Cayman's Annexin V PE Assay Kit employs a PE-conjugated annexin V as a probe for phosphatidylserine on the outer membrane of apoptotic cells. DAPI is used as a marker of cell membrane permeability seen in very late apoptotic or necrotic cells. This kit is valuable for researchers looking to assess the degree of apoptosis induced by experimental compounds, and can be useful in pharmacology, immunology, cancer, or physiology research.