Caspase-3 plays a key role in the regulation of apoptosis. Initially synthesized as a precursor protein, it is activated by proteolytic cleavage of the N-terminus. The Cleaved/Total Caspase-3 Base Kit provides basic components for the quantitative determination of the p20 and p17 cleavage (ASP175) products of caspase-3 and total caspase-3 in human whole cell lysates. Base kits generally include only MSD plates coated with the capture antibody, SULFO-TAG-labeled antibody, and MSD proprietary read buffer. (See product insert for a list of kit components). Base kits are most commonly used for high-throughput screening and assay development.