Detection of cell death in human skin wounds of various ages by an in situ end labeling of nuclear DNA fragments

The time-dependent appearance of signs of cell death was investigated in human skin wounds using in situ end labeling of DNA fragments (ISEL). In the dermal layer an average of not more than 0.3 positively stained fibroblastic cells/0.01 cm x 0.01 cm was found up to a postinfliction interval of approximately 6 h. Average numbers exceeding 1 positive cell/0.01 cm x 0.01 cm were first detectable in a skin wound after 24 h. Therefore, average numbers greater than 1 labeled cell/ 0.01 cm x 0.01 cm indicate a postinfliction interval of approximately 1 day. An increase in the average number of positively stained cells occurred with increasing wound age. Values exceeding 3 cells/0.01 cm x 0.01 cm were first detectable 19 days after wound infliction. Accordingly, values of more than 3 labeled cells indicate a postinfliction interval of approximately 3 weeks or more. Since low numbers of labeled fibroblastic cells or even negative results were found in wounds of advanced age, only positive results provide information which can be useful for a forensic age estimation of human skin wounds.