Detection of genetically modified ingredients in seed samples from Heilongjiang soybean field

A total of 210 soybean samples collected from different areas of Heilongjiang Province were analyzed by PCR to detect the presence of RR (Roundup Ready) soybean ingredient. Results showed that CaMV35S promoter was not detected in all samples. CP4-EPSPS gene was amplified in 13 samples, but all of them were proved to be false positives in restriction endonuclease digestion analysis of PCR products. Further analysis by nested PCR indicated that there were no RR soybean ingredients in the samples. Besides, the amplified fragments of 0x1 by CP4-EPSPS primers were sequenced, and the results confirmed again the fact that this fragment was not from CP4-EPSPS gene.