The overall purpose of this project was to examine the compatibility of common sample preparation methods for highly challenging samples, such as those recovered from missing persons' cases, with two massively parallel sequencing (MPS) chemistries designed for forensic identification; and the project also assessed the tolerance of these two chemistries and platforms for high levels of PCR inhibitors commonly associated with skeletal and decomposed human remains.
The first of three studies assessed the baseline inhibitor tolerance of two forensic MPS systems to PCR inhibitors. Results and discussion are provided for CE-STR Kit comparison and MPS. The second of the three studies assessed sample preparation compatibility with two MPS chemistries. The overall results of this study indicate that all extraction methods tested were effective in removing high amounts of inhibitors from blood, hair, and bone tissues. All extraction methods produced quantifiable DNA with little or no PCR inhibition detected, demonstrating that all extraction methods were efficient and suitable for preparing samples for MPS. The report concludes that forensic laboratories can be confident that when DNA is extracted from skeletal and hair samples using one of the common methods tested in this study, extracts are equally compatible with both MPS workflows. The third study evaluated two MPS systems and chemistries with extremely challenging skeletal samples. Overall, both sequencing platforms produced quality data for the types of challenged remains analyzed. MPS generated reliable sequencing data from environmentally challenged human skeletal samples and provided more genetic data in 22 of the 24 samples compared with CE (capillary electrophoresis) -based fragment analysis. Results suggest that MPS may recover more probative information from samples, although CE-based STR typing is still a robust method for identifying skeletal samples when DNA quantity and quality is sufficient. 1 table and 7 references