The Cathepsin Activity Kits are fluorescence-based and utilize the preferred substrate sequence for each cathepsin, labeled with AFC (amino-4-trifluoromethyl coumarin). Cell lysates or other samples that contain cathepsins will cleave the synthetic substrate to release free AFC that can be easily quantified using a fluorometer or a fluorescence plate reaser. The cathepsin assays are easy to perform and can be adapted to 96-well plate format. Assay conditons have been optimized to obtain the maximal activity. Active cathepsin and cathepsin inhibitors are also available separately.

Activation of calpain is involved in many physiological and pathological processes (e.g., apoptosis). The Calpain Activity Kit provides a simple and convenient means for analyzing calpain activity in apoptotic and other samples. The assay is based on fluorometric detection and quantitation of the cleavage of a calpain substrate at 505 nm using a fluorometer or a fluorescence plate reader. The kit contains both positive and negative controls. Comparison of the fluorescence intensity from a treated sample with a normal control allows determination of the changes in calpain activity. Active calpain and calpain inhibitors and antibodies are also available separately.