As the cell death field matured, focus shifted away from describing the morphological aspects of cell death to assessing the underlying biology. As a result, today’s assay methodologies are based on detecting specific biological aspects of the cell death process including caspase activation, protein cleavage, mitochondrial functioning, loss of phospholipid membrane asymmetry, and DNA fragmentation.

Many different models of cell death have emerged including necrosis, apoptosis, anoikis, caspase-independent apoptosis, autophagy, endoplasmic reticulum stress, Wallerian degeneration, excitotoxicity, erythropoiesis, platelets, cornification and lens (reviewed in Melino et al. 2005). However, apoptosis continues to be a popular, although loosely defined term that is used differently by different investigators to measure and describe cell death. In general, anything that looks like apoptosis has been called apoptosis which has contributed to the complexity of the cell death literature (Vaux et al. 1999). Researchers should keep in mind that cell death assays detect a biological aspect or mechanism of cell death versus being exclusive to a particular type of cell death such as apoptosis or necrosis.

IMGENEX offers a wide range of products and assays for detecting and analyzing cell death. Collectively, these products encompass a variety of techniques including flow cytometry, western blot analysis, immunohistochemisty, fluorescence microscopy, and ELISA. As cell death occurs through different mechanisms, which may be present in various combinations, the Nomenclature Committee on Cell Death (NCCD) encourages investigators studying cell death to use more than one assay whenever possible (Kroemer et al. 2005).