Indicated detection of two unapproved transgenic rice lines contaminating vermicelli products.

We analyzed the DNA fragments extracted from four rice vermicelli products. The Bacillus thuringiensis (Bt) rice line, which has a construct similar to the GM Shanyou 63 line, was detected in some vermicelli products by identification of the junction region sequence between rice Act1 promoter and the Cry1Ac gene, and that between Cry1Ac and nos. In addition, we also detected a different Bt rice line by means of the junction region sequence between the maize ubiquitin promoter and cry1Ab gene and that between the cauliflower mosaic virus 35S promoter and the hygromycin phosphotransferase in some vermicelli products. Accordingly, we for the first time have detected the two transgenic Bt rice lines contaminating rice vermicelli samples. Furthermore, we developed a duplex real-time polymerase chain reaction (PCR) method for the simultaneous detection of both Bt rice lines.