Abstract: Referring to the sequences of some promoter, terminator and exotic gene, the primers 35SCP142 and CPNOS165 were designed. Sensitivity has been obviously improved by optimizing the primers which could make the length of amplicon shorten from 170bp to 100bp. Up to 0.01ng exotic gene could be detected in a 25μl volume PCR amplification system. In order to detect the exotic gene in soybean oil, two primers 35SCP318 and 35SCP114 for NEST-PCR (nest polymerase chain reaction) have been designed, with which DNA fragments of exotic gene have been amplified and detected. Accuracy of the new primers also have been estimated by being applied to several kinds of products, including GMOs and NON-GMOs. Verfied by sequencing, new primers namely 35SCP142, CPNOS165 and NEST-PCR primers posses high specificities, and could be used for exotic genes detection.

Key words: exotic gene detection, sensitivity, accuracy, primer, NEST-PCR