Rapid and accurate detection of genetically manipulated soybean using polymerase chain reaction

Abstract

Background: It is controversy over the GM products consumption around the world. However, the limitations of food supplies and population growth have forced the posterity to use transgenic products. Accurate strategies for consumption and use of proper diagnostic methods are crucial in this regard. Materials and methods: The soybean commercial samples were purchased as a control from supermarkets located in Tehran. Considerable attention was paid to collecting samples from different brands. In this investigation, in order to identify the soybean oil in products, randomly, 25 raw oil and soybean oil samples were collected and numbered. An equivalent of 50 g of each sample was prepared for testing. In order to determine the transgenic soya samples, the specific primers for the 35S promoter region of mosaic virus CaMV35S and nephaline synthase (NOS) transcription terminator were designed from Agrobacterium. The sequence of the CaMV35S promoter and the NOS terminator were obtained according to that of Lipp and Brodmann investigation. The PCR product size for 35S and NOS primers was 195 and 180 bp, respectively. Results: By PCR technique the specific Soybean (164bp), GMONOS180 (180bp) and GMO35S (195bp) genes were amplified. Among the 25 tested oils, 9 (36%) were GM, being a high percent and of these nine transgenic cases, two had CaV-35s, and also were nos-positive, indicating of their transfusion certainty (GM). This high percentage of transgenic oils is possibly due to the lack of awareness of the producers. Conclusion: The microbiological and chemical methods alone cannot control the quality of food products, and detect the presence of transgenes. Therefore, the use of PCR technique is important in controlling the quality of this product. In cases where manufacturers and importers of products prepare and distribute transgenic products without labeling, they can be easily prevented from misuse and thus PCR as complementary and helpful to determine the composition and quality of the product.