Comparative Testing Report on the Quantification of Maize Line DAS-59122-7 and Oilseed rape Line GT73 (RT73) - Comparative testing round: ILC-EURL-GMFF-CT-01/12

In the frame of Regulation (EC) No 882/2004, the European Union Reference Laboratory for Genetically Modified Food and Feed has the duty to organise comparative testing rounds and to ensure an appropriate follow-up of these activities. This report describes the outcome of the fifth comparative testing round ILC-EURL-GMFF-CT-01/12. Participants had to determine the content of oilseed rape event GT73 and maize event 59122 in two test items denoted genomic DNA levels 1 and 2, containing different GM percentages of both GM events. This comparative testing round was organised in collaboration with the Food Safety and Quality Unit of the Institute for Reference Materials and Measurements (Geel, BE). The test items were produced in-house. The Food Safety and Quality Unit managed the on-line registration and submission of results. A total of 160 laboratories were invited to participate in ILC-EURL-GMFF-CT-01/12. Eighty laboratories from 36 countries returned results, of which 59 were National Reference Laboratories, six were only members of the European Network of GMO Laboratories, three were only Official control laboratories and 12 were laboratories from third countries. Five laboratories including one National Reference Laboratory and four laboratories from third countries did not submit results. In this fifth comparative testing round 92 % to 98 % of participants gained a satisfactory z-score in the range of -2 to +2 for the results expressed in mass/mass % depending on the GM content and the GM event. However, a lower percentage (38 – 93 %) of z-scores within the working range of -2 to +2 was calculated for those participants that expressed the results in copy/copy %.JRC.I.3-Molecular Biology and Genomic