Electron Microscopes

Electron Microscopes

1. Advantages

   • Higher resolution
   • Higher magnification
   • Fine detail can be observed
   • SEM can provide 3D image

2. Disadvantages

   • Specimen is dead
   • Natural colours can not be seem
   • Specimen needs to be dehydrated
   • Expensive
   • Not portable
   • Technical expertise required
   • There is likely to be artifacts
     • Artifact - A structure that is not part of the specimen.
   • Heat is generated
   • Vacuum pump required
   • Specimen and electrons need to be contained

3. There are two types of electron microscopes

   • Scanning Electon Microscopes
     • Images are 3D
       • Depth of field
       • Internal structures can't be seen
     • Resolution = 0.5 nm
       • Cannot achieve same resolution as TEM
     • Magnification = x 100,000
   • Transmission Electron Microscopes
     • Images are 2D
     • Internal structures can be seen
     • Resolution = 0.1 nm
     • Magnification = x 500,000

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