Quantification of GMO soybean DNA in processed food by quantitative competative polymerase chain reaction | |
| Author | Mahapatra, Cecon Tapaswini |
| Call Number | AIT Thesis no.BT-03-12 |
| Subject(s) | Transgenic plants Soybean--Genetics Quantitative genetics |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. BT-03-12 |
| Abstract | Genetically modified crops for herbicide tolerance, insecticide tolerance etc. are being increasingly being introduced to the world's food supply. But the public are not able to accept it properly due to the risks associated with it. So this forced the concerned authorities to put regulations on the use of the GMO and to label the GMO products to give a choice to the consumers. Threshold limit of GMO labeling differs from country to country. Soy is on of the major crop to be genetically modified. The Round up Ready modification of soybean enables it to tolerate the glyphosate herbicide. So to quantify the GMO in case of the processed foods of soy, we developed the quantification system for natural gene of soy i.e. AAT and the genetically modified gene of soy. Because there is chances of the presence of the other ingredients containing RRS gene in the processed foods. QC-PCR is on of the most accepted technique by the European Union for GMO quantification, The QC-PCR is the coamplification of the known amount of internal standard with the unknown quantity of the target. Thus with proper calibration, it is possible to detect the % GMO content in a sample. The use of the Internal standard also reduces the inter-lab differences in the assay system. The internal standard for AA T was prepared using a modified insertion of an extra oligo nucleotide sequence in the middle of the AA T gene. The middle insertion of the primers with extra sequence were used with outer AAT primers to amplify the two half modified segments having complementarity among them, The recombinant PCR was done to ligate them by recombination and extension with Taq. Thus the constructed standard segment was cloned to pGEM-T vector and transformed to E.coli .The cloned plasmids were calibrated as internal standard for the equivalence amount of various amounts of plasmid concentration with 1 % GMO using standard GMO sample. The calibration was done by comparing the band intensity on the electrophoresis gel with the help of image analysis software. The same process was repeated for QC-PCR of RRS. But while calibrating, the RRS internal standard was calibrated for the equivalence amount of various GMO% using using standard GMO sample. For the quantification of GMO of sample , different amount of the standard equivalent to various GMO % were coamplified using the same amount of the unknown target template. The resulting band intensity of the target and the standard was analysed with the KODAK soft ware. The target giving equal band intensity with the standard corresponds to the % GMO content in the sample. By knowing the amount of AA T and RRS gene present , we can calculate the %GM of soy. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. BT-03-12 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Stevens, Willem F.; |
| Examination Committee(s) | Suwalee Chandrkrachang;Athapol Noomhorm;Sunee Nitisinprasert; |
| Scholarship Donor(s) | The Royal Netherlands Government; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2003 |