Recovery of trace DNA and its application to DNA profiling of shoe insoles

In recent years, the analysis of trace amounts of DNA has become a necessary and useful forensic tool. DNA profiles can be obtained from items that have been worn or handled, due to the presence of transferred DNA derived from skin cells. Shoeprints collected from crime scenes that match a suspects shoe can link a shoe to the crime scene. A DNA profile from inside the shoe can link a wearer to a shoe thus increasing the evidential value of the forensic evidence. In this work, variation in the amount of DNA recovered from hands and feet of different individuals is investigated. Sites for sampling DNA from shoe insoles are compared and a protocol for the subsequent sampling and extraction is developed. Finally, a case study is described where DNA analysis of shoe insoles has provided forensic evidence.