A preliminary study on detecting human DNA in aquatic environments: Potential of eDNA in forensics

Marie Antony Dass; Craig D H Sherman; Roland A H van Oorschot; Dadna Hartman; Gemma Carter; Annalisa Durdle

doi:10.1016/j.fsigen.2024.103155

A preliminary study on detecting human DNA in aquatic environments: Potential of eDNA in forensics

Forensic Sci Int Genet. 2024 Oct 8:74:103155. doi: 10.1016/j.fsigen.2024.103155. Online ahead of print.

Authors

Marie Antony Dass¹, Craig D H Sherman², Roland A H van Oorschot³, Dadna Hartman⁴, Gemma Carter⁵, Annalisa Durdle⁶

Affiliations

¹ School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong 3220, Australia. Electronic address: [email protected].
² School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong 3220, Australia.
³ Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod 3085, Australia; School of Agriculture, Biomedicine and Environment, La Trobe University, Bundoora 3086, Australia.
⁴ Victorian Institute of Forensic Medicine, 65 Kavanagh Street, Southbank 3006, Australia; Department of Forensic Medicine, Monash University, 65 Kavanagh Street Southbank, Melbourne, Victoria 3006, Australia.
⁵ Victorian Institute of Forensic Medicine, 65 Kavanagh Street, Southbank 3006, Australia.
⁶ School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong 3220, Australia; Office of the Chief Forensic Scientist, Victoria Police Forensic Services Department, Macleod 3085, Australia.

PMID: 39383603
DOI: 10.1016/j.fsigen.2024.103155

Abstract

Human environmental DNA (eDNA) application have not been fully applied or adequately considered in the fields of eDNA and forensics. Nonetheless, this technique holds great potential as a complementary tool for detecting human DNA in aquatic environments, particularly in cases involving crimes connect to such environments. However, the detectability or stability of eDNA can vary depending on several factors. Therefore, this preliminary study investigates the detection and degradation rates of human eDNA, as well as the recovery of nuclear short tandem repeat (STR) profiles and mitochondrial DNA (mtDNA) sequencing, using water samples from both saltwater and freshwater sources. To conduct the experiment, whole human blood was spiked into the water samples. Water samples were then filtered using a 5 µm pore size filter, and samples were collected at various time intervals up to 23 days. A human specific qPCR assay targeting HV1 region of human mtDNA was used to detect human eDNA. Results demonstrated that human eDNA remains detectable for up to 36 hours in freshwater samples and up 84 hours in saltwater samples. The limit of detection (LOD) of human eDNA, (205 copies/µl), was achieved after 60 hours in freshwater and 180 hours in saltwater samples. Partial STR profiles could be recovered up to 24 hours for freshwater and saltwater. Results from mtDNA sequencing indicate that full mtDNA profiles could be recovered from freshwater samples up to 48 hours and remained detectable up to 72 hours in saltwater. Overall, the findings of this study underscore the importance of considering and incorporating human eDNA analysis as a valuable tool in forensic practice. By harnessing the power of eDNA, law enforcement agencies can enhance their investigation capabilities, improve the accuracy of forensic reconstructions, and ultimately contribute to the resolution of cases involving aquatic environments. Further research and validation are needed to optimize and expand the utilization of eDNA techniques in forensic investigations.

Keywords: Aquatic environments; Blood; DNA decay; Environmental DNA (eDNA); Forensic; MtDNA; MtDNA sequencing; STR profile.