​Detecting Apoptosis and Cell Death

​Annexin V

Annexin V belongs to the annexin family of intracellular proteins that bind to phosphatidylserine (PS) in a calcium-dependent manner. In viable cells, PS is located on the inner leaflet of the plasma membrane. While maintaining an intact plasma membrane, cells undergoing early apoptosis will experience a loss of membrane asymmetry involving the translocation of PS to the external leaflet. Fluorescently labeled Annexin V may be used to specifically target and identify cells engaged in the early stages of apoptosis.

 During late apoptosis or necrosis, plasma membrane integrity is lost, which allows for the access of live cell impermeant DNA dyes such as Propidium Iodide (PI) and 7-Aminoactinomycin D (7-AAD). The dual staining of cells with Annexin V and either PI or 7-AAD will effectively resolve viable, early apoptotic and late apoptotic/necrotic cell populations by flow cytometry. Early apoptotic cells will exclude 7-AAD and PI, staining positive for Annexin V only, while late stage apoptotic and necrotic cells will exhibit positive staining, due to the passage of these dyes into the cell nucleus.

 Product Data

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