title: Removal of humic substances from soil DNA using aluminium sulfate.
abstract: Direct extraction of soil DNA has become essential for the study of soil microorganisms. Humic substances co-extracted during DNA retrieval is a big problem because it greatly inhibits the enzymes involved in manipulating DNA. Popular commercial kits available for soil DNA extraction are unable to overcome this problem. Here we report an effective protocol for the removal of humic substance from soil DNA. The protocol involves flocculation of the humic substance by excessive Al(3+), then removal of superfluous Al(3+) via pH adjustment and finally release of soil microbial DNA by SDS lysis. This technique is superior to that employed by the UltraClean Soil DNA Kit and can be applied to a wide variety of soils.
authors.affiliation: Laboratory of Molecular Microbiology, College of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
authors.forename: Dexian
authors.initials: D
authors.lastname: Dong
authors.forename: An
authors.initials: A
authors.lastname: Yan
authors.forename: Haiming
authors.initials: H
authors.lastname: Liu
authors.forename: Xuehong
authors.initials: X
authors.lastname: Zhang
authors.forename: Yuquan
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000534:Alum Compounds / Q000737:chemistry*; D004269:DNA, Bacterial / Q000302:isolation & purification*; D005427:Flocculation; D006812:Humic Substances / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D012988:Soil Microbiology
chemical_list: D000534:Alum Compounds; D004269:DNA, Bacterial; D006812:Humic Substances; C041524:aluminum sulfate