Low-Dose Electron Microscopy of Individual Biological Macromolecules
Structural details at a resolution in the range 7–15 Å have now been demonstrated for a number of biological macromolecules [1, 2, 13]. The main limitation to visualizing such high-resolution details has been the damage to macromolecular fine structure caused by the large electron dosages employed in conventional electron microscopy . Reduction of electron dosages, however, results in recorded images with an extremely poor signal- to-noise ratio. This ratio is further reduced by the need to sacrifice conventional staining methods if one aims at high resolution. This problem has been effectively overcome by averaging over a large number of unit cells, which is easy to achieve for the ordered two- dimensional arrays which occur in a number of biological objects.
KeywordsMigration Cage Glutamine Choline Macromolecule
Unable to display preview. Download preview PDF.
- 3.Frank J, Goldfarb W, Kessel M (1978) Image reconstruction of low and high dose micrographs of negatively stained glutamine synthetase. Proc 9th Int Congr Electron Microsc, vol II, pp 8–9. TorontoGoogle Scholar
- 4.Frank J, Goldfarb W (1980) Methods for averaging of Single molecules and lattice fragments. This volumeGoogle Scholar
- 6.Frank J (1978) Reconstruction of non-periodic objects using correlation methods. Proc 9th Int Congr Electron Microsc, vol III, pp 87–93. TorontoGoogle Scholar
- 7.Frank J, Shimkin B (1978) A new image processing Software system for structural analysis and contrast enhancement. Proc 9th Int Congr Electron Microsc, vol I, pp 210–211. TorontoGoogle Scholar
- 15.Zingsheim HP, Neugebauer, DCh, Barrantes FJ; Frank J (1980) Image averaging of the acetyl- choline reeeptor. This volumeGoogle Scholar