Extraction of genomic DNA from the lipid-, polysaccharide-, and polyphenol-rich coconut (Cocos nucifera L.)

Abstract

One prerequisite to reliable molecular biology work is that the genomic DNA of a sample be of good quality. Coconut is quite difficult to work on because of the high lipid and polysaccharide content of its endosperm and the high polyphenol content of its leaves. This study aimed to determine which protocol to use and which part of the coconut tree is most appropriate to extract good-quality genomic DNA. Genomic DNA from the solid endosperm was found to be of poor quality because of high levels of lipid and galactomannan contaminants. By using a modified protocol by Cheung et al. (1993) as modified by Rogers et al. (1996) and by Dellaporta et al. (1983) as modified by Datta et al. (1997), genomic DNA extracted from the young leaves of the first emergent frond provided enzyme-digestible, good-quality DNA. The modification involved the use of a higher salt concentration (2 M instead of 0.5 M) in the extraction buffer and the use of polyvinylpolypyrrolidone. Moreover, this modified protocol did not involve the use of organic solvents.