Proteasome Activity Fluorometric Assay Kit I can be used for assaying the constitutive proteasomes' chymotrypsin-like activity in vitro using purified proteasome, cell lysates or tissue extracts. The proteasome cleaves Suc-LLVY-AMC, and the released AMC fluorescence can be monitored using a plate reader or fluorometer at the excitation/emission wavelength of 360nm/460nm, respectively.