Mrs. Wolodkowicz

Biology 1H

The Magical Microscope Lab

  1. Purpose: to study the use of the light microscope
  2. Materials: paper, pencil, scissors, microscope, slides, cover slips, toothpicks, & water.
  3. Procedure:
  4. Practice naming all of the parts of the microscope with your lab partner as seen in diagram A.
  5. Turn on the microscope.
  6. Rotate the course adjustment knob so that the stage is at is lowest point.
  7. Draw a tiny lower case “e” on paper.
  8. Place the “e” on a slide & place the slide on the microscope stage. Make sure that the specimen is placed over the iris (the hole that allows the light to come through).
  9. Rotate the nose piece so that “low power” (either 4x or 10x depending on the scope) is in place). The student will hear a click when it is in place.
  10. Turn the “course adjustment knob” until the specimen (“e”) comes into view.
  11. Now turn the fine adjustment to bring the specimen into clear focus.
  12. Next view the specimen under high power (40x). The student may need to move his/her slide around to bring the specimen back in view. DO NOT USE THE COURSE ADJUSTMENT UNDER HIGH POWER!! Only the fine adjustment.
  13. Remove “e”. On the slide, add one drop of water.
  14. Using a toothpick, gently scrap the inside of the cheek.
  15. Mix this with the water.
  16. Add a drop of methylene blue to the mixture. Stir with toothpick.
  17. Prepare a “wet-mount” slide by place cover slip at a 45o angle to the solution and gently laying it flat.
  18. Observe under both low and high power following previous directions on their use.
  19. Results: Draw the letter “e”, then in low & in high power. Draw the cheek cells in both low and high power as well. Make sure to label the drawings and note total magnification.
  20. Conclusion: Write a brief conclusion and answer the following questions.
  21. How did the “e” as seen through the microscope differ from the way an “e” normally appears?
  22. When you slide the “e” to the left, what direction does it appear to move?
  23. What is the purpose of place the cover slip at a 45o angle to a slide?
  24. What happens to your view when you move from low power to high power? Does the view become smaller or larger; is the view more detailed or less detailed?