An efficient purification and fractionation of genomic DNA from soil by modified troughing method

AIMS: The aim of this study was to utilize a modified troughing method for purification of large genomic DNA obtained from microbiota in natural environment and for fractionation of genomic DNA into many size ranges that facilitates construction of metagenomic library. METHODS AND RESULTS: Genomic DNA extracted from soil or termite gut was purified by the modified troughing method which utilized gel electrophoresis in the presence of 30% PEG8000. The method performed better than various purification kits and allowed no significant loss in the amount of DNA recovered. In addition, the efficiency of the modified troughing method for DNA size fractionation was investigated. DNA size fractionation was achieved with repetitive rounds of electrophoresis and DNA collection to obtain DNA with many size ranges. CONCLUSIONS: The modified troughing method is a simple and efficient method for purification of genomic DNA and for DNA size fractionation. SIGNIFICANCE AND IMPACT OF THE STUDY: The modified troughing method is a straightforward and inexpensive technique readily available for anyone working with environmental genomic DNA. It facilitates cloning of genomic DNA and enhances rapid discovery of useful bioactive compounds from microbial resources.