Annexin V-PE/7-AAD Apoptosis Detection Kit

Description

The Annexin V–PE/7-AAD Cell Apoptosis Detection Kit is designed to detect early apoptosis using PE (phycoerythrin)–labeled Annexin V as a fluorescent probe. In viable cells, phosphatidylserine (PS) is confined to the inner leaflet of the plasma membrane. During early apoptosis, PS is translocated to the outer leaflet and exposed to the extracellular environment. Annexin V is a 35–36 kDa Ca²⁺-dependent phospholipid-binding protein that binds PS with high affinity. This enables selective labeling of early apoptotic cells.
7-AAD is a nucleic acid dye similar to propidium iodide but with a narrower emission spectrum, which reduces spectral overlap and is well suited for multicolor flow cytometry. It cannot penetrate intact cell membranes but readily enters cells with compromised membrane integrity and binds DNA. When used together: live cells are Annexin V⁻/7-AAD⁻; early apoptotic cells are Annexin V⁺/7-AAD⁻; late apoptotic or necrotic cells are double-positive (Annexin V⁺/7-AAD⁺).