scholarly journals Effective detection of histochemical reaction products by phase contrast electron microscopy

2009 ◽  
Vol 23 (S1) ◽  
Author(s):  
Nobuteru Usuda ◽  
Kimie Atsuzawa ◽  
Kuniaki Nagayama
Keyword(s):  
Electron Microscopy ◽  
Phase Contrast ◽  
Reaction Products ◽  
Histochemical Reaction

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

Studies of Oxide Formation on Copper Thin Films by Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 316-317
Author(s):  
G. G. Hembree ◽  
M. A. Otooni ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Electron Diffraction ◽  
Single Crystal ◽  
Crystal Surface ◽  
Crystal Defects ◽  
Diffraction Reflection ◽  
Reaction Products ◽  
Intermediate Energies ◽  
Crystal Films ◽  
Reflection Electron Microscopy

The formation of oxide structures on single crystal films of metals has been investigated using the REMEDIE system (for Reflection Electron Microscopy and Electron Diffraction at Intermediate Energies) (1). Using this instrument scanning images can be obtained with a 5 to 15keV incident electron beam by collecting either secondary or diffracted electrons from the crystal surface (2). It is particularly suited to studies of the present sort where the surface reactions are strongly related to surface morphology and crystal defects and the growth of reaction products is inhomogeneous and not adequately described in terms of a single parameter. Observation of the samples has also been made by reflection electron diffraction, reflection electron microscopy and replication techniques in a JEM-100B electron microscope.A thin single crystal film of copper, epitaxially grown on NaCl of (100) orientation, was repositioned on a large copper single crystal of (111) orientation.

New challenges to image processing posed by cryo-Electron microscopy of single particles

1991 ◽  
Vol 49 ◽  
pp. 422-423
Author(s):  
Joachim Frank
Keyword(s):  
Electron Microscopy ◽  
Phase Contrast ◽  
Particle Orientation ◽  
Single Particles ◽  
Contrast Transfer Function ◽  
Virtual Absence ◽  
Cryo Electron Microscopy ◽  
Spatial Frequencies ◽  
New Challenges ◽  
Particle Images

Compared with images of negatively stained single particle specimens, those obtained by cryo-electron microscopy have the following new features: (a) higher “signal” variability due to a higher variability of particle orientation; (b) reduced signal/noise ratio (S/N); (c) virtual absence of low-spatial-frequency information related to elastic scattering, due to the properties of the phase contrast transfer function (PCTF); and (d) reduced resolution due to the efforts of the microscopist to boost the PCTF at low spatial frequencies, in his attempt to obtain recognizable particle images.

Imaging sub-micron objects with light microscopy: Visualization of the T-4 bacteriophage

1989 ◽  
Vol 47 ◽  
pp. 834-835
Author(s):  
Malcolm Brown ◽  
Reynolds M. Delgado ◽  
Michael J. Fink
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Focal Plane ◽  
Phase Contrast ◽  
Dark Field ◽  
E Coli ◽  
Polystyrene Beads ◽  
Television Camera ◽  
Transmission Electron ◽  
Universal Microscope

While light microscopy has been used to image sub-micron objects, numerous problems with diffraction-limitations often preclude extraction of useful information. Using conventional dark-field and phase contrast light microscopy coupled with image processing, we have studied the following objects: (a) polystyrene beads (88nm, 264nm, and 557mn); (b) frustules of the diatom, Pleurosigma angulatum, and the T-4 bacteriophage attached to its host, E. coli or free in the medium. Equivalent images of the same areas of polystyrene beads and T-4 bacteriophages were produced using transmission electron microscopy.For light microscopy, we used a Zeiss universal microscope. For phase contrast observations a 100X Neofluar objective (N.A.=1.3) was applied. With dark-field, a 100X planachromat objective (N.A.=1.25) in combination with an ultra-condenser (N.A.=1.25) was employed. An intermediate magnifier (Optivar) was available to conveniently give magnification settings of 1.25, 1.6, and 2.0. The image was projected onto the back focal plane of a film or television camera with a Carl Zeiss Jena 18X Compens ocular.

Microtexture of shock reaction products of niobium and silica mixtures

1999 ◽  
Vol 14 (7) ◽  
pp. 3169-3174 ◽  
Author(s):  
Reiko Murao ◽  
Masae Kikuchi ◽  
Kiyoto Fukuoka ◽  
Eiji Aoyagi ◽  
Toshiyuki Atou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Shock Compression ◽  
Pressure Range ◽  
Reaction Products ◽  
Small Particles ◽  
Powder Mixtures ◽  
X Ray ◽  
Transmission Electron

Shock compression experiments on powder mixtures of niobium metal and quartz were conducted for the pressure range of 30–40 GPa by a 25-mm single-stage propellant gun. Chemical reaction occurred above 35 GPa, and products were found to be mainly so-called “Cu3Au-type” Nb3Si, which contained a small amount of oxygen. Microtextures of the specimen were examined by scanning and transmission electron microscopy. A field-emission transmission electron microscope was used for energy-dispersive x-ray analysis of microtextures in small particles found in the SiO2 matrix, and various species with different Nb/Si ratio and oxygen content were shown to be produced through the nonequilibrium process of shock compression.

