Comparison of Different DNA Extraction Methods from Leaves and Roots of Eurycoma longifolia Plant

Extraction of good quality DNA from medicinal plant tissue is always a difficult task due to the presence of polysaccharides and polyphenolic compounds. Eurycoma longifolia contain these secondary metabolites as they are responsible for its therapeutic activity and this pose a challenge in isolation of high quality DNA from this plant. In this study, DNA was isolated from leaves and roots of Eurycoma Longifolia using modified Cetyltrimethylammonium bromide (CTAB) extraction method and three different commercial (NucleoSpin Plant II, DNeasy and resin wizard) methods with the aim of finding the method that will produce DNA of good quality. The DNA extracted by these four methods was analysed according to their yield, purity and amplification success. After evaluation, the result shows that there is remarkable disparity that exists among the four methods in terms of yield and purity of the total genomic DNA. In terms of yield, the CTAB method has the highest concentration in both leaves and roots (296.3 +/- 46.96 and 272.4 +/- 121.5 respectively) when compared to the other commercial kits. As such, the gel electrophoresis with this method has the brightest band. In terms of purity, the A(260/280) absorbance ratio obtained from the modified CTAB method in both leaves and root tissues was above 1.8 indicating that the DNA extracted using this method are of good quality. Further evaluation of the DNA quality of various extraction methods was done by amplifying the internal transcribed spacer 2 (ITS2) regions. The result shows that the genomic DNA extracted from the tested the protocols were successfully amplified except that of the wizard method. The overall result demonstrated that the modified CTAB methods followed by NucleoSpin Plant II methods are the most efficient methods for the extraction of DNA of high quality from the leaves and roots tiisues of Eurycoma longifolia.