[Isolation of RNA containing a polyadenylic acid sequence by chromatography on unmodified cellulose].

A new modification of the procedure of the isolation of polyA-containing RNAs is worked out, which makes possible to isolate this RNA fraction free of considerable contamination with rRNA. The administration of 0.0001 M EDTA-Na2 provides the absence of RNA aggregation and prevents non-specific RNA binding on cellulose columns, which takes place when more high EDTA-Na2 concentrations in elution solutions are applied. Under these conditions synthetic polyA in model experiments practically completely binds with cellulose in a broad range of concentrations. It permits to use the procedure described for the preparative isolation of RNA fractions, containing polyA sequences.