Purpose:

My goal is to learn more about staining and to compare between a stained slide and a non-stained slide.

Hypothesis:

If I use staining I would be able to see the cells and organisms better. It will be focused more on the cell and would not be too bright to see.

Materials:

  • Microscope
  • Prepared microscope slides
  • Cover slips
  • Lens paper
  • Tweezers
  • Medicine dropper
  • Water
  • Onion
  • Iodine solution
  • Paper towel

Procedure:

  1. 1. Gather all materials you need to do your experiment.
  2. 2. Use some tweezers to get the skin of the onion when you cut it in half.
  3. 3. Use a medicine dropper to drop a little water on the slide.
  4. 4. Place your onion skin on the drop of water.
  5. 5. Place a cover slip on top of the onion skin.
  6. 6. Now place the slide between the clips and the stage.
  7. 7. Observe and adjust with the course and fine adjustment knob, to get an accurate picture.
  8. 8. When you have pictured it, take the slide off the stage and wait for the next step.
  9. 9. Now use iodine solution to stain the slide. Place a paper towel on one side of the slide and iodine on the other.

10. When you have stained the cell, Place it again on the stage and adjust.

11. Compare between the non-stained and the stained onion skin.

12. Draw the onion cell as a diagram on a separate piece of paper.

13. Clean up all the materials you used and return them to your instructor.

Observations:

When I put the slide without the stain it was harder for me to figure out the difference between the cell and the background.

Questions:

  1. 1. The most difficult part was when I had to flatten the onion so that there would be no bubbles.
  2. 2. The nucleus was less clear without the stain because it was too bright. But when I put the stain it became clearer.
  3. 3. Because when we water a plant, the water goes to the vacuoles and holds it up. But when it tilts that means the plant is lacking water.

Conclusions:

I saw the nucleus only when it wasn’t stained. But when I got it stained I even saw the ribosome and some other organelles. My results were accurate and I learnt to try staining the slide whenever I can to see the cell and other things better on the microscope. I

How do you interpret your observations?

I think that when there is stain around the cell, then our eye can focus more on the brighter side of the slide. This staining make a difference which allows us to see the cell better.


 

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