The enormous sensitivity of modern DNA analytical techniques entails a high risk of picking up DNA traces from individuals not involved in the crime case investigated. Resulting mixed DNA profiles are difficult to be assigned to perpetrators. In rape cases, sperms of several rapists, or a high proportion of victim DNA may lead to mixed traces as well.
To avoid such problems and at the same time to further increase the analytical sensitivity, we propose to analyze traces that eo ipso represent individual genomes. These comprise single sperm cells, single skin flakes, and single telogen hairs. DNA extraction protocols will be optimized for these trace types, and their minute amounts of DNA will be preamplified using whole genome amplification (WGA) techniques. The WGA products will be subjected to conventional forensic DNA analysis thereafter. By this means, hitherto problematic trace types will be made amenable to forensic DNA analysis.