Swabs as DNA Collection Devices for Sampling Different Biological Materials from Different Substrates

• Published in: Journal of forensic sciences Vol. 59; no. 4; pp. 1080 - 1089
• Main Authors: Verdon, Timothy J., Mitchell, Robert J., van Oorschot, Roland A. H.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-07-2014; Wiley Subscription Services, Inc
• Subjects: Blood Chemical Analysis; Body fluids; cotton swab; Deoxyribonucleic acid; DNA; DNA - isolation & purification; DNA extraction; DNA Fingerprinting; Equipment Design; evidence sampling; flocked swab; foam swab; forensic genetics; forensic science; Forensic sciences; Humans; Materials Testing; polyester swab; rayon swab; Saliva - chemistry; Specimen Handling - instrumentation; Touch; trace DNA; DNA extraction; evidence sampling; flocked swab; polyester swab; forensic genetics; forensic science; foam swab; rayon swab; cotton swab; trace DNA
• ISSN: 0022-1198; 1556-4029
• DOI: 10.1111/1556-4029.12427

Currently, there is a variety of swabs for collection of biological evidence from crime scenes, but their comparative efficiency is unknown. Here, we report the results of an investigation into the efficiency of different swab types to collect blood, saliva and touch DNA from a range of substrates. The efficiency of extracting blood and saliva from each swab type was also tested. Some swabs were significantly more effective than others for sampling biological materials from different substrates. Swabs with the highest sampling efficiency, however, often did not have the highest extraction efficiency. Observations were recorded regarding practicality of each swab in a variety of situations. Our study demonstrates that selection of sampling device impacts greatly upon successful collection and extraction of DNA. We present guidelines to assist in evaluation of swab choice.