Journal of Clinical Chemistry and Laboratory Medicine
Open Access

Transmission Electron Microscopy: Technology Using Electrons for Magnifying Images of Specimens

Miha Mugerli^{* *}Correspondence: Miha Mugerli, Department of Medicine, University of Ljubljana, Ljubljana, Slovenia, Email:

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Description

A beam of electrons is transmitted through a material to create a picture in the microscopy technique known as Transmission Electron Microscopy (TEM). Most frequently, the specimen is a suspension on a grid or an ultrathin slice that is less than 100 nm thick. As the beam passes through the specimen, a picture is created as a result of the electrons interactions with it.

An imaging device, such as a fluorescent screen, a sheet of photographic film, or a sensor like a scintillator linked to a charge-coupled device, is then used to magnify and focus the image. The operating modes of TEM instruments include diffraction, spectroscopy, Scanning TEM (STEM) imaging, conventional imaging, and combinations of these. Since a single column of atoms is thousands of times smaller than a resolvable object observed in a light microscope, this allows the equipment to capture extremely fine detail.

In contrast to scanning electron microscopy, which can only provide information on the morphology of a specimen, this technology may provide information about the structure, crystallization, morphology, and stress of a substance. Although sample preparation can take longer, TEM requires very thin specimens that are semi-transparent to electrons. This method is applicable to several fields, including forensic science, gemology, and materials science as well as medical research, where it is utilized to study viruses and bacteria, for instance. An electron beam is fired from an electron gun within a transmission electron microscope. The gun uses electromagnetic coils and voltages of up to several million volts to accelerate the electrons to extraordinarily high speeds. A condenser lens with a large aperture that eliminates high angle electrons concentrates the electron beam into a narrow, compact beam. The ultra-thin specimen is traversed by the electrons when they reach their top speed, and depending on how transparent the sample is to electrons, different portions of the beam are transmitted. The portion of the beam that is emitted by the sample is focused into an image by the objective lens. The vacuum system, another part of the TEM, is crucial for preventing collisions between electrons and gas atoms. A diffusion pump operates at a low enough pressure to operate at a low enough vacuum, which is then raised to a level that is high enough for activities using either a rotary pump or a diaphragm pump. A third vacuum system might be used because high voltage TEMS need very high vacuum levels. The micrograph, a picture created by the TEM, is projected onto a luminescent screen to be seen. The electron beam causes this screen to produce photons when it passes through it. Under the screen, a film camera can be used to capture the image, or a Charge-Coupled Device (CCD) camera can capture it digitally. TEMs can be employed in silicon chip and computer chip manufacture, as well as semiconductor analysis and production.

In the physical, chemical, and biological sciences, transmission electron microscopy is a crucial analytical technique. Because the wavelength of an electron is significantly shorter than that of a photon, TEM can be used to see particles with far higher magnification and resolution than is possible with a light microscope. In comparison to a scanning electron microscope, which can only be used to scan and view a sample's surface, it also offers images with a better resolution. Scientists may observe specimens down to the atomic level-less than 1 nm using TEM.

Conclusion

TEMs are useful in the study of cancer, viruses, and materials, as well as in the study of pollution, nanotechnology, and semiconductors, as well as in other disciplines including palaeontology and palynology. Due to the short de Broglie wavelength of electrons, transmission electron microscopes can image at a substantially better resolution than light microscopes. Technology businesses utilize TEMs to locate defects, fractures, and damages in microscopic items; this information can be used to solve issues or create more robust, effective products. TEMs are very high in demand nowadays and used in almost every field including medical, biotechnological and industrial field as well.