Touch DNA on objects can be analysed at low cost using simplified direct amplification methods

Previous studies reported in the literature demonstrate that a range of sampling vehicles can be used effectively for forensic analysis of human DNA in direct amplification reactions. In this study we compared Copan microFLOQ ® swabs with a range of alternative sampling vehicles, using touch DNA samples donated by 15 different volunteers. MicroFLOQ swabs performed well, as did 3 mm diameter discs punched from analytical filter paper. The 3 mm discs could be used in a 5 µl PCR volume, increasing sensitivity, and reducing costs when compared with other methods that require a larger PCR volume. Other inert sampling vehicles, such as interdental toothbrushes and toothpicks also gave good results in direct amplification. The study found a large variation in results between the 15 touch DNA donors, demonstrating the importance of validating touch DNA recovery techniques with a large pool of donors.