Advances in ultrarapid freezing for the preservation of cellular ultrastructure
Article first published online: 4 FEB 2005
Copyright © 1986 Wiley-Liss, Inc.
Journal of Electron Microscopy Technique
Volume 3, Issue 2, pages 177–210, 1986
How to Cite
Gilkey, J. C. and Staehelin, L. A. (1986), Advances in ultrarapid freezing for the preservation of cellular ultrastructure. J. Elec. Microsc. Tech., 3: 177–210. doi: 10.1002/jemt.1060030206
- Issue published online: 4 FEB 2005
- Article first published online: 4 FEB 2005
- Manuscript Accepted: 28 JUN 1985
- Manuscript Received: 27 DEC 1984
- Cellular ultrastructure;
- Ultrarapid freezing;
- Ice crystal formation
Most of our current knowledge of cellular ultrastructure is derived from studies of chemically fixed and chemically cryoprotected preparations. In the first part of this review, we document the many artifacts associated with chemical techniques that render them unsuitable for further refinement of our understanding of cellular ultrastructure. The best method currently available for the preservation of cellular ultrastructure is ultrarapid freezing. The second part of this review is a consideration of the physics of ice crystal formation in biological systems, which suggests that ice crystals will be present in any frozen, uncryoprotected specimen. We define an ultrarapidly frozen preparation as one in which the ice crystals are so small as to be invisible at the electron microscopic level. Improvements in the ease of application and reliability of ultrarapid freezing techniques have reached the point that these techniques can be used by anyone requiring the best achievable preservation of cellular ultrastructure. In the third part of this review, we describe and critique the five methods of ultrarapid freezing in current use.