IMGENEX’s FLICA Apoptosis Detection Kits use a novel approach to detect active caspases. The FLICA (Fluorochrome Inhibitor of Caspases) methodology is based on a cell permeable, non toxic fluorochrome-labeled inhibitor that covalently binds to the catalytic site of active caspases.  Active caspases are responsible for downstream proteolytic cleavages which lead to cell disassembly and eventual death. Caspases are synthesized as proenzymes (pro-caspases) that undergo proteolytic activation, either autocatalytically or in a cascade initiated by cell death inducers.  The presence of active caspases is a widely accepted marker of mammalian apoptosis.  FLICA has become an essential tool is labeling active caspases with fluorochrome conjugated caspase inhibitors.

FLICA Methodology Bites

·  The labeled caspase inhibitor does not bind to pro-caspases. Hence, the presence of the labeled caspase inhibitor in the cell is a marker of apoptosis.  Caspase inhibitor labeled binding sites can be quantified by flow cytometry  (FAM Kits) or fluorescence microscopy (SR Kits).

·  It is interesting to note that once the labeled caspase inhibitor is bound to the caspase, the caspase is not active and cannot perform its proteolytic death inducing cleavage function. In essence, labeled caspase inhibitors will not only identify where caspases have been activated but will also essentially stop the process of downsteam cleavage caused by active caspases.