A. Monerans
1. Place three or four beans in 100 mL of water and let stand for 4-5
days to grow a rich bacterial culture.
2. Bacteria can be viewed more easily if they are fixed and stained.
Fixing means killing the cells and fastening them to the slide. They are
stained by soaking them in a staining solution. To fix the bacteria, place
a drop of the culture on a slide, hold the slide with the smear upward
and pass quickly and repeatedly through a bunsen burner flame until the
smear is dried.
3. Place a drop of crystal violet stain on the smear and let stand
for 30 seconds. Rinse the slide gently in a beaker of water.
4. Observe and make a detailed drawing of as many types of bacteria
as you can.
B. Protists
1. Prepare a protist culture by adding the dried protists mixture to
100 mL water in a small culture dish. Do not shake or stir the mixture.
Some particles will sink while some will float. Incubate at 20-22 oC
for 4-5 days. Be sure to check the culture daily and replace any water
that evaporates.
2. Using a depression slide, make a wet mount of the protist culture.
3. Prepare detailed drawings of a few protists. Use the guide to identify
them if you can. You can fix and stain them if you like. Also, you can
slow the movement of the protists by adding a drop of methyl cellulose.
C. Fungi
1. Cover the bottom