has detection method has measured entity has substrate has participant viability measurement method caspase activity determination Caspases are cysteine proteases which play an important role in apoptosis. They are synthesized and stored in cells as inactive procaspases. Once apoptosis is initiated in a cell, the procaspases get activated by proteolytic cleavage. This sets in motion a caspase cascade, which leads to the activation of proteins involved in the chromatin fragmentation and finally culminates in cell death. fluorescence microscopy Caspase-3 DEVD-NucView 488