Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

Digital image processing for high resolution electron microscopy

1988 ◽  
Vol 107 (2) ◽  
pp. 521-530 ◽  
Author(s):  
W. Coene ◽  
A. F. de Jong ◽  
D. van Dyck ◽  
G. van Tendeloo ◽  
J. van Landuyt
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
High Resolution ◽  
Digital Image Processing ◽  
Digital Image ◽  
High Resolution Electron Microscopy ◽  
Resolution Electron

Periodic Extension in Optical Diffraction Analysis

1982 ◽  
Vol 40 ◽  
pp. 428-429
Author(s):  
R. Gronsky ◽  
C.S. Murty
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Considerable Increase ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Diffraction Spectrum ◽  
Optical Bench ◽  
Instrumental Performance ◽  
Resolution Electron ◽  
Diffraction Effects

Although the more traditional applications of optical diffractograms in high resolution electron microscopy are related to determining instrumental performance, a significant advantage can also be achieved with this technique in the analysis of fine microstructural detail. Optical microdiffraction utilizes a field-limiting aperture in the optical bench system to selectively obtain the diffraction spectrum of specific segments of high resolution negatives, with a considerable increase in spatial resolution. Unfortunately the diffraction effects from the sampling aperture itself often interfere with the interpretation of results

On the interpretation of electron diffraction patterns from materials containing planar boundaries: the intergrowth tungsten bronzes

1990 ◽  
Vol 429 (1876) ◽  
pp. 91-117 ◽  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Electron Diffraction ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
General Interest ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Diffraction Patterns

Materials containing planar boundaries are of general interest and complete understanding of their structures is important. When direct imaging of the boundaries by, for instance, high-resolution electron microscopy, is impracticable, details of their structure and arrangement may be obtained from electron diffraction patterns. Such patterns are discussed in terms of those from intergrowth tungsten bronzes as specific examples. Fourier-transform calculations for proposed structures have been made to establish, in conjunction with optical-diffraction analogues, the features of the far-field diffraction patterns. These results have been compared with diffraction patterns obtained experimentally by transmission electron microscopy. The aim of the study, to show that the arrangement of the boundaries in these complicated phases can be deduced from their diffraction patterns without the need for high-resolution imaging, has been achieved. The steps to be taken to make these deductions are set out.

In or on? Location of noble metal particles on zeolite/binder support

1995 ◽  
Vol 53 ◽  
pp. 406-407
Author(s):  
G. E. Spinnler ◽  
J. Liu
Keyword(s):  
Electron Microscopy ◽  
Noble Metal ◽  
Analytical Techniques ◽  
Sample Surface ◽  
High Resolution Electron Microscopy ◽  
Metal Particles ◽  
State University ◽  
Microscopy Imaging ◽  
Transmission Imaging ◽  
Resolution Electron

The location of metal particles contained in a zeolite-alumina binder support matrix has been difficult to solve using analytical techniques including electron microscopy. Imaging of metal particles, particularly noble metal particles on relatively light matrices such as zeolites or aluminas, has been easily accomplished using high angle annular darkfield imaging (HAADF). Since transmission imaging provides a projection through the sample, location of the particles in the sample or on the surface is not obvious. Surfacesensitive signals such as secondary electrons (SE) and Auger electrons (AE) are necessary to detect particles on the sample surface. HAADF, SE, and AE imaging have been applied to locate noble metal particles in a zeolite support with an alpha alumina binder.The samples were analyzed in a UHV HB501S STEM (MIDAS, Microscope for Imaging and Diffraction Analysis of Surfaces) at the Center for High Resolution Electron Microscopy at Arizona State University. The samples were prepared by crushing and dry deposition on a holey carbon grid.

Molecular imaging of Organo-Calcium salts by High Resolution Electron Microscopy and Image Processing

1990 ◽  
Vol 48 (1) ◽  
pp. 590-591
Author(s):  
G. Miller ◽  
J.R. Fryer ◽  
W. Kunath ◽  
K. Weiss
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Unit Cell ◽  
Recording Device ◽  
Resolution Electron

Unfortunatly Wolfgang Kunath died January 1990High resolution electron microscopy and image processing are being used to determine the molecular packing within the crystal unit cell of the, organic-azo calcium salt. Due to the beam sensitive nature of the organic moiety which contains both aromatic and and aliphatic components, low dose techniques were used. This concisted of, searching the sample in the diffraction mode to find single crystals exibiting point like reflection to at least .2nm resolution, (fig. 1). Focusing and astigmatism correction was performed by moving the beam of the crystal (off axis). The beam was then moved on axis and a series of four, 10 e/A images taken, (fig. 2). Images were primarily recorded using an on line T.V. recording device. These images were then available for processing using the Semper image processing system. Two crystal orientations were found. Type 1 consisted of thin plate like crystals up to 5um diameter and generally 10nm to 20nm thick. Type 2 were thicker crystals with a 3.2nm lattice spacing. The power specrta of the first low dose images were calculated to asses the quality of the of the structural information present. For the type 1 crystal the power spectrum had to show at least second order reflections in two directions ( fig. 3 ). Type 2 crystals showed the 3.2nm reflection often down to the fith order. These crystals also showed parallel side bands corresponding to a d-spacing of about .8nm. With these results the unit cell was found to be tetragonal with a= .78nm b= 3.2nm c= .78nm. In accordance with the diffraction patterns exibited.

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