During apoptosis, activated caspase-3 cleaves several substrates, including poly(ADP-ribose) polymerase, which it specifically targets at the amino sequence DEVD. Ac-DEVD-AFC is a fluorogenic substrate for activated caspase-3 (Km = 9.7 μM), as well as related caspases. Caspase activity can be quantified by fluorescent detection of free AFC (also known as 7-amino-4-trifluoromethylcoumarin), which is excited at 400 nm and emits at 505 nm.
