Electron Microscopy: An Overview

Electron microscopy is a technique that uses a beam of accelerated electrons to illuminate and produce images of specimens. Using electron microscopy, much greater magnification levels and resolution can be achieved than with a light microscope because the wavelength of electrons is so much shorter than that of photons.

This enables scientists to study small specimens in fine detail and look at the ultrastructure of cells, microorganisms, crystals and metals, for example. Electron microscopes are much larger and more expensive instruments than the light microscope.

There are two main types of electron micrscope, namely, the transmission electron microscope and the scanning electron microscope.

Laboratory Electron Microscope - Image Copyright: science photo / Shutterstock
Laboratory Electron Microscope - Image Copyright: science photo / Shutterstock

The Inventors of the Electron Microscope

It was in 1931 that the German scientists Max Knoll and Ernst Ruska developed the first model of an electron microscope. Ruska followed this with another prototype two years later that could provide a greater resolution than the light microscope, an achievement for which he received a Nobel prize fifty years later.

The Differences Between a Transmission Electron Microscope and a Scanning Electron Microscope

A transmission electron microscope produces an image by passing a high voltage electron beam through a very thin specimen that is semi-transparent to electrons. The beam that is transmitted through the specimen carries structural information about the specimen, which can then be magnified by the microscope. By contrast, a scanning electron microscope detects secondary electrons that arise from the surface as a result of excitation by the original electron beam.

The scanning electron dicroscope does produce lower resolution images than the transmission electron microscope, but since it uses surface electron interactions, it can image bulk samples and provide a much greater depth of field. This enables scientists to achieve 3D information about the physical features of the specimen.

Scanning transmission electron microscopy combines the technology of both the scanning electron microscope and the transmission electron microscope and can be performed using either piece of equipment. Similarly to transmission electron microscopy, samples need to be very thin as the technique mainly involves looking at the electron beam transmitted through and emerging from the specimen.


Electron microscopes include the following components:

  • An electron gun to produce and accelerate the electrons
  • A series of magnetic lenses to help direct and focus the electron beam
  • An objective lens, which produces the first, intermediate image
  • A vacuum system to ensure electrons do not collide with molecules of air
  • An image capturing system, which may be a charge-coupled device (CCD) camera, an imaging plate or negative film.

Applications of Electron Microscopy

Electron microscopy has many wide ranging applications in science and technology.

It can provide high resolution information about cells, organelles, tissues, microorganisms, biopsy samples, macromolecules, crystals and metals.

It has been used to study pathogens such as viruses and bacteria and is particularly valuable in the study of emerging diseases and germs used in bioterrorism. It has previously been used as a technique in the diagnosis of diseases such as smallpox, hepatitis B, gastroenteritis and parvovirus B19.

Electron microscopy also has applications in the electronics industry where it is used to control manufacturing processes. The technology is used worldwide in various other industrial applications including aeronautics, the manufacture of motor vehicles and the clothing industry, to name but a few.

In forensics, the technique is used for the analysis of clothing fibres and blood and gunshot residues, for example.


Of Interest

Clinical Microbiology Reviews Journal, Modern uses for electron microscopy in virus detection:: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2772359/

Further Reading

Last Updated: Jul 24, 2023

Deborah Fields

Written by

Deborah Fields

Deborah holds a B.Sc. degree in Chemistry from the University of Birmingham and a Postgraduate Diploma in Journalism qualification from Cardiff University. She enjoys writing about the latest innovations. Previously she has worked as an editor of scientific patent information, an education journalist and in communications for innovative healthcare, pharmaceutical and technology organisations. She also loves books and has run a book group for several years. Her enjoyment of fiction extends to writing her own stories for pleasure.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Fields, Deborah. (2023, July 24). Electron Microscopy: An Overview. News-Medical. Retrieved on July 12, 2024 from https://www.news-medical.net/life-sciences/Electron-Microscopy-An-Overview.aspx.

  • MLA

    Fields, Deborah. "Electron Microscopy: An Overview". News-Medical. 12 July 2024. <https://www.news-medical.net/life-sciences/Electron-Microscopy-An-Overview.aspx>.

  • Chicago

    Fields, Deborah. "Electron Microscopy: An Overview". News-Medical. https://www.news-medical.net/life-sciences/Electron-Microscopy-An-Overview.aspx. (accessed July 12, 2024).

  • Harvard

    Fields, Deborah. 2023. Electron Microscopy: An Overview. News-Medical, viewed 12 July 2024, https://www.news-medical.net/life-sciences/Electron-Microscopy-An-Overview.aspx.


The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
New study reveals how RNA polymerase opens the transcription bubble in real time