1. The Microscope Ms. Palmer 7 th Grade

2. The History Hans and Zacharias Janssen of Holland in the 1590’s created the “first” compound microscope Anthony van Leeuwenhoek and Robert Hooke made improvements by working on the lenses Anthony van Leeuwenhoek 1632-1723 Robert Hooke 1635-1703 Hooke Microscope

3. The History Zacharias Jansen 1588-1631 The “First” Microscope

4. Microscopes There are two types of microscope –Light –Electron

5. Properties of Microscopes Magnification: The process of enlarging something in appearanceMagnification: The process of enlarging something in appearance Resolution: Ability to distinguish the individual parts of aResolution: Ability to distinguish the individual parts of a object object

6. Types of Microscopes Light: Use lenses to bend light and magnify an objectLight: Use lenses to bend light and magnify an object

7. Types of Microscopes Electron: Uses beams of electrons instead of light to magnify an imageElectron: Uses beams of electrons instead of light to magnify an image

8. How a Microscope Works Convex Lenses are curved glass used to make microscopes (and glasses etc.) Convex Lenses bend light and focus it in one spot.

9. How a Microscope Works Ocular Lens (Magnifies Image) Objective Lens (Gathers Light, Magnifies And Focuses Image Inside Body Tube) Body Tube (Image Focuses) Bending Light: The objective (bottom) convex lens magnifies and focuses (bends) the image inside the body tube and the ocular convex (top) lens of a microscope magnifies it (again).

10. The Parts of a Microscope

11. Body Tube Nose Piece Objective Lenses Stage Clips Diaphragm Light Source Ocular Lens Arm Stage Coarse AdjCoarse Adj. Fine Adjustment Base Skip to Magnification Section

12. Body Tube The body tube holds the objective lenses and the ocular lens at the proper distance Diagram

13. Nose Piece The Nose Piece holds the objective lenses and can be turned to increase the magnification Diagram

14. Objective Lenses The Objective Lenses increase magnification (usually from 10x to 40x) Diagram

15. Stage Clips These 2 clips hold the slide/specimen in place on the stage. Diagram

16. Diaphragm The Diaphragm controls the amount of light on the slide/specimen Turn to let more light in or to make dimmer. Diagram

17. Light Source Projects light upwards through the diaphragm, the specimen and the lenses Some have lights, others have mirrors where you must move the mirror to reflect light Diagram

18. Ocular Lens/Eyepiece Magnifies the specimen image Diagram

19. Arm Used to support the microscope when carried. Holds the body tube, nose piece and objective lenses Diagram

20. Stage Supports the slide/specimen Diagram

21. Coarse Adjustment Knob Moves the stage up and down (quickly) for focusing your image Diagram

22. Fine Adjustment Knob This knob moves the stage SLIGHTLY to sharpen the image Diagram

23. Base Supports the microscope Diagram

24. Magnification

25. To determine your magnification…you just multiply the ocular lens by the objective lens Ocular 10x Objective 40x:10 x 40 = 400 Objective Lens have their magnification written on them. Ocular lenses usually magnifies by 10x So the object is 400 times “larger”

26. Caring for a Microscope Clean only with a soft cloth/tissue Make sure it’s on a flat surface Don’t bang it Carry it with 2 HANDS…one on the arm and the other on the base

27. Carry a Microscope Correctly

28. Using a Microscope Start on the lowest magnification Don’t use the coarse adjustment knob on high magnification…you’ll break the slide!!! Place slide on stage and lock clips Adjust light source (if it’s a mirror…don’t stand in front of it!) Use fine adjustment to focus

29. How to make a wet-mount slide … 1 – Get a clean slide and coverslip from your teacher. 2 – Place ONE drop of water in the middle of the slide. Don’t use too much or the water will run off the edge and make a mess! 3 – Place the edge of the cover slip on one side of the water drop. You do not need to use the stage clips when viewing wet-mount slides! 5 – Place the slide on the stage and view it first with the red-banded objective. Once you see the image, you can rotate the nosepiece to view the slide with the different objectives. 4 - Slowly lower the cover slip on top of the drop. Cover Slip Lower slowly

30. Let’s give it a try... 1 – Turn on the microscope and then rotate the nosepiece to click the red-banded objective into place. 2 – Place a slide on the stage and secure it using the stage clips. Use the coarse adjustment knob (large knob) to get it the image into view and then use the fine adjustment knob (small knob) to make it clearer. 4 – When you are done, turn off the microscope and put up the slides you used. 3 – Once you have the image in view, rotate the nosepiece to view it under different powers. Draw what you see on your worksheet! Be careful with the largest objective! Sometimes there is not enough room and you will not be able to use it!