Electron microscope

Definition

An electron microscope uses beams of electrons to create highly magnified images of specimens, allowing for the visualization of structures at the nanometer scale. It provides much greater resolution than light microscopes.

5 Must Know Facts For Your Next Test

1. Electron microscopes have two main types: Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM).
2. The resolution of an electron microscope can be up to 0.1 nanometers, far surpassing that of a light microscope.
3. Specimens must be placed in a vacuum and often require special preparation, including staining with heavy metals.
4. TEM provides detailed internal structures by transmitting electrons through thin samples, while SEM offers 3D surface images by scanning specimens with a focused beam.
5. Electron microscopes cannot be used to view living organisms because the vacuum environment and electron exposure would damage or kill them.

Review Questions

• What are the two main types of electron microscopes and how do they differ?
• Why can't electron microscopes be used to view live specimens?
• What preparation is typically required for specimens being viewed with an electron microscope?

Related terms

Transmission Electron Microscope (TEM): A type of electron microscope that transmits electrons through a thin specimen to form detailed images.

Scanning Electron Microscope (SEM): A type of electron microscope that scans a focused beam of electrons across a specimen's surface to create detailed 3D images.

Resolution: The ability to distinguish two adjacent points as separate entities in microscopy; higher in electron microscopes compared to light microscopes.