Martha O'Brien1, Danielle Moehring1, Justin Callaway2, Jenny Ting2, Mike Scurria3, Tim Ugo3, Laurent Bernad3, James Cali1 and Dan Lazar1
1Promega Corporation, 2800 Woods Hollow Rd, Madison, WI, 53711; 2Dept. of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599; 3Promega Biosciences LLC, 277 Granada Dr, San Luis Obispo, CA 93401
To simplify and provide a more direct means of detecting cell-based caspase-1 activity, we developed a sensitive, homogeneous, plate-based assay that eliminates the need for significant sample processing. The assay employs a single-step format combining a caspase-1 substrate, Z-WEHD-aminoluciferin, with a thermostable luciferase in an optimized, lytic reagent. Assay specificity for caspase-1 is confirmed by the subsequent use of a caspase-1 inhibitor, Ac-YVAD-CHO. The assay can be used to measure caspase-1 activity directly in cell cultures or to monitor released caspase-1 activity in culture medium from treated cells. Using this assay system, caspase-1 activation has been demonstrated in numerous cell culture models of inflammasome activation.