Seed Testing of GMOs (Food Crops)

A plant, such as cotton or soyabean, is considered genetically modified when genetic material from outside of that organism is inserted into DNA sequence. Plants grown from seed harvested from genetically modified plants will also contain the genetic modification. To date, the most common genetic modifications in crops confer an herbicide or an insecticide resistance to the plant. This resistance is achieved through production of a novel protein encoded by the inserted DNA sequence. Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. The most frequently used approach in the field of genetically modified organism (GMO) quantification in food or feed samples is based on the 5'-3'-exonuclease activity of Taq DNA polymerase on specific degradation probes. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness.