electron microscope (redirected from Electronic Microscope)

microscope /mi·cro·scope/ (mi´kro-skōp) an instrument used to obtain an enlarged image of small objects and reveal details of structure not otherwise distinguishable.

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acoustic microscope  one using very high frequency ultrasound waves, which are focused on the object; the reflected beam is converted to an image by electronic processing.

binocular microscope  one with two eyepieces, permitting use of both eyes.

compound microscope  one consisting of two lens systems.

corneal microscope  one with a lens of high magnifying power, for observing minute changes in the cornea and iris.

darkfield microscope  one designed to permit diversion of light rays and illumination from the side, so that details appear light against a dark background.

electron microscope  one in which an electron beam, instead of light, forms an image for viewing on a fluorescent screen, or for photography.

fluorescence microscope  one used for the examination of specimens stained with fluorochromes or fluorochrome complexes, e.g., a fluorescein-labeled antibody, which fluoresces in ultraviolet light.

infrared microscope  one in which radiation of 800 nm. or longer wavelength is used as the image-forming energy.

light microscope  one in which the specimen is viewed under visible light.

phase microscope , phase-contrast microscope one altering the phase relationships of the light passing through and that passing around the object, the contrast permitting visualization without the necessity of staining or other special preparation.

scanning microscope , scanning electron microscope an electron microscope in which a beam of electrons scans over a specimen point by point and builds up an image on the fluorescent screen of a cathode ray tube.

simple microscope  one consisting of a single lens.

slit lamp microscope  a corneal microscope with a special attachment that permits examination of the endothelium on the posterior surface of the cornea.

stereoscopic microscope  a binocular microscope modified to give a three-dimensional view of the specimen.

ultraviolet microscope  one that utilizes reflecting optics or quartz and other ultraviolet-transmitting lenses.

x-ray microscope  one in which x-rays are used instead of light, the image usually being reproduced on film.

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electron microscope

n. Abbr. EM

Any of a class of microscopes that use electrons rather than visible light to produce magnified images, especially of objects having dimensions smaller than the wavelengths of visible light, with linear magnification approaching or exceeding one million (10⁶).

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electron microscope,

an electronic instrument that scans cell and tissue sections with a beam of electrons instead of visible light. The specimen is stained with electron-opaque dyes. With its high magnification power, it creates an image that can be photographed or viewed on a fluorescent screen. Compare scanning electron microscope. See also electron microscopy.

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microscope,

n an instrument containing a powerful lens system for magnifying and viewing near objects.

Microscope, Confocal Laser Scanning (CLSM),

n.pr a microscope equipped with a laser beam light source, electronic image detector, and computer for image storage and processing that is used in the laboratory to perform high-resolution, three-dimensional microscopy.

microscope, dark-field,

n a microscope that has a special condenser and objective with a diaphragm or stop by which light is scattered from the object with the result that the object appears bright and the background dark.

microscope, electron,

n a microsope in which electron beams with wavelengths shorter than those of visible light are used in place of visible light, allowing much greater resolution and magnification of the object.

microscope, electron, scanning (SEM),

n an electron microscope capable of reflecting electrons from the specimen surface, resulting in a three-dimensional image of the surface that provides both high resolution and a great depth of focus view of the object.

microscope, interference,

n a microscope designed to split entering light into two beams that pass through the specimen and are recombined in the image plane, allowing visualization of refractile object details that are not possible with a single beam.

microscope, phase-contrast,

n a specially constructed microscope that has a special condenser and objective containing a phase-shifting mechanism whereby small differences in refraction can be made visible to intensity or contrast in the images. It is particularly helpful in examining living or unstained cells and tissues. This is an excellent aid in the education and motivation of patients in the understanding and control of dental plaque.

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electron

any of the negatively charged particles arranged in orbits around the nucleus of an atom and determining all of the atom's physical and chemical properties except mass and radioactivity. Electrons flowing in a conductor constitute an electric current; when ejected from a radioactive substance, they constitute the beta particles.

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electron acceptor

see oxidant.

electron beam

the stream of electrons that flows from the anode to the cathode in the x-ray tube and then interacts with the tungsten target to produce x-rays.

electron carrier

a molecule associated with membrane-bound proteins that accepts and transfers electrons.

electron donor

see reductant.

electron micrographs

photographic images of electron microscopic fields.

electron microscope

see electron microscope.

electron microscopy

technology of using an electron microscope.

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microscope

an instrument used to obtain an enlarged image of small objects and reveal details of structure not otherwise distinguishable.

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acoustic microscope

one using very high frequency ultrasound waves, which are focused on the object; the reflected beam is converted to an image by electronic processing.

binocular microscope

one with two eyepieces, permitting use of both eyes simultaneously.

bright-field microscope

the standard bench microscope used in histology and requiring stained tissue sections.

compound microscope

the standard laboratory microscope used in veterinary science; consists of a two lens system whereby the image formed by the system near the object (objective) is magnified by the one nearer the eye (eyepiece).

darkfield microscope

used for examining unstained, often living cells, in which light is only directed into the objective lens if it is deflected by an object in its path. The object is thus viewed as a white structure in an otherwise black (darkfield) background.

electron microscope

one using an electron beam of very short wavelength as the source of illumination. It has a resolving power of 2 nm (which is 100 times greater than with the light microscope). Includes the transmission electron microscope and the scanning electron microscope (below). See also immunoelectron microscopy.

fluorescence microscope

one used for the examination of specimens stained with fluorochromes or fluorochrome complexes, e.g. a fluorescein-labeled antibody, which fluoresces in ultraviolet light. See also fluorescence microscopy.

interference microscope

a microscope similar to the phase contrast microscope but delivers a three-dimensional image. Called also Nomarski interference phase microscope.

light microscope

used for examining unstained or stained particles or the cellular structure of tissues that have been cut into sections and stained. It has a resolving power of 0.2 μm. Modern light microscopes have an eyepiece and objective lenses which provide magnification, and a condenser beneath the stage which gathers and focuses light on the object being examined.

operating microscope

one designed for use in performance of delicate surgical procedures, e.g. on the middle ear, eye or small vessels of the heart.

phase microscope, phase-contrast microscope

a form of light microscope useful for examining living, unstained structures, including animal cells and bacteria, e.g. leptospira. The phase of the light wave passing through different structures in the cell, e.g. nucleus vs. thin part of the cytoplasm, is changed by different amounts and thereby provides contrast.

polarizing microscope

based on the phenomenon of birefringence; useful in the study of bone and muscle.

scanning electron microscope (SEM)

an electron microscope that produces a high-magnification image of the surface of a metal-coated specimen (shadow casting) by scanning an electron beam and building up an image from the electrons reflected at each point. Particularly useful for determining the three-dimensional structure of objects.

simple microscope

one that consists of a single lens.

specular microscope

one used in the examination of the corneal endothelium.

stereoscopic microscope

a binocular microscope modified to give a three-dimensional view of the specimen.

surgical microscope

see operating microscope (above).

transmission electron microscope, TEM

one that resembles an inverted light microscope in that the beam of electrons generated from a heated filament at the top of the instrument passes down through a column where it is focused by magnetic coils (lenses) and is differentially scattered when it passes through the specimen. The image is recorded either on a photographic plate or on a phosphorescent screen.

ultraviolet microscope

uses an ultraviolet light source; useful in histochemical studies; only photographic images are available.