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What is an Electron Microscopy?

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Introduction

Electron Microscopy

What is an Electron Microscopy?                          image00.jpg

        Microscopes are used to look at objects that cannot be seen by the naked eye. There are two types of microscopes: light microscopes which use light to see the image these microscopes use lenses and light to project the

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Middle

How does it work?

  1. Electrons are fired from an electron gun.
  2. Electrons then travel through a vacuum.
  3. They go through the specimen and objective lens.
  4. The electrons then hit a flourescent screen and make light.
  5. The light makes a picture (electron micrograph), which is visible to the human eye.

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Conclusion

They can focus using magnets so can get very good micrographs.

Disadvantages

  • Very expensive.
  • Very big.
  • Sometimes artefacts are made (not what is in the specimen can be seen)
  • Hard to cut specimen so thin.
  • Sometimes electrons do not pass.
  • Living specimens cannot be seen.
  • Must be stained in very expensive stains such as gold and silver.

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