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Full-Text Articles in Life Sciences
The Glass Knife In Ultramicrotomy, Lahja Sevéus, Cecilia Tarras-Wahlberg
The Glass Knife In Ultramicrotomy, Lahja Sevéus, Cecilia Tarras-Wahlberg
Scanning Electron Microscopy
To obtain the best ultrathin sections in ultramicrotomy and cryoultramicrotomy, a high quality knife is of paramount importance. Glass knives were introduced for ultramicrotomy, in the manually broken form, in 1950. Since the introduction of mechanical knifemakers, the production of glass knives has become a standardized laboratory routine. In conventional ultramicrotomy different knife angles are used to cover different specimens and embedding media. The 50° knife broken with a small deviation of the score from the diagonal of the square gives a long useful edge, especially if damping during breaking is used. The 50° knife is, therefore recommended as the …
Preparation Of Cryosections For Biological Microanalysis, Karl Zierold
Preparation Of Cryosections For Biological Microanalysis, Karl Zierold
Scanning Electron Microscopy
The element distribution in biological cells and tissues can be revealed by electron probe microanalysis from ultrathin cryosections. In particular, the distribution of physiologically important and often mobile elements such as Na, Mg, P, S, Cl, K, and Ca can be studied in cryosections on an ultrastructural level. The cryopreparation technique required for this purpose consists of 1. cryofixation, 2. cryosectioning, 3. cryotransfer including freeze-drying and carbon coating if necessary, 4. energy dispersive X-ray microanalysis in a cold stage equipped scanning transmission electron microscope. The lateral analytical resolution of this method is less than 50 nm in freeze-dried ultrathin (about …
Two Opposing Theories Of The Cell: Experimental Testing By Cryomethods And Electron Microscopy, L. Edelmann
Two Opposing Theories Of The Cell: Experimental Testing By Cryomethods And Electron Microscopy, L. Edelmann
Scanning Electron Microscopy
A main controversial issue in cell biology concerns the molecular mechanism responsible for K+ accumulation in living cells and Na+ exclusion from them. The alternative theoretical descriptions of these phenomena are based on different assumptions about the physical state of cellular Na+, K+ and H2O. In this article it is shown with striated muscles how cryomethods and microanlytical electron microscopy may be used to test the opposing theories. It is concluded that these methods may yield more realistic informations about the physical state of cellular K+ and Na+ than measurements with …
Problems Associated With The Preparation Of Cell Suspensions For X-Ray Microanalysis Highlighted By The Comparison Of Results With Those Obtained From Tissue Sections, A. Warley, M. D. Kendall, I. W. Morris
Problems Associated With The Preparation Of Cell Suspensions For X-Ray Microanalysis Highlighted By The Comparison Of Results With Those Obtained From Tissue Sections, A. Warley, M. D. Kendall, I. W. Morris
Scanning Electron Microscopy
Fully quantitative X-ray microanalysis of freeze dried frozen sections allowed the concentration of monovalent ions in the nuclei of mouse thymocytes in tissue sections to be compared with those from thymocytes which had been isolated by a simple preparation procedure. Isolated cells showed increased concentrations of Na and Cl. This was further investigated in the rat where the size of the thymus a 11 owed comparison between different isolation media using cells derived from the same animal. Use of autologous serum as the final suspending medium gave reproducible results, whereas with suspension in BSS, or 20% dextran the results were …