIE, Nadereh. Application of Sodium Dodecyl Sulfate Coated Iron Oxide Magnetic Nanoparticles for the Extraction and Spectrofluorimetric Determination of Propranolol in Different Biological Samples. J. Mex. Chem. Soc [online]. 2016, vol.60, n.3, pp.108-116. ISSN 1870-249X.. A new analytical approach was developed involving magnetic solid-phase extraction (MSPE) and spectrofluorimetric determination of propranolol (PRO) in biological fluids. A urine or plasma sample was prepared and adjusted to pH 3-4, then PRO was quickly extracted using Fe3O4 magnetic nanoparticles (MNPs) modified by the surfactant sodium dodecyl sulfate (SDS) and determined applying spectrofluorimetry. Experimental conditions, such as the amount of MNPs and SDS, pH value, standing time, desorption solvent and maximal extraction volume have been adjusted to optimize the extraction process and to obtain analytical characteristics of the method. Linearity was observed in the analytes ...
The paper reviewed the application these years of fluorescence spectrophotometry in environmental monitoring.The content includes the principle,the establishment of methods,the study of fluorescence system and the development of the combination with other techniques. It indicated that fluorescence method is sensitive, selective, less sample using and simple. It is an effective way for the analysis of trace elements and substances in complicated environmental samples. It will have a broad prospect in environmental analysis with the combination with other techniques.
We compared various spectroscopic properties of a norfloxacin-single stranded DNA complex with those of norfloxacin-double stranded DNA complex. Norfloxacin binds to both double- and single stranded DNA, and we observed the following spectroscopic changes for both complexes: hypochromism in the norfloxacin absorption region in the absorption spectrum, the characteristic induced CD spectrum consisting of a weak positive band at 323 nm and a strong positive band at 280-300 nm followed by a negative band in the 260 nm region, a strong decrease in the fluorescence intensity and a red-shift in the fluorescence emission spectrum, and shorter fluorescence decay times. These results indicate that the environments of the bound norfloxacin in both DNAs are similar, although the equilibrium constant of the norfloxacin-single stranded DNA was twice as high as the norfloxacin-double stranded DNA complex. Both complexes were thermodynamically favored with similar negative ΔGo. Negative ΔHo terms contribute ...
Berland, K.M., So, P.T., Gratton, E. 1995. Two-photon fluorescence correlation spectroscopy: method and application to the intracellular environment. Biophys J. 68(2):694-701. PubMed. Chen Y, Müller JD, So PTC, Gratton E. 1999. The photon counting histogram in fluorescence fluctuation spectroscopy. Biophys J. 77: 553-567. PubMed. Elson EL. 2001. Fluorescence correlation spectroscopy measures molecular transport in cells. Traffic 2(11):789-96. PubMed. Elson EL, Magde D. 1974. Fluorescence correlation spectroscopy. I. Conceptual basis and theory. Biopolymers, 13(1):1-27. Kask P, Palo K, Ullmann D and Gall K. 1999. Fluorescence-intensity distribution analysis and its application in biomolecular detection technology. Proc Natl Acad Sci USA 96:13756-13761. PubMed Kis-Petikova K, Chen Y, Müeller JD, Gratton E. 2000. Application of scanning fluorescent correlation spectroscopy for determination of particle shape. Biophys. J., 78(1), 2603. Koppel DE, Axelrod D, Schlessinger J, Elson EL, Webb WW. 1976. ...
291309859 - EP 1259805 A1 2002-11-27 - LIPOPROTEIN ASSAY - [origin: WO0153829A1] A method of assaying to determine the identity and/or concentration or relative concentration in a sample solution of a particular one of a number of different target molecule types, comprise the steps of: i) adding to the sample a probe substance which binds to the or each target molecule type and which when so bound fluoresces under appropriate excitation; ii) performing a time-resolved fluorescence measurement on the sample; and iii) making said determination from analysis of the time decay data obtained from said time-resolved fluorescence measurement.[origin: WO0153829A1] A method of assaying to determine the identity and/or concentration or relative concentration in a sample solution of a particular one of a number of different target molecule types, comprise the steps of: i) adding to the sample a probe substance which binds to the or each target molecule type and which when so bound fluoresces under appropriate
The detailed analysis of the processes of electronic energy relaxation in a substance, taking place after the short optical impulses of excitation, shows that mathematical models of the detected optical intensity decay can not be expressed by a combination of elementary mathematical functions. In the present work we suggest the approach to the parameter estimation of the decay curves, obtained from the time-resolved fluorescence experiments, based on the computer simulation methods. By means of simulation elementary processes of energy relaxation can be reproduced with the highest level of the detailed elaboration. Given processes are characterized by a set of parameters which have to be estimated. For the estimation we tried several methods, which do not require calculation of the derivatives, as in widespread Marquardt algorithm, that could be difficult for the decay curves, represented by a simulation model. The main advantage of the proposed approach is that it is possible to estimate the ...
