Abstract
DNA has been isolated from different mammalian tissues. The DNA preparations were free from RNA, protein and polysaccharides and have a similar range of sedimentation coefficients (approx. 24s). Protein was removed by a 2-stage extraction with a phenol-cresol mixture by using a detergent with 4-aminosalicylate in the 1st stage and sodium chloride in the 2nd. Polysaccharides remained in solution when DNA was precipitated with 2-butoxyethanol in the presence of 0. 5 [image]-sodium chloride and 1.5 [image]-sodium benzoate. Ribosomal RNA was removed by precipitation in the presence of 3 [image]-sodium chloride at 0[degree], when DNA remained soluble.