抄録
Proficiency testing of the assay for detecting unauthorized genetically modified (GM) rice was conducted. Test samples prepared from genomic DNA extracted from non-GM rice and two types of positive control plasmid DNA for qualitative PCR test and for real-time PCR test were sent to 33 laboratories for the purpose of detection using the Japanese official method. The test samples for qualitative PCR testing were prepared to be 1 v/v % and 0.05 v/v % in the ratio of the plasmid DNA for qualitative PCR to genomic DNA, and the test samples for real-time PCR testing were prepared to be 0.6 v/v % and 0.12 v/v % in the ratio of the plasmid DNA for real-time PCR to genomic DNA. For the proficiency testing, 31 of 33 laboratories correctly identified all samples. However, two laboratories reported incorrect identification of the non-GM samples. We considered that the incorrect results were due to contaminations of the reaction mixture with plasmid DNA or other interfering DNA. For the real-time PCR analysis, some laboratories using the specific real-time PCR device reported elevated baseline in the multicomponent analysis. The results of this proficiency testing study suggest that the proficiency testing using plasmid DNA samples was useful tool to investigate important factors affecting the reliability of detection results of unauthorized genetically modified rice.