Article Three-dimensional excitation emission matrix fluorescence spectroscopy and gel-permeating chromatography to characterize extracellular polymeric substances in aerobic granulation. Three-dimensional excitation emission matrix (EEM) fluorescenc...
Steady State Spectrofluorometer from HORIBA Scientific. The FluoroLog-3, a modular instrument, is the Worlds Most Sensitive Spectrofluorometer
Fluorescence correlation spectroscopy (FCS) is a very useful tool for examining mobility and interactions in a variety of systems including membranes. FCS is highly sensitive to small differences in the diffusion rates of proteins and lipids, which allows for instance to characterize differences in phase behavior of lipid bilayers. FCS is used to analyze the binding of diffusible ligands to membrane receptors, such as membrane proteins or glycolipids. Changes in the fluorescence brightness parameter reveal membrane protein oligomerization. Moreover, the use of dual-color fluorescence cross-correlation (dcFCCS) allows to assess protein-protein binding in cases, where binding does not lead to significant changes in diffusion rates. The dual-color cross-correlation technique can also be employed to detect dynamic co-localization of labeled cargo molecules in small, mobile carriers, such as transport vesicles. Owing to the use of fluorescent labels, FCS is highly specific and can be applied both to ...
In flow cytometry, the fluorescence decay time of an excitable species has been largely underutilized and is not likely found as a standard parameter on any imaging cytometer, sorting, or analyzing system
Nanosecond time-resolved emission spectral techniques have been applied to the problem of the origin and nature of the well-known temperature-dependent spectral shifts characteristic of the aminophthalimides in alcohol solvents. It is demonstrated that the temperature-dependent spectral shifts are in fact due to time-dependent spectral shifts. At least two relaxation times characterize this phenomenon. One relaxation time is observed to be subnanosecond in character and may be associated with the exciplex that presumably is present in the system. The other relaxation time is presumably associated with the non-specific dipolar reorientation although it has distinctly different characteristics from the solvent dielectric relaxation time. Wavelength-dependent fluorescence decay that can be explained by the time dependence of the emission spectrum is also observed. (Author)(*IMIDES
Department of Biological Sciences, Texas Tech University, Lubbock 79409, USA. [email protected] The function of Lhca4, a gene encoding the photosystem 1 type IV chlorophyll a/b-binding protein complex in Arabidopsis, was investigated using antisense technology. Lhca4 protein was reduced in a number of mutant lines and abolished in one. The inhibition of protein was not correlated with the inhibition of mRNA. No depletion of Lhca1 was observed, but the low-temperature fluorescence emission spectrum was drastically altered in the mutants. The emission maximum was blue-shifted by 6 nm, showing that chlorophyll molecules bound to Lhca4 are responsible for most of the long-wavelength fluorescence emission. Some mutants also showed an unexplainable delay in flowering time and an increase in seed weight.. MeSH Terms ...
To understand the function of cellular protein networks, spatial and temporal context is essential. Fluorescence correlation spectroscopy (FCS) is a single-molecule method to study the abundance, mobility and interactions of fluorescence-labeled biomolecules in living cells. However, manual acquisition and analysis procedures have restricted live-cell FCS to short-term experiments of a few proteins. Here, we present high-throughput (HT)-FCS, which automates screening and time-lapse acquisition of FCS data at specific subcellular locations and subsequent data analysis. We demonstrate its utility by studying the dynamics of 53 nuclear proteins. We made 60,000 measurements in 10,000 living human cells, to obtain biophysical parameters that allowed us to classify proteins according to their chromatin binding and complex formation. We also analyzed the cell-cycle-dependent dynamics of the mitotic kinase complex Aurora B/INCENP and showed how a rise in Aurora concentration triggers two-step complex ...
