Touch DNA in forensic science: The use of laboratory-created eccrine fingerprints to quantify DNA loss

Jessica Tang; Jennifer Ostrander; Ray Wickenheiser; Ashley Hall

doi:10.1016/j.fsisyn.2019.10.004

Touch DNA in forensic science: The use of laboratory-created eccrine fingerprints to quantify DNA loss

Forensic Sci Int Synerg. 2019 Oct 23:2:1-16. doi: 10.1016/j.fsisyn.2019.10.004. eCollection 2020.

Authors

Jessica Tang¹, Jennifer Ostrander¹, Ray Wickenheiser², Ashley Hall¹

Affiliations

¹ University of Chicago at Illinois, Department of Biopharmaceutical Sciences, 833 S. Wood St, Chicago, IL, 60612, USA.
² New York State Police Crime Lab System, 1220 Washington Avenue, Building 30, Albany, NY, 12226, USA.

Abstract

Touch samples typically contain a limited quantity of DNA, which can be further reduced during collection and analysis. It is not clear, however, at which point(s) the majority of the DNA is lost because there is not a reliable positive control to track the quantity of DNA through the analysis procedures. To take the first step in bridging this gap, we established a set of laboratory-created eccrine, or mock, fingerprints containing known quantities of DNA. Next, we defined a set of process controls to quantify loss at key fail points in the collection/extraction procedures, analyzing a total of 1200 mock fingerprints deposited on four different surfaces. We quantified DNA loss to the surface, the swab and at extraction, completing the evaluation with ANOVA. With better understanding of DNA yields and the mechanisms of loss, targeted process improvements will bring touch DNA samples into even more routine use with standardized, optimized procedures.

Keywords: DNA loss; Fingerprint; Forensic; Touch DNA.