Patent ID: 7332278

Claim:
A homogenous assay method for directly detecting a donor-product produced in a group transfer reaction in the presence of a donor molecule, the method comprising the steps of: a) reacting a donor molecule which is adenosine triphosphate (ATP), with an acceptor in the presence of a catalytically active enzyme to form the donor-product which is adenosine diphosphate (ADP) and an acceptor phosphate, such that the ATP is partially consumed; b) combining the ADP produced in a group transfer reaction with a tracer and an antibody to provide a reaction mixture, the antibody being specific for the ADP, the tracer comprising the ADP conjugated to a fluorophore, and capable of binding to the antibody to produce a detectable change in fluorescence polarization; c) measuring the fluorescence polarization of the mixture to obtain a measured fluorescence polarization; and d) comparing the measured fluorescence polarization with a characterized fluorescence polarization value corresponding to a known ADP concentration to directly detect the ADP produced in the group transfer reaction.