Persistence of immersed blood and hair DNA: A preliminary study based on casework. (October 2017)

• Record Type: Journal Article
• Authors: Frippiat, Christophe; Gastaldi, Agathe; Van Grunderbeeck, Séverine
• Is Part Of: Journal of forensic and legal medicine. Volume 51(2017)
• Page Start: 1
• Page End: 8
• Publication Date: 2017-10
• Subjects: Hair -- Blood -- Waterway -- Trace persistence -- Water degradation -- DNA stability in water; Medical jurisprudence -- Periodicals; Forensic sciences -- Periodicals; Forensic Medicine -- Periodicals; Médecine légale -- Périodiques; Electronic journals; 614.1
• DOI: 10.1016/j.jflm.2017.07.009
• Languages: English
• ISSNs: 1752-928X

Abstract

Abstract: In some cases, evidence is collected from rivers, canals, lakes or sink pipes. To determine the utility of analyzing these samples and for cases in which DNA was recovered from submerged bulletproof vest parts, we evaluated the time necessary to degrade the blood and, subsequently, DNA on bulletproof vests. In a second experiment, also based on cases, blood was diluted in water from a kitchen sink pipe and incubated at room temperature for different times. Subsequently, DNA quality was assessed. In a parallel experiment, hair roots were incubated in spring water for different time periods. This study demonstrates that after one week of immersion of the bulletproof vest parts in a canal only one sample from more than 100 samples gave a partial genetic profile. No genetic profile were obtained for the 99 other samples. After one month immersion and despite the finding that blood remained detectable on bulletproof vest parts, no genetic profile was obtained for all samples using the classical STR approach. For longer immersion times, no genetic profiles were obtained. In sink pipe water, an incubation time of 72 h (h) was necessary before significant blood degradation occurred. Nevertheless, high inter-sample variability was observed. This high variability may be explained by the variability of water composition coming from nine different sink pipes. For hair root cells incubated in water, we observed that more than 90% of the DNA was degraded after 72 h. Highlights: In many cases, evidence is recovered from water. More than 90% of the DNA from hair root cells is degraded after 72 h. Bulletproof vest stained with fresh human blood were immersed in an waterway for a period ranging from 1 week to 6 months.