The AffiDETECT® Annexin V-FITC/PI Apoptosis Detection Kit is designed to detect apoptosis in various cell types with a combination of Annexin V-FITC and propidium iodide (PI). Its optimized protocols save time and make the kit ideal for laboratories needing robust results.
Overview:
In healthy cells, phosphatidylserine (PS) only distributes in the inner layer of the cell membrane lipid bilayer. At the early stage of apoptosis, PS is turned from the inside of the lipid membrane to the outside. Annexin V, a Ca2+ dependent phospholipid binding protein with a molecular weight of 35-36 kD, has a high affinity to PS and can be used to detect to detect the externalization of PS. Annexin V is recognized as one of the sensitive indicators of early apoptosis. Apoptosis can be detected by fluorescence microscopy or flow cytometry using Annexin V probe conjugated to FITC (a green fluorescent).
This kit also includes propidium iodide (PI), a dye for nucleic acid that cannot penetrate the intact cell membrane of healthy or early apoptotic cells. PI can penetrate the membrane of late apoptotic and necrotic cells, and stain these cells with red fluorescence. Using both Annexin V and PI, this kit can used to distinguish cells at different apoptotic periods, i.e. live cells (Annexin V-/PI-), early apoptotic cells (Annexin V+/PI-), and late apoptotic/dead cells (Annexin V+/PI+).