Screening for Genetically Modified Maize in Raw and Processed Foods Sold Commercially in Southern Nigeria Border States

Background and Objective: Due to the increasing number of Genetically Modifided Organisms cultivation and delayed approval of biosafety law in Nigeria, it became necessary to screen maize products in order to determine the identity of the consumed foodstuffs. The study was designed to screen for the presence of regulatory genes (35S promoter and NOS terminator) and common transgenes in food products sold in Southern Nigeria. Materials and Methods: DNA was extracted from the raw and processed maize foods sold commercially in Southern Nigeria using the Cetyltrimethylammonium bromide method, followed by qualitative Polymerase Chain Reaction (PCR) to detect genetically modified maize. The recombinant DNA target sequences were detected with specific primers for CaMV 35S, nopaline synthase terminator, Bt-176 and NK603 genes. Certified reference materials were used as positive controls while organic maize grains and absence of template DNA served as negative controls. Results and Conclusion: Bt-176 maize event (for insect resistance) was detected in two samples while the NK603 maize event (for herbicide tolerance) was detected in three samples. Four imported raw maize samples, four cereal food brands (two Nigerian made, two imported) and three imported canned corn brands were genetically modified and unlabelled. The results showed that Nigerians were already consuming GM maize before the biosafety law was enacted.