title: Imaging of DNA by scanning force microscopy.
abstract: The scanning probe microscopies applied to the sequencing of DNA is a challenging goal attempted by several groups. But one limitant parameter has been the sample preparation of DNA molecules. Here we report how to hold DNA molecules fixed on mica substrate and we show the three-dimensional configuration of double-stranded DNA obtained with our scanning force microscope. We can image DNA under negative supercoiling, a feature of general importance controlling the activities of DNA. We compared the electron micrographs of a carbon replica of the same DNA specimen with scanning force images which demonstrates well the feasibility and accuracy of our scanning probe measurements.
authors.affiliation: Group of Applied Physics, University of Geneva, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Zenhausern
authors.forename: M
authors.initials: M
authors.lastname: Adrian
authors.forename: B
authors.initials: B
authors.lastname: ten Heggeler-Bordier
authors.forename: R
authors.initials: R
authors.lastname: Emch
authors.forename: M
authors.initials: M
authors.lastname: Jobin
authors.forename: M
authors.initials: M
authors.lastname: Taborelli
authors.forename: P
authors.initials: P
authors.lastname: Descouts
mesh_terms: D004247:DNA / Q000648:ultrastructure*; D004278:DNA, Superhelical / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D013048:Specimen Handling
chemical_list: D004278:DNA, Superhelical; D004247:DNA