Detection of genetically modified soybean by monoclonal and polyclonal antibodies

Abstract

Rationale The safety of Genetically modified (GM) soy still remains controversial despite its advantages in cultivation. Since soy has been consumed commonly in Korea, it is necessary to investigate for developing detection methods of GM soy which carries the added gene and express 5-enol-pyruvyl-shikimate-3-phosphate synthase (EPSPS) in foods. Methods CP4EPSPS protein remaining in different soy products were detected by western blot. Soybean proteins from different soy products were extracted and separated by SDS-PAGE with modified Laemmli methods and then transferred to NC membrane. By using purified CP4EPSPS protein expressed in E. coli protein expression system, specific monoclonal and polyclonal antibodies were obtained. CP4EPSPS protein was analyzed by immunobot using CP4EPSPS-specific polyclonal antibody (pAb, 1:1000 diluted) or monoclonal antibody (mAb, 1:2000 diluted). Results Purified CP4EPSPS protein was detectable in a concentration of 0.006 μg or 0.0006 μg by using monoclonal or polyclonal antibody, respectively. Two of 9 investigated soybean curd products showed binding reactivity with CP4EPSPS specific polyclonal antibodies. Conclusions The results of this study showed that CP4EPSPS proteins remained in processed soy products like soybean curd could be detected by western blot using monoclonal and polyclonal antibodies.