Validating Touch DNA Collection Techniques Using Cotton Swabs

Abstract

Touch or trace DNA analysis has become an important routine of the forensic laboratory workload and a useful tool for investigators. Most samples, such as touch DNA, are collected using cotton swabs and choosing the right collection technique when using a cotton swab can improve DNA recovery from the surfaces. Therefore, this paper investigates three recovery techniques commonly used with cotton swabs and validate different conditions on the collected swabs such as drying prior freezing or direct freezing to see how they affect the amount of DNA recovered. The results show that there is a significant difference between the three recovery techniques used to recover touch DNA with cotton swab (p<0.001), similarly with the cotton swab tested conditions prior extraction (p<0.001).