PCR technology for screening genetically modified soybeans

Abstract

Genetically modified (GM) crops involve transferring a specific stretch of DNA into the plant’s genome and giving it new or different characteristics. Since the first industrial application of transgenic crops in the United States in 1996, GM crops are becoming increasingly common in the market. At present, not all crops in the Chinese market are clearly marked as to whether they are GM crops or not. In order to protect consumer’s option to select their preferred products, we decided to conduct experiments to identify soybeans on the market. We hypothesized that soybeans on the market with unknown origin were GM soybeans. Then we established a detecting method using genetic technology and screened the soybeans. In this study, we used GTS 40-3-2 as a positive control, which contains genomic DNA, foreign DNA enolpyruvylshikimate-3-phosphate synthase (EPSPS) and other exogenous elements, and GTS 40-3-2 SOYA BEAN (blank) as negative control, which contains genomic DNA only. To amplify the foreign DNA, we optimized the polymerase chain reaction (PCR) procedure by attempting different annealing temperatures to establish the PCR detection method. According to the electrophoresis results, in the samples from a local store, only genomic DNA lectin could be amplified, which indicated the samples were non-GM soybeans. Our study not only provides a detection method but also lays a foundation for testing soybean and processed soybean products of unknown origin.