Comparing qualitative and quantitative results of some DNA extraction methods from genome of pathogenic and saprophytic mycobacteria

Abstract

Given that the first step in performing molecular techniques such as PCR (Polymerase Chain Reaction (is having enough high quality DNA, the aim of this study was to compare five different extraction methods of genomic DNA of mycobacteria in order to introduce the best method. For this purpose, pure colonies of Mycobacterium avium paratuberculosis were used as pathogenic mycobacterium and also a saprophytic strain called Mycobacterium phelei. The quality and quantity of the obtained DNA by each method was calculated, measured and evaluated respectively; based on extracted DNA concentrations (nanograms per microliter) at a wavelength of 260 nm and also optical density (OD) ratio based on the 260/280 wavelength by using the Nanodrop technique. The highest and lowest amounts of mycobacterial genome DNA was extracted using the CTAB (Cetyltrimethylammonium bromide) and boiling methods respectively. Comparison of the purity of extracted DNA also indicated that the highest purity was obtained using the CTAB method and the lowest using the boiling method. Also no significant differences were observed regarding the quality of extracted DNA from pathogenic and saprophytic mycobacteria among the evaluated extraction methods. Thus, according to the results of this study it appears that using the CTAB method is the most suitable way to extract genomic DNA for molecular detection of mycobacteria in different samples.

Keywords

• DNA extraction
• Genome
• Mycobacterium
• Pathogen
• Saprophyte