A procedure for the preparation of bacterial DNA that employs dimethyl sulfoxide to induce the lysis of cells.

A protocol for the preparation of DNA from Escherichia coli and Bacillus subtilis without the use of lysozyme as a permeabilizing agent is described. This preliminary step is carried out by treating the cells with dimethyl sulfoxide. A 5-min incubation of the cell pellet in the pure solvent, followed by the treatment with sodium dodecyl sulfate, is sufficient to induce cell lysis. The plasmid DNAs obtained by this method were equivalent in purity and quantity to the material prepared from lysozyme-digested cells and amenable to restriction and ligation. Transformation by plasmid and genomic DNAs prepared from dimethyl sulfoxide-treated cells was demonstrated.