Rapid screening of roundup ready soybean in food samples by a hand-held PCR device

Abstract

Insulated isothermal PCR (iiPCR) method was recently available for rapid on-site detection of roundup ready soybean (RRS; event GTS40-3-2) in food materials and products. Performance of this method was evaluated in this study. The 100% detection endpoint for the RRS by iiPCR was found in samples containing 0.1% RRS, equivalent to the results of the reference real-time PCR (rtPCR). Analysis of nucleic acids of soybean-based processed food products indicated 95% agreement between the iiPCR and rtPCR for RRS detection. By testing soybean milk and tofu samples using simple pretreatment methods, we found that the agreements between iiPCR and rtPCR methods of the aforementioned samples were 80% and 90%, respectively. Replicated tests of all discrepant samples implied that these samples had trace amounts of RRS, suggesting that the iiPCR system is more sensitive than the rtPCR method. In conclusion, the iiPCR technology can be a useful point-of-need tool to help make a timely decision in the consumption of genetically modified organisms.

Keywords: genetically modified organisms; insulated isothermal PCR technology; manual DNA extraction cartridge; on-site detection; roundup ready soybean.