Historically, the distinction between various types of cell death has been based on the morphology of the cells as they undergo the process. The classification of cell death as apoptosis or necrosis now depends on morphological and biochemical criteria, in addition to the circumstances that lead to these processes.(1-3)
The necrosis phenomenon involves swelling of the plasma membrane and other organelles, eventually leading to their rupture. Cells undergoing the apoptotic process shrink and increase in density while maintaining organelle integrity until relatively late in the course of events.