Detection of genetically modified organisms (GMOs) by PCR: a brief review of methodologies available

The discovery of the molecules that bear the genetic information of any living organisms among which DNA (DeoxyriboNucleic Acid) plays a central role has been a revolution for life sciences. Taking the advantage of the universality of the genetic code, researchers have succeeded to associate DNA sequences coming from different organisms using molecular biology techniques and to integrate foreign DNA within plants. These genetically-modified organisms (the so called GMOs) have the ability to synthesise some additional proteins which confer new properties on them. Improving the protection of agricultural crops is one of the sought advantages by the gene transfer. According to the European regulation, the new foodstuffs made from genetically modified soya or maize, must be labelled. The control of the labelling of such foodstuffs is based on the detection of the foreign DNA sequences born by the genetically-modified organisms. One of the analytical methods used for enforcement of this regulation is the Polymerase Chain Reaction (PCR) method. The principle of the PCR method is to multiply specific sequences of DNA, malting them detectable. This highly sensitive method offers the advantage of detecting DNA molecules which are more thermostable than proteins. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.