Purity: Single spot by TLC. A synthetic peptide that irreversibly inhibits activity of caspase family proteases and blocks apoptosis. The inhibitor is designed as a methyl ester to facilitate cell permeability. The product can be used for both in vitro and in vivo studies. (CAUTION: If the intended use is on purified or recombinant enzymes, esterase should be added to generate free carboxyl groups).