Electron microscopy

  • Electron microscopes use a beam of electrons instead of visible light

  • The beam of electrons have a shorter wavelength than light

    • therefore resolution visible in the specimen is higher than light microscopy


microscope viewing ranges


Types of electron microscope

  • scanning electron microscope (SEM)

    • electrons pass across the surface of the specimen

    • 3D image

    • specimen coated in gold/heavy metals

    • lower resolution than TEM


    • SEM

  • transmission electron microscope (TEM)

    • electrons pass through specimen

    • 2D image

    • specimen must be very thin

    • highest resolution


    • TEM

  • similarities

    • dead specimen

    • vacuum needed

    • large and expensive

    • complex specimen preparation

    • artefacts likely

      • artefacts look like part of the microscope sample but are actually a side effect of sample preparation or the conditions in the microscope

      • can occur in both light and electron microscopy

    • images are black and white but can be coloured