Background: The accumulation of fibrillar deposits of amyloid beta-peptide (A beta) in brain parenchyma and cerebromeningeal blood vessels is a key step in the pathogenesis of Alzheimers disease. In this report, polymerization of A beta was studied using fluorescence correlation spectroscopy (FCS), a technique capable of detecting small molecules and large aggregates simultaneously in solution. Results: The polymerization of A beta dissolved in Tris-buffered saline, pH 7.4, occurred above a critical concentration of 50 mu M and proceeded from monomers/dimers into two discrete populations of large aggregates, without any detectable amount of oligomers. The aggregation showed very high cooperativity and reached a maximum after 40 min, followed by an increase in the amount of monomers/dimers and a decrease in the size of the large aggregates. Electron micrographs of samples prepared at the time for maximum aggregation showed a mixture of an amorphous network and short diffuse fibrils, whereas only ...
The retinoic acid receptor (RAR) is a member of the nuclear receptor superfamily. This ligand‐inducible transcription factor binds to DNA as a heterodimer with the retinoid X receptor (RXR) in the nucleus. The nucleus is a dynamic compartment and live‐cell imaging techniques make it possible to investigate transcription factor action in real‐time. We studied the diffusion of EGFP-RAR by fluorescence correlation spectroscopy (FCS) to uncover the molecular interactions determining receptor mobility. In the absence of ligand, we identified two distinct species with different mobilities. The fast component has a diffusion coefficient of D1 = 1.8−6.0 µm2/second corresponding to small oligomeric forms, whereas the slow component with D2 = 0.05−0.10 µm2/second corresponds to interactions of RAR with the chromatin or other large structures. The RAR ligand‐binding‐domain fragment also has a slow component, probably as a result of indirect DNA‐binding through RXR, with lower affinity ...
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TY - JOUR. T1 - Binding of apolipoprotein E inhibits the oligomer growth of amyloid-β peptide in solution as determined by fluorescence cross-correlation spectroscopy. AU - Ly, Sonny. AU - Altman, Robin. AU - Petrlova, Jitka. AU - Lin, Yu. AU - Hilt, Silvia. AU - Huser, Thomas R. AU - Laurence, Ted A.. AU - Voss, John C. PY - 2013/4/26. Y1 - 2013/4/26. N2 - One of the primary neuropathological hallmarks of Alzheimer disease is the presence of extracellular amyloid plaques resulting from the aggregation of amyloid-β (Aβ) peptides. The intrinsic disorder of the Aβ peptide drives self-association and progressive reordering of the conformation in solution, and this dynamic distribution of Aβ complicates biophysical studies. This property poses a challenge for understanding the interaction of Aβ with apolipoprotein E (apoE). ApoE plays a pivotal role in the aggregation and clearance of Aβ peptides in the brain, and the ε4 allele of APOE is the most significant known genetic modulator of ...
We demonstrate a smartphone-integrated handheld detection instrument capable of utilizing the internal rear-facing camera as a high-resolution spectrometer for measuring the colorimetric absorption spectrum, fluorescence emission spectrum, and resonant reflection spectrum from a microfluidic cartridge insert
Rhodopsin self-associates in the plasma membrane. At low concentrations, the interactions are consistent with a monomer-dimer equilibrium (Comar et al., J Am Chem Soc 136(23):8342-8349, 2014). At high
Metallic nano-antennas provide strong field confinement and intensity enhancement in hotspots and thus can ultimately enhance fluorescence detection and provide ultra small detection volumes. In solution-based fluorescence measurements, the diffraction limited focus driving the nano-antenna can outshine the fluorescence originating from the hotspot and thus render the benefits of the hotspot negligible. We introduce a model to calculate the effect of a nano-antenna, or any other object creating a nontrivial intensity distribution, for fluorescence fluctuation measurements. Approximating the local field enhancement of the nano-antenna by a 3D Gaussian profile, we show which hotspot sizes and intensities are the most beneficial for an FCS measurement and compare it to realistic antenna parameters from literature.. © 2014 Optical Society of America. Full Article , PDF Article ...
