Apoptosis is an important form of physiologic cell death displayed by an enormous variety of tissues under divergent conditions. The recent attention toward apoptosis in virtually all aspects of modern biology indicates that rapid and accurate differentiation between apoptosis and necrotic death is of considerable interest.
Apoptosis is distinguishable from necrosis on the basis of several criteria.
We show that necrotic cells do display detectable DNA damage. We report that a recovery period is necessary for expression of increasing apoptotic but not necrotic DNA damage. We show that apoptosis increases with prolonged hyperthermia and confirm that the mode of death changes from apoptosis to necrosis with higher heat loads, producing a greater fraction of cells showing damage. In addition, we show that for necrotic cells, DNA tail moment reflects sensitivity to prolonged exposure without a concomitant change in tail length.