Invitrogen™ eBioscience™ Annexin V Apoptosis Detection Kits

Description

• Easily distinguish cells undergoing early and late apoptosis with eBioscience and Annexin V Apoptosis Detection kits for flow cytometry analysis
• These kits utilize viability dye-conjugated annexin V to label phosphatidylserine (PS), an early marker of apoptosis, on the extracellular membrane
• In late-stage apoptosis, as cell integrity is lost, both annexin V and the viability dye traverse and bind PS on the interior of the plasma membrane
• Annexins are a family of calcium-dependent phospholipid-binding proteins that preferentially bind phosphatidylserine (PS)
• Under normal physiologic conditions, PS is predominantly located in the inner leaflet of the plasma membrane
• Upon initiation of apoptosis, PS loses its asymmetric distribution across the phospholipid bilayer and is translocated to the extracellular membrane leaflet marking cells as targets of phagocytosis
• Once on the outer surface of the membrane, PS can be detected by fluorescently labeled annexin V in a calcium-dependent manner
• In early-stage apoptosis, the plasma membrane excludes viability dyes such as propidium iodide (PI), 7-AAD, or fixable viability dyes such as eFluor 450
• These cells will stain with annexin V but not a viability dye, thus distinguishing cells in early apoptosis
• However, in late-stage apoptosis, the cell membrane loses integrity, thereby allowing annexin V to also access PS in the interior of the cell
• A viability dye can be used to resolve these late-stage apoptotic and necrotic cells (annexin V, viability dye-positive) from the early-stage apoptotic cells (annexin V positive, viability dye-negative)
• Current viability stains available with the eBioscience Annexin V Apoptosis Detection kits include FITC, eFluor 450, allophycocyanin (APC), phycoerythrin (PE), PE-cyanine7, and biotin.