Electron microscopy of liquid crystalline DNA: direct evidence for cholesteric-like organization of DNA in dinoflagellate chromosomes

Chromosoma. 1989 Oct;98(4):280-6. doi: 10.1007/BF00327314.


Freeze-fracture-etch replicas of concentrated DNA solutions which appeared, by polarized light microscopy, to be in a cholesteric-like liquid crystalline state were examined by high resolution transmission electron microscopy (TEM). Individual DNA molecules were resolvable, and the microscopic morphologies observed for such replicas confirmed the cholesteric organization of DNA molecules in this liquid crystalline state. Furthermore, replica morphologies were strikingly similar to TEM images of dinoflagellate chromosomes in both thin section and freeze-etch replicas, providing strong support for the cholesteric DNA packing model proposed for the organization of DNA in these chromosomes by Bouligand and Livolant.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Chromosomes / ultrastructure*
  • Crystallization
  • DNA / ultrastructure*
  • Dinoflagellida / genetics*
  • Dinoflagellida / ultrastructure
  • Freeze Etching
  • Nucleic Acid Conformation


  • DNA