Quantitative detection method for Roundup Ready soybean in food using duplex real‐time PCR MGB chemistry

BACKGROUND: Methodologies that enable the detection of genetically modified organisms (GMOs) (authorized and non‐authorized) in food and feed strongly influence the potential for adequate updating and implementation of legislation together with labeling requirements. Quantitative polymerase chain reaction (qPCR) systems were designed to boost the sensitivity and specificity on the identification of GMOs in highly degraded DNA samples; however, such testing will become economically difficult to cope with due to increasing numbers of approved genetically modified (GM) lines. Multiplexing approaches are therefore in development to provide cost‐efficient solution. RESULTS: Construct‐specific primers and probe were developed for quantitative analysis of Roundup Ready ^® soybean (RRS) event glyphosate‐tolerant soybean (GTS) 40‐3‐2. The lectin gene (Le1) was used as a reference gene, and its specificity was verified. RRS‐ and Le1‐specific quantitative real‐time PCR (qRTPCR) were optimized in a duplex platform that has been validated with respect to limit of detection (LOD) and limit of quantification (LOQ), as well as accuracy. The analysis of model processed food samples showed that the degradation of DNA has no adverse or little effects on the performance of quantification assay. CONCLUSION: In this study, a duplex qRTPCR using TaqMan minor groove binder‐non‐fluorescent quencher (MGB‐NFQ) chemistry was developed for specific detection and quantification of RRS event GTS 40‐3‐2 that can be used for practical monitoring in processed food products. Copyright © 2010 Society of Chemical Industry