scholarly journals Coated-vesicle shells, particle/chain material, and tubulin in brain synaptosomes. An electron microscope and biochemical study.

1976 ◽  
Vol 69 (3) ◽  
pp. 608-621 ◽  
Author(s):  
T Kadota ◽  
K Kadota ◽  
E G Gray

Coated vesicles (CVs), plain synaptic vesicles (PSVs), and nonvesicular flocculent material were isolated from synaptosomes and examined with goniometry and high-resolution electron microscopy after either negative staining or various biochemical procedures. The flocculent material (i.e. the presynaptic matrix material except CV shells) is largely composed of particulate or elongated (chainlike) structures; some of this material (here referred to as particle/chain material) is attached to PSVs. The results obtained were: (a) the proteinaceous properties of the CV coat (also referred to as CV shell) and the particle/chain material were demonstrated with chymotrypsin; (b) the CV shell, studied with various negative-staining techniques, differs from the particle/chain material since it has no 3-4-nm globular subunits and reacts differently to alkaline pH; (c) the particle/chain material consists of aggregates of 3-4-nm globular subunits, four of which yield 8-10-nm fine particles; and these particles can be further aggregated into chains 8-10 nm wide and up to 30-60 nm long showing a "hollow" core; (d) vinblastine sulfate induced ringlike or helical crystalloid precipitates closely resembling the vinblastine-induced microtubule crystals reported in the literature, but vinblastine had no effect on either the CV shell material or the particle/chain material.

Author(s):  
Sumio Iijima

We have developed a technique to prepare thin single crystal films of graphite for use as supporting films for high resolution electron microscopy. As we showed elsewhere (1), these films are completely noiseless and therefore can be used in the observation of phase objects by CTEM, such as single atoms or molecules as a means for overcoming the difficulties because of the background noise which appears with amorphous carbon supporting films, even though they are prepared so as to be less than 20Å thick. Since the graphite films are thinned by reaction with WO3 crystals under electron beam irradiation in the microscope, some small crystallites of WC or WC2 are inevitably left on the films as by-products. These particles are usually found to be over 10-20Å diameter but very fine particles are also formed on the film and these can serve as good test objects for studying the image formation of phase objects.


2001 ◽  
Vol 16 (2) ◽  
pp. 407-412 ◽  
Author(s):  
M. Muralidhar ◽  
M. Jirsa ◽  
K. Iida ◽  
N. Sakai ◽  
M. Murakami

Microstructure of (Nd, Eu, Gd)Ba2Cu3O7−δ (NEG-123) samples with (Nd, Eu, Gd)2BaCuO5 (NEG-211) particles were observed by transmission electron microscopy. High-resolution electron microscopy observation demonstrated that the density of microstructural defects was small around the NEG-211 secondary phase particles. Furthermore, the 123/211 interfaces were found to be very clean and sharp. Chemical compositional analysis of the submicron secondary phase particles revealed that these fine particles are not composed of NEG-211 but Eu2BaCuO5 (Eu-211) or Gd2BaCuO5 (Gd-211).


Author(s):  
R.W. Horne

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.


Author(s):  
J. A. Hugo ◽  
V. A. Phillips

A continuing problem in high resolution electron microscopy is that the level of detail visible to the microscopist while he is taking a picture is inferior to that obtainable by the microscope, readily readable on a photographic emulsion and visible in an enlargement made from the plate. Line resolutions, of 2Å or better are now achievable with top of the line 100kv microscopes. Taking the resolution of the human eye as 0.2mm, this indicates a need for a direct viewing magnification of at least one million. However, 0.2mm refers to optimum viewing conditions in daylight or the equivalent, and certainly does not apply to a (colored) image of low contrast and illumination level viewed on a fluorescent screen through a glass window by the dark-adapted eye. Experience indicates that an additional factor of 5 to 10 magnification is needed in order to view lattice images with line spacings of 2 to 4Å. Fortunately this is provided by the normal viewing telescope supplied with most electron microscopes.


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