A rapeseed-specific gene, Acetyl-CoA carboxylase, can be used as a reference for qualitative and real-time quantitative PCR detection of transgenes from mixed food samples

Polymerase chain reaction (PCR) methods are very useful techniques for the detection and quantification of genetically modified organisms (GMOs) in fo od samples. These methods rely on the amplification of transgenic sequences and quantification of the transgenic DNA by comparison to an amplified ref erence gene. Reported here is the development of specific primers for the r apeseed (Brassica napus) BnACCg8 gene and PCR cycling conditions suitable f or the use of this sequence as an endogenous reference gene in both qualita tive and quantitative PCR assays. Both methods were assayed with 20 differe nt rapeseed varieties, and identical amplification products were obtained w ith all of them. No amplification products were observed when DNA samples f rom other Brassica species, Arabidopsis thaliana, maize, and soybean were u sed as templates, which demonstrates that this system is specific for rapes eed. In real-time quantitative PCR analysis, the detection limit was as low as 1.25 pg of DNA, which indicates that this method is suitable for use in processed food samples which contain very low copies of target DNA.