High-resolution atomic-force microscopy of DNA: the pitch of the double helix

FEBS Lett. 1995 Sep 11;371(3):279-82. doi: 10.1016/0014-5793(95)00906-p.

Abstract

Using a cationic lipid bilayer, we show that DNA can be reliably adsorbed to the bilayer surface for atomic force microscopy (AFM) in aqueous buffers at high resolution. The measured width of the dsDNA is close to 2 nm, and a periodic modulation on dsDNA is reproducibly detected by the AFM. The measured period is 3.4 +/- 0.4 nm, in excellent agreement with the known pitch of the double helix. The right-handedness of the double helix is directly discernible in high resolution AFM images. Thus, this approach can be readily applied to the study of DNA-protein interactions, as well as sequence mapping at high resolution.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • DNA / chemistry*
  • DNA, Bacterial / chemistry
  • Membranes, Artificial
  • Microscopy, Atomic Force
  • Nucleic Acid Conformation*
  • Reproducibility of Results

Substances

  • DNA, Bacterial
  • Membranes, Artificial
  • DNA