Collaborative validation of an event-specific quantitative real-time PCR method for genetically modified rice event...

In this study, a collaborative trial of validating a real-time PCR method for the TT51-1 rice event was organized, including six participating laboratories. In this validation, serially diluted solutions from homogeneous genomic DNA of the TT51-1 event were used to construct standard curves of the TT51-1 event and phospholipase D (PLD) assays. The PCR efficiency was 95%, and the R(2) coefficient was 0.99 for the TT51-1 system. The mean quantitative values for blind samples containing 0.1%, 0.5% 1%, 5%, and 10% (w/w) TT51-1 corresponded to 0.1%, 0.51%, 1.06%, 4.83%, and 9.62%, respectively, with a bias (%) ranging from -3.77% to 5.87%. The repeatability and reproducibility were all below 25% across the entire dynamic range. Furthermore, the measurement uncertainties of the quantitative results were estimated to be 0.10%, 0.20%, 0.40%, 1.76%, and 3.52% (w/w) for the tested samples. Both the LOD and LOQ were calculated to be 0.22%. This collaborative trial demonstrated that the TT51-1 method produces reliable, comparable, and reproducible results for a given sample set and can be adopted as a detection standard for testing laboratories.