Read independent reviews on NANOPHOX - Photon Cross-correlation Spectroscopy for size and stability analysis of nano-suspensions and emulsions from 1 nm to 10,000 nm from Sympatec GmbH on SelectScience
Transmembrane domains (TMD) connect the inner with the outer world of a living cell. Single TMD containing (bitopic) receptors are of particular interest, because their oligomerization seems to be a common activation mechanism in cell signaling. We analyzed the composition of TMDs in bitopic proteins within the proteomes of 12 model organisms. The average number of strongly polar and charged residues decreases during evolution, while the occurrence of a dimerization motif, GxxxG, remains unchanged. This may reflect the avoidance of unspecific binding within a growing receptor interaction network. In addition, we propose a new experimental approach for studying helix-helix interactions in giant plasma membrane vesicles using scanning fluorescence cross-correlation spectroscopy. Measuring eGFP/mRFP tagged versions of cytokine receptors confirms the homotypic interactions of the erythropoietin receptor in contrast to the Interleukin-4 receptor chains. As a proof of principle, by swapping the TMDs, ...
This invention relates to a diagnostic apparatus and particularly to an apparatus for the diagnosis of malignant tumor and the method of using the apparatus for diagnosis. The apparatus employs an ultraviolet light source with an emitting waveband of 3000A-4000A. Light from the light source is transmitted through a bundle of quartz optic fibers to the surface of the tumor, whether benign or malignant, to stimulate it, which then generates a specific intrinsic fluorescence spectrum. The intrinsic fluorescence spectrum reflected from the surface of the tumor is transmitted by a second bundles of glass fibers placed near it to a color resolution means, then processed by a scanning means and a circuit means, and displayed recorded by a display recording means. The display may be a graphic presentation of the intrinsic fluorescence spectrum of the tumor that is tested. If the graphic presentation displayed includes a single peak within the range of the blue color band, it indicates that the tumor being
Fast and non-invasive, diagnostic techniques based on fluorescence spectroscopy have the potential to link the biochemical and morphologic properties of tissues to individual patient care. One of the most widely explored applications of fluorescence spectroscopy is the detection of endoscopically invisible, early neoplastic growth in epithelial tissue sites. Currently, there are no effective diagnostic techniques for these early tissue transformations. If fluorescence spectroscopy can be applied successfully as a diagnostic technique in this clinical context, it may increase the potential for curative treatment, and thus, reduce complications and health care costs. Steady-state, fluorescence measurements from small tissue regions as well as relatively large tissue fields have been performed. To a much lesser extent, time-resolved, fluorescence measurements have also been explored for tissue characterization. Furthermore, sources of both intrinsic (endogenous fluorophores) and extrinsic ...
There are various fluorescent probes such as ANS (anilinonapthalene 8-sulphonate) and N-methyl-2-anilino-6-naphthalene sulphonate (MNS). They both contain charged and hydrophobic areas and therefore are situated at the water-lipid interface of the membrane. The fluorescent properties of the molecule vary with its mobility and also with the polarity of the environment. Studies with the ANS probe has shown that structural changes occur in mitochondrial membrane during oxidative phosphorylation. These probes have also helped in giving information about the structural features of the plasma membrane. ...
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 …
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 ...
This thesis describes the development of sensitive and high-resolution fluorescence spectroscopic and microscopic techniques and their application to probe biomolecules and their interactions in solution, lipid membrane model systems and in cells. Paper I-IV are largely focused on methodological developments. In paper I, a new fluorescence method based on fluorescence correlation spectroscopy (FCS) for detecting single particles was realized, requiring no fluorescent labeling of the particles. The method can yield information both about the diffusion properties of the particles as well as about their volumes. In paper II, a modified fluorescence cross correlation spectroscopy procedure with well characterized instrumental calibration was developed and applied to study cis interactions between an inhibitory receptor and its Major Histocompatibility Complex class I ligand molecule, both within the same cellular membranes. The quantitative analysis brought new insights into the Nature killer cells ...
The cell membrane is organized in to different structures and it has been difficult to visualize these structures since they are believed to possess sizes below the optical resolution limit. Hence the development of new tools probing the biophysical properties of membranes is necessary. Imaging FCS is one such tool which allows the measurement of mobility at contiguous locations on cell membranes of live cells by analyzing the autocorrelation functions. In this thesis, Imaging FCS is being extended to Imaging FCCS enabling one to calculate cross-correlations and to extract parameters from the same. The next part discusses methods to characterize organization of membranes. The last part describes the study of membrane proteins and anti-microbials carried out using Imaging FCS. Unlike single point FCS which yields only mobility, imaging FCS provides mobility and heterogeneity and proved to be a valuable biophysical tool to characterize the dynamics and organization of cell membranes ...
