Two quantitative multiplex real-time PCR systems for the efficient GMO screening of food products

Abstract

According to the EU and Swiss food legislation, only deregulated traits of transgenic plants are allowed to be imported and sold to the consumer. In order to control imports of soya and maize products from retailers, efficient and reliable methods for the detection and quantification are a prerequisite. The screening for specific DNA elements characteristic of transgenic plants is crucial for further analysis and has a major impact on the efficiency of the whole analysis workflow. To allow laboratories to efficiently and reliably screen food products for transgenic plant products, two novel multiplex real-time polymerase chain reaction (PCR) systems were developed and validated. One system determines DNA contents from maize, soya, cauliflower mosaic virus (CaMV) 35S promoter (P35S), NOS terminator from Agrobacterium tumefaciens and CaMV, and the second PCR system simultaneously detects DNA sequences from figwort mosaic virus promoter (PFMV), from bar gene of Streptomyces hygroscopicus, from gene coding for phosphinothricin acetyltransferase (PAT) and from a DNA construct of enolpyruvyl shikimate phosphate synthase gene (CP4-EPSPS) and Arabidopsis thaliana (CPT2). The tests exhibit good specificity and a limit of detection of at least 0.1 % for all analytes.