Fluorophore double stranded probe-multiplex quantitative PCR method for detecting transgenic component of promoter derived from Cauliflower Mosaic Virus and nos terminator derived from Agrobacterium tumefaciens simultaneously

The article is to establish multiplex PCR method for quantitative detecting transgenic component promoter derived from Cauliflower Mosaic Virus (CaMV 35S) and nos terminator derived from Agrobacterium tumefaciens (Tnos) in foods. According to the specific sequence of CaMV 35S and Tnos which have been used in genetically modified organisms (GMOs) frequently, and the sequence of soybean endogenous lectin gene, three pairs of primers and corresponding fluorophore double stranded probes (FDSP) were designed to allow for quantitative detecting of GMOs. FDSP designed with maximal specificity also showed the greatest detection sensitivity, and the ease in design, the simple single-dye labeling chemistry. FDSP-multiplex quantitative PCR (FDSP-MQPCR) methods were established for the detection of transgenic component CaMV 35S and Tnos simultaneously. Ten soybean flour samples were tested with FDSP-MQPCR method. The method gives five positive-samples with quantitative results in 5 h, and accuracy rate is above 97.0%. The described methods enabled a sensitive, specific, simple, and accurate detection of transgenic component and thus provide a useful tool for quantitative analysis of raw and processed food products. FDSP-MQPCR method has not only improved detection efficiency and result credibility, but also has guaranteed the better accuracy and repetitiveness.