Electron Microscopy 101: Types, Applications, Mechanisms, and Pricing

Electron microscopy (EM) refers to various techniques that use an electron beam to determine the structure and composition of a sample. EM enables you to uncover details that are too small to be seen under standard light microscopes.

This technology helps you unveil an entire world hidden in your midst --- from platelets in a blood vessel to the individual proteins that dot the platelet’s surface, from microscopic gaps in a steel beam to the individual atoms within the beam.

In this article, we’ll discuss what electron microscopes do, how much is an electron microscope, the different types of electron microscopes available, and how each works.

What does an Electron Microscope Do?

Optical or light microscopes aren't suited for specific applications, such as detecting viruses, bacteria, or molecules. Electron microscopes are far more powerful as it allows researchers to observe these things in nanoscale dimensions.

Electron wavelengths are up to 100,000 times shorter than visible light photon wavelengths. They allow EMs to have the level of resolution that makes it possible to examine the structure of much smaller objects.

The ultrastructure of inorganic and biological specimens, such as crystals, metals, biopsy samples, cells, and microbes, is studied in detail using electron microscopes. They can also be utilized in numerous industrial applications to aid in quality control and failure analysis efforts. Micrographs are produced by today's electron microscopes, which use specialized digital cameras and frame grabbers to capture important details of a sample specimen.

How does an Electron Microscope Work?

Similar to an optical microscope, an electron microscope has four essential parts but with a few key differences.

Instead of a light source, an electron microscope utilizes a beam of fast-moving electrons.

End-users are required to prepare the specimen and hold it inside a vacuum chamber without the presence of air. Since electrons are easily scattered by air particles, which include gas molecules such as oxygen and nitrogen, the electron beam would be thrown off course if there's no vacuum. Biological samples tend to evaporate quickly in a vacuum if the sample doesn't undergo preparative steps ahead of time.

Instead of lenses, the electron beam flows through a network of electromagnets. The glass lenses of a regular microscope bend or refract light beams traveling through them to magnify the specimen. The coil-shaped electromagnets of an electron microscope bend the beams in the same way.

Instead of viewing magnified samples through an eyepiece, the microscope image is captured as a photograph, also known as an electron micrograph, or shown on a computer screen.

There are various electron microscope types on the market, each of which operates somewhat differently. All of them create high-resolution photographs, while some are better suited for specific materials than others.

Different Types of Electron Microscopes

Transmission Electron Microscope (TEM)

The TEM is commonly referred to as the original electron microscope. It illuminates specimens with a high-voltage electron beam and generates a flat image.

An electron gun, which is often loaded with tungsten filament as the source, produces the beam. TEMs are often used in electron diffraction mode. However, the electrons must travel through exceedingly thin sections of the material to be studied that are roughly 100 nanometers thick.

Creating specimens this thin is generally challenging and technically complex. Some samples may even require dehydration or chemical fixation before cutting into thin slices becomes possible. Some may also require staining to improve visibility.

Serial-Section Electron Microscope (ssEM)

ssEMs are a subset of TEM. They generate images of multiple thin sections in a given sequence.

Scanning Electron Microscope (SEM)

An SEM electron microscope is similar to a key copying machine. When a key is replicated, the machine traces over the original key to cut an exact reproduction onto a blank. The copy is traced out from one end to the other rather than produced all at once, while the specimen being studied is considered the original key.