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MOLB Chapter 3
Observing Microorganisms Through a Microscope
Term | Definition |
---|---|
Simple microscope | has only one lens |
Compound Microscope | has 2 or more lenses |
Compound Light Microscope | used to observe living organisms, resolution up to .2 micrometers, magnifies up to 2000x, requires stains |
Darkfield microscope | able to see things you cannot see in CLM because of the dark background |
Phase contrast microscope | similar to CLM, shows 3D image and internal structures |
Fluorescence Microscopy | uses higher wavelengths of light than can be absorbed |
Confocal | stain specimen, hit with blue light and reconstruct with a computer to get 3D view |
Transmission Electron Microscopy | magnify 10,000x resolution 20nm, look inside cells |
Scanning Electron Microscopy | 10 nm resolution, magnification 10,000, allows view of cell surface |
Staining | coloring organisms with the application of dye |
Smear | applying organisms to a slide |
Fixed | act of attaching the specimen to the slide |
need for staining | live/unstained cells have little contrast with surrounding medium, making them difficult to see, researchers use staining to make discoveries about cell behavior by observing specimens |
Basic dyes | chromaphore is a cation (+) |
acidic dye | chromaphore is an anion (-) |
Negative stain | staining only the background |
simple stains | only use one dye |
Mordant | amplifies appearance of the primary stain |