Use of a Sequence‐Specific DNA‐Binding Ligand to Probe the Environments of EcoRI Restriction Endonuclease Cleavage Sites

Abstract

The DNAs of bacteriophage lambda and adenovirus were incubated with the sequence-specific DNA-binding ligand 6,4′-diamidino-2-phenylindole. Digestion of the ligand DNA complexes with EcoRI nuclease and subsequent agarose gel electrophoresis demonstrated that the ligand inhibited nuclease activity at some sites, but not at others. The results suggest that.diamidino-2-phenylindole can be used to probe the immediate environments of the EcoRI cleavage sites.