Microscopy
- Created by: Jasmin
- Created on: 17-09-13 18:59
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- Microscopy
- 1 m
- 10-3m - millimetre
- x1000
- 10-6m - micrometre (um)
- x1000
- 10-12m - picometre (pm)
- x1000
- 10-6m - micrometre (um)
- x1000
- 10-3m - millimetre
- Object: material placed under microscope
- Image: appearance of this material as viewed
- Magnification: process of enlarging something only in appearance, not in physical size
- Magnification = size of image/size of object IAM
- Resolution: ability of a microscope or telescope to distinguish between images/features that are close together
- Greater resolution greater clarity in image
- size of object = size of image/bar length x bar scale
- Light microscope
- Max resolving power: 200nm
- Magnification: up to x2000
- Specimens
- Living or dead
- Thin sections of tissue easily prepared 1um in thickness for good detail
- Image
- Staining not necessary so real colours can be observed
- Staining allows colour images
- Cost: within budget of individuals and schools
- Electron microscope
- Adv
- Electron beam has short wavelength and microscope can resolve objects well - high
- Electrons are negatively charged the beam can be focused using electromagnets
- Max resolving power: 2nm
- Magnification: up to x500000
- Scanning (only looks at surface, no detail of inside)
- Speciman
- Dead
- Must be thin
- Image
- Slow down electron beam hits secondary detector produces sharper image of high resolution in 3D
- Staining using metal necessary - gold cheapest form coating
- black and white but false colours can be added by photographic technique
- Speciman
- Short wavelength than light microscope
- Cost: within budget of unis and research labs only
- Transmission (can see through) best resolution
- Image
- Produced on screen, can be photographed to give photomicrograph (photo of image produced by microscope)
- In bw complex staining process required uses heavy positive ions for staining
- Speciman must be thin allow electrons to penetrate
- Image
- Adv
- 1 m
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