Development of an Event-Specific Detection Method for Genetically Modified Maize IE034 by Quantitative Real-Time PCR

The insect-resistant transgenic maize event IE034 has been proved to be one of the most commercially developed transgenic maize events in China. This study was aimed to develop a stable and reliable quantitative detection method to monitor this new transgenic maize event. Here, we developed a novel event-specific real-time PCR method for this genetically modified maize event IE034. The resulting 134 base pair (bp) amplicon was designed according to the 5′ junction of inserted sequence and flanking maize genome sequence. Standard curve of the IE034 5′ event-specific sequence showed good linear regression and high PCR efficiency when using the IE034 pure line samples as calibrator. The limit of detection (LOD) for the IE034 detection method was estimated at approximately 8 initial template copies, and the limit of quantification (LOQ) was estimated at about 40 copies. The accuracy of this quantitative real-time PCR method was verified by screening four mixed DNA samples with known levels of the IE034 event (5, 1, 0.5, and 0.23 %, respectively). The quantified biases deviated from 8.7 to −12.2 %, and the relative standard deviation (RSD) ranged from 2.7 to 12.7 %. These data indicated that this new-developed IE034 event-specific real-time PCR method is suitable and reliable for the quantification of IE034 maize and its derivates.