Review of GMO detection and quantification techniques

The need to monitor and verify the presence and the amount of GMOs in agricultural crops and in products derived thereof has generated a demand for analytical methods capable of detecting, identifying and quantifying either the DNA introduced or the protein(s) expressed in transgenic plants, because these components are considered as the fundamental constituents. Several laboratories have therefore developed methods either based on DNA detection using the polymerase chain reaction (PCR) technique, or on protein detection using enzyme linked immunosorbent assays (ELISA). Although much progress has been achieved in the development of genetic analysis methods, such as those based on the use of polymerase chain reaction (PCR), several other analytical technologies that can provide solutions to current technical issues in GMO analysis are emerging. These include, mass spectrometry, chromatography, near infrared spectroscopy, micro fabricated devices, DNA chip technology and nanoscale GMO analysis. The development and application of reliable detection and quantitative analytical methods is essentials for the implementation of labelling rules. Appropriate sampling strategies and methods for sample preparation, as well as methods development and application to detect GMOs and their derivatives must then be followed by the establishment of validation criteria and performance assessment. Since reference samples are an indispensable part of any analytical protocol, criteria for manufacturing standard reference materials must also be considered. In order to create confidence in the testing procedures and complement enforcement requirements, there is an urgent need for using methods that are validated and•officially recognised at an international level. To date, several methods for different food matrices have been submitted to validation trials. Although encouraging, the resulting reports have presented rather limited statistical analysis, which suggests a more precautionary approach in their evaluation. Indeed, the methods subjected to ring trials varied significantly in their reliability, robustness and reproducibility. Even though claims of very high sensitivity were sometimes made, they were often not supported by appropriate statistical analysis and detailed performance studies. More validation studies, especially on the quantitative PCR methods, need to be performed to provide new extraction methods for food matrices and novel GMO constructs. Considerable work remains to be done, therefore, in response to the increasing demands of consumers and policy makers to give confidence that food products on the market meet the requirements of the rapidly evolving EU legislation