To enable not only long sequence read but also high throughput in a DNA sequencer, the single molecule sequencing method based on direct observation of processive DNA polymerization is very promising. In this method, only incorporated nucleotides labeled with fluorescent dye should be detected under high concentration of unreacted nucleotides. Enhanced local field produced by plasmonic nanostructure is very suitable for such application because of its small size of a few ten nanometers. We have fabricated platinum bowtie nanostructure arrays producing fluorescence enhancement and have evaluated the performance using two-photon photoluminescence and single molecule fluorescence measurements. To enable use of multicolor dye labeling, visible light excitation around 500 nm is preferable, so that gold well known as a plasmonic material cannot be used. We explored suitable materials comprehensively by electromagnetic simulation and consequently chose platinum. Observation of bright photoluminescence from Pt
PA-Mode Single Wavelength allows the detection and fusion of photoacoustic signals with detailed anatomical images. Using a tuneable near infrared laser, the subject is illuminated at the desired wavelength (680-970nm and 1200-2000nm*) in order to visualize chromophores such as hemoglobin, melanin, dyes and nanoparticles.
What is Fluorescence Spectroscopy? Fluorescence is a type of luminescence caused by photons exciting a molecule, raising it to an electronic excited state. Overview of what is fluorescence, what is a fluorescence spectrum, what materials exhibit fluorescence.
TY - JOUR. T1 - The sentinel margin. T2 - Intraoperative ex vivo specimen mapping using relative fluorescence intensity. AU - Van Keulen, Stan. AU - Nishio, Naoki. AU - Birkeland, Andrew. AU - Fakurnejad, Shayan. AU - Martin, Brock. AU - Forouzanfar, Tim. AU - Cunanan, Kristen. AU - Colevas, A. DImitrios. AU - Van Den Berg, Nynke S.. AU - Rosenthal, Eben. PY - 2019/8/1. Y1 - 2019/8/1. N2 - Purpose: Despite major advancements in surgical oncology, the positive margin rate for primary head and neck cancer resection remains around 15%-30%. In particular, the deep surface margin is the most challenging to adequately assess. Inadequate margins are directly correlated to poor survival, and as such, mitigation of these rates is critical to improve patient outcomes. We have developed an ex vivo imaging strategy that utilizes fluorescence intensity peaks (relative to background signal) of an injected anti-EGFR antibody conjugated to a fluorescent probe to locate potential close or positive margins on the ...
Fluorophores currently used as fluorescent probes offer sufficient permutations of wavelength range, Stokes shift and spectral bandwidth to meet requirements imposed by instrumentation (e.g., 488 nm excitation), while allowing flexibility in the design of multicolor labeling experiments. Our online Fluorescence SpectraViewer (www.invitrogen.com/handbook/spectraviewer) provides an interactive utility for evaluating these factors during the experimental design process (Using the Fluorescence SpectraViewer-Note 23.1). The fluorescence output of a given dye depends on the efficiency with which it absorbs and emits photons, and its ability to undergo repeated excitation/emission cycles. Absorption and emission efficiencies are most usefully quantified in terms of the molar extinction coefficient (EC) for absorption and the quantum yield (QY) for fluorescence. Both are constants under specific environmental conditions. The value of EC is specified at a single wavelength (usually the absorption ...
The research of biomolecular processes on the level of single molecules and in volume ranges equivalent to the size of a single bacterium is of immense importance, both in basic research and in industrial high-throughput screening. The combination of modern confocal optics, new fluorescent dyes, sensitive photomultipliers and improved data processing has revolutionised the technique of fluorescence correlation spectroscopy (FCS). Over the past few years this has led to its widespread application, and alongside the technological advances in hardware development, Greiner Bio-One worked hand-in-hand with customers and instrument suppliers to develop the glass bottom microplates. These better satisfy the requirements of fluorescence correlation spectroscopy with regard to optical clarity and deformation when compared to standard polystyrene plates ...
