Electron Microscopy - Test, Procedure & Cost

Electron microscopy is used to obtain ultrahigh-resolution images of individual atoms of materials of cells. These resulting microstructure and mesostructure images are usually used to investigate the sample properties and behavior.

These electron microscopes produce electron micrographs using technical digital cameras and frames to capture the images.

The science of microbiology exhibits its development to the electron microscope. The study of microorganisms like bacteria, virus, and other pathogens by electron microscopes have made the treatment of diseases very effective.

Electron microscopy is of two main types:

• * Scanning electron microscopy (SEM)
• * Transmission electron microscopy (TEM)

Scanning electron microscopy (SEM) uses a relatively low-power electron beam for imaging and interaction with the sample.

Transmission electron microscopy (TEM) uses a high-energy beam of electrons to transmit electrons through a sample to create a 2D image at the highest possible resolution.

Advantages of Electron microscope

• * It has very high magnification
• * It has incredibly high resolution
• * Materials are rarely distorted by preparation.
• * It is possible to investigate a greater depth of field
• * It is used in Diverse applications

What is it used for?

An electron microscope is an instrument that uses a beam of electrons to magnify a specimen. It is mainly used to observe the internal structure of cells and the ultrastructure of surfaces.

It is used in conjunction with a variety of ancillary techniques (e.g. thin sectioning, immuno-labeling, negative staining) to answer specific questions. EM images provide key information on the structural basis of cell function and of cell disease.

It is used in materials science, biomedical research, quality control, and failure analysis. The use of electrons as the imaging radiation source allows for greater spatial resolution (on the tens of picometers scale) as compared to the resolution achieved using photons in optical microscopy. In addition to surface topography, information about crystalline structure, chemical composition, and electrical properties are obtainable through electron microscopy.

Working Principle of Electron microscope

Electron microscopes always occupy signals generated from the interaction of an electron beam with the sample to obtain information about structure, morphology, and composition.

• * Electrons are generated by an electron gun.
• * The electron beam is focused by two sets of condenser lenses on the specimen and then into a thin tight beam.
• * To move electrons down , an increasing voltage is applied between the tungsten filament and anode.
• * The specimen that is to be examined is made extremely thin, at least 200 times thinner than those used in the optical microscope.
• * Ultra-thin sections of 20-100 nm are cut which are already placed on the specimen holder.
• * The electronic beam passes through the specimen and electrons are scattered depending upon the thickness of  different parts of the specimen.
• * The denser regions in the specimen scatter more electrons and therefore appear darker in the image since fewer electrons strike that area of the screen. In contrast, transparent regions are brighter.
• * The electron beam coming out of the specimen passes to the objective lens, which has high power and forms the intermediate magnified image

What is the difference between a regular microscope and an electron microscope?

The difference between a regular microscope and an electron microscope is that it uses a beam of electrons to produce images. A regular microscope uses light to magnify a specimen.