Annexin V-EGFP/PI Apoptosis Detection Kit

The Annexin V-EGFP/PI Cell Apoptosis Detection Kit uses EGFP-labeled Annexin V probe and propidium iodide (PI) to detect early apoptosis with double stain.

The Annexin V-EGFP/PI Cell Apoptosis Detection Kit is designed to detect early apoptosis using EGFP-labeled Annexin V as a fluorescent probe. In normal viable cells, phosphatidylserine (PS) is localized on the inner leaflet of the plasma membrane. During early apoptosis, PS is translocated to the outer leaflet and becomes exposed to the extracellular surface. Annexin V is a 35–36 kDa Ca²⁺-dependent phospholipid-binding protein with high affinity for PS, allowing it to selectively bind to the membranes of early apoptotic cells through exposed phosphatidylserine.

The kit also contains propidium iodide (PI) to differentiate viable and early apoptotic cells from late apoptotic or necrotic cells. PI is a nucleic acid dye that cannot penetrate intact cell membranes but readily enters cells with compromised membranes, staining their nuclei red. When used together, live cells remain Annexin V⁻/PI⁻, early apoptotic cells are Annexin V⁺/PI⁻, and late apoptotic or necrotic cells exhibit double-positive staining (Annexin V⁺/PI⁺).