Application of enhancement strategies for the improvement of discriminating forensic DNA profiles from human bones

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
Jessica Marie McLamb (Creator)
Institution
Western Carolina University (WCU )
Web Site: http://library.wcu.edu/
Advisor
Kelly Grisedale

Abstract: Although DNA profiling techniques are considered a powerful method for identification, problems arise when low quantity and/or quality DNA is tested. Analyzing samples with low template DNA using standard genotyping techniques like STR typing can yield no or an incomplete profile, making conclusive identification nearly impossible. One challenging forensic sample material is bone. For example, DNA within bone can be degraded due to harsh environmental conditions even when the structure of the bone appears to be relatively well preserved. Consequently, the amount of usable DNA in bones can be limited which complicates downstream applications for DNA profiling. This study investigated techniques that would improve obtaining a discriminating DNA profile from human bones. First, the performances of three commercial DNA extraction kits were evaluated for the recovery of genomic DNA from human bones. The PrepFiler® BTA Forensic DNA Extraction Kit recovered the highest DNA yield according to qPCR data and was used for additional bone extractions. Next, purified DNA from a total of 12 bone samples was subject to genotyping methods using capillary electrophoresis (CE) as well as massively parallel sequencing (MPS) to determine which strategy would produce the most discriminating DNA profile. The genotyping techniques evaluated were: CE-based STR analysis with the GlobalFiler® PCR Amplification Kit, whole genome amplification (WGA) with the REPLI-g® Mini Kit for improved CE-based STR detection, and MPS for STR/SNP analysis using the Ion PGM™ and MiSeq® FGx™ platforms. Random match probabilities were calculated to determine the discriminatory power of the resulting DNA profiles. Although the Ion PGM™ SNP profiles had the highest RMPs, the GlobalFiler® STR profiles produced similar discriminatory power. Considering the time and labor required for MPS, one could argue STR analysis using traditional CE may be better suited for DNA profiling of challenging bone samples. However, the MPS technologies provide additional information that CE-methods can’t, such as Y-haplogroup and biogeographical ancestry predictions from SNP analyses.

Additional Information

Publication
Thesis
Language: English
Date: 2017
Keywords
Bones, DNA, DNA profiling, Forensic science

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