Apoptosis and necrosis are two processes by which cells die. Apoptosis is an active, regulated disassembly of the cell from within. During apoptosis, phosphatidylserine is translocated from the inner to the outer surface of the cell, allowing the dying cell to be engulfed by phagocytic cells. Annexin V is a 35 kD Ca2+-dependent phospholipid binding protein with a high affinity for phosphatidylserine.

Apoptosis and Necrosis Quantitation Kits
Apoptosis and Necrosis Quantitation Kit pairs green fluorescent CF™488A-Annexin V with a selection of membrane impermeant red fluorescent nucleic acid dyes to distinguish early apoptotic cells from late apoptotic and necrotic cells with compromised membrane integrity. The nucleic acid dyes also allow visualisation of nuclear morphology to distinguish late apoptotic cells with compromised plasma membranes from necrotic cells. CF™488 is significantly brighter and more photostable than traditional green dyes like fluorescein.
The Apoptosis and Necrosis Quantitation Kit provides a convenient assay for detecting apoptotic (green) and necrotic (red) cells within the same cell population by flow cytometry or fluorescence microscopy. The Apoptosis and Necrosis and Healthy Cells Quantitation Kit includes a membrane permeable blue fluorescent dye (excitation/emission bound to DNA: 350/461 nm) for staining the nuclei of the entire cell population.

Apoptosis Kits with CF™488A-Annexin V and 7-AAD or Propidium Iodide
These kits pair green fluorescent CF™488 Annexin V for detection of apoptotic cells with a red fluorescent vital dye for detection of necrotic and late apoptotic cells with compromised membrane integrity. 7-AAD is useful for fluorescence microscopy, due to minimal fluorescence spill-over of 7-AAD in the green channel, while propidium iodide is recommended for flow cytometry.

Apoptosis & Necrosis Quantitation Kit Plus
These kits feature ethidium homodimer III, a membrane-impermeant nucleic acid dye developed at Biotium with higher affinity for DNA and higher fluorescence quantum yield than propidium iodide. The Apoptotic, Necrotic and Healthy Cells Quantitation Kit Plus also includes a membrane permeable blue fluorescent DNA dye (Ex/Em with DNA 350/461 nm) to allow visualisation of the total cell population.