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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 |