scholarly journals THE SUBMICROSCOPIC ORGANIZATION OF AXON MATERIAL ISOLATED FROM MYELIN NERVE FIBERS

1953 ◽  
Vol 98 (3) ◽  
pp. 269-276 ◽  
Author(s):  
E. De Robertis ◽  
C. M. Franchi
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Phase Contrast ◽  
Nerve Fibers ◽  
Myelinated Nerve ◽  
Myelinated Nerve Fibers ◽  
Dense Granules ◽  
Small Clusters ◽  
Membranous Material ◽  
The Way

A technique has been developed for the extrusion of axon material from myelinated nerve fibers. This material is then compressed and prepared for observation with the electron microscope. All the stages of preparation and purification of the axon material can be checked microscopically and in the present paper they are illustrated with phase contrast photomicrographs. Observation with the electron microscope of the compressed axons showed the presence of the following components: granules, fibrils, and a membranous material. Only the larger granules could be seen with the ordinary microscope. A considerable number of dense granules were observed. Of these the largest resemble typical mitochondria of 250 mµ by 900 mµ. In addition rows or small clusters of dense granules ranging in diameter from 250 to 90 mµ were present. In several specimens fragments of a membrane 120 to 140 A thick and intimately connected with the axon were found. The entire axon appeared to be constituted of a large bundle of parallel tightly packed fibrils among which the granules are interspersed. The fibrils are of indefinite length and generally smooth. They are rather labile structures, less resistant in the rat than in the toad nerve. They varied between 100 and 400 A in diameter and in some cases disintegrated into very fine filaments (less than 100 A thick). The significance is discussed of the submicroscopic structures revealed by electron microscopy of the material prepared in the way described.

HIGH RESOLUTION ELECTRON MICROSCOPE STUDY OF CdTe-Cd0.6Mn0.4 Te SUPERLATTICES

1985 ◽  
Vol 56 ◽  
Author(s):  
C. CHOI ◽  
N. OTSUKA ◽  
L. A. KOLODZIEJSKI ◽  
R. L. GUNSHOR-a
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Phase Contrast ◽  
Electron Microscope Study ◽  
Lattice Mismatch ◽  
Thick Layer ◽  
High Resolution Electron Microscopy ◽  
Misfit Dislocations ◽  
Resolution Electron ◽  
High Resolution Electron Microscope

AbstractStructures of CdTe-Cd0.6Mn0.4Te superlattices which are caused by the lattice mismatch between suterlattice layers have been studied by high resolution electron microscopy (HREM). In thin-layer superlattices, the crystal lattice in each layeris elastically distorted, resulting in the change of the crystal symmetry from cubic to rhombohedral. The presence of the small rhombohedral distrotion has been confirmed through a phase contrast effect in HREM images. In a thick-layer superlattice, the lattice mismatch is accommodated by dissociated misfit dislocations. Burgers vectors of partial misfit dislocations have been identified from the shift of lattice fringes in HREM images.

Phase-contrast and electron-microscopic observations on a membranous complex in primary spermatocytes of the mouse

1975 ◽  
Vol 18 (1) ◽  
pp. 1-17
Author(s):  
A. Pleshkewych ◽  
L. Levine
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Phase Contrast ◽  
Cultured Cells ◽  
Light And Electron Microscopy ◽  
Cytoplasmic Inclusion ◽  
Electron Microscopic ◽  
Secondary Spermatocyte ◽  
Living Mouse ◽  
Circular Contour

A prominent cytoplasmic inclusion present in living mouse primary spermatocytes has been observed by both light and electron microscopy. It began to form at prometaphase and continued to increase in thickness and length as the cells developed. By metaphase it was a distinct sausage-shaped boundary that enclosed a portion of the cytoplasm between the spindle and the cell membrane. At the end of metaphase, the inclusion reached its maximum length. At telophase, it was divided between the daughter secondaries. The inclusion persisted as a circular contour in the interphase secondary spermatocyte. Electron microscopy of the same cultured cells that were previously observed with light microscopy revealed that the inclusion was a distinctive formation of membranes. It consisted of agranular cisternae and vesicles, and was therefore a membranous complex. Many of the smaller vesicles in the membranous complex resembled those found in the spindle. The cisternae in the membranous complex were identical to the cisternal endoplasmic reticulum of interphase primary spermatocytes. Nevertheless, the organization of vesicles and cisternae into the membranous complex was unique for the primaries in division stages, since such an organization was not present in their interphase stages.

Coelomomyces canadense stat. et comb. nov. (Blastocladiales: Coelomomycetaceae) from Psectrocladius sp. G (Diptera: Chironomidae)

1978 ◽  
Vol 56 (18) ◽  
pp. 2303-2306 ◽  
Author(s):  
Richard A. Nolan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Contrast ◽  
Field Phase ◽  
Species Status ◽  
Bright Field ◽  
Latin Diagnosis ◽  
Taxonomic Criterion ◽  
Sporangial Wall ◽  
Scanning Electron

Resistant sporangia of Coelomomyces chironomi var. canadense Weiser and McCauley were examined by bright-field, phase-contrast, and scanning electron microscopy (SEM). The use of SEM facilitated the observation of previously undescribed complex furrows in the sporangial wall. The taxonomic criterion for varietal status is discussed, and the variety is elevated to species status. Coelomomyces canadense (Weiser and McCauley) Nolan stat. et comb. nov. is described with an emended Latin diagnosis.

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