PCR Detection of GMO in Food and Feed

The term "genetically modified organism (GMO)" has become a controversial topic in many countries as its benefits for both food producers and consumers are accompanied by potential biomedical risks and environmental side effects. In this thesis, I attempt to summarize up-to-date knowledge about genetically modified (GM) crops. I also introduce different methods for detecting GMOs in food and feed. In the practical part of this thesis, thirty food and feed samples containing maize were randomly collected from different sources. The aim of this study was to test these samples for the presence of GMO, verify the information given on the label, and check that it complies with the EU legislation requiring that any food or feed containing more than 0.9% GM content has to be labeled. The next aim was to optimize the method for DNA extraction from the tested samples. In order to isolate genomic DNA from the samples, I used the NucleoSpin Food kit and the MagCore Automated Nucleic Acid Extractor. The concentration of extracted DNA was evaluated by ultraviolet (UV) absorption using a BioSpec-nano spectrophotometer. The gene coding for the zein storage protein of maize was used to confirm the presence of amplifiable maize DNA. DNA extraction was followed by PCR protocols using different sets of primers to detect four maize events: Bt11, Bt176, Mon810, and T25. Agarose gel electrophoresis was used for the separation of DNA fragments that were subsequently visualized using InGenius manual gel documentation system. In spite of the curent regulations, none of the three samples tested positive for the presence of MON810 maize had any such indication on their label. The samples that claimed to be "GMO free" on their label actually did not show the presence of any of the GM maize events tested