Atomic force microscopy of DNA on mica and chemically modified mica

Scanning Microsc. 1992 Dec;6(4):911-8.

Abstract

Atomic force microscopy (AFM) was used to image circular DNA adsorbed on freshly cleaved mica and mica chemically modified with Mg(II), Co(II), La(III), and Zr(IV). Images obtained on unmodified mica show coiling of DNA due to forces involved during the drying process. The coiling or super twisting appeared to be right handed and the extent of super twisting could be controlled by the drying conditions. Images of DNA observed on chemically modified surfaces show isolated open circular DNA that is free from super twisting, presumably due to strong binding of DNA on chemically modified surfaces.

Publication types

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

MeSH terms

  • Adsorption
  • Aluminum Silicates / chemistry*
  • Artifacts
  • DNA, Circular / ultrastructure*
  • Escherichia coli / genetics
  • Microscopy / methods*
  • Nucleic Acid Conformation
  • Reproducibility of Results

Substances

  • Aluminum Silicates
  • DNA, Circular
  • mica