The Human Cheek Cell Microscope Lab Period: _____ Date: _________
What kind of tissue are you able to observe from your cheek sample?
To learn the parts of and how to use the microscope.
To find specimens using low, medium, and high power.
To make a wet mount slide.
To view your own (or your partner’s) cheek cells under the microscope. To compare plant and animal cells.
Procedure of Investigation
1. Add one drop of methylene blue to the middle of a clean slide. Be careful! Methylene blue will stain your clothes and skin. 2. Use the flat side of a toothpick to gently scratch the inside of your cheek. DO NOT GOUGE YOUR CHEEK - you don’t need chunks of skin and definitely don’t want to draw blood. 3. Gently swish the toothpick in the drop of dye on the slide. Some of your cheek cells should drift off into the dye. 4. Throw the toothpick away.
5. Stand a thin glass cover slip on its edge near the drop of dye. 6. Slowly lower the other side of the cover slip until it covers the dye completely. Make sure there are no air bubbles. 7. Make sure the lowest power lens (the shortest lens) is in place over the stage. Place the slide onto the stage of the microscope. 8. Look through the eyepiece and turn the coarse focus knob (the largest knob) until an image comes into focus. It should look like scattered blobs. Move the slide around until a nice cluster of blobs moves into the center of your image. 9. Use the fine focus knob (the smallest knob) to make the image as focused as possible. 10. Draw a picture of what you see in the circle below. Label the picture “Human cheek cells 40x”. Label as many organelles of the cell as you can see.
11. Looking from the SIDE of the microscope, rotate the lenses to the highest powered lens (400x). If you need to, use the fine focus knob (the smallest knob) to get the image into focus. DO NOT USE THE LARGE KNOB!! If you cannot see clearly with good resolution then switch to medium power (100x). 12. Draw a picture of what you see in the circle below. Label the picture “Human cheek cells” 100x or 400x”. Label as many organelles of the cell as you can see.
13. Please turn off light and switch to the lowest power lens and THEN remove the slide.
14. Why is methylene blue necessary?
15. What observations were you able to find when evaluating your cheek cell?
Notes and Drawings
Please go to http://biologycorner.com/anatomy/histology/ to get a live view of slides containing different types epithelial cells. Draw what you see, define what the tissue is, and describe where those cells are found.