The Study On Detection Of Genetically Modified Soybean Products

Transgenic technology gets rapid development in recent years. In2013, biotech cropshectares is175million hectares, which has increased by more than100-fold comparing with1.7million hectares in1996. It hasn’t reached on final conclusion whether geneticallymodified food is safe or not so far. However, because of its unpredictable potential risk,consumers request their right to know and choose. If food containing genetically modifiedingredients, it should be identified according to the laws and regulations in China In fact, agreat deal of food is not identified in accordance with the provisions of laws and regulations.Moreover, it is much more difficult to carry out effective about genetically modified rawmaterials entering the processing. Hence, detection of genetically modified products becomesone of the important tools to implement supervision effectively.At present, qualitative PCR methods based on nucleic acid and real-time fluorescencequalitative PCR are frequently-used in detection of genetically modified products. In recentyears, Loop-mediated Isothermal Amplification (LAMP) has been used in detectinggenetically modified products. The comparision of these used detection methods was useful tochoose the right method for detection and improve the efficiency and accuracy of detection.The main contents and results of article included:⑴The comparison of selecting the DNA extraction methods. Reformedhexadecyltrimethylammonium bromide (CTAB) method, reformed Wizard Genomic DNAPurification Kit and Wizard Magnetic DNA Purification System were used to extract DNAfrom soybean product samples including tofu, dried tofu, fried tofu, dried beancurd sticks andfermented beancurd. And the concentration and purity of DNA from different samples werestudied. The results show that though reformed CTAB method is more complicated, theextraction DNA can meet the research requirement and is applicable to5types of soybeanproduct. And the cost of a single sample is much lower than other two methods, which is asuitable method using in large quantities of test.⑵Study on the comparision of the detection methods in genetically modifiedproducts. The differences of nucleic acid qualitative PCR，real-time fluorescence PCR andLoop-mediated Isothermal Amplification（LAMP）were evaluated on stability, sensitivity and specificity. The results show that all of the3methods could meet the requirement of thecurrently detection standard in China, but had different specificity in different exogenousgenes.⑶The soybean products in bulk and prepackaged were investigated to understand thestatus of genetically modified food in Guangzhou. By dint of CTAB method，genomic DNAin the samples were extracted. The exogenous gene such as CaMV35S，NOS and EPSPS wereused as the detection primers to genetically detection on the samples by qualitative PCRmethods based on nucleic acid，real-time fluorescence qualitative PCR and Loop-mediatedIsothermal Amplification（LAMP）method. The results showed that87of159soybeanproducts in bulk and18of48prepackaged soybean products contained genetically modifiedingredients. The soybean products in bulk had no package and food label, and soybeanproducts in prepackaged had no label of genetically modified organism (GMO), so themanagement of GMOs in soybean product should be enhanced.