Event-specific method for the quantification of cotton line 'LLCotton25' using real-time PCR v. 1.01 : validation report, validated method, cotton seeds sampling and DNA extraction

The JRC as European Union Reference Laboratory for GM Food and Feed (EURL-GMFF), established by Regulation (EC) No 1829/2003, in collaboration with the European Network of GMO Laboratories (ENGL), has carried out a collaborative study to assess the performance of a quantitative event-specific method to detect and quantify the LLCotton25 transformation event in cotton DNA (unique identifier ACS-GHøø1-3). The collaborative trial was conducted according to internationally accepted guidelines (1, 2). In accordance with Regulation (EC) No 1829/2003 of 22 September 2003 on genetically modified food and feed and with Regulation (EC) No 641/2004 of 6 April 2004 on detailed rules for the implementation of Regulation (EC) No 1829/2003, Bayer CropScience provided the detection method and the samples (genomic DNA extracted from wild-type and 100% LLCotton25). The JRC prepared the validation samples (calibration samples and blind samples at unknown GM percentage [DNA/DNA]). The collaborative trial involved eleven laboratories from seven European countries. The results of the international collaborative trial met the ENGL performance requirements and the scientific understanding about satisfactory method performance. Therefore, the EURL-GMFF considers the method validated as fit for the purpose of regulatory compliance. The results of the collaborative study are made publicly available under http://gmo-crl.jrc.it/.