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12 Cards in this Set
- Front
- Back
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What is the max resolution of light microscopes?
resolution of bac? animal cell? |
0.2 micrometers is max.
bac: 1micrometer, animal: 10 micrometers |
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How do you obtain contrast in light microscopy?
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-must stain specimens because stains can absorb certain wavelengths so that color images can be made.
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What are four types of microscopy?
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1. Bright field
2. Phase constrast 3. Differential interference contrast 4. Dark field |
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Florescence microscope : what are the three barries
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1. first barrier filter: only blue light can go thru
2. beam-splitting mirror: reflects light below 510 nm (blue), but transmit light above 510nm (green). 3. second barrier filter: only green light can go through (520-560) |
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Indirect Immunocytochemistry
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Labeling proteins with Ab and fluorescence markers. Have antibody #1 bind to protein of interest. THen antibody #2 that lights up will bind to antibody #1 and show where protein is indirectly.
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How do you visualize thick samples?
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-Must slice into very thin slices using a machine. Microtome arm with sample will move up and down to slice with a fixed blade.
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Confocal fluorecense microscopy
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-a laser is shone through a pinhole that passes through a mirror and down to the object at the pt of focus. Light will emit from the object that is stained but detector will only see the pin point of focus.
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Transmission electron microscope
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works from top to bottom, uses magnetic coil and electron gun, way better resolution than light microscope
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How can you use EM-immunogold to localize proteins when looking through microscope?
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-Works in same principle as indirect immuno staining, except will show up as black dot because gold particles are electron dense and will appear as black dot under EM
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Scanning EM
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shows images of the surfaces
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Resolving power of EM?
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2 nm (vs 0.2 um of light)
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How to you resolve at molecular levels?
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1. X-ray diffraction: uses protein crystals
2. NMR |
