Electron microscopes are essential tools in modern research and industrial applications, offering a level of detail and resolution that traditional optical microscopes simply can't match. While optical microscopes use visible light to observe specimens, electron microscopes use a beam of electrons to magnify objects at the nanoscale, allowing scientists and engineers to see viruses, bacteria, molecules, and even individual atoms.
In this post, we’ll take a closer look at what electron microscopes do, the different types available, and how they work to unlock the mysteries of the smallest structures on Earth.
Electron microscopes provide the magnification needed to observe objects far too small for light microscopes to detect. These microscopes can magnify structures at the nanometer scale, enabling researchers to view bacteria, viruses, molecules, and even individual atoms with stunning precision.
Unlike optical microscopes, which rely on visible light, electron microscopes use electron wavelengths that are significantly shorter, allowing for much higher resolution. This capability makes them essential tools in studying the ultrastructure of biological specimens like cells and tissues, as well as inorganic materials such as metals and crystals. Electron microscopes also play a critical role in industrial settings, where they are used for quality control, failure analysis, and more.
Electron microscopes operate similarly to optical microscopes but use electrons instead of light to achieve much higher magnification. The process begins with an electron source, which emits a beam of electrons powered by a filament. This beam passes through a vacuum chamber, as air particles would scatter the electrons and distort the image. Preparing the specimen for the vacuum is crucial, especially for biological samples that could evaporate without proper preparation.
Once inside the microscope, the electron beam is focused by electromagnetic lenses. These coils of electromagnets bend the electron beam in much the same way glass lenses bend light in an optical microscope. The electron beam then interacts with the specimen, producing a highly magnified image. Instead of viewing the specimen through an eyepiece, the image is captured as an electron micrograph or displayed on a computer screen.
This method makes it possible to view incredibly small objects with high resolution, revealing detailed structures of biological and inorganic materials alike.
There are several types of electron microscopes, each designed to handle specific materials and applications. While all electron microscopes deliver high-resolution images, certain types are better suited for specific tasks. Below are the main types:
The transmission electron microscope (TEM) is the original form of the electron microscope. It uses a high-voltage electron beam to pass through a thinly sliced specimen, creating a flat, highly detailed image. TEMs are commonly used for biological and material science research, where high resolution is necessary, though preparing samples is often technically challenging and requires precise techniques such as dehydration or chemical fixation.
Serial-section electron microscopy (ssEM) is a subset of TEM that involves imaging multiple thin sections in sequence. This technique is used to study three-dimensional structures, as it creates a series of images that can be reconstructed into a 3D model.
The scanning electron microscope (SEM) works differently than a TEM by scanning the surface of a specimen with an electron beam to create a three-dimensional image. SEM is ideal for analyzing surface details and is often used in industries like materials science and electronics for quality control and failure analysis.
In reflection electron microscopy (REM), an electron beam interacts with a sample’s surface, and elastically scattered electrons are detected to produce an image. REM is useful for observing surface processes and changes in materials.
STEM combines the techniques of TEM and SEM, scanning a focused electron beam over a small area of the specimen while collecting detailed data. STEM microscopes can operate in both transmission and scanning modes, making them versatile tools for both structural and analytical research.
STM microscopes use a sharp metallic probe to scan the surface of a specimen at the atomic level. Unlike SEM and TEM, STM does not rely on electron beams but measures the tunneling current between the probe and the specimen, allowing researchers to map atomic structures with exceptional detail.
AFM operates similarly to STM but doesn’t require the specimen to be electrically conductive. It uses a mechanical probe to "feel" the surface, making it possible to produce atomic-scale images of non-conductive materials such as plastics and biological specimens.
Cryo-electron microscopy (Cryo-EM) uses frozen samples and gentler electron beams to study specimens that would otherwise be damaged by high-energy electrons or vacuum conditions. This technique is particularly useful for biological samples, allowing researchers to capture images of molecular structures in their native state.
The cost of an electron microscope can vary significantly depending on the type, features, and the specific needs of your laboratory. Prices are influenced by factors such as the model, the detector types, and the resolution capabilities. Generally, electron microscopes can be categorized into the following price ranges:
Several factors can influence the final cost, including the microscope's resolution, the types of detectors used, and any additional features needed for specific applications. For example, Cryo-EM microscopes with specialized cryo stages for biological samples tend to cost more due to the advanced technology involved.
It's also important to consider additional costs such as maintenance, software, and operator training. Advanced microscopes often require specialized training to ensure users can operate them effectively.
For labs working within tighter budgets, exploring used or refurbished electron microscopes is a cost-effective option. These microscopes can offer substantial savings while still delivering reliable performance for many applications.
Purchasing an electron microscope can be a major financial commitment, with prices often exceeding several hundred thousand dollars depending on the model and features. While owning the equipment may make sense for labs with significant capital and long-term needs, leasing is increasingly becoming the smarter choice for many labs, especially those looking for greater financial flexibility and access to the latest technology.
Advantages of Buying:
Advantages of Leasing:
For most labs, the flexibility and financial advantages of leasing outweigh the long-term commitment of ownership, making it an ideal option for labs that need to stay adaptable while managing costs.
Leasing an electron microscope is a cost-effective solution that provides flexibility, access to the latest technology, and the convenience of included maintenance, making it the ideal choice for many labs. Whether your lab is just starting out or looking to upgrade its equipment without a major financial burden, leasing can help you stay competitive and efficient.
At Excedr, we offer leasing options for a wide range of electron microscopes, including SEMs, TEMs, STEMs, and more. Our leasing agreements include maintenance and repairs, ensuring your equipment remains fully functional and up to date. Additionally, if your lab requires other types of microscopes—such as x-ray, infrared, confocal, or fluorescence microscopes—we have options to suit your needs.
Contact us today to learn more about how our flexible leasing programs can provide your lab with the high-end electron microscopes it needs without the large upfront investment.
