Ready-to-use fluorometric substrate for caspase-3/CPP32 (Km = 9.7 µM) and related caspases that recognize the amino acid sequence DEVD. The sequence DEVD is based on caspase-3 cleavage site in poly (ADP-ribose) polymerase (PARP). CPP32 and related caspase activity can be quantified by fluorescent detection of free AFC after cleaved from the peptide substrate DEVD-AFC at Ex. = 400 nm and Em. = 505 nm, using a fluorometer or a multi-well fluorescence plate reader. Alternatively, a shift in fluorescence from blue to green upon cleavage can be visualized using a hand-held long-UV lamp.