Objectives:
Observe animal cells
Materials per student (or team):
• microscope
• clean microscope slide and cover slip
• clean flat toothpick for each student (never share toothpicks)
• eye dropper
• stain – methylene blue staining solution (iodine solution can be used as an alternative stain)
• paper towels
Procedures:
1. Use the eye dropper to put a drop of methylene blue stain on a slide. (Be careful as it will stain clothing.)
2. Take a flat toothpick and gently scrape the inside of your cheek to collect some epithelial cells.
3. Gently swirl the cells on the toothpick into the methylene blue drop on the slide. (Throw out the toothpick.)
4. Carefully place a coverslip over the cells on the slide at an angle to push out any air bubbles.
5. Observe the cells under the microscope at 40x, 100x and 400x. Start with low power to locate the cells. Then switch to higher power. Use the fine adjustment only.
6. Draw the cheek cells at three different magnifications.
Study a typical animal cell to compare to your cheek cell.
Compare to a plant cell investigation.
