Event-specific qualitative and quantitative PCR detection of genetically modified rapeseed Topas 19/2

The herbicide-tolerant transgenic rapeseed Topas 19/2 (synonym HCN92) has been approved for environmental release in Canada, Japan, Australia and the USA, and exported to a number of other countries as raw material. The purpose of this study was to establish event-specific qualitative and quantitative detection methods for Topas 19/2. The 3′-integration junction sequence spanning the host plant DNA and the integrated transgene of the Topas 19/2 event was isolated and identified. The event-specific qualitative detection method was established to produce an amplicon of 110 basepairs (bp) with an absolute detection limit of 10 initial template copies. The event-specific quantitative detection method was developed with the limit of detection (LOD) and limit of quantification (LOQ) being approximately 5 and 50 initial template copies, respectively. The developed real-time PCR systems were assessed using two mixed rapeseed samples with known Topas 19/2 contents. Expected results were obtained.