Document Type

Theses, Masters


Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence



Publication Details

Successfully submitted for the award of Master of Philosophy (M.Phil) to the Technological University Dublin, 1999.


In recent years, Genetically Modified (GM) foods have become increasingly common on our supermarket shelves. Consumer concerns regarding their safety have prompted codes of practice and legislation requiring labelling of all GM-food-containing products. Labelling requires some means of verification. There is no simple means of detecting GM food and until recently, there were no tests available. The object of this study was to develop a simple, rapid and user-friendly method of detecting genetically modified foods. The study concentrated on the detection of GM tomatoes, using a commercially available tomato paste. The method of choice was the Polymerase Chain Reaction (PCR) targeting the selectable marker gene Neomycin Phosphotransferase II (NPTII). The selectable marker gene confers resistance to the antibiotic kanamycin, and is used to detect newly transformed plants in the laboratory. NPT II has commonly been used as a selectable marker and therefore can be used to test for many species of transgenic plants. A PCR method to detect NPT II was developed and applied to genetically modified tomato paste. Commonly used plant DNA extraction methods proved unsuitable and an extraction method based on microwave treatment of the paste was developed. This increased both the sensitivity and reproducibility of the PCR method. It was also attempted to develop a method to detect genetically modified soy using PCR, by targeting the cauliflower mosaic virus promoter gene.