Patent ID: 8859220

Claim:
A method of determining the effect of a compound on a non-luminogenic enzyme activity in an assay sample not containing living cells, comprising: (a) contacting a compound for testing, a non-luminogenic enzyme, wherein the non-luminogenic enzyme utilizes or produces ATP, a substrate for the non-luminogenic enzyme, and a nucleotide selected from ATP and ADP, so as to produce a first reaction mixture; (b) contacting the first reaction mixture with a reagent composition comprising luciferase, luciferin, and a tolerance enhancement agent so as to produce a second reaction mixture, wherein the tolerance enhancement agent comprises at least one of a detergent or a non-detergent, and is present in an amount effective to substantially protect the activity of the luciferase from interference from the compound, thereby reducing the likelihood of a false positive resulting from the interfering effect of the compound, wherein the non-detergent comprises polyethylene glycol, polyvinyl pyridine, or crown ether; (c) detecting luminescence in the second reaction mixture; and (d) determining the effect of the compound, if any, on the non-luminescent enzyme activity by comparing the luminescence of the second reaction mixture to a control reaction mixture.