Microwaves: Application in Electron Microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 140-141
Author(s):  
Anthony S-Y Leong ◽  
David W Gove
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Chemical Reactions ◽  
Electromagnetic Waves ◽  
Tissue Fixation ◽  
Primary Method ◽  
Dipolar Molecules ◽  
Wide Range ◽  
Time Required ◽  
Cryostat Sections

Microwaves (MW) are electromagnetic waves which are commonly generated at a frequency of 2.45 GHz. When dipolar molecules such as water, the polar side chains of proteins and other molecules with an uneven distribution of electrical charge are exposed to such non-ionizing radiation, they oscillate through 180° at a rate of 2,450 million cycles/s. This rapid kinetic movement results in accelerated chemical reactions and produces instantaneous heat. MWs have recently been applied to a wide range of procedures for light microscopy. MWs generated by domestic ovens have been used as a primary method of tissue fixation, it has been applied to the various stages of tissue processing as well as to a wide variety of staining procedures. This use of MWs has not only resulted in drastic reductions in the time required for tissue fixation, processing and staining, but have also produced better cytologic images in cryostat sections, and more importantly, have resulted in better preservation of cellular antigens.

Automated Serial-Section Polishing Tomography

2008 ◽  
Author(s):  
J.A. Hunt ◽  
P. Prasad ◽  
E. Raz
Keyword(s):  
Electron Microscopy ◽  
Complex Systems ◽  
Light Microscopy ◽  
Serial Section ◽  
Computer Control ◽  
Tomographic Reconstruction ◽  
Polished Surface ◽  
Serial Sectioning ◽  
Wide Range ◽  
User Intervention

Abstract Tomographic reconstruction of a wide range of materials can be accomplished via mechanical polishing serial-sectioning – alternately polishing away material and imaging the remaining polished surface with optical (or electron) microscopy. Under computer control it is possible to acquire 2-D images of hundreds of sections without user intervention and assemble them for 3-D visualization and measurements. In general, the resulting 3-D images permit significantly better understanding of the structure of complex systems than would be possible with a few strategically acquired 2-D images at various depths. Herein we report what we believe is the first general implementation of automated Serial-Section Polishing Tomography (SSPT) and reconstruction using light microscopy.

scholarly journals Analysis of Premature Wear-Out of Aircraft Gun Barrel by Applying a Transmission Electron Microscopy (TEM)

2017 ◽  
Vol 40 (1) ◽  
pp. 67-107
Author(s):  
Krzysztof Łęczycki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Light Microscopy ◽  
Material Microstructure ◽  
Gun Barrel ◽  
Thin Foils ◽  
Transmission Electron ◽  
Physico Chemical ◽  
Wide Range

Abstract Firing from gun armament generates a wide range of physico-chemical phenomena contributing to the degradation of barrel material, e.g. pressure, high temperature, chemically aggressive character of post-detonation gases and friction of a driving band. In this work the technique of thin foils was used in Transmission Electron Microscopy (TEM) to study the influence of physicochemical phenomena on the material microstructure of aircraft gun barrel. A mechanism and reason of premature wear-out of the barrel under consideration was also outlined by utilising light microscopy and hardness measurements.

scholarly journals Microscopic study of edema in hydatidiform mole

2014 ◽  
Vol 14 (3) ◽  
pp. 261-268
Author(s):  
Olivar C. Castejón ◽  
Aury Caraballo ◽  
Oliver Castejón ◽  
Elizabeth Cedeño
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Basement Membrane ◽  
Light Microscopy ◽  
Hydatidiform Mole ◽  
Three Dimensional ◽  
Wide Range ◽  
Observation Protocol ◽  
Microscopy Techniques ◽  
Scanning Electron

Objectives: the purpose of this study is to use light microscopy and scanning electron microscopy to determine the effect of edema on the structure of the molar vesicle. Methods: samples were taken from the complete hydatidiform mole and processed using conventional light and scanning electron microscopy techniques and an observation protocol that identified four variables: factors underlying the development of edema; the condition of the trophoblast basement membrane, development of the villi, accumulation and degeneration of sulphated mucosubstances at stromal level. Results: light microscopy showed a permeable trophoblastic basement membrane, a swollen syncytium, edematous regions disorganizating the stromal region and causing ischemic necrosis of cells. Using scanning electron microscopy, the basement membrane was found to be distended and thickened, with large irregular holes for the entry and movement of liquid, leaving a wide range of fluids during the influx process and depriving stromal cells of nutrition. Conclusions: a new three-dimensional view of the changes brought about by the entry of fluids into the stroma of molar hydropic vesicles was provided by scanning electron microscopy and confirmed by light microscopy, thereby explaining the changes occurring at the level of the stroma as an effect of the edema.

