Early apoptotic cells stain green and contain bright green dots in the nuclei as a consequence of chromatin condensation and nuclear fragmentation
. Late apoptotic cells also incorporate ethidium bromide and therefore stain orange, but, in contrast to necrotic cells, the late apoptotic cells show condensed and often fragmented nuclei.
Morphological changes in apoptosis are chromatin condensation and nuclear fragmentation
. Apoptotic DNA fragmentation is a key feature of apoptosis, characterized by the activation of endogenous endonucleases with subsequent cleavage of chromatin DNA into internucleosomal fragments of approximately 180-200 base pairs (bp) [27, 28].
AIF moves directly to the nucleus, where it produces chromatin condensation and nuclear fragmentation
, while cytosolic cytochrome c sets in motion the terminal events of apoptosis in of necrosis and apoptosis.