Image converters for the high-voltage electron microscope

Author(s):  
Murray Vernon King ◽  
Donald F. Parsons

One of the major concerns of biological electron microscopists has been that of obtaining images of biological specimens with minimal radiation damage. The problem of designing more sensitive imaging devices and materials for the high-voltage electron microscope (HVEM) becomes pressing because: 1) the relative insensitivity of conventional photographic materials to 1-MeV electrons requires inordinately long exposures unless measures are taken to enhance the sensitivity of photographic recording; 2) the relative insensitivity of conventional viewing screens requires excessive beam intensities for scanning the specimen and focusing the image unless means are found to obtain a visible image at lower beam current densities; 3) an increasing part of the practice of high-voltage electron microscopy has involved taking multiple images from the same specimen area, as in taking stereo pairs or more extensive tilt series for three-dimensional reconstruction --- this feature is inherent in high-voltage electron microscopy, and it is occasioned by the wealth of detail offered by semithin sections, which requires three-dimensional methods for decipherment

Author(s):  
Brenda R. Eisenberg ◽  
Lee D. Peachey

Analysis of the electrical properties of the t-system requires knowledge of the geometry of the t-system network. It is now possible to determine the network parameters experimentally by use of high voltage electron microscopy. The t-system was marked with exogenous peroxidase. Conventional methods of electron microscopy were used to fix and embed the sartorius muscle from four frogs. Transverse slices 0.5-1.0 μm thick were viewed at an accelerating voltage of 1000 kV using the JEM-1000 high voltage electron microscope at Boulder, Colorado and prints at x5000 were used for analysis.The length of a t-branch (t) from node to node (Fig. 1a) was measured with a magnifier; at least 150 t-branches around 30 myofibrils were measured from each frog. The mean length of t is 0.90 ± 0.11 μm and the number of branches per myofibril is 5.4 ± 0.2 (mean ± SD, n = 4 frogs).


Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.


Author(s):  
G. E. Tyson ◽  
M. J. Song

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.


2016 ◽  
Vol 57 (6) ◽  
pp. 918-921 ◽  
Author(s):  
Kazuhisa Sato ◽  
Shunya Tashiro ◽  
Yohei Yamaguchi ◽  
Takanori Kiguchi ◽  
Toyohiko J. Konno ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document