Laser microdissection in forensic genetics: genetic analysis of sexual abuse evidence

Laser microdissection is a novel technique of cell separation under microscopic view utilizing a laser beam. It has been used for cell separation from mixed samples in forensic genetics, such as vaginal smear in cases of sexual assault. In a rape investigation, few cells are usually recovered as the only evidence available for the assailant identification. When analysing a resistant cell type such as sperms, an effective and reliable method is required. This study aims to optimise the genetic analysis of laser microdissected sperms and to take the optimal protocol into practice. The goal is to develop a technique capable of recovery of reliable genotyping results from just a few cells. Genetic analysis was optimised for sperms separated from pure semen samples by laser microdissection. After optimisation, it was validated for sperms recovered from a vaginal smear. In the resulting genetic profiles some artifacts occured, that have been reported in samples with low DNA content. Possible solutions of these artifacts occurrence and elimination are discussed. In conclusion, the developement of an efficient and reliable genetic analysis method was successful: 10 sperms were recovered from vaginal smear and the genotyping result was capable of individual identification of the sperm donor. Powered by TCPDF..