What is a scanning electron microscope?
The scanning electron microscope is a piece of device that uses high -energy electron rays to generate information about the microscopic sample. The generated information is then divided into a sample image. Scanning electron microscopes are up to 250 times more powerful than light microscopes and can increase images of up to 500,000 times. One nanometer is one billion meter or approximately four billion thumb. These microscopes can generate accurate images of organisms as small as viruses, and even bacteriophages, which are viruses that infect bacteria. This is because microscopes have a wide depth of field, allowing objects in the background and forefront concentrated at the same time. As a result, scanning electron microscopy is very useful for determining the surface structure and 3D shape of the samples.
As the machine works, the correct preparation of the sample is a vital aspect of the scanning ElekTron microscopy. Preparation is two important parts. The first is that the samples must be coated in an electrically conductive substance such as gold, platinum or chrome. This is important to reduce electrostatic accumulation during the process. The second important aspect is that the samples are examined in a vacuum, which means they must be completely dry. For this reason, biological samples are chemically fixed by a substance such as formaldehyde to maintain the tissue structure.
The operation of the scanning electron microscope includes an electron gun, magnetic lenses and electron detector. Once the sample is placed on the ICROSCOPE Mstage and the process begins, the electron gun begins to shoot. The weapon fires the electron beam over the anode, then with two magnetic lenses and then an electron detector.
In conjunction with a microscope condenser lens, this process effectively concentrates the electron beam so that it can accurately hit the sample. When this happens, the electrons begin to interact with the sample and detectedRY in the microscope calculates the number of interactions that occur. The number of interactions then dictates how pixels appear on the monitor that shows images. The more interactions that occur, the brighter the pixels appear. The pixel brightness contrast is a picture.
scanning images of an electron microscope are generated without the use of light waves; Therefore, the pictures are always in black and white. These are highly detailed three -dimensional images and, despite the lack of color, are extremely accurate. Images can be colored to look more vivid and improve contrast.