This biotinylated apopain inhibitor has successfully been used for the affinity purification - on a streptavidin-agarose column - of caspase-3 (apopain), the enzyme that cleaves the poly(ADP-ribose) polymerase (PARP). Biotinyl-DEVD-CHO showed an inhibitory activity comparable to that of the N-acetylated analog inhibitor (H-2496) (IC₅₀ = 0.2 nM).