Background: Apoptosis is the cell’s natural mechanism for programed cell death, and is a critical function to maintain homeostasis in our bodies. External and intrinsic signals activate caspases causing cells to shrink. Changes in cell membrane structure signal macrophages to phagocytize the apoptotic cell. The dysregulation of apoptosis is a symptom in cancer as the prevention of cancer is one of the main functions of apoptosis. 1 This assay can be used to assess potential anticancer drugs that target various stages of apoptosis in both the intrinsic and extrinsic pathways.
Principle: Apoptosis can be assayed at different stages of membrane malformation, caspase activation or DNA content. Target cells are cultured in the presence of test article and assayed for apoptosis. To identify apoptotic cells by flow cytometry membrane binding dyes (Annexin V) and DNA-intercalator (7-AAD, Propidium Iodide are utilized in conjunction with the assessment of caspase expression, to measure and identify apoptotic cells.