2. Introduction to the Microscope  History  Types  Care  Parts  Focusing

3. First Things First… Our textbook has an online edition: –www.biologygmh.com/ose/www.biologygmh.com/ose/ –Access code: BBC31020F2 Other things to note: –www.biologygmh.comwww.biologygmh.com –Glencoe 2009

4. History Pg. 181 picture! Hooke and Leeuwenhoek improved the microscope to help improve their views of the cell Modern microscopes are call compound light microscopes

5. What They Do Through a series of lenses, microscopes magnify an image Microscope Video The ability to see something clearly is called resolution As you add lenses, the resolution will decrease

6. Types: Compound Light Microscopes Series of glass lenses and visible light work together to form the magnified image Each lens magnifies the image of the previous lens Example- two lenses, each magnify 10 times the object size- 10 x 10 = 100 Stain is often used because most cells are transparent

7. Transmission Electron Microscopes Greater magnification is needed (CLM only go to 1000 times magnification) –Up to 500,000 x During WWII, TEM was created No lenses- magnets aim a beam of electrons at slices of cells. –Thicker parts of the specimen will absorb different amounts of electrons Disadvantages: must be nonliving cells, sliced very thin and stained with heavy metals

8. Scanning Electron Microscope Directs electrons over the surface of the specimen Produces a 3-D image Can only use dead cells, as well Photomicrographs

9. Always carry with 2 hands- one on the arm and one the base When finished using the microscope, always return it to the low power setting Only use lens paper for cleaning Do not force knobs Always store covered Keep objects clear of desk and cords Keep out of direct sunlight because it may damage your eyes! Wrap cord around nosepiece to ensure the life of the cord

10. Eyepiece AKA Ocular Lens Body Tube Revolving Nosepiece Arm Objective Lens Stage Stage Clips Coarse Focus Fine Focus Base Diaphragm Light

11. Steps to focusing an object on low power: 1.Make sure the lowest power objective is in place 2.Place the slide on the stage under the stage clips 3.Turn the coarse adjustment know to bring the object into focus 4.Use the fine adjustment knob to focus the specimen 5.When finished, remove the slide and check to make sure the low power objective is in use Microscope Video

12. Follow steps to focus using low power Click the nosepiece to the longest objective Do NOT use the Coarse Focusing Knob Use the Fine Focus Knob to bring the slide Note: Use your book pg. xxviii