The extraction and purification of microbial DNA from sediments

A new method for the isolation of intracellular and extacellular DNA from a range of sediment types has been developed. This method is based upon the direct lysis of cells in the sediment, extraction of released DNA from the sediments and its subsequent purification by CsCL-EtBr gradient centrifugation and/or hydroxyapatite chromatography. Yields of 26 μg intracellular DNA and 1 μg extracellular DNA have been obtained per gram of sediment.