Author Identifier
Date of Award
2026
Keywords
DNA, GVP, proteomics, dual DNA protein extraction, PrepFiler, co isolation, biomarker, forensic identification, hair proteomics
Document Type
Thesis - ECU Access Only
Publisher
Edith Cowan University
Degree Name
Master of Medical and Health Science by Research
School
School of Medical and Health Sciences
First Supervisor
Julie Sartori
Second Supervisor
Jemma Berry
Third Supervisor
Joel Gummer
Fourth Supervisor
David Coall
Abstract
Forensic science has well-developed and routinely used methods to uniquely identify individuals. Identification focuses largely on DNA profiling as the gold standard; however, its effectiveness can be limited in highly degraded or low quantity samples where DNA may be absent or insufficiently abundant. Proteomics has emerged as a complementary tool, offering greater molecular stability of the sample and ability to recovery genetically variant peptides (GVPs) which reflect genetic variation. These peptides enable individual identification analogous to SNP and STR markers in DNA. Given that DNA viability cannot be predetermined prior to testing, retaining all molecular identifiers is essential for maximising evidentiary value. This study developed a dual extraction workflow capable of isolating both DNA and protein from the same forensic sample without compromising DNA yield, quality, or compatibility with existing preparative pipelines.
The research evaluated two PrepFiler based DNA extraction kits and systematically assessed potential protein collection points within each workflow. Protein isolation strategies, digestion conditions and contaminant removal methods which included S-Trap purification of peptides, were tested to ensure compatibility with downstream LC-MS analyses. Lysis buffer formulations were compared to determine suitability across two sample types, blood, and hair.
A proof of application focused on human hair, an abundant but underutilised forensic sample that is routinely encountered yet frequently unsuitable for nuclear DNA profiling due to the absence of DNA containing follicles. Despite these limitations hair shafts are comprised mostly of keratin protein, making them highly suitable for proteomic genotyping. This research demonstrates the potential to expand forensic capabilities by showing individual identification from hair in circumstances where DNA is degraded, limited or entirely absent.
Overall, this research established a practical, integrated dual DNA-protein method that provides a baseline for strengthening human identification capabilities and expanding the evidentiary utility of samples, particularly hair, that have historically been constrained by DNA based limitations.
Access Note
Access to this thesis is embargoed until 13th June 2027
Recommended Citation
Cross, B. (2026). Preserving genetically variant peptides in the pursuit of DNA evidence. Edith Cowan University. https://doi.org/10.25958/2stq-z958