9 | Electron Microscopes

Electron Microscopes

  • Another type of microscope is called an electron microscope.
  • Electron microscopes use beams of electrons for viewing objects.
  • They are large and very powerful microscopes that require specially trained technicians to operate them.
  • There are two main types of electron microscopes – scanning electron microscopes and transmission electron microscopes.
  • A scanning electron microscope (SEM) produces images of the surface structure of an object.
  • The specimen does not need to be sliced as electrons reflect off the specimen.
  • A transmission electron microscope (TEM) produces images of the internal structure of an object.
  • The specimen needs to be sliced very thinly as electrons pass through the specimen.

 

 scanning electron microscope  transmission electron microscope

Scanning electron microscopes (left) and transmission electron microscopes (right) are very powerful microscopes.

(Images: Teupdeg, Wikimedia Commons; David J Morgan, Wikimedia Commons)

 

  • Images produced by electron microscopes are black and white, but they can be converted to colour using false colour imaging.

 

 scanning electron microscope image dust mite  transmission electron microscope image phage particles

Image of a dust mite taken with a scanning electron microscope (left).
Image of virus particles taken with a transmission electron microscope (right).

(Images: WikiImages, Pixabay; Dartmouth College Electron Microscope Facility, Wikimedia Commons)