Applications of Correlative Microscopy in Diagnostic and Investigative Pathology

1998 ◽  
Vol 4 (S2) ◽  
pp. 1044-1045
Author(s):  
D. N. Howell ◽  
S. E. Miller
Keyword(s):  
Electron Microscopy ◽  
Infectious Diseases ◽  
Light Microscopy ◽  
Clinical Research ◽  
Diagnostic Information ◽  
Cell Suspensions ◽  
Correlative Microscopy ◽  
Tissue Sections ◽  
Wide Range ◽  
Conventional Light Microscopy

Correlative microscopy is employed in a great variety of settings by both diagnostic and investigative pathologists. Combinations of conventional light microscopy (LM), immunohistology, and electron microscopy (EM) are used in a wide range of diagnostic settings, including the analysis of tumors, autoimmune disorders, and infectious diseases. Valuable diagnostic information is also frequently obtained by simultaneous or sequential examination of exfoliated or aspirated cell suspensions (cytopathology) and tissue sections (histopathology) from the same lesion. An even wider range of correlative microscopic methods is employed by pathologists in basic and clinical research. The rationales for using correlative techniques are many and varied, but in most cases fall within a limited number of categories.Pathologists frequently use a second microscopic or preparative technique to improve on the resolution afforded by an initial technique. Electron microscopy is often used to refine the analysis of features initially detected by routine LM or immunohistology.

Pseudoglandular Elements in Schwannomas

2005 ◽  
Vol 129 (9) ◽  
pp. 1106-1112
Author(s):  
Christopher A. Robinson ◽  
Bernadette Curry ◽  
N. Barry Rewcastle
Keyword(s):  
Electron Microscopy ◽  
Schwann Cell ◽  
Light Microscopy ◽  
Proliferative Activity ◽  
Biological Significance ◽  
Growth Potential ◽  
Anatomic Site ◽  
Wide Range ◽  
Variable Morphology ◽  
Mechanisms Of Development

Abstract Context.—Uncommon examples of schwannomas are seen in which a coexisting glandular component is present. The pseudoglandular schwannoma is a relatively recently described variant in which cystic spaces are lined by pseudocolumnar or cuboidal-like neoplastic Schwann cells exhibiting an epithelial-like appearance. Objectives.—To determine the incidence of pseudoglandular elements in schwannomas, to describe the variable morphology of the schwannomas that may contain pseudoglandular elements, and to discuss the potential mechanisms of development and biological significance of these elements. Design.—We screened 202 schwannomas from any anatomic site for the presence of pseudoglandular elements and examined these with light microscopy, immunohistochemistry, and electron microscopy. Results.—Sixteen (7.9%) of the schwannomas contained pseudoglandular elements, which ranged from poorly to well organized in appearance and which were found in schwannomas exhibiting a wide range of morphologic appearances. The Schwann cell nature of the cells composing these elements was apparent both immunohistochemically and ultrastructurally. The frequency of proliferative activity within these elements was no greater than that observed throughout the remainder of the respective schwannomas. Conclusions.—Our observations suggest that, rather than representing a distinct phenotypic schwannoma variant, pseudoglandular elements likely arise as a response to a degenerative phenomenon, perhaps reflecting the propensity that the Schwann cell has to palisade formation. Such elements may be found within a variety of schwannoma variants and do not appear to possess a unique growth potential.

The Critical Point Drying Method Applied to Scanning Electron Microscopy of L-929 Cells

1970 ◽  
Vol 28 ◽  
pp. 278-279
Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott
Keyword(s):  
Electron Microscopy ◽  
Carbon Dioxide ◽  
Surface Tension ◽  
Critical Point ◽  
Freeze Drying ◽  
Attractive Alternative ◽  
Crystal Formation ◽  
Critical Point Drying ◽  
Time Required ◽  
Scanning Electron

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

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.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Tumor Diagnosis

1982 ◽  
Vol 40 ◽  
pp. 262-265
Author(s):  
Bruce Mackay
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Diagnosis ◽  
Light Microscopy ◽  
Clinical Examination ◽  
Ultrastructural Study ◽  
Diagnostic Procedures ◽  
Specific Diagnosis ◽  
Transmission Electron ◽  
Microscopic Diagnosis

The broadest application of transmission electron microscopy (EM) in diagnostic medicine is the identification of tumors that cannot be classified by routine light microscopy. EM is useful in the evaluation of approximately 10% of human neoplasms, but the extent of its contribution varies considerably. It may provide a specific diagnosis that can not be reached by other means, but in contrast, the information obtained from ultrastructural study of some 10% of tumors does not significantly add to that available from light microscopy. Most cases fall somewhere between these two extremes: EM may correct a light microscopic diagnosis, or serve to narrow a differential diagnosis by excluding some of the possibilities considered by light microscopy. It is particularly important to correlate the EM findings with data from light microscopy, clinical examination, and other diagnostic procedures.

Immunocytochemistry. A Review of Methodology for Electron Microscopic Applicaiton

1974 ◽  
Vol 32 ◽  
pp. 328-329
Author(s):  
Joseph E. Mazurkiewicz
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Ultrastructural Level ◽  
Electron Microscopic ◽  
Biological Interest ◽  
Investigative Approach ◽  
Immunologic Activity ◽  
Dense Label

Immunocytochemistry is a powerful investigative approach in which one of the most exacting examples of specificity, that of the reaction of an antibody with its antigen, isused to localize tissue and cell specific molecules in situ. Following the introduction of fluorescent labeled antibodies in T950, a large number of molecules of biological interest had been studied with light microscopy, especially antigens involved in the pathogenesis of some diseases. However, with advances in electron microscopy, newer methods were needed which could reveal these reactions at the ultrastructural level. An electron dense label that could be coupled to an antibody without the loss of immunologic activity was desired.

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