Lab: Cell Study
Purpose:
To prepare, examine and compare various cell specimens, both
plant and animal.
Materials:
Microscope
Onion skin
Cheek tissue
Prepared human blood slide
2 slides
Paper Towel
Slide preparation cart
Iodine stain
Methylene blue stain
Prepared frog blood cell
2 cover slips
Procedure:
Part I: Comparing human blood with frog blood.
1. Examine a prepared slide of frog blood under low mag. (40x)
and progress up to high mag. (400x).
2. Draw 2 to 3 cells, indicating the shape and any structural
details you can see. Label the organelles you see. Include
the magnification.
3. When you are using the high power objective, the field of
view is 400μm. Under the drawings you made in step 2,
estimate the approximate size of a typical frog blood cell.
4. Repeat the above 3 steps for the prepared slide of human
blood.
Part II: Preparing wet mount slides of a typical plant cell and a
typical animal cell.
1. Prepare a slide of onion skin. Stain it using the iodine stain.
(for more instruction see handout on “Wet Mounts”)
2. Examine your slide first under low mag. (4x) And then under
medium mag. (100x)
3. Draw about five cells, indicating the shape and arrangement
of these cells. Include any structural details you observe.
Include the magnification.
4. When you are using the medium objective, the field of view
is 1600 μm. Under the drawing you made in step 3, estimate
the approximate size of a typical onion cell. (see the board
for an example calculation)
5. Prepare a slide of cheek cells that are stained with
methylene blue.
6. Examine these cells first under low mag. (4x) And then
progress up to high mag. (400x)
7. Draw 2 to 3 cheek cells, paying attention to structural
details you observe. Include the magnification.
8. Estimate the size of a typical cheek cell. Remember that
you are viewing them under high magnification; field of view
is about 400 µm.
Discussion Questions:
1. What are the main differences between red blood cells and
white blood cells?
2. What does the onion cell have that the cheek cell does not?
3. What is the purpose of adding the iodine stain to the onion
and the Methylene blue stain to the cheek cell?