The influence of different cryopreparations on the distribution of ions in bullfrog myocard cells.
Bullfrog heart muscle trabecula are shock-frozen in liquid propane cooled by liquid nitrogen and then processed for X-ray microanalysis in two different ways: 1. Freeze-drying followed by vacuum embedding. 2. Cryoultramicrotomy and freeze-drying. Stained sections of freeze-dried, embedded tissue exhibit detailed ultrastructure, but are useless for X-ray microanalysis. Unstained, dry cut plastic-sections are suitable for X-ray microanalysis, but the ultrastructure appears faint. Higher electron optical contrast and peak-to-background ratio of X-ray spectra are generally obtained in freeze-dried cryosections. Both preparation methods show that the X-ray spectra are influenced by the quality of cryofixation. The phosphorus/potassium ratio in nuclei increases with increasing ice crystal size.
Meyer
R
R
Schmitz
M
M
Zierold
K
K
D000818:Animals; D004577:Electron Probe Microanalysis; D005612:Freeze Drying; D005615:Freezing; D007477:Ions; D008854:Microscopy, Electron; D009206:Myocardium / Q000032:analysis* / Q000648:ultrastructure; D011892:Rana catesbeiana; D013194:Staining and Labeling; D014021:Tissue Preservation / Q000379:methods*
D007477:Ions