Procedure
Part A - Human Cheek Epithelium

A view of three human cheek epithelial cells and many tiny bacteria under a compound light microscope observed at 40X magnification. The cells are stained with methylene blue with arrows pointing to parts of you observe. The alphabetically labeled parts to which the arrows points are: A. inside of one of the cells, B. the darkly stained structure at the center of one of the cells, C. Small structures in the body of one of the cells, D. dark structure inside the nucleus, E. outermost lining of one of the cell, F. many tiny structures outside of the epithelial cells.

• View the image of a human cheek epithelial cell in Figure 3.1.
• In lab this is what you would see under the microscope after staining the cells taken from inside your own mouth.
• The cells on this slide have been stained with methylene blue to make them easier to see.
• These cells are being viewed with the high power objective (40X) lens.
• The 3 large cheek cells are covered in many tiny bacterial cells.
• Recall in lab 2 we saw bacterial cells with a total magnification of 1000x. These have a total magnification of 400x. That is why the bacteria appear as only tiny specks on the outside of the larger cheek cells.
• Use Figure 3.1 to answer questions in Part A of the Lab Report