SPECIAL GUEST EDITOR SECTION Detection of Genetically Modified Organisms in Foods

tion 1139/98, foods and food ingredients that are to be delivered to the final consumer in which either protein or DNA resulting from genetic modification is present, shall be subject to additional specific la-beling requirements. Since 1994, genetically al-tered tomatoes, squash, potatoes, canola, cotton, and soy have been on the market. Recently, in-sect-resistant and herbicide-tolerant maize variet-ies have been introduced. Soy and maize are 2 of the most important vegetable crops in the world. During the past 4 years, both protein- and DNA-based methods have been developed and ap-plied for detection of transgenic soy and maize, and their derivatives. For protein-based detection, specific monoclonal and polyclonal antibodies have been developed; for immunochemical detec-tion, Western blot analysis and enzyme-linked immunosorbent assays are the most prominent ex-amples. For detection of genetically modified or-ganisms (GMOs) at the level of DNA, polymerase chain reaction-based methods are mainly used. For these reactions, highly specific primer sets are needed. This study compares the principally differ-ent methods. Specificity of methods and the possi-ble risks of false-positive or false-negative results are considered in relation to sampling, matrix ef-fects, and food processing procedures. In addition, quantitative aspects of protein- and DNA-based GM detection methods are presented and dis-cussed. This is especially relevant as EC regula-tion 49/2000, which defines a threshold for an unin-tentional comingling of 1%, came into force o