The Apoptosis and Necrosis Quantitation Kit Plus is a simple, convenient assay for quantifying apoptotic (green; Abs/Em: 490/515 nm) and necrotic (red; Abs/Em with DNA: 528/617 nm) cells within the same cell population by flow cytometry or fluorescence microscopy. Apoptosis is accompanied by phosphatidylserine (PS) translocation from the inner to the outer leaflet of the plasma membrane. Exposed PS is recognized by Annexin V, a calcium-dependant high-affinity phospholipid-binding protein. CF488A conjugated Annexin V stains apoptotic cells green. CF488A is spectrally similar to fluorescein (FITC), but is brighter and more photostable. Necrosis results from severe cellular injury causing loss of plasma membrane integrity. Ethidium homodimer III (EthD-III), a membrane impermeant high-affinity DNA binding dye stains cells with compromised membranes red. It is superior option to propidium iodide (PI) or ethidium homodimer I due to higher DNA affinity and fluorescence quantum yield.