Traditionally, a unique GMO test must be validated for each GMO and for each type of matrix (e.g., seed, processed food). The modular approach, on the other hand, takes a GMO test and validates it step by step. Because different GMO tests have steps in common, the modular approach allows the application of a single, validated step to a wide range of GMOs and matrices. This should greatly improve the efficiency and feasibility of developing and carrying out tests for many different GMOs in many different forms. This task aims to develop, define, verify, and standardise the modular approach to GMO testing.
Holst-Jensen and Berdal (2004) have proposed to introduce the concept of ‘modularity’ for the analytical procedures and validation of methods in GMO analysis. The basic idea is that in general after sampling from bulk lots, GMO analysis consists of a limited set of distinct steps that represent a certain elementary unit with the process, the so-called 'module'. In GMO analysis stricto sensu, after sampling, a laboratory analytical sample is subject to the following steps of modular analysis: sub-sampling, sample homogenization, analyte extraction, target detection and finally target quantification.
Within the Co-Extra project, a number of aspects directly concerning the validity of the modular approach have been assessed, especially technology equivalence, the lack of bias-introduction by module interchange and the determination of the measurement uncertainty, if necessary, and the mathematical expression of module interactions and inter-dependencies.
According to the obtained results within the Co-extra project, the "modular approach" can be considered as a useful approach in GMO analysis. Co-extra documents valid modularity for: DNA content determination, for DNA extraction, for the reliable use of PCR in a wide range of % GM content and for the application of different calibrators in GMO quantification by real time PCR.
As such, the "modular approach" provides a good basis for developing a cost-effective validation process by the stakeholder. Such approach requires however generally accepted performance criteria for the different types of detection methods (e.g. ENGL criteria), accepted statistical evaluation tools (such as AMPE, SeedCalc, etc.) and appropriate reference materials (such as the IRMM CRMs). Further efforts will have to be made to integrate the use of all these elements in the future (e.g. CRMs certified for target copy numbers).
Modular Approach Implemented - Pros, Cons and Future Perspectives
Public Deliverables of the Co-Extra project
|NAME / ORGANISATION||CONTACT INFORMATION|
|Joint Research Centre (JRC), Italy||
|Institute for Agricultural and Fisheries Research (ILVO), Belgium|
|National Veterinary Institute (NVI), Norway|
|LGC Limited (LGC), United Kingdom|
|Groupe d'Intérêt Public – Groupe d'Etude Et de controle des Variétés et des Semences (GIP-GEVES), France|
|Instituto Superiore Di Sanita (ISS), Italy|
|Laboratoire de la Direction Générale de la Concurrence, de la Consommation et de la Répression des Fraudes de Strasbourg (DGCCRF), France|
|University of Parma (UPAR), Italy|
|National Institute of Biology (NIB), Slovenia|