Caspase activity in a normal cell, confocal micrograph

A confocal micrograph showing caspase activity in a normal cell. On receipt of signals that trigger apoptosis, there is a cascade of caspase activity in the cell, leading to the events that make up apoptosis. Nuclei are stained blue, cytochrome c green, and cleaved caspase-3 red (none in this non-apoptotic cell).