In flow cytometry, annexin V is commonly used to detect apoptotic cells by its ability to bind to phosphatidylserine, a marker of apoptosis when it is on the outer leaflet of the plasma membrane.

The formation of an annexin A5 shield blocks the entry of phospholipids into coagulation (clotting) reactions.

Without the shield, there is an increased quantity of phospholipid molecules on cell membranes, speeding up coagulation reactions and causing the blood-clotting characteristic of the antiphospholipid antibody syndrome.

[6][7][8] Platelets also expose PS and PE on their surface when activated, which serves as binding site for various coagulation factors.

Annexin A5 has been shown to interact with Kinase insert domain receptor[10] and Integrin, beta 5.