the fractions eluted by 175 mm ( nh4 ) 2so4 ( de-b ) from the deae-sephadex column and those eluting with rna polymerase i on the subsequent heparin-sepharose column ( hs-b ) were used in a run-off transcription assay using xho i-cleaved cloned rat rdna .
C0035678
rna polymerase i
C0040649
transcription