Abstract
It is very important to avoid contaminations when we perform tests to detect genetically modified organisms (GMO) using methods based on PCR techniques. Heat-treatment by autoclaving is usually recommended in the testing protocol to sterilize reagents and avoid the effects of contaminants. However, for GMO testing, the effective conditions of heat-treatment have not been determined yet. Three factors, including genomic DNA, a PCR product and ground powder, can affect the result of GMO testing through contamination. Therefore, we investigated the effective conditions of heat-treatment to avoid the influences of the three contaminants described above, using qualitative and quantitative PCR methods. Ground soy powder, genomic DNA extracted from etiolated soy bean, and the plasmid DNAs used as the calibration standard in the quantitative PCR method for GM soy were used as test materials. To avoid contamination in the laboratory, the plasmid DNAs were used as test materials instead of a PCR product. The lectin gene was not detected in the genomic DNA samples and the plasmid DNA samples that were treated at 121℃ for 20 min and 10 min, respectively. On the other hand, the gene was detected in the ground powder sample treated at 121℃ for 30 min by using both qualitative and quantitative methods. However, the measured value was markedly decreased compared with the non-treated sample. In conclusion, the risk of contamination affecting GMO testing can be effectively reduced by heat treatment at 121℃ for 30 min.
