Immunoproteasome Activity Fluorometric Assay Kit I was designed for assaying the immunoproteasomes" chymotrypsin-like activity in vitro using purified proteasome, cell lysates or tissue extracts. The proteasome cleaves Ac-ANW-AMC and the released AMC fluorescence can be monitored using a plate reader or fluorometer at the excitation/emission wavelength of 360nm/460nm, respectively.