Apoptosis is an active, programmed process of autonomous cellular dismantling that avoids eliciting inflammation. In apoptosis, phosphatidylserine (PS) is transferred to the outer leaflet of the plasma membrane. As a universal indicator of the initial/intermediate stages of cell apoptosis, the appearance of phosphatidylserine on the cell surface can be detected before morphological changes are observed.

Necrosis is characterized as a passive, accidental cell death resulting from environmental perturbations with uncontrolled release of inflammatory cellular contents. Loss of plasma membrane integrity represents a straightforward approach to demonstrate late stage apoptosis and necrosis.

AAT Bioquest offers Cell Meter™ Apoptotic and Necrotic Detection Kits as a set of tools for monitoring cell viability. Our Cell Meter™ detection kits are optimized to simultaneously detect cell apoptosis, necrosis and healthy cells with a flow cytometer or fluorescence microscope. The phosphatidylserine (PS) sensor used in Kit 22843 has deep red fluorescence (Ex/Em = 630/660 nm) upon binding to membrane PS. Membrane-impermeable Nuclear Green™ DCS1 (Ex/Em = 490/525 nm) is used to label the nucleus while CytoCalcein™ Violet 450 (Ex/Em = 405/450 nm) is provided for labeling live cell cytoplasm.