title: Electron microscopic visualization of restriction sites on DNA molecules.
abstract: DNA molecules were adsorbed to a polylysine-treated carbon film and digested directly on the film by restriction enzymes. After washing the film with 1 M NaCl, 0.4% Kodak Photo-Flo and 9% formamide, each cleavage site introduced was visualized as a gap under the electron microscope. By measuring the gapped positions on linear DNA molecules induced by other enzymes, a single EcoRI site on a lambda dv1 molecule and three HinHI sites on an fd1RF molecule were mapped at the positions expected from the cleavage maps, respectively. This electron-microscopic procedure may be useful for the construction of a cleavage map.
mesh_terms: D000327:Adsorption; D004262:DNA Restriction Enzymes; D004279:DNA, Viral; D008854:Microscopy, Electron; D009690:Nucleic Acid Conformation; D011107:Polylysine; D013379:Substrate Specificity
chemical_list: D004279:DNA, Viral; D011107:Polylysine; D004262:DNA Restriction Enzymes