A new method for the preparation of DNA-cellulose

DNA immobilized on cellulose or agarose has been found very useful for the separation and purification of DNA-binding proteins (1–4). A variety of methods for DNA immobilization has been proposed, including absorption (3), entrapment in gels (4), and covalent binding (1). In the course of a study of the behavior of a complex between histones and immobilized DNA, we have met the need of a particularly stable DNA-cellulose preparation, i.e., involving not only covalent bonds between the nucleic acid and the polysaccharide, but bonds resistent to extremes of pH, particularly in the alkaline region. It has been found that cellulose activated with cyanuric chloride affords a convenient material for the preparation of DNA-cellulose, which has the following favorable characteristics: (i) It can be prepared by an easy and reproducible method; (ii) double-stranded DNA is bound in satisfactory amounts; (iii) the material is very stable, even in urea and in alkaline conditions.