Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g. a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: A deuterated ?-ketoamido steric specific compound of the formula wherein D denotes a deuterium atom on a steric specific carbon atom.

Abstract: Substrates for ?-lactamase of the general formula I in which one of X and Y is a fluorescent donor moiety and the other is a quencher (which may or may not re-emit); R? is selected from the group consisting of H, lower (i.e., alkyl of 1 to about 5 carbon atoms) and (CH2)nOH, in which n is 0 or an integer from 1 to 5; R? is selected from the group consisting of H, physiologically acceptable metal and ammonium cations, CHR2OCO(CH2)nCH3, —CHR2OCOC (CH3)3, acylthiomethyl, acyloxy-alpha -benzyl, delta-butyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, acyloxyalkyl, dialkylaminocarbonyloxymethyl and aliphatic, in which R2 is selected from the group consisting of H and lower alkyl; A is selected from the group consisting of S, O, SO, SO2 and CH2; and Z? and Z? are linkers for the fluorescent donor and quencher moieties.

Abstract: The invention provides a compound, useful as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and candidate drugs identified by these methods.

Abstract: Substrates for ?-lactamase of the general formula I in which one of X and Y is a fluorescent donor moiety and the other is a quencher (which may or may not re-emit); R? is selected from the group consisting of H, lower (i.e., alkyl of 1 to about 5 carbon atoms) and (CH2)nOH, in which n is 0 or an integer from 1 to 5; R? is selected from the group consisting of H, physiologically acceptable metal and ammonium cations, —CHR2OCO(CH2)nCH3, —CHR2OCOC(CH3)3, acylthiomethyl, acyloxy-alpha-benzyl, delta-butyrolactonyl, methoxycarbonyloxymethyl, phenyl, methylsulphinylmethyl, beta-morpholinoethyl, dialkylaminoethyl, acyloxyalkyl, dialkylaminocarbonyloxymethyl and aliphatic, in which R2 is selected from the group consisting of H and lower alkyl; A is selected from the group consisting of S, O, SO, SO2 and CH2; and Z? and Z? are linkers for the fluorescent donor and quencher moieties.

Abstract: The invention provides methods of using an optical molecular probe or sensor to screen candidate drugs for their interaction with at least one cytochrome P450 enzyme.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: The invention provides methods of using a compound as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and kits for performing these methods.

Abstract: The invention provides a compound, useful as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and candidate drugs identified by these methods.

Abstract: Substrates for &bgr;-lactamase of the general formula I 1

Abstract: The invention provides methods of using a compound as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and kits for performing these methods.

Abstract: The invention provides a compound, useful as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and candidate drugs identified by these methods.

Abstract: The present invention is directed to nucleic acid molecules that encode a cytosolic form of beta-lactamase, cells that include such nucleic acid molecules and methods for their use. These cells can be used in a variety of methods, such as methods for monitoring the expression of a gene or biochemical activity.

Abstract: The invention provides a compound, useful as an optical probe or sensor of the activity of at least one cytochrome P450 enzyme, and methods of using the compound to screen candidate drugs, and candidate drugs identified by these methods.

Abstract: The present invention is directed to nucleic acid molecules that encode a cytosolic form of beta-lactamase and cells that include such nucleic acid molecules. These cells can be used in a variety of methods, such as methods for monitoring the expression of a gene.

Abstract: The present invention relates to methods for increasing the signal-to-noise ratio of an enzyme assay by contacting a sample comprising a membrane compartment with an inhibitor of an enzyme, contacting the sample with a substrate for the enzyme, and determining the activity of the enzyme. The method can be in a heterogeneous or homogeneous format. The methods of the present invention can be used for a variety of purposes, such as increasing the dynamic range of an enzyme assay, extending the useful loading time or assay measurement time of an enzyme assay, profiling the level of an enzyme in a sample, modulating the threshold activity of an enzyme assay, screening test compounds for activity, identifying modulators, identifying an inhibitor of an enzyme, and detecting membrane permeability. The present invention also relates to compounds useful in these methods.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention also provides a system and method of screening test chemicals in fluorescent assays using photon reducing agents. The present invention also provides compositions, pharmaceutical compositions, and kits for practicing these methods.

Abstract: The present invention provides a method for reducing undesirable light emission from a sample using at least one photon producing agent and at least one photon reducing agent (e.g. dye-based photon reducing agents). The present invention further provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one collisional quencher. The present invention also provides a method for reducing undesirable light emission from a sample (e.g., a biochemical or cellular sample) with at least one photon producing agent and at least one quencher, such as an electronic quencher. The present invention further provides a method of determining bound and free analyte in a sample using at least one photon reducing agent. The present invention also provides a method of screening test chemicals in fluorescent assays using photon reducing agents.