DETECTION OF GENETICALLY MODIFIED MAIZE FOOD PRODUCTS BY THE POLYMERASE CHAIN REACTION DETECCIÓN DE PRODUCTOS DE MAIZ GENETICAMENTE MODIFICADOS POR LA REACCIÓN EN CADENA DE LA POLIMERASA

Resumen A polymerase chain reaction (PCR) was applied to detect genetically modified (GM) maize and soybean food product, using specific 35S promoter primers for inserted chimerical genes in maize or soybean. The PCR detected food products that include ingredients obtained from GMOs in maize grains and flour, as well as processed in foods such as tortillas (Mexican crepe), corn chips, corn and soybean oils. Beside the promoter, the PCR also detected zeine and lectin genes for maize and soybean, respectively, which confirmed the identity of the analyzed samples. The presence of transgenic material was also confirmed by detecting the terminator Tnos region. High quality DNA from samples permitted an accurate detection of GM in food products while low quality DNA could lead to false negatives. The event Bt-176 and non-GM maize were used as positive and negative controls, respectively. Three types of GM food-products (grain, flour and soybean oil) resulted positive, while flour products (tortilla and...