Identification of Recombinant DNA from Genetically Modified BT-11 Maize

Detection of recombinant DNA segment from foods/feeds/kernels is important for the labelling and safety assessment of genetically modified (GM) foods. In this study, polymerase chain reaction (PCR) assay was performed to detect the recombinant DNA and maize intrinsic gene sequence from the genetically modified Btll and non- Bt maize. DNA was extracted from freeze dried GM Btll (N58, Novartis Seed Company) maize powder and freeze-dried powder from Non-GM isoline of the Btll maize. Primer pair IVO11-5' and CRO11-3' was designed to amplify a part of the region of the insect resistant Cry 1 Ab gene sequence that was inserted in GM Btll maize. A primer pair ZEO1-ZEO2 was also designed to detect the maize intrinsic zein (ze 7) gene to assess the efficiency of all reactions, thereby eliminating any false negatives. To confirm the reproducibility, specificity and sensitivity of the designed primers, PCR was performed on diluted genomic DNAs extracted from GM and source of non-GM maize. A parallel negative control was run each time to avoid the contamination. DNA extraction kits were able to extract good quality DNA from the crushed maize samples. Recombinant Cry 1 Ab gene (437 bp) and maize intrinsic zein (ze 1) gene (242 bp) sequence were successfully amplified from the freeze dried Btll and non-Bt maize powder in this investigation. The reproducibility, specificity and sensitivity of the detection were high and therefore, can be concluded that this method could be used for fast and easy screening of Bt gene in the food products and GM Bt crops and could be used in the safety assessment procedure of Bt crops.