Using the Microscope for the Cheek & Onion Cell Lab

1. Using the Microscope for the Cheek & Onion Cell Lab

2. Carrying a Microscope A B

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

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

5. 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

6. 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

7. 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.

8. Preparing a wet mount • Start with a clean slide and coverslip. • Hold the slide and coverslip by their edges to avoid getting your fingerprints on their surfaces. • Using tweezers, position the specimen in the centre of the slide. • With the medicine dropper, place one drop of water on the specimen. • Hold a coverslip over the sample at a 45° angle. One edge of the coverslip should touch the surface of the slide near the specimen. • Lower the opposite edge of the coverslip over the sample. Make sure that no bubbles form beneath the coverslip.

9. Animal Cell

10. Plant Cell

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

12. Cheek Cell

13. Epidermal Onion Cell

14. 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

15. Dispose Biological material

16. Dispose Sharps

17. Clean Up