Activation of caspases plays a central role in apoptosis. The CaspGLOW™ Fluorescein Active Caspase-2 Staining Kit provides a convenient means for sensitive detection of activated caspase-2 in living cells. The assay utilizes the caspase-2 inhibitor, VDVAD-FMK, conjugated to FITC (FITC-VDVAD-FMK) as a marker. FITC-VDVAD-FMK is cell permeable, nontoxic, and irreversibly binds to activated caspase-2 in apoptotic cells.