PCR screening of feed products for the detection of genetically modified soybean

Department of Microbiology and Biotechnology, University of Food Technologies, Plovdiv, Bulgaria

^* Corresponding author: petyastefanova@uft-plovdiv.bg

Abstract

After the development and approval for commercial use of more than 570 genetically modified crop events worldwide, the ability of qualitative identification and quantification of transgenic materials in feed has become an essential necessity and a serious challenge in terms of feed safety. In the present study, a PCR screening of feed products for the detection of GM soybeans was conducted. The CTAB extraction method yielded high-quality DNA extracts, with concentrations ranging from 145.25 ng/µl to 442.68 ng/µl and excellent purity (A₂₆₀/A₂₈₀ = 1.80 – 1.88). The LOD of the PCR method for soybean DNA detection was less than 1 soybean genome copy, demonstrating the high sensitivity of the method. The concentration of 0.01% target DNA was determined as LOD of both PCR methods for the detection of the CaMV 35S promoter and the EPSPS gene. Therefore, they could be applied for the screening of various feed products for the presence of genetically modified DNA. Furthermore, the CaMV 35S promoter and the EPSPS gene were observed in 77.78% of the analyzed feed products. This demonstrated the widespread distribution of GM crops in feed and set the necessity of strict control for the presence of GMO in the feed industry.