Term
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Definition
1000 nm=1 micron
1000 microns= 1 mm
1000 mm= 1m |
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Term
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Definition
| the use of any microscope that uses visible light to observe specimens |
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Term
| types of light microscopy |
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Definition
compound light
darkfield
phase-contrast
differential interference contrast
flourescence
confocal |
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Term
| parts of compound light microscope |
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Definition
ocular lens- re-magnifies the image
body tube- transmits image from objective lens-ocular lens
arm-to hold
objective lenses- primary lens, magnifies specimen
stage- holds the slide in position
condenser- focuses light through specimen
diaphragm- controls amount of light entering condenser
illuminator- light source
base- to hold
fine focusing knob
course focusing knob |
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Term
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Definition
| the image from the objective lens is magnified again by the ocular lens |
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Term
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Definition
| objective lens x ocular lens |
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Term
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Definition
| the ability of the lenses to distinguish two points |
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Term
| shorter wavelengths of light provide |
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Definition
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Term
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Definition
| measure of light bending ability of medium |
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Term
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Definition
| used to direct light into the lense |
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Term
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Definition
| dark objects are visible against a bright background, light rays are directed through the specimen. light reflected off the specimen does not enter the objective lense |
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Term
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Definition
| light objects are visible against a dark background, light reflected off the specimen enters the objective lens |
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Term
| phase-contrast microscopy |
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Definition
| accentuates diffraction of the light that passes through a specimen |
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Term
| Differential interference contrast microscopy |
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Definition
| accentuates diffraction of the light that passes through a specimen; uses two beams of light |
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Term
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Definition
| uses UV light, fluorescent substances absorb UV light and emit visible light, cells may be stained with fluorescent dyes (fluorochromes) |
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Term
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Definition
| cells are stained with fluorochrome dyes, shore-wavelength (blue) light is used to excite the dyes, the light illuminates each place in a specimen to produce a three-dimensional image. up to 100 microns deep |
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Term
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Definition
| cells are stained with fluorochrome dyes, two photons of long-wavelength (red) light are used to excite dyes, used to study cells attached to a surface. up to 1 mm deep |
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Term
| Scanning acoustic microscopy (SAM) |
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Definition
| measures sound waves that are reflected back from an object, used to study cells attached to a surface. resolution 1micron, pic is=(biofilm) |
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Term
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Definition
| uses electrons instead of light, shorter wavelength of electrons gives greater resolution |
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Term
| Transmission Electron Microscopy (TEM) |
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Definition
| ultra-thin sections of specimens, a beam of electrons passes through specimen, an electromagnetic lens is used to focus the beam of electrons much like the condenser in a light microscope. specimens may be stained with heavy-metal salts. 10,000-100,000x; resolution 2.3 nm |
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Term
| Scanning Electron Microscopy (SEM) |
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Definition
| An electron gun produces a beam of electrons that scans the surface of a whole specimen, secondary electrons emitted from the specimen produce the image. 1000-10,000x; resolution 20 nm |
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Term
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Definition
Scanning tunneling microscopy (STM) uses a metal probe to scan a specimen. resolution 1/100 of an atom
Atomic force microscopy (AFM) uses a metal-and-diamond probe inserted into the specimen. Produces 3D images. |
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Term
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Definition
| coloring the microbe with a dye that emphasizes structures |
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Term
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Definition
| a thin film of a solution of microbes on a slide, usually fixed to attach the microbes to the slide and to kill the microbes (using hear) |
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Term
| stains consist of a positive and negative ion |
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Definition
in a basic dye, chromophore is a cation
in an acidic dye, the chromophore is an anion
staining background= negative staining |
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Term
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Definition
| use of a single basic dye |
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Term
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Definition
| used to hold down a stain or coat the specimen to enlarge it. necessary for Gram stain |
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Term
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Definition
| used to distinguish between bacteria |
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Term
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Definition
| classifies bacteria into gram-positive (tend to be killed by penicillin and detergents THICK WALL), or gram-negative (are more resistant to antibiotics THIN WALL) |
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Term
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Definition
| stained waxy cell wall is not decolorized by acid-alcohol |
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Term
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Definition
used to distinguish parts of cells.
capsule stain, endospore stain, flagella stain |
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Term
| Hans Christian Gram (1884) |
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Definition
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Term
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Definition
| carbol fuchsin, methylene blue, crystal violet, safranin, malachite green(stain cell body) |
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Term
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Definition
| acidic fuchsin, nigrosin (negative), eosin |
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