The Cathepsin S Inhibitor Screening Assay Kit is designed to measure the protease activity of Cathepsin S for screening and profiling applications. The Cathepsin S assay kit comes in a convenient 96-well or 384-well format, with enough purified Cathepsin S (amino acids 17-331), its substrate, and Cathepsin Buffer for 96 or 384 reactions. This kit includes the inhibitor E-64 as control.

Figure 1: Illustration of the assay principle.
The substrate is an internally quenched fluorogenic substrate. Proteolysis releases the highly fluorescent Mca from the quencher. Fluorescence intensity increases proportionally to the activity of the protease.