since the location of the ecori sites in rdna is known , and the specificity of the two exonucleases for 5 ' and 3 ' ends of dna strands has been established , the hybridization of the different partially digested rdna fragments with either 18s or 28s rrna could be interpreted in terms of polarity of the coding strand of rdna , and consequently of the rna ( see models in figure 1 ) .
C0035701
rrna
C0035668
rna