Detection of genetically modified foods -: Past and future

The best-known examples for genetically modified crops in Europe are the Roundup Ready soybean from Monsanto and the various transgenic maize varieties. These can be found in various forms in an estimated 30.000 food-products. Consumer concern prompted the European Commission to issue labelling regulations for food-products which require the presence of transgenic material to be indicated. In countries outside of the European Union, these regulations tend to differ from country to country, ranging from no labelling requirements to import bans on products containing genetically modified material. Most genetically modified materials (maize kernels, soy beans) do not differ morphologically or in taste from their conventional counterparts, and in order to enforce the labelling regulations, detection methods are required which can distinguish the varieties containing the transgenic sequences. Several methods for the detection of transgenic material have been developed and validated. These range from physico-chemical (MALDI-TOF) and protein based methods (ELISA) to the most frequently used DNA-based methods (PCR, real-time PCR). The basics of these methods are discussed and the problems and limits of each method explained.