Advancing forensic SNP typing: Insights from an interlaboratory study of the FORCE panel

Area of Science:

• Forensic genetics
• Molecular biology
• Genotyping technologies

Background:

• The FORensic Capture Enrichment (FORCE) panel is a standardized set of single nucleotide polymorphism (SNP) markers for forensic applications.
• Evaluating the performance of different enrichment assays is crucial for advancing forensic DNA analysis.

Purpose of the Study:

• To assess the efficacy of amplicon-based and capture-based enrichment assays in producing FORCE genotypes.
• To compare the performance of four different manufacturer-developed assays across multiple laboratories.

Main Methods:

• Twelve DNA samples, including varying quantities, degraded DNA, and inhibited samples, were tested.
• Fifteen international laboratories participated, using one of four available enrichment assays.
• Eighteen distinct methods were evaluated based on user-defined sequencing and analysis parameters.

Main Results:

• All four assays successfully generated full FORCE SNP genotypes from high-quality DNA samples.
• Significant variability in call rates was observed between and within assays, influenced by read count and enrichment type.
• Robust SNP recovery was achieved at 0.3 ng DNA input across all assays.
• An amplicon-based assay demonstrated high SNP call rates even at 0.03 ng DNA input.
• Capture and single primer extension assays showed consistent high SNP call rates with degraded DNA (150-200 bp fragments).

Conclusions:

• The evaluated FORCE genotyping assays are capable of producing reliable results, even with challenging forensic samples.
• Optimization of laboratory parameters is recommended to minimize data variation and facilitate wider adoption of SNP-based forensic methods.