Development of pBT63, a positive control plasmid for qualitative detection of genetically modified rice

Abstract

Plasmids containing polymerase chain reaction (PCR) target sequences are widely used as positive controls for analyses of genetically modified food. To eliminate amplification of false positives due to plasmid contamination, we developed a qualitative PCR control plasmid containing amplicons with an additional internal restriction enzyme recognition site. We designed a control plasmid template having target sequence with additional BamHI site for detecting genetically modified rice line Shanyou 63 (Bt63). The target amplicons derived from the designed plasmid were completely digested by BamHI, whereas amplicons derived from the unaltered Bt63 genomic DNA template could not be digested. Thus, our control plasmid enables distinction between detection of false positives (caused by amplicons derived from the plasmid) and true positives (due to the presence of Bt63 rice genomic DNA) in qualitative PCR testing of genetically modified rice products.