1. MICROSCOPES Copyright Cmassengale 1

2. Microscopy and Measurement produce an enlarged image of an object  Microscopes – produce an enlarged image of an object  Used to study organisms, cells, and cell parts magnification  Increase in apparent size is called magnification resolution  The ability to show details clearly is called resolution  Microscopes vary in both magnification and resolution Copyright Cmassengale 2

3. Compound Light Microscopes  Specimen glass slide  Specimen mounted on a glass slide  Must be thinly sliced or very small lenses  Pair of lenses  Ocular  Ocular lens (eye piece)  Objective  Objective lens (nose piece) LIVE specimens  Can be used to study LIVE specimens Copyright Cmassengale 3

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6. Magnification  Magnification  Magnification determined by multiplying power of both lenses  Eyepiece 10X times Objective power (20X, 40X…)  Highest 1000X  Highest Maximum magnification is around 1000X Copyright Cmassengale 6

7. Electron Microscope  Transmission EM (TEM) beam of electrons  Uses a beam of electrons to produce an enlarged image of very thinly sliced specimen on screen or photographic plate magnetic lenses  Image focused by magnetic lenses  200,000X magnification  Cannot be used to view living specimens Copyright Cmassengale 7

8.  Scanning EM (SEM)  3D  3D image not sliced for viewing  Specimens not sliced for viewing  Surface sprayed with fine metal coating  Also uses electron beam and fluorescent screen or photographic plates  100,000X magnification  Cannot be used to view living specimens Copyright Cmassengale 8

9.  Electron Microscope: ClickClick for Video on how an Electron Microscope worksforhowworks We are notWe are not alone.flv alone!We are not alone.flv

10. Microscope Care and Use  Always carry the microscope by holding the arm of the microscope with one hand and supporting the base with the other hand  Place the microscope on a flat surface. The arm should be positioned toward you  Look through the eyepieces. Adjust the diaphragm so that light comes through the opening in the stage

11. Place a slide on the stage so that the specimen is in the field of view. Hold it firmly in place by using the stage clips Always focus first with the coarse adjustment and the low-power lens. Once the object is in focus on low power, the high-power objective can be used. Use ONLY the fine adjustment to focus the high-power lens. Store the microscope covered.