Use of Light Microscope

Name _________________
Period_________________

Onion & Cheek Cell Lab
Purpose: In this lab, you will prepare and observe cells from both a plant (onion) and an animal (your own cheek!!).
Materials: You will need the following materials: glass slide, coverslip, toothpick, iodine stain, onion tissue, and your own cheek.
Assignment: Your assignment is to prepare and observe as many samplings of both types of cells as possible and sketch them in the spaces provided on the back of this sheet. You are also required, on your sketch, to label any visible parts or organelles, as well as list what magnification you used. Lastly, you need to write down any other interesting observations (difference between cells, cool things you saw, etc.) on this sheet or another piece of paper.
Procedure:
For the onion cell:
1. Get a glass slide and place a small amount of onion tissue in the center. 2. Add a small drop of iodine stain directly to the tissue. Careful, iodine is not toxic, but it will stain both your skin and your clothes.
3. Place a coverslip over the newly stained tissue.
4. Put the slide on the microscope, making sure the microscope is on
LOW POWER!
5. Go through the three powers, focusing each time, making sketches, and writing down observations. Be sure to write what magnification you used for each sketch.
6. Be sure to label any parts you see. You may be able to see: cell wall, nucleus, and cytoplasm.
For the cheek cell:
1. Clean off your slide from above or get a clean slide (in case you want to compare them later.
2. Add a drop of iodine to the empty slide.
3. Using the blunt (not sharp) end of a toothpick, gently scrape the inside of your cheek.
4. Swirl the toothpick end, now with cheek cells, in the iodine drop on the slide.
5. Place a coverslip on the stained cheek cells.
6. Observe under the microscope like you did for the