The red fluorescent sulforhodamine 101 annexin V (Texas-Red Annexin V) can be used to detect apoptotic cells. The human anticoagulant annexin V is a 35- 36 kilodalton, Ca²⁺-dependent phospholipid-binding protein with high affinity for phosphatidylserine (PS). In normal viable cells, PS is located on the inner leaflet of the cytoplasmic membrane. In apoptotic cells, however, PS is translocated from the inner to the outer leaflet of the plasma membrane, where it can be detected by a fluorescently labeled annexin V.

• l_ex\l_em(pH7) = 586/605 nm
• Red solution
• Store at -20?C and protect from light