Abstract: Activity of enzymes and enzyme conjugates is detected using novel substrates made from a class of fluorophores, generally including quinazolinones (quinazolones), benzimidazoles, benzothiazoles, benzoxazoles, quinolines, indolines, and phenanthridines, having the general formula: ##STR1## where carbon atoms of --C.sup.1 .dbd.C.sup.2 -- are joined to complete a first 5- or 6-membered aromatic ring which optionally contains one of the hetero atoms N, O or S,and carbon atoms of --C.sup.4 --N.dbd.C.sup.3 -- are joined to complete a second 5- or 6-membered aromatic ring that contains a nitrogen between C.sup.3 and C.sup.4 and optionally contains an additional hetero atom N, O or S,where the first and second aromatic rings may be joined by a 5- or 6-membered bridging ring that contains at least the C.sup.2 from the first aromatic ring and the C.sup.

Abstract: Novel fluorescent dyes based on the rhodol structure are provided. The new reagents contain functional groups capable of forming a stable fluorescent product with functional groups typically found in biomolecules or polymers including amines, phenols, thiols, acids, aldehydes and ketones. Reactive groups in the rhodol dyes include activated esters, isothiocyanates, amines, hydrazines, halides, acids, azides, maleimides, aldehydes, alcohols, acrylamides and haloacetamides. The products are detected by their absorbance or fluorescence properties. The spectral properties of the fluorescent dyes are sufficiently similar in wavelengths and intensity to fluorescein or rhodamine derivatives as to permit use of the same equipment. The dyes, however, show less spectral sensitivity to pH in the physiological range than does fluorescein, have higher solubility in non-polar solvents and have improved photostability and quantum yields.

Abstract: The invention relates to use of fluorescent compounds of the formula: ##STR1## where R contains between 4 and about 10 carbons and is optionally saturated or unsaturated, and is linear or branched or contains an alicyclic or aromatic ring; and the symbol .PSI. depicts the presence of the counterion used to neutralize the positive charge on the dye. The fluorescent dye dissolved in a biologically compatible solution stains a wide variety of living cells with a red nucleic acid stain after brief incubation in low concentrations of dye, without the requirement of permeabilizing reagents. Detection of the fluorescence can be used alone or in combination with measurement of other markers or properties of the cells to identify, discriminate or sort viable cells.

Abstract: The invention describes the preparation and use of fluorescent stains for nucleic acids derived from unsymmetrical cyanine dyes. In particular, the invention describes unsymmetrical cyanine dyes having a saturated or unsaturated cyclic substituent. The dyes of the invention possess superior fluorescent characteristics when complexed with nucleic acids, and have utility in any application which requires detection of nucleic acids. The presence of the cyclic substituent results in improved permeability in a wide range of living cells, resulting in improved detection of intracellular nucleic acids.

Abstract: The invention relates to fluorescent dyes that are substituted or unsubstituted derivatives of 1-[isoindolyl]methylene-isoindole that are bound through both isoindole nitrogens to a boron difluoride moiety, forming a fluorescent dibenzopyrrometheneboron difluoride compound ##STR1## whose fluorescence properties are modified by the selection of appropriate chemical substituents.The dibenzopyrrometheneboron difluoride compound is optionally substituted by hydrogen, halogen cyano, sulfo, alkali or ammonium salts of sulfo, carboxy, substituted or unsubstituted alkyl, perfluoroalkyl, alkoxy, alkylthio, nitro, amino, monoalkylamino, dialkylamino, substituted or unsubstituted aryl substituents, substituted or unsubstituted heteroaryl substituents, or additional substituted or unsubstituted fused benzo rings or substituted or unsubstituted fused heteroaromatic rings.

Abstract: The invention relates to nucleic acid stains that are homo- or heterodimers of unsymmetrical cyanine dyes, where at least one dye unit of the dimer is a substituted or unsubstituted benzazolium- or naphthazolium-pyridinium derivative, which dye unit is linked to another unsymmetrical cyanine dye unit, that is the same or different by an aliphatic chain containing one or more heteroatoms; such that the fluorescence of the dye molecules, when bound to nucleic acids, is enhanced. These dimers of unsymmetrical cyanine dyes have spectral properties and binding affinities superior to related monomers. In addition, the dyes can be tailored to absorb and emit in a wide range of wavelengths, which can be further varied by energy transfer mixtures, making the dyes useful for applications that involve simultaneous use of multiple dyes.

Abstract: This invention describes novel sensors for ions that are based on the combination of xanthylium-based dyes with metal-binding N,N'-diaryldiaza crown ethers. These sensors are primarily useful for detection and quantitation of alkali-metal ions in aqueous solution. Binding of the ion results in a change in the fluorescence properties of the indicating dye that can be correlated with the ion concentration. Methods are provided for attaching reactive groups on these sensors for conjugation to dyes, lipids and polymers and for enhancing entry of the indicators into living cells.

Abstract: Fluorescent compounds useful in the determination of chloramphenicol acetyltransferase (CAT) enzyme activity are described. The compounds are "fluorescent derivatives related in structure to chloramphenicol and are acylated in the presence of CAT to produce fluorescent mono- and diacylated products, which are then physically separated from the reaction mixture and quantitated by means of their fluorescence and/or absorbance. Fluorescent molecules conjugated to chloramphenicol include derivatives of fluorescein, rhodamine, coumarin, dimethylaminonaph-thalene sulfonic acid (dansyl), pyrene, anthracene, nitrobenz-oxadiazole (NBD), acridine and dipyrrometheneboron difluoride.

Abstract: The subject invention provides a method for analyzing the metabolic activity in cells by improving the retention of a detectable reporter molecule only in intact cells where a particular enzyme is present. In particular, improved retention results from a two part process involving conjugation of haloalkyl-substituted derivatives of a reporter molecule with intracellular cysteine-containing peptides while unblocking the reporter molecule. The method for analyzing metabolic activity of cells involves the use of a substrate having the formXR-REPORTER-BLOCKwherein -BLOCK is a group selected to be removable by action of a specific analyte, to give REPORTER spectral properties different from those of the substrate,-REPORTER- is a molecule that, when no longer bound to BLOCK by a BLOCK-REPORTER bond, has spectral properities different from those of the substrate, andXR-- is a haloalkyl moiety that can covalently react with an intracellular thiol (Z--S--H) to form a thioether conjugate (Z--S--R--).