Annexin V-Biotin (Reagent)

Apoptosis, a term that describes regulated cell death, is a fundamental feature of many processes including normal development, homeostasis, and disease. Early during the process of apoptosis, cells lose their phospholipid membrane asymmetry and expose phosphatidylserine (PS) at the cell surface. This process can be monitored by using Annexin V which is a Ca2+-dependent, phospholipid-binding protein with high affinity for PS that is useful for identifying apoptotic cells with exposed PS. Translocation of PS to the external cell surface is not unique to apoptosis, but occurs also during cell necrosis. The difference between these two forms of cell death is that during the initial stages of apoptosis the cell membrane remains intact, while when necrosis occurs the cell membrane loses its integrity and becomes leaky. Therefore, necrotic cells are easily stained with Propidium Iodide (PI) as well as Annexin V, where as Apoptotic cells stain only with Annexin V.