scholarly journals Macromolecular substructure in nuclear pore complexes by in-lens field-emission scanning electron microscopy

Scanning ◽  
1997 ◽  
Vol 19 (6) ◽  
pp. 403-410 ◽  
Author(s):  
T. D. Allen ◽  
G. R. Bennion ◽  
S. A. Rutherford ◽  
S. Reipert ◽  
A. Ramalho ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Pore Complexes ◽  
Scanning Electron

scholarly journals Characterization of the nuclear envelope, pore complexes, and dense lamina of mouse liver nuclei by high resolution scanning electron microscopy.

1977 ◽  
Vol 72 (1) ◽  
pp. 118-132 ◽  
Author(s):  
R H Kirschner ◽  
M Rusli ◽  
T E Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Mouse Liver ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Liver Nuclei ◽  
Pore Complexes ◽  
Triton X ◽  
Scanning Electron

We have used high resolution scanning electron microscopy (SEM) to study the nuclear envelope components of isolated mouse liver nuclei. The surfaces of intact nuclei are covered by closely packed ribosomes which are distinguishable by SEM from nuclear pore complexes. After removal of nuclear membranes with the nonionic detergent Triton X-100, the pore complexes remain attached to an underlying, peripheral nuclear lamina, as described by others. The surface of this dense lamina is composed of particulate granules, 75-150 A in diameter, which are contiguous over the entire periphery. We did not observe the pore-to-pore fibril network suggested by other investigators, but such a structure might be the framework upon which the dense lamina is formed. Morphometric analysis of pores and pore complexes shows their size, structure, and density to be similar to that of other mammalian cells. In addition, several types of pore complex-associated structures, not previously reported by other electron microscope (EM) techniques, are observed by SEM. Our studies suggest that the major role of the dense lamina is associated with the distribution, stability, and perhaps, biogenesis of nuclear pore complexes. Treatment of isolated nuclei with a combination of Triton X-100 and sodium deoxycholate removes membranes, dense lamina, and nuclear pore complexes. The resulting "chromatin nuclei" retain their integrity despite the absence of any limiting peripheral structures.

scholarly journals High resolution scanning electron microscopy of the nuclear envelope: demonstration of a new, regular, fibrous lattice attached to the baskets of the nucleoplasmic face of the nuclear pores.

1992 ◽  
Vol 119 (6) ◽  
pp. 1429-1440 ◽  
Author(s):  
M W Goldberg ◽  
T D Allen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Nuclear Envelope ◽  
Nuclear Lamina ◽  
Objective Lens ◽  
Nuclear Pore ◽  
Nuclear Pore Complexes ◽  
Triturus Cristatus ◽  
Scanning Electron

The nuclear envelope (NE) of amphibian oocytes can be readily isolated in relatively structurally intact and pure form and has been used extensively for structural studies. Using high resolution scanning electron microscopy (HRSEM), both surfaces of the NE can be visualized in detail. Here, we demonstrate the use of HRSEM to obtain high resolution information of NE structure, confirming previous data and providing some new information. NEs, manually isolated from Triturus cristatus oocytes, have been mounted on conductive silicon chips, fixed, critical point dried and coated with a thin, continuous film of chromium or tantalum and viewed at relatively high accelerating voltage in a field emission scanning electron microscope with the sample within the objective lens. Both nucleoplasmic and cytoplasmic surfaces of the nuclear pore complexes (NPC) have been visualized, revealing the cytoplasmic coaxial ring, associated particles, central plug/transporter and spokes. The nucleoplasmic face is dominated by the previously described basketlike structure attached to the nucleoplasmic coaxial ring. In Triturus, a novel, highly regular flat sheet of fibers, termed the NE lattice (NEL) has been observed attached to the distal ring of the NPC basket. The NEL appears to be distinct from the nuclear lamina. Evidence for the NEL is also presented in thin TEM sections from Triturus oocytes and GVs and in spread NEs from Xenopus. A model is presented for NEL structure and its interaction with the NPCs is discussed.

A New Image Processing Technique for STEM

1974 ◽  
Vol 32 ◽  
pp. 432-433
Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Elastic Scattering ◽  
Field Emission ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Energy Analyzer ◽  
Scanning Microscope ◽  
Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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