Direct imaging of an adsorbed layer by high-resolution electron microscopy

The value of high-resolution electron microscopy as a technique in coal science and technology is illustrated by reference to the study of the onset, on heating, of the crystallinity of relatively unstructured coals and carbonaceous solids; by the detection of changes, upon use, that occur in hydrodesulphurization catalysts; and by the direct imaging of structural features in ( a ) metal catalysts supported on graphitic carbons and ( b ) graphite intercalates of the kind known to be potentially useful in Fischer-Tropsch and related syntheses, which are commercially viable in the conversion of coal to petrols and chemicals. The technique is also capable of imaging directly the structure of a range of zeolites, including the A, X and Y types, and the ZSM-5 zeolitic catalysts, which figure eminently in the conversion of methanol to petrol. The advantages of high-resolution microscopy, compared with X-ray based methods for the problems peculiar to coal science, are stressed.

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Direct imaging of CdTe(001) surface reconstructions by high-resolution electron microscopy

Surface Science ◽

10.1016/0039-6028(91)90644-8 ◽

1991 ◽

Vol 254 (1-3) ◽

pp. 119-124 ◽

Cited By ~ 25

Author(s):

Ping Lu ◽

David J. Smith

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

High Resolution Electron Microscopy ◽

Direct Imaging ◽

Resolution Electron ◽

Surface Reconstructions

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077268 ◽

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.

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Electron microscopy of rabbit FC crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077220 ◽

1983 ◽

Vol 41 ◽

pp. 730-731

Author(s):

Robert A. Grant ◽

Laura L. Degn ◽

Wah Chiu ◽

John Robinson

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

High Resolution Electron Microscopy ◽

Molecular Replacement ◽

X Ray ◽

X Ray Crystallography ◽

Resolution Electron ◽

Replacement Technique ◽

Hydrated Crystal ◽

Molecular Structure Analysis

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.

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