Isolation of DNA from yeast by chromatography on hydroxyapatite

A simple procedure is described for isolation of purified non degraded total DNA from yeast cells. The procedure involves conversion of the cells into spheroplasts by enzymatic treatment, lysis of the spheroplasts in 8 M urea - 0.24 M sodium phosphate buffer - 0.01 M EDTA (ethylendiamintetraacetic acid, sodium salt) - 1% SDS (sodium dodecyl sulphate), deproteinization of the lysate with chloroform-phenol and separation of the DNA from proteins, RNA and other contaminants by hydroxyapatite chromatography. The yield is about 90% of the DNA in the starting material (spheroplasts).