Light & Electron Microscopes 5.0 / 5 based on 1 rating ? BiologyCellular processes and structureASAQA Created by: LillyCreated on: 06-01-13 21:43 Light Microscopes They use light and a system of lenses to magnify images of small samples . Advantages Image is shown in colour Cheaper than electron microscopes Smaller, easier to use The samples is alive Disadvantages Lower reolution than electron microscopes An additional lamp is needed 1 of 4 Electron Microscopes Use elrctrons instead of light to form an image. Advantages: Clearer resolution-more detail No additional lamp is needed Greater depth of field Disadvantaes: Mor expensive than light microscopes Big, so harder to use 2 of 4 Scanning Electron Microscope (SEMs) Scan a beam of electrons across the specimen Knocks off electrons from specimen, which are gathered in a cathode ray tube, which forms an image. Advantages Can be used on thick specimens Produces a 3D image Disadvantage Expensive Large Must be kept in an area with minimal electricm magnetic or vibration interference Lower resolution than TEMs 3 of 4 Transmission electron microscope (TEMs) Uses electromagnets to focus beams of electrons, dense areas of specimen absorb more electrons Advantages Higher Resolution than SEMs Small objects can be seen clear Wavelength of electrons shorter Powerful magnification- greater detail Disadvantages Can only be used on thin specimens All water has to be removed in a vaccum, so the cell must be dead Black & white image produced Potential artifacts from extensive sample preparation 4 of 4
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