| Abstract: | There are two common approaches for the detection of Genetically Modified Organisms (GMOs): DNA based methods, mainly founded on the Polymerase Chain Reaction (PCR), which detect genetically modified DNA sequences, and protein based methods, relying on immune assays (e. g. Enzyme‐Linked Immunosorbent Assay, ELISA). The latter detect and measure levels of proteins expressed by transgenic genes. Official standard tests, yet to come, will be based on these two methodologies. DNA based tests are now preferred for their sensitivity and their capability to detect a wider range of constructs. Protein‐based immune assay tests, although less sensitive, are quicker and require less lab skills. Collaborative study results put in evidence that PCR tests are generally well suited for detecting the presence of GMOs on a qualitative basis (yes/no). Difficulties arise when GMOs have to be quantitatively identified in food ingredients. Real‐Time, or kinetic PCR, points out quantification and interpretation limits when quantification has to be done on a very small total DNA amount. An essential requirement for PCR‐based techniques is the knowledge of the GMO‐specific DNA sequence target. Many labs find it difficult to keep up with the rate at which life science companies are creating new GMOs and the finding of adequate reference standards to be used as positive analytical controls. |
