Term
| What type of microscope uses 2 lenses with the ocular in the eyepiece and the objective in the nose-piece with a beam of tungsten light illuminating the specimen? |
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Definition
| Brightfield light microscopes |
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Term
| What kind of micorscope has the condenser such that the light is directed obliquely causing the light to deflect off the specimen, making it appear light against a dark background? |
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Definition
| Darkfield light microscopes |
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Term
| What kind of microscope uses a UV light source and folourescent dies on a specimen? |
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Definition
| Flourescent light microscopes |
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Term
| What kind of microscope uses special objectives and condenser that allows the light to refract differently through cell components of varying density, resulting in refractile edges in the specimen? |
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Definition
| Phase contrast light microscopes |
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Term
| What type of microscope contains a device that separates the light into 2 beams out of phase that yields a 3D image? |
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Definition
| Differential interference contrast light microscope |
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Term
| What kind of microscope is used to create a 3D image of the specimen via optically sectioning the sepcimen with lasers? |
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Definition
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Term
| What are the steps of the gram stain? |
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Definition
| Staining with crystal violet, fixing of crystal violet into the cell well with mordant, decoloraizer with 95% ethanol (destains gram-negative) which locks the crystal violet with gram-positive, safranin counterstain to stain the gram-negative pink/red (gram positive remians purple) |
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Term
| Acid fast stains are used primarily to identify what? |
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Definition
| Mycobacterium sp. due to high contentof myucolic acid |
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Term
| Describe the Ziehl-Heelsen method of acid fast staining |
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Definition
| Carbol-fuschin stains red with steam heating to enhance penetration, HCl/alcohol destains non-acid fast microorganisms, methylene blue counterstain non-acid fast microorganisms |
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Term
| Describe the Liefson's Flagellar stain |
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Definition
| Mordant is used with a stain to encrust stain onto flagella to increase thickness |
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Term
| Describe an endospore stain |
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Definition
| Use of malachite green to stain spores, steam heat allows penetration of stain, safranin secondary stain, spores are green, vegetative cells are pink/red |
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Term
| What kind of culture media favor the growth of distinct groups of microorganisms while inhibiting others? |
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Definition
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Term
| What kind of culture media distinguishes microorganisms having a defined metabolic activity over others, allowing for an observable change in a specific chemical reaction? |
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Definition
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Term
| Describe mannitol salt agar. What does it select for? |
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Definition
| 7.5% salt inhibits all but staphylococci (selective), pH indicator turns red to yellow indicating acid production (differential) |
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Term
| PEA agar media (Phenylethyl alcohol agar with blood) supports what type of bacteria? How? |
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Definition
| Supports gram-positive, phenyl-ethyl alcohol inhibits gram-negative |
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Term
| Columbia CNA (colistin, naladixic acid) blood agar selects for what? |
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Definition
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Term
| Tinsdale mediums isolate for what type of bacteria? |
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Definition
| Corynebacterium diptheriae |
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Term
| How is tinsdale medium selective |
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Definition
| Potassium tellurite is inhibitory to gram-positive and most gram-negative microorganisms except Corynebacterium sp. which forms black colonies, reduces the metal tellurite to tellurium (black precipitate) |
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Term
| Egg yold medium is selective for what type of bacteria? |
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Definition
| Screens for lecithinase activity such as in Clostridium sp. by degradation of phospholipids into insoluble diglycerides |
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