IMAGE-IT LIVE RED POLY CASPASE 1 KIT，I35101，Invitrogen

The Image-iT™ LIVE Red Poly Caspases Detection Kit employs a novel approach to detect active caspases that is based on a fluorescent inhibitor of caspases (FLICA™) methodology, essentially an affinity label. The reagent associates a fluoromethyl ketone (FMK) moiety, which can react covalently with a cysteine, with a caspase-specific amine acid sequence. For poly caspases, this recognition sequence is valine-alanine-aspartic acid (VAD). A sulforhodamine group (SR) is attached as a reporter. The FLICA reagent is thought to interact with the enzymatic reactive center of an activated caspase via the recognition sequence, and then to attach covalently through the FMK moiety. The FLICA inhibitor is cell permeant and noncytotoxic. Unbound FLICA molecules diffuse out of the cell and are washed away; the remaining red-fluorescent signal is a direct measure of the amount of active caspase that was present at the time the inhibitor was added.