Patent ID: 7727739
Filing Date: 2010-06-01
Classification: C12Q,G01N

Abstract:
1. In a method of measuring the activity of an enzyme in cleaving a substrate, said substrate including at least one fluorescent label bound to a polymer which includes one or more tyrosine, tryptophan, phenoxy, indolyl or nitro-phenylalanine moieties, said moieties being separated from said at least one fluorescent label by a linkage group cleavable by said enzyme, the improvement comprising the steps of: i) measuring the fluorescence lifetime of the at least one label of the substrate in a reaction buffer which is suitable for said enzyme to cleave said substrate; ii) adding said enzyme to said reaction buffer; and iii) measuring any increase in fluorescence lifetime of the at least one fluorescent label following step ii); wherein said increase in fluorescence lifetime indicates substrate cleavage and is used to determine enzyme activity; further wherein said at least one fluorescent label is an acridone dye of formula: wherein: groups R Z R