Abstract
A technique for the examination of specimens at low electron beam intensity has been presented. Sections micrographed with this technique showed numerous knife scratches and frequently contained bands running parallel to the knife edge. Banding with an average spacing of 0.2 µ appeared to result from periodic distortion produced by impact of the knife. At the beam intensities customarily employed, differential sublimation and probably flow of the methacrylate resulted in obliteration of the bands and all but the deepest knife scratches. In addition, changes in the size, shape, and orientation of certain structures were noted. Artifacts resulting from incineration or sublimation of tissue components fixed in formalin were illustrated, and the suggestion was made that such instability to the electron beam accounted in part for the differences observed in osmium- and formalin-fixed tissues. The deformation revealed in serial sections was discussed, and it was pointed out that shortening in the axis perpendicular to the knife edge was associated with elongation in the axis parallel to the cutting edge, the elongation usually occurring locally without change in the width of the section. It was noted that the material causing contamination of the surface of sections during examination exhibited no structure but caused progressive loss of contrast.
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- DRAPER M. H., HODGE A. J. Electron-induced microincineration with the electron microscope. I. Distribution of residual mineral content in vertebrate striated muscle. Aust J Exp Biol Med Sci. 1950 Sep;28(5):549–557. doi: 10.1038/icb.1950.54. [DOI] [PubMed] [Google Scholar]
- LATTA H., HARTMANN J. F. Use of a glass edge in thin sectioning for electron microscopy. Proc Soc Exp Biol Med. 1950 Jun;74(2):436–439. doi: 10.3181/00379727-74-17931. [DOI] [PubMed] [Google Scholar]
- MORGAN C., BERGOLD G. H., MOORE D. H., ROSE H. M. The macromolecular paracrystalline lattice of insect viral polyhedral bodies demonstrated in ultrathin sections examined in the electron microscope. J Biophys Biochem Cytol. 1955 May 25;1(3):187–190. doi: 10.1083/jcb.1.3.187. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MORGAN C., ELLISON S. A., ROSE H. M., MOORE D. H. Serial sections of vaccinia virus examined at one stage of development in the electron microscope. Exp Cell Res. 1955 Dec;9(3):572–578. doi: 10.1016/0014-4827(55)90086-0. [DOI] [PubMed] [Google Scholar]
- MORGAN C., ELLISON S. A., ROSE H. M., MOORE D. H. Structure and development of viruses observed in the electron microscope. II. Vaccinia and fowl pox viruses. J Exp Med. 1954 Sep 1;100(3):301–310. doi: 10.1084/jem.100.3.301. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PALADE G. E. A small particulate component of the cytoplasm. J Biophys Biochem Cytol. 1955 Jan;1(1):59–68. doi: 10.1083/jcb.1.1.59. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PALADE G. E. A study of fixation for electron microscopy. J Exp Med. 1952 Mar;95(3):285–298. doi: 10.1084/jem.95.3.285. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PORTER K. R., BLUM J. A study in microtomy for electron microscopy. Anat Rec. 1953 Dec;117(4):685–710. doi: 10.1002/ar.1091170403. [DOI] [PubMed] [Google Scholar]
- ROZSA G., WYCKOFF R. W. G. The electron microscopy of dividing cells. Biochim Biophys Acta. 1950 Nov;6(2):334–339. doi: 10.1016/0006-3002(50)90107-7. [DOI] [PubMed] [Google Scholar]
- WATSON M. L. A method for complete extraction of embedding material from tissue sections for the electron microscope. Biochim Biophys Acta. 1953 Mar;10(3):349–354. doi: 10.1016/0006-3002(53)90264-9. [DOI] [PubMed] [Google Scholar]
- WATSON M. L., AVERY J. K. The development of the hamster lower incisor as observed by electron microscopy. Am J Anat. 1954 Jul;95(1):109–161. doi: 10.1002/aja.1000950105. [DOI] [PubMed] [Google Scholar]
- WILLIAMS R. C., KALLMAN F. Interpretation of electron micrographs of single and serial sections. J Biophys Biochem Cytol. 1955 Jul 25;1(4):301–314. doi: 10.1083/jcb.1.4.301. [DOI] [PMC free article] [PubMed] [Google Scholar]
