analyses of the rna extracted from the cells labeled with [ 3h ] uridine by agarose gel electrophoresis and by poly ( u ) -sepharose column chromatography show that the contents of ribosomal precursor rna and poly ( a ) -containing rna are both low in the methylnitrosourea-treated cells as compared with those in the untreated cells and that the reduction in the contents of these kinds of rna is almost completely prevented by the addition of 3-aminobenzamide to the culture medium .
C0035701
ribosomal
C0035668
rna