title: Direct extraction of microbial community DNA from humified upland soils.
abstract: This paper describes a protocol effective at extracting high yields of high-purity microbial community DNA from humified soils. DNA was extracted from soil by lysozyme, SDS and freeze-thaw lysis, precipitated and then subjected to a double caesium chloride density gradient centrifugation stage before concentrating and washing. Evaluation using three soils yielded up to 30 micrograms DNA g-1 dry soil, with absorbance ratios at 260:230 nm and 260:280 nm of 1.6-2.0. The DNA extracted from the three soils was digested by four restriction enzymes and a 16S rDNA eubacterial product was amplified by PCR. These tests indicated that the DNA obtained by the protocol was sufficiently pure for molecular biological analysis.
authors.affiliation: Cellular and Environmental Physiology Department, Scottish Crop Research Institute, Invergowrie, Dundee, UK.
authors.forename: C D
authors.initials: CD
authors.lastname: Clegg
authors.forename: K
authors.initials: K
authors.lastname: Ritz
authors.forename: B S
authors.initials: BS
authors.lastname: Griffiths
mesh_terms: D004269:DNA, Bacterial / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology
chemical_list: D004269:DNA, Bacterial