Optimised cetyltrimethylammonium bromide (CTAB) DNA extraction method of plant leaf with high polysaccharide and polyphenolic compounds for downstream reliable molecular analyses

摘要

Yam (Dioscorea species) and banana (Musa species) leaf sample contain high levels of polysaccharide and polyphenolic compounds. Extraction of good quality DNA from such leaves is usually problematic. Therefore, there is a need to extract good quality DNA in order to perform downstream DNA analysis, especially for the detection of viruses due to their low titration in some infected leaves. The cetyltrimethylammonium bromide (CTAB) DNA extraction method was selected in order to optimise DNA extraction from plant material with high level of polysaccharides. Four steps of the Lodhi et al. (1994) method were modified to be user friendly in less resource laboratories of developing countries. Yield and purity of the extracted DNAs were quantified using a NanoDrop 2000 spectrophotometer and by migration on an agarose gel after polymerase chain reaction (PCR) amplification. The results of the DNA yields and purity were in the range of 287.40±2.23 to 424.95±1.85 ng/ul and 2.10±0.05 to 2.19±0.04, respectively. Modification was found to yield DNA of reasonable quantity, quality and purity. Furthermore, the method can be used in a laboratory with less sophisticated waste disposal system.