Developmental validation of a fully integrated sample-to-profile rapid human identification system for processing single-source reference buccal samples.

UNLABELLED: Short tandem repeat (STR) DNA typing is a global standard for human identification. Current practice involves highly trained forensic analysts, operating in a laboratory setting, using multiple instruments to process samples and analyze the data. Here, we report the developmental validation of a fully integrated and automated DNA profiling system, the RapidHIT® System, capable of producing up to five high quality STR profiles with full controls in approximately 90min using PowerPlex®16 HS RapidHIT chemistry. The system integrates all sample handling steps: starting from lysis of cells on buccal swabs or other buccal sample types through DNA extraction, normalization, amplification,capillary array electrophoresis, detection, and integrated software analysis. The results describe the developmental validation of the RapidHIT™ System for buccal samples processed with the DNA IQ™ extraction chemistry using a guandinium chaotropic agent and paramagnetic beads followed by amplification using a modified version of PowerPlex 16 HS chemistry (PowerPlex 16 HS RapidHIT chemistry), and capillary electrophoresis with manual review of genotyping data following interpretation guidelines. All processing from the buccal swab to generation and processing of the profile occurs on the RapidHIT platform. RESULT: are concordant with traditional methods, with 88% first pass success rates for both the CODIS and PowerPlex 16 loci. Average peak height ratios were 0.89 for buccal swabs. The system produces full profiles from swabs with at least 176 ng of saliva DNA. Rapid DNA identification systems will significantly enhance capabilities for forensic labs, intelligence, defense, law enforcement, refugee and immigration applications, and kinship analysis.

Developmental validation of the GlobalFiler(®) express kit, a 24-marker STR assay, on the RapidHIT(®) System.

Rapid DNA typing provides a transformative solution to help forensic laboratories and law enforcement agencies solve and prevent crimes. The RapidHIT(®) System is a fully integrated instrument with a simplified user interface enabling an operator to run the system and obtain a DNA profile from a sample in less than two hours. The integration and developmental validation of the NDIS-approved 24 loci GlobalFiler(®) Express kit expands the capabilities of the RapidHIT System to increase discrimination power, reduce adventitious matches, and improve cross-border data sharing capabilities. Developmental validation studies were performed according to the SWGDAM guidelines and tested several critical areas of performance including three sensitivity studies, inhibited samples, thermal cycling parameters, and cross-contamination. Validation studies indicate that the optimized PCR parameters and sensitivity of the system is capable of generating STR profiles from buccal or blood swab reference samples. Results were concordant with genotypes produced using standard bench thermal cyclers and capillary electrophoresis platforms. Furthermore, swabs can be retrieved from the system and re-run or reprocessed with traditional bench chemistries, e.g. Y-STRs, to gain additional information. Our results demonstrate that the GlobalFiler Express assay run on the RapidHIT System is reliable for generating profiles from reference samples after forensic review.