The application of digital PCR to characterize genomic DNA certified reference materials of genetically modified papaya YK1601

Certified reference materials (CRMs) are essential in the detection of genetically modified organisms (GMOs), as they ensure the accuracy, comparability, and traceability of test results across time and laboratories, while also supporting international trade and market regulation. In this study, fresh leaves of genetically modified (GM) papaya YK1601 were used to prepare genomic DNA (gDNA) CRMs with transgenic contents of 50% and 5%. The certified values for three property values of this batch of gDNA CRMs were jointly determined by nine qualified laboratories using digital PCR. Homogeneity assessment confirmed good uniformity, with a minimum sample intake of 2 μL. Stability assessment demonstrated that the gDNA CRMs are stable when transported at temperatures below 37°C (preferably under cold-chain conditions) and can be stored at 4°C or -20°C for up to six months, with no more than 10 freeze-thaw cycles permitted during use. This study establishes a metrological benchmark for detecting GM papaya YK1601 and its derived products, while also providing measurement support for evaluating new detection methods and instruments for GM papaya.