Annexin V-FITC Early Apoptosis Detection Kit

Annexin V belongs to the annexin family of proteins consisting of over 160 members. All annexin family members share the same charactersistic of Ca2+-dependent binding to negatively charged phospholipid surfaces (1). During early apoptosis, phosphatidylserine (PS) is translocated from the cytosolic side of the plasma membrane to the cellular surface. This translocation exposes PS to the extracellular environment with the plasma membrane left intact (2). Annexin V protein demonstrates high affinity, specificity, and sensitivity for PS and can be used as a marker of early apoptosis. In order to rule out "leaky" necrotic cells, annexin V must be used in tandem with reagents that determine the integrity of the cell membrane, such as propidium iodide (2). 1.Boersma, H.H. et al. (2005) J Nucl Med 46, 2035-50. 2.Vermes, I. et al. (1995) J Immunol Methods 184, 39-51.