Аннотация:Not only separation of native, two-stranded DNA from denatured molecules but more distinct fractionation of single-stranded DNA was demonstrated on unmodified powdery and microgranular cellulose. Denatured DNA, absorbed on cellulose, was eluted from a column as two asymmetric peaks by 0,12 M and 0.05 M NaCl (for I and II peaks, respectively). Absorption and fractionation of denatured DNA and poly-A containing RNA on unmodified cellulose was apparently achieved on the basis of the same principles.