1. Our Microscope 6 th Grade Science Certain materials are included under the fair use exemption of the U.S. Copyright Law and have been prepared according to the multimedia fair use guidelines and are restricted from further use. Photo by D. Tresten, 2002

2. Eye piece Body tube Base Coarse adjustment knob Arm Fine adjustment knob Revolving nosepiece Diaphragm Light source Stage opening Stage clips Stage Magnify 10 X Objective lens

3. Magnify 10x Support / Hold lenses in place Support microscope Focus quickly but imperfectly (coarsely) Hold body tube/Carry Focus very slowly more perfectly (actually moves the stage away from/toward the objectives) To turn objectives (lenses) into place over specimen To magnify 40x Allow more/less light Send light up through specimen Allow light to reach specimen / Catch spilled matter To magnify about 10X Hold slide To magnify about 4X

4. IMPORTANT! Watch How Light Travels Through a Microscope Note: Just study the vertical (up and down) portion of the light beam! The horizontal (right/left) portion is not in our microscope. Molecular Expressions Microscopy Primer: Anatomy of the Microscope - Transmitted Light Microscopy Optical Pathways: Interactive Java Tutorial

5. Which type of lens is in a microscope? Convex Lens (Pooches out in the middle!) Concave Lens (Caves in in the middle!) Check out how a convex lens works in your eyes! Molecular Expressions Microscopy Primer: Light and Color - Human Vision: Interactive Java TutorialMolecular Expressions Microscopy Primer: Light and Color - Human Vision: Interactive Java Tutorial See how a concave lens works: Molecular Expressions: Light and Color - Bi-Concave Lenses: Interactive Java TutorialMolecular Expressions: Light and Color - Bi-Concave Lenses: Interactive Java Tutorial See a convex lens here: http://en.wikipedia. org/wiki/Lens_(opti cs) http://en.wikipedia. org/wiki/Lens_(opti cs) http://en.wikipedia.org/wiki/Image:Lens_and_wavefronts. gif Light waves

6. In Which Objects would Convex Lenses be Used? Click to see 7 images

7. In Which Objects might Concave Lenses be Used? Click to see 7 images

8. Total Magnification - What is it? To find the total magnification at which a microscope is set, just multiply the power of the eyepiece (10x) times the power of the objective that is in place. Click to practice finding total magnification…

9. Practice calculating Total Magnification: If the eye piece is 10 x and the objective lens is 40 x the magnificaiton is... If the eye piece is 10 x and the objective lens is 20 x the magnificaiton is... If the eye piece is 10 x and the objective lens is 10 x the magnificaiton is... 400x 200x 100x

10. How do you take care of a microscope?

11. Care of the Microscope, Always carry a microscope with _______ hands, one on the ______ and the other on the ________. two arm base

12. Clean lenses with ______ _________ only. lens paper NEVER touch _________ with finger tips. lenses

13. Always keep the scope _____ from the _______ of the _________. Care of the Microscope Page 3 of 3 away edge table

14. How to Use the Microscope

15. 1.STAGE down! (away from objectives) 2.Twist 4x (Low-Power) OBJECTIVE until it clicks into place! (using nosepiece NOT objectives) 3.Stage CLIPS out! 4.SLIDE on 5.Stage CLIPS back in (carefully placed on top of slide) 6.Set disc diaphragm to smallest hole 7.Switch on LAMP Before using the Scope, Wake It Up: Use of the Microscope Page 1

16. 1.Make sure that the stage is all the way DOWN and slide is in place. Down In place

17. 2.Set Disc Diaphragm to “Least Light” (Setting 5 or 1)

18. Close-up of disc diaphragm (as seen from underneath the stage) Do you see the largest hole that lets the most light pass? Which hole transmits the least light?

19. 3. Set Scope to Low Power (100x) In other words, set the 10x objective in place over the stage opening. 10x Objective

20. 4. Looking from the side, use the coarse adjustment knob to raise the stage as close as possible to the objectives…

21. 5. Looking through the eyepiece for the first time (with both eyes open), use the fine adjustment knob until the specimen is in sharp, clear focus.

22. Use of the Microscope Page 3 6. If there is too little light, rotate the disc diaphragm to another opening. How to Focus on a Specimen, Cont’d:

23. Note: If the object is a blur or just a shadow (like this one is), it is NOT in focus. Keep turning the fine adjustment knob until it is in sharp focus.

24. What is this? “Field of Vision” in a Microscope Pointer in eyepiece

25. Always put our microscopes “to bed” after labs: Use of the Microscope Page 4 1.Lamp off 2.Unplug 3.Stage down (Away from objectives) 4.All slides are removed 5.Clips IN 6.Clean stage 7.Dust cover ON 8.Put all slides and other materials in proper places

26. Wet Mount with a Squashed Air Bubble in It

27. How to Add More Water to a Wet Mount without Starting All Over Again!

28. Why Learn to Use a Microscope? To see cool things like anything on the following web page! http://www.molecularexpressions.com /moviegallery/pondscum.html http://www.molecularexpressions.com /moviegallery/pondscum.html