FREEZE-FIXATION OF LIVING CELLS AND ITS USE IN ELECTRON MICROSCOPY,
Abstract
The freezing process in cells depends primarily on the freezing rapidity, the frosthardiness of the object, and the concentration of the anti-freeze solution (glycerin) in the cytoplasm. Compressed yeast was the test object used in most experiments. The influence of the freezing rapidity manifests itself in three different ways: cell water crystallizes either externally or within the cell, or an amorphous solidification (vitrification) takes place. The determination of the freezing point, supercooling capacity, and recrystallization point offers an explanation for the above effects, and leads to a physical understanding of the phenomenon of frosthardiness. Physical study shows the manner in which the anti-freeze solution increases frosthardiness; physiological experiments illustrate some side-effects of glycerin. Successful freezing of living cells depends primarily on the choice of suitable freezing speed and anti-freeze solution. Depending on the frosthardiness of the object (that is, depending on the lowest point of re-crystallization in the cells), the ultimate temperature of the freezing process should not be below -50 to -70C. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 11, 1965
- Accession Number
- AD0837455
Entities
People
- H. Moor
Organizations
- United States Army Biological Warfare Laboratories