Mason, K.E., et al. Development of a Protein‐based Human Identification Capability from a Single Hair. Journal of Forensic Sciences. 8/2/2019.
Shed human hair (lacking root nuclear DNA) frequently contributes important information to forensic investigations involving human identification. Detection of genetic variation observed in amino acid sequences of hair proteins provides a new suite of identity markers that augment microscopic hair analysis and mitochondrial DNA sequencing. In this study, a new method that completely dissolves single hairs using a combination of heat, ultrasonication, and surfactants was developed. Dissolved proteins were digested and genetically variant peptide (GVP) profiles were obtained for single hairs (25 mm) via high-resolution nanoflow liquid chromatography-based mass spectrometryand a novel exome-driven bioinformatic approach. Overall, 6519 unique peptides were identified and a total of 57 GVPs were confirmed. Random match probabilities ranged between 2.6 × 10-2 and 6.0 × 10-9 . The new bioinformatic strategy and ability to analyze GVPs in forensically relevant samples sizes demonstrate applicability of this approach to distinguish individuals in forensic contexts.