Apoptosis imaging with annexin

Patent Granted In molecular biology, an annexin A5 affinity assay is a test to quantify the number of cells undergoing apoptosis. The assay uses the protein annexin A5 to tag apoptotic and dead cells, and the numbers are then counted using either flow cytometry or a fluorescence microscope.[1] The annexin a5 protein binds to apoptotic cells in a calcium-dependent manner using phosphatidylserine-containing membrane surfaces that are usually present only on the inner leaflet of the membrane.