Cell Structure — Lab Prep

  1. Visualizing Onion and Cheek Cells
    • Immediately before the experiment, wash and peel onion bulbs for the class.
    • Remove the entire brown outer skin and cut the onion in half with a knife. Pull apart the layers of the onion. The thin, nearly transparent film layers within the onion will be used by the students.
    • Place the onion film into a Petri dish and then place this into the refrigerator until the students arrive.
    • Bring out the microscopes and set them on the lab bench.
    • Set the microscopes to the lowest magnification and plug them into an electrical outlet.
    • Clean the lenses with lens paper or laboratory wipes and test the knobs to make sure the lenses focus properly.
    • Make sure that the stage can be moved.