We have shown that cold perfusion of hearts generates reactive oxygen and nitrogen species (ROS/RNS). In this study, we determined 1) whether ROS scavenging only during cold perfusion before global ischemia improves mitochondrial and myocardial function, and 2) which ROS leads to compromised cardiac function during ischemia and reperfusion (I/R) injury. Using fluorescence spectrophotometry, we monitored redox balance (NADH and FAD), O(2)(*-) levels and mitochondrial Ca(2+) (m[Ca(2+)]) at the left ventricular wall in 120 guinea pig isolated hearts divided into control (Con), MnTBAP (a superoxide dismutase 2 mimetic), MnTBAP (M) + catalase (C) + glutathione (G) (MCG), C+G (CG), and N(G)-nitro-L-arginine methyl ester (L-NAME; a nitric oxide synthase inhibitor) groups. After an initial period of warm perfusion, hearts were treated with drugs before and after at 27 degrees C. Drugs were washed out before 2 h at 27 degrees C ischemia and 2 h at 37 degrees C reperfusion. We found that on reperfusion the MnTBAP
Neubauer, H.; Gaiko, N.; Berger, S.; Schaffer, J.; Eggeling, C.; Tuma, J.; Verdier, L.; Seidel, C.; Griesinger, C.; Volkmer, A.: Orientational and dynamical heterogeneity of rhodamine 6G terminally attached to a DNA helix revealed by NMR and single-molecule fluorescence spectroscopy. Journal of the American Chemical Society 129 (42), pp. 12746 - 12755 (2007 ...
The sensitivity of EtB"Out" is identical to that of EtBr. Under UV light, EtB"Out" emits green fluorescence when bound to DNA or RNA. EtB"Out" can be excited at 290 nm and 490 nm. The fluorescence emission peak of EtB"Out" when it bound to DNA is at 537 nm.. ...
Time-resolved measurements were made of the gas composition at the exhaust port of a direct-injection two-stroke engine operating at 2000 rpm and an air-fuel ratio of 30:1. A high-speed sampling valve capable of 1.0 ms (12 CAD) time resolution was used to collect samples 1 cm downstream of the exhaust port of the engine. The time-resolved NOx, CO2 and CO concentrations decreased continuously during the scavenging process due to the dilution by short-circuited air. The hydrocarbon emissions, however, behaved significantly differently from the other species. At the time of exhaust port opening the concentration was low, it reached a maximum value by BDC, then decreased slightly in the latter part of the scavenging event. The dilution rates calculated for the hydrocarbon data gave negative values, indicating that there was a significant production of hydrocarbons during the gas exchange period. By using the dilution rate obtained from the CO2 data, the fraction of the total measured hydrocarbon ...
Frequency-domain fluorescence lifetime imaging microscopy (FD-FLIM) is a fast and accurate way of measuring fluorescence lifetimes in widefield microscopy. However, the resolution of multiple exponential fluorescence decays has remained beyond the reach of most practical FD-FLIM systems. In this paper we describe the implementation of FD-FLIM using a 40MHz pulse train derived from a supercontinuum source for excitation. The technique, which we term multi-harmonic FLIM (mhFLIM), makes it possible to accurately resolve biexponential decays of fluorophores without any a priori information. The systems performance is demonstrated using a mixture of spectrally similar dyes of known composition and also on a multiply-labeled biological sample. The results are compared to those obtained from time correlated single photon counting (TCSPC) microscopy and a good level of agreement is achieved. We also demonstrate the first practical application of an algorithm derived by G. Weber [1] for analysing mhFLIM ...
Fluorescence enhancement of QDs coupled to NPAs.(a) QD fluorescence intensity as a function of average incident laser power in three cases-on a glass slide, o
Two compounds of organic molybdate-alkali salt: [H(4,4-bipy)]2[K2Mo8O26](I) and H3 [Na Mo8 O26] (4,4-bipy)5 (H2O)4 (II), with beta-[Mo8O26]4- anion, were synthesized. The relationship between their properties and structures was studied by using FTIR, Raman, NIR-Vis and fluorescence etc. They possess isolating beta-[Mo8O26]4- anion, whose terminal O atoms combine with alkali. The FTIR and Raman spectra showed that the vibrational frequencies of the group are related to the structure of the materials. In UV-Vis spectra of compound (I) and (II), there is a characteristic wide peak at 280-300 nm. The fluorescence spectra of compound (I) and (II) were studied, which showed that the wide emission peak is from 450 to 650 nm and excited by 350 nm for compound (I), and the emission peak is from 400 to 550 nm and excited by 325 nm for compound (II). For compound (I), the intensity of emission becomes stronger with decreasing of temperature, and so does the fluorescence lifetime.
