Analysis of Apoptosis by Flow Cytometry

Based on morphological, biochemical, and molecular criteria two distinct modes of cell death can be recognized: necrosis and apoptosis (1 –5 ). Necrosis generally results from enzymatic digestion of the cells and denaturation of its proteins as the response to gross injury. An early event of necrosis is swelling of cell mitochondria, followed by rupture of the plasma membrane and release of the cytoplasmic contents. The necrotic cells is eosinophilic, and its nucleus becomes either pycnotic or karyorrhectic, or it may disappear in the process of karyolysis. Fully developed myocardial infarct, encephalomalacia, or caseous changes in tuberculosis are examples of necrosis. The process triggers an inflammatory reaction in the surrounding tissues, which often results in scar formation.