Integrated Procedure for GMO Testing in Specialized Laboratories
GMO testing of foodstuffs represents an important tool for assessing compliance with EU legislation on transgenic plants derived food and feed (Querci et al., 2005). This paper describes the main features of the analytical steps encompassed in the GMO testing procedures performed in our laboratory. Qualitative and quantitative determination of transformation event Bt176 in maize grains is used to exemplify how the methods are employed. Bt176 is no longer approved for commercialization within the EU but represents an adequate example for a case study in this field because of the availability of information and data on the subject. It is also well suited for tests using the instruments in our laboratory. The main analytical steps for GMO testing of raw and processed plant matrices are as follows: obtaining of a representative laboratory sample by employing special strategies; sample preparation (e.g. milling, separation of different fractions) in order to obtain the test sample; DNA extraction using the QIAamp DNA Stool Kit (Qiagen) was used; assessment of the extracted DNA by spectrophotometric readings and agarose gel electrophoresis; qualitative testing based on classical PCR aimed at detection taxon specific or transgenic specific DNA; quantitative testing based on real-time PCR using the RoundUp Ready Soya Qt KIT (Biotools). The analyses were conducted using experimental designs that satisfy all requirements and recommendations for this type of analyses (see ISO 21570:2006; Querci et al., 2005; Foti, 2004). The validation and interpretation of results is also presented.