Four new SYBR® Green qPCR screening methods for the detection of Roundup Ready®, LibertyLink®, and CryIAb traits in genetically modified products

SYBR (R) Green qPCR methods for the detection of the Roundup Ready (R) "CP4-EPSPS", LibertyLink (R) "PAT" and "BAR," and the Bacillus thuringiensis "Cry-IAb" traits as present in genetically modified organisms (GMO) were developed. Their specificity, sensitivity, and PCR method efficiency were determined. All methods are specific and generate amplicons of 108, 73, 109, and 69 bp, respectively, for "CP4-EPSPS," "CryIAb," "PAT," and "BAR" targets. They perform well at low target levels and can detect down to 5 copies of their respective targets extracted from a sample. The PCR efficiency of the methods ranges between 91 and 109%. Due to their trait-specific nature, these methods allow an efficient screening between the different GMO. In this way, the number of possible GMO candidates present in a sample can be reduced what results in lower global costs due to limiting of further the number of analytical identification steps. The application of these methods in CoSYPS GMO analysis is illustrated using two GEMMA proficiency test samples and a reference material from the GM rapeseed event RF3. This set of SYBR (R) Green qPCR trait-specific methods represents a very interesting novel set of GMO analysis methods allowing cost-effective identification of GM materials in products.