Gender identification of dried human bloodstains using fluorescence in situ hybridization.

Identification of the gender of an individual(s) from whom a bloodstain is derived represents important evidence in medicolegal cases. The efficacy of fluorescence in situ hybridization (FISH) using chromosome X and Y centromeric probes was tested to determine its ability to identify correctly the gender of extracted dried bloodstains. In this preliminary study, FISH correctly identified the gender of 2-week-old dried bloodstains in prepared mixtures of male-to-female blood as low as 1%. The technique is accurate, rapid, sensitive, easily performed and readily available. This application of FISH as a forensic laboratory technique holds great promise.