Activation of ICE-family proteases/caspases initiates apoptosis in mammalian cells. The Caspase-10 Colorimetric Assay Kit provides a simple and convenient means for assaying the activity of caspases that recognize the sequence AEVD. The assay is based on spectrophotometric detection of the chromophore p-nitroanilide (pNA) after cleavage from the labeled substrate AEVD-pNA. The pNA light emission can be quantified using a spectrophotometer or a microtiter plate reader at 400- or 405 nm.