Quantitative detection of the 35S promoter and the NOS terminator using quantitative competitive PCR

DNA-based analytical methods are often used to verify the presence of genetically modified organisms (GMOs) in food. In Switzerland, a preliminary study, organized by a subcommission of the Swiss Food Manual, of different polymerase chain reaction (PCR) systems for the detection of GMOs showed that the application of qualitative PCR systems can lead to interlaboratory differences of at least a factor of 10. These differences can be diminished using internal standards (competitors). The quantitative competitive (QC) PCR for the detection of the 35S promoter or the NOS terminator in food samples is presented. The GMO content of food samples can be determined using QC-PCR.