A method of detecting and quantifying viable cells in a sample. The method includes fluorescently staining the cells by adding a fluorescent dye into the sample or putting the sample in contact with the fluorescent dye. A quenching dye is then added to the stained sample, or the sample is put into contact with the quenching dye, at a pH different from the pH in the viable cells. The quenching dye used is permeable through the membrane of a viable cell and does not readily absorb fluorescence of ...

The invention pertains to a non-fluorescent label which is suitable for making a charge-transfer fluorescent probe having a donor-bridge-acceptor structure, characterized in that the label comprises a maleimide moiety and the donor-bridge-acceptor structure, wherein the bridge is a group which leads to an all-trans orbital coupling of the donor and the acceptor, and the donor-bridge-acceptor structure has a higher energy charge-transfer emissive state than at least one non-emissive state of part...

An analyte detection system utilizing a combination of fluorescent labels for labeling particles and an analyte specific fluorescent analyte detection dye. The particles contain a combination of fluorescent labels for coding the particles and an analyte specific fluorescent dye. The particles can be used to identify and quantify analytes in an analytical sample by reaction of the analytical sample with the particles. An analytical device can identify the particles according to the combination of...

A method of assaying the antioxidant capacity of a sample, the method including preparing an extraction solution including a solubility enhancing compound, adding the sample to the extraction solution, extracting the antioxidants present in the sample, adding a fluorescent probe to the extract, adding a free radical generator to the extract, detecting the fluorescence intensity decay of the probe in the presence of the sample over time, and calculating the antioxidant capacity of the sample base...

The present invention provides a method for the chromatographic fingerprinting, chemical and therapeutic standardization, bar-coding of the fingerprints and preparation of a data base for Enterprise Resource Planning (ERP) and Customer Relationship Management (CRM) machines and applications of medicines in general and traditional medicines in particular; this invention includes a software based instrumental method and a novel method of fingerprinting and standardization is proposed for the above...

A biochemical analysis kit includes a biochemical analysis unit including a substrate capable of attenuating radiation energy and light energy and formed with a plurality of absorptive regions to be spaced apart from each other, and a stimulable phosphor sheet including a support formed with a plurality of stimulable phosphor layer regions in substantially the same pattern as that of the plurality of absorptive regions, the plurality of absorptive regions of the biochemical analysis unit and the...

In a method of formaldehyde determination by measuring the fluorescence of a fluorescent substance formed by allowing a formaldehyde-containing solution to react with a reagent capable of forming said fluorescent substance from formaldehyde, the improvement comprising measuring the fluorescence in the presence of a serum albumin.

A system and method of optically measuring Na.sup.+ and K.sup.+ in a sample such as blood which contains high concentrations Na.sup.+ (up to 160 mM) and K.sup.+ (up to 6.5 mM) using a photoluminescent probe having intrinsic analyte-induced lifetime changes. Specifically, the use of lifetime-based sensing of Na.sup.+ and K.sup.+ at the extracellular concentrations present in whole blood or, blood serum. The preferred embodiment uses phase-modulation fluorometry.

In a method of formaldehyde determination by measuring the fluorescence of a fluorescent substance formed by the reaction of a formaldehyde-containing solution with a fluorescent reagent capable of forming said fluorescent substance by the reaction with formaldehyde, the improvement which comprises using as said fluorescence reagent a compound represented by the general formula CH.sub.3 C(NH.sub.2).dbd.CHCO.sub.2 R, wherein R represents an alkyl group having 1 to 4 carbon atoms.

The present invention is directed to a method for the rapid screening of potential reactants, catalysts, and associated process conditions. In an embodiment, the invention comprises a method for evaluating catalyst efficacy in polymerization reactions by the determination of product molecular weight and Fries products.