DNA laddering

DNA laddering is a phenomenon seen in laboratory tests; it is a sensitive indicator of programmed cell death, specifically of apoptosis.

Endonuclease activation is a characteristic feature of apoptosis. This degrades genomic DNA at internucleosomal linker regions and produces 180- to 185- base-pair DNA fragments. On agarose gel electrophoresis, these give a characteristic &quot;laddered&quot; appearance. The dying cell's morphological changes are short-lived and difficult to detect. DNA laddering has therefore become a sensitive method to distinguish apoptosis from ischemic or toxic cell death.