Microbiology 42 = Electron Microscope (Part- 02) | Specimen Preparation in Electron Microscope скачать в хорошем качестве

Microbiology 42 = Electron Microscope (Part- 02) | Specimen Preparation in Electron Microscope

Download "Solution Pharmacy" Mobile App to Get All Uploaded Notes, Model Question Papers, Answer Papers, Online Test and other GPAT Materials - https://play.google.com/store/apps/de... An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects. A scanning transmission electron microscope has achieved better than 50 pm resolution in annular dark-field imaging mode. Electron microscopes use shaped magnetic fields to form electron-optical lens systems that are analogous to the glass lenses of an optical light microscope. Electron microscopes are used to investigate the ultrastructure of a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. Industrially, electron microscopes are often used for quality control and failure analysis. Modern electron microscopes produce electron micrographs using specialized digital cameras and frame grabbers to capture the images. Composition of an electron microscope- (1) The electron gun generates electrons. (2) Two sets of condenser lenses focus the electron beam on the specimen and then into a thin tight beam. (3) To move electrons down the column, an accelerating voltage (mostly between 100 kV-1000 kV) is applied between the tungsten filament and anode. (4) The specimen 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 is already placed on the specimen holder. (5) The electronic beam passes through the specimen and electrons are scattered depending upon the thickness or refractive index of different parts of the specimen. (6) 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. (7) The electron beam coming out of the specimen passes to the objective lens, which has high power and forms the intermediate magnified image. (8) The ocular lenses then produce the final further magnified image. Get in touch with the solution by just clicking the following links- Facebook Group-   / solutionpharamcy   Facebook Page-   / pharmavideo   New Channel (Pharmacy Dictionary)    / @pharmacydictionary   Instagram-   / solutionpharmacy   E-Mail for official and other work - solutionpharmacy@gmail.com LinkedIn-   / pushpendrakpatel   #solutionpharmacy #Pharmacologyclass #Pharmacognosyvideos #GPATonlinetest #GPATclass #GPATvideos #Microbiologyclass#Microbiology#