Developmental validation of the rapidpuncher, an automated laser-based sampling system that eliminates cross-contamination in the forensic analysis of FTA cards.

Abstract

The rapidPuncher is an advanced, fully automated laser sampling system designed for forensic and diagnostic genetic laboratories, enabling precise disc-shaped sample cutting from FTA cards (by burning a ring) for DNA extraction. Its laser cutting method eliminates physical contact, which solves the long-standing problem of possible cross-contamination that comes with traditional mechanical punching tools. This study provides developmental validation of the rapidPuncher, encompassing evaluations of linearity, cross-contamination risk, and efficacy in STR and mtDNA profiling. Validation tests using blood, buccal swabs, and saliva on FTA media showed that the platform allows for precise, contamination-free sample excision. The DNA yields and quality were similar to those of traditional sample preparation, and the STR and mtDNA profiles were always reliable. The integrated vision system automates the process of identifying high biological material saturation sites, which facilitates reproducibility. Comparative testing confirmed no significant transfer of DNA to blank FTA cards. The rapidPuncher complies with ISO/IEC 17025 and ISO/IEC 21043 standards for forensic laboratory practice and greatly improves the automation of laboratory workflows, reduces the risk of human error, and ensures high accuracy for forensic casework and molecular diagnostics.