interference microscope

in·ter·fer·ence mi·cro·scope

a specially constructed microscope in which the entering light is split into two beams that pass through the specimen and are recombined in the image plane where the interference effects make the transparent (invisible) refractile object details become visible as intensity differences; permits measurements of light retardation, index of refraction, and thickness and mass of specimen; it is useful in the examination of living or unstained cells.

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.