EXTRACTION AND PURIFICATION OF SOIL MICROBIAL GENOMIC DNA FROM TAIHU AREA AND PRIMARY CONSTRUCTION OF PLASMID LIBRARIES

A method has been developed for extracting genomic DNA from samples of Taihu area. In this method, the environmental samples were treated first by grinding and freezing/thawing and subsequently by SDS/proteinase K and CTAB-based DNA extraction. The crude extraction from these samples was purified by dialysis bag and Nucleaotrap respectively. Both purification methods resulted in complete removal of the brown color from crude DNA solution. The purified DNA could be digested well by 4 kinds of restriction enzymes and was pure enough for amplification of 16S rDNA gene and other random primers. Mixed genomic DNA libraries for the environmental samples were constructed by inserting part restriction digesting fragments (3-8 kb) into plasmid pSK- and then transforming competent E. coli JM109 with the resultant plamids. Fig 6, Ref 7