Comparative Studies on the Extraction of Metagenomic DNA from Various Soil and Sediment Samples of Jammu and Kashmir Region in Prospect for Novel Biocatalysts

Abstract

A modified and efficient method has been developed for extracting high molecular weight (HMW) DNA free of inhibitors (humic substances) from soil and sediment samples of Jammu and Kashmir region. The method includes precipitation of extracted soil and sediment DNA with 0.5 volumes of 50% polyethylene glycol (PEG) and 0.1 volumes of 1M NaCl (sodium chloride) followed by treatment with 2% CaCl 2 (calcium chloride).The results of this method were compared with the other reported procedures. The method exhibited good yield and significantly improved the quality of DNA with efficient removal of humic substances. The purity of the extracted DNA from soil and sediment samples was validated by restriction analysis and PCR amplification. DNA extracted from different samples could be purified in one hour with 2% CaCl 2 treatment resulting in DNA pure enough to be processesed for gene cloning techniques. Standard protocol of [9] was used for the extraction of DNA from brackish waters. This paper presents in detail the method which can be used successfully in overcoming the limitation of most of the reported protocols for soil and sediment DNA extraction and purification.