New certified reference materials for the quantification of MIR162 maize

The JRC produced a set of GMO reference materials certified for their mass fraction of MIR162 maize. They can be used for the detection of MIR162 maize by quantitative polymerase chain reaction (qPCR) in food and feed products.

MIR162 maize (unique identifier SYN-IR162-4) developed by Syngenta Crop Protection AG (Basel, CH), has been modified with a vip3Aa20 gene that encodes the Vip3Aa20 protein which protects against larvae from Lepidopteran insects (butterflies and moths). Event MIR162 maize also contains a second transgene, the Phosphomannose Isomerase (pmi) gene that was used as selection marker [1], [2].

Syngenta asked the JRC to produce MIR162 maize CRMs fulfilling the demand of EU Regulation No 1829/2003 [3] to make reference materials available for GMO events (re)authorised for the EU food and feed market. The set of CRMs consists of ERM-BF446a, ERM-BF446b, ERM-BF446c, ERM‑BF446d, ERM-BF446e, all containing different mass fraction levels of MIR162 maize. The concentration of MIR162 maize in ERM-BF446c and ERM-BF446d were chosen to be close to the 0.1 (m/m) % threshold for feed, and the 0.9 % labelling threshold respectively, established by EU legislation [4], [3]. ERM-BF446b is intended to be used as calibrant for the official qPCR method.

The new set of CRMs (ERM-BF446) and the qPCR method for MIR162 maize, validated by the EURL-GMFF [5], will maintain the arbitrary reference system required for the comparable quantification of MIR162 maize and are essential for GMO testing and official control laboratories to quantify this GM event in food and feed products.