cGAS TR-FRET Inhibitor Screening Assay Kit

Cayman's cGAS TR-FRET Inhibitor Screening Assay Kit provides a robust and easy-to-use time-resolved Forster resonance energy transfer (TR-FRET) platform for identifying novel inhibitors of human cGAS, which is a cystosolic dsDNA sensor that detects microbial pathogens. This assay utilizes a mouse anti-rabbit monoclonal immunoglobulin G (IgG) directly labeled with a europium (Eu3+) chelate as a donor molecule and fluorescently labeled 2'3'-cGAMP as the acceptor molecule. In the presence of an anti-2'3'-cGAMP antibody, the donor and acceptor are brought into close proximity resulting in a FRET from the donor to the acceptor upon excitation of the Eu3+-conjugated IgG at 340 nm and an emission from the acceptor at 665 nm. In the assay, production of 2'3'-cGAMP by cGAS in the presence of dsDNA, ATP, and GTP results in the displacement of fluorescently labeled 2'3'-cGAMP from the anti-2'3'-cGAMP antibody, resulting in a loss of TR-FRET signal. Inhibition of cGAS maintains the signal. The cGAS inhibitor CU-76 is included as a positive control.