Fig. 2.

Estimates of the time course of cell death and the appearance of the nuclear stigmata (chromatin condensation and DNA fragmentation) of apoptosis. A, Values at four time points after washing for the two methods that we used to estimate cell survival: counts of intact nuclei after plasma membrane lysing using a hemocytometer, and counts of intact cells from coverslips after fixation and methylene blue staining. B, Percentages of cells with nuclear chromatin condensation and nuclear DNA fragmentation at the same four time points.