The mitochondrial electrochemical gradient is often disturbed during apoptosis and can be detected using cationic dyes such as DePsipher™ (5,5’6,6’- tetrachloro-1,1’,3,3’-tetraethylbenz-imidazolylcarbocyanine iodide) or MitoShift™ (tetramethylrhodamine ethyl ester). Activation of caspases, or cysteinyl proteases, is a necessary event for execution of the apoptotic response. Some of the caspases