| Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 90 === Abstract
Currently, PCR is the primary method for analyzing genetically modified organism (GMO) in soybean ingredients and its processed food. However, The degradation of DNA by heat is a crucial factor in PCR analysis. This experiment showed that when DNA were heated at 100 ℃ for 180 minutes or at 121 ℃ for 60 minutes, PCR products fragment which above 444 bp would become undetectable due to above treatments, whereas PCR product under 318 bp can be detected. This experiment identified RRS by targeting at two genes in soybean ingredient and its processed food: one of which is the soybean-specific LeB primer in the Lectin gene (PCR product fragment 219 bp), and the other is CTEP primer in RRS transgenic gene CTP-EPSPS (PCR product fragment 318 bp). The result showed that soybean ingredient has a sensitivity of 0.01 %, whereas the processed food showed 0.1 % sensitivity. As general PCR is replaced by multiplex PCR for testing, though the sensitivity of multiplex PCR on soybean ingredient decreased from 0.01 % to 0.1 %, and processed food decreased from 0.1 % to 1 %, it offers a wide range of benefits such as reduction of human error, prevention of false negative, and acceleration of the analysis process. SYBR Green I method of LightCycler was used for RRS quantification. The result of 5 % RRS quantification were found to be 5.3 %, 5.3 %, 5.7 %, with the C.V. values of 4.2 % far lower than the EU quantified value of 25 %. As regards to RRS self-processed food, while the quantification results of Lectin gene and CTP-EPSPS gene would drop along with processing, their RRS amount were conserved (5 % RRS in soybean was 5.6 %, 5 % RRS in soymilk was 5.7 %, 5 % RRS in topi was 4.9 %, and 5 % RRS in vegetable chicken was 4.6 %). Hence, the quantification method established in this study can be both applied to RRS quantification in soybean ingredient and soybean processed food directly.
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