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Title

P309 – Strength in Numbers: Assessing the Role of Digital PCR in the Forensic DNA Typing Workflow

10:25

Friday August 21^st

Station 17

Duration: 12 minutes

04. Forensic biology

Peter Vallone

Commercial digital PCR (dPCR) systems have been available for over 15 years and currently serve the clinical diagnostic, biopharmaceutical, and infectious disease communities. At metrology institutes such as the United States National Institute of Standards and Technology (NIST), dPCR is a primary tool for assigning certified values to DNA- and RNA-based reference materials. The primary advantage of dPCR is its ability to directly quantify nucleic acid copies by partitioning target templates and detecting target DNA or RNA molecules using fluorescence-based TaqMan assays. This approach eliminates reliance on external standard curves required for quantitative PCR (qPCR) or on indirect measurement methods such as UV spectroscopy and fluorometry.

Because dPCR provides absolute quantification without a standard curve, it offers a pathway to significantly greater inter-laboratory reproducibility. By providing high precision (CVs < 10%) and improved performance with inhibited or highly degraded samples compared to traditional qPCR, dPCR may prompt practitioners to ask: “How could dPCR support current quantitation efforts and new applications in my forensic workflow?”

Drawing on in-house exemplar data and examples from the current literature, this presentation outlines the fundamentals of dPCR and discusses its advantages and limitations for forensic extract quantification. The discussion will extend to non-STR-related applications, including body fluid identification and epigenetics. Key considerations for implementation will be presented, including dynamic range, target multiplexing, inhibition tolerance, and the practical balance between internal validation requirements and cost-to-throughput ratios. Evaluating these issues will help a laboratory decide whether dPCR is a beneficial tool and whether validating such a new technology is worth the investment of time and resources.

Authors

Peter Vallone (National Institute of Standards and Technology, United States of America)
Ya-Chih (Jessica) Chen (The George Washington University, United States of America)
Erica Romsos (National Institute of Standards and Technology, United States of America)

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P309 – Strength in Numbers: Assessing the Role of Digital PCR in the Forensic DNA Typing Workflow

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