electron micrographs are exhibited that demonstrate the usefulness of the technique in visualizing double- and single-stranded dna , escherichia coli rna polymerase ( nucleosidetriphosphate : rna nucleotidyltransferase , ec 2.7.7.6 ) in negative stain , and polymerase complexed to poly ( da-dt ) and to an 1100 base-pair restriction fragment of bacteriophage t7 dna containing the early promoters .
C0035681
rna polymerase
C0035673
rna nucleotidyltransferase