Comparison and Optimization of Methods for Metagenomic DNA Extraction from the Frozen Soil of the Glacier No.1 in the Tianshan Mountains

Abstract:

This study is aiming to establish a method for total DNA extraction from the frozen soil of the Glacier No.1 in the Tianshan Mountains. Four DNA extraction methods（SDS-CTAB，TENP，TEN and Zhou method）were used for DNA extraction from the frozen soil，and the yield，purity and integrity of the total DNA produced were compared. Among the four extraction methods tested，TEN method produced the highest purity with a A260/A280 and A260/A230 ratio of （1.82±0.40）and（0.97±0.38），respectively，and the yield of TEN method was（392±44） ng/g frozen soil. We further modified the TEN method by adding a pretreatment step. The A260/A280 and A260/A230 ratio of the extracted DNA reached（1.92±0.15）and（2.03±0.31），respectively，and the DNA yield of TEN4 method reached（449±61） ng/g frozen soil. 16S rDNA，26S rDNA PCR analysis，and restriction digestion analysis of the DNA extracted by TEN method further proved that the DNA was qualified for the construction of a meta-genomic DNA library. In summary，a modified TEN method suitable for DNA extraction from the frozen soil of the Glacier No.1 in the Tianshan Mountains was established，which could be used for meta-genomic DNA library construction.