A spectrometric technique to determine microorganism detection and identification by taking advantage of the inherent extracellular enzymes present in living organisms, as opposed to dead, non-enzyme producing organisms. These enzymes are harnessed in the in vivo reactions with a non-fluorescent dye containing a select organic functional group that is known to be cleaved or hydrolyzed by the certain enzyme. The dye is tailored such that one of the products fluoresces, so that by employing a conventional spectrofluorometer, the rate of fluorescence can be determined. By subjecting the same bacterial sample to a number of different non-fluorescent dyes, a pattern of fluorescent rates emerge. By employing the pattern recognition set to standard microorganism fluorescent response curves, microorganism detection and identification can be determined. Thus, the present invention concerns a process for determining microorganism detection, identification and concentration.
Fluorescence‐lifetime imaging microscopy (FLIM) is a technique to generate images, in which the contrast is obtained by the excited‐state lifetime of fluorescent molecules instead of their intensity and emission spectrum
Syncom has developed new fluorescent dyes with improved stability and improved tunable emission characteristics for efficient remote LED application as a member of the project "OPERA". In this EU-funded project leading companies and institutes in LED lighting technology, including Philips, WACKER, Nanocomp, the Delft University of Technology and Syncom have joined forces with the goal to develop the next generation of energy-efficient, sustainable and affordable LED lighting systems. These light converting elements are inexpensive, have higher phosphor-conversion efficiencies than inorganic phosphors, are wavelength-tunable, manufactured in Europe, and ecologically sustainable.. Up to now the commercially available organic molecules are not photo stable enough or show poor emission characteristics. Syncom has been able to design and prepare new fluorescent dyes with a huge improvement in photochemical stability and with the desired tunable absorption emission spectra.. General structures of some ...
B) Traces showing position of the piezo drive during one cycle of the sine-wave scan (top) and corresponding output from the fluorescence detector after addition of sync pulses (bottom). The fluorescence signal was obtained while scanning into an oocyte, and the extreme downward deflection of the scan (trough of sine wave at center of scan cycle) corresponds to the position of the coverglass. Two broad fluorescence peaks are apparent, resulting as the spot scanned from within the oocyte toward the cover glass (left), and again as the objective moved back in the reverse direction (right). The fluorescence deep within the oocyte is low because of light scattering and absorption, and irregular troughs arise as the spot moves through organelles. The fluorescence profiles on the "down" and "up" scans are not perfect mirror images because of lateral hysteresis in the translator. (C) Axial linescan image showing reflectance from a mirrored slide as the microscope focus was advanced by hand in 2-µm ...
He fluorescence enhancement must be the AP site involved. The optical properties of SG bound in the AP site environment should be different from that directly
Despite the fact that multi-channel sensors could afford comprehensive information for the analysis of basic biological or physiological processes, the design of such nanosensors based on luminescent metal-organic frameworks (LMOFs) is still in its infancy. Herein, we constructed a three-channel ratiometric LMOF-ba
Our Lightning-Link® antibody labeling kits allow direct conjugation of primary antibodies, proteins or peptides with only 30 seconds hands-on time.. We have over 35 fluorescent dyes in our expanding range, therefore if the antibody conjugate you require isnt available on the market, you can now prepare your own conjugate in less than 20 minutes, with a 100% yield from the unconjugated antibody! The simplicity and convenience of Lightning-Link® antibody labeling kits therefore provides additional ease and flexibility in panel design for multi-colour flow cytometry.. View Our Range of Fluorescent Labels. Please feel free to contact us if you require any other fluorochromes that are not on our list.. ...
HORIBA Scientific (HORIBA), the global leader in fluorescence spectroscopy systems, announces the Delta Series, their newest generation of time-correlated single photon counting (TCSPC) fluorescence lifetime systems. They are designed to be faster, simpler, and more affordable than any other lifetime solution on the market.