A DNA extraction and purification method using an ion-exchange resin type kit for the detection of genetically modified papaya in processed papaya products

A method for the extraction and purification of genomic DNA from processed papaya products is essential for the detection of approved genetically modified (GM) papaya, according to GM labeling regulations, and unapproved GM papaya, to restrict the import or sale of products containing it. Here, we investigated methods for the extraction of DNA from processed papaya products, including dried papaya, canned papaya and papaya jam. The extraction of DNA from dried papaya and canned papaya required a pre-digestion step, using RNase, cellulase and proteinase K. In the case of papaya jam, α-amylase was found to be indispensable to obtain DNA with high yield and purity. The DNA yield was considerably higher when an ion-exchange resin type kit (IER-100G) was used, compared with other five methods (IER-20G, QIAamp DNA Stool Mini Kit, DNeasy Plant Maxi Kit, GM Quicker 3 Kit and Wizard Cleanup Resin System). We developed a suitable method for the extraction and purification of DNA from processed papaya products, which could be used to detect GM papaya.