Caspase 13 (ERICE), an orthologue of human caspase 4, is a cysteine protease which may be detected using a variety of chromogenic and fluorogenic peptide substrates built around the LEED (Leu-Glu-Glu-Asp) sequence. These substrates include: Ac-LEED-pNa (acetyl-Leu-Glu-Glu-Asp-p-nitroanalide), chromogenic and Ac-LEED-AMC (Acetyl-Leu-Glu-Glu-Asp- amino-4-methylcoumarin), fluorogenic.