SCREENING METHODS FOR IDENTIFICATION OF G ENETICALLY-MODIFIED FOOD OFPLANT-ORIGIN

In 1994, the first genetically modified plant was approved for cultiva tion and commercialization as a foodstuff in the USA. Now, at least fi fteen genetically modified plants have been approved additionally. In Canada and other countries further applications for transgenic plants are pending. Altough the regulatory frameworks concerning the commerci alization of Novel Food differ within EC, foods derived from genetical ly modified plant varieties (i.e. rapeseed, radicchio, soybeans, tobac co) have been introduced into commerce in Europe. At present an approp riate labelling of foods developed by means of new DNA techniques is s till being discussed. Consequently, approaches for detection of DNA in foods derived from genetically modified organisms are necessary to co ntrol the correct labelling of foods and for the safety of producers a nd consumers. For the detection of transferred DNA the polymerase chai n reaction (PCR) or hybridization techniques can be used. A prerequisi te for detection is a minimum number of copies and the information abo ut the sequence of the introduced genetic material. DNA sequences whic h are responsible for the new traits (structural genes, i.e. for herbi cide or virus resistance) and which do not occur naturally in the host plant, are necessary for the specific detection. But the detection ca n also be performed with genes which funktion as control elements or m arker genes (promotor, terminator, nptll-gene). This paper describes a screening method for the detection of six different transgenic plants by the polymerase chain reaction (PCR). The presence of the transferr ed control elements were determined with primer pairs specific for the CaMV 35S promotor, NOS terminator (Nopalin synthethase) and the nptll gene (Neomycinphosphotransferase).