Fig. 1.

Principle of the annexin V apoptosis detection. (A) After initiating apoptosis, cells translocate the membrane phosphatidylserine from the inner face of the plasma membrane to the cell surface. Once on the cell surface, phosphatidylserine can be easily detected by staining with a fluorescent conjugate of Annexin V, a protein that has a high affinity for phosphatidylserine. (B) Structure of phosphatidylserine-bindig annexin V. Annexin A5 core (PDB code 1A8A) domains are intracellular phosphatidylserine-binding domains.