Diffusion, Microscope & Cell Lab

1. Diffusion, Microscope & Cell Lab 02

2. Activity 1 Diffusion experiment Methylene blue MW 320g/mole Potassium permagnate MW 150 g/mole Form Hypothesis T0 initial diameter T60 final diameter Room temp Fridge

3. Carrying a Microscope A B

4. Storing The Microscope • Return the lowest power objective in place • Wrap the cord around the base • Return dustcover

5. Cleaning the Microscope • Use lens paper on all glass parts of the microscope. • Clean oil immersion lens with chemicals provided by your instructor

6. Parts of the Microscope • Ocular • Body tube • Nosepiece • Objective lenses (10, 40, 100x) • Arm • Course adjustment knob • Fine adjustment knob • Stage • Stage clips • Aperture • Diaphragm • Light • Base

7. Microscope Parts • Ocular • Body tube • Stage clip • Revolving nose piece • Objective • Arm • Stage • Diaphragm • Lever to move stage clip • Course adjustment • Fine adjustment • Light source • Base

8. Using the microscope • Always observe using the LOWEST POWER objective first. • Focus using the COARSE ADJUSTMENT KNOB to bring the object into focus. Bring the object into sharp focus by using the fine adjustment knob. • Focus, and then move to a higher power objective, if needed. • Use only the FINE ADJUSTMENT KNOB when using the HIGHEST (longest) POWER OBJECTIVE. • Keep both eyes open to reduce eyestrain. • Determine total magnification of the object by multiplying the power of the ocular (10x) the power by the power of the objective.

9. Preparing a slide • Using a pipet or dropper, add a drop of water or another solvent to a clean microscope slide. Then, place the specimen in the water. • Place the edge of a coverslip on the slide so that it touches the edge of the water. • Slowly lower the coverslip to prevent the formation of air bubbles.

10. Oil Immersion Lens 100x 40x

11. Animal Cell

12. Plant Cell

13. Activity 2 • Prepare wet mount • Cheek cell • Elodea cell • Onion cell • Look at specimen under high power and draw what you see. • Use proper clean-up technique

14. Cheek Cell

15. Elodea

16. Epidermal Onion Cell

17. Activity 3 • Prepare wet mount for dissecting scope • Pond water • Look at specimen under high power and draw what you see. • Use proper clean-up technique

18. Dispose Biological material

19. Dispose Sharps

20. Clean Up

21. Microscope Parts Quiz

22. Microscope Quiz • Which objective uses oil? • If your ocular is 10x and your objective is 40x what is the total magnification of your image? • Why do you need a cover slip and how do you avoid an air bubble? • What is the difference between a light microscope and a dissecting microscope? 1.

23. Instructor’s Notes: • Materials & Equipment • 5 dissecting scopes • 5 light microscopes • Cover slips • Slides (box) • Droppers • Water in dropper • Oil and cleaner for oil immersion lens • Lens paper • Onion • Elodea • Toothpicks (box) • Sharps and biohazard bag • disinfectant • 5 Rulers • 10 agar plates plus a few extra • Methylene blue • Potassium permagnate • Razor blade to cut plants • Pondwater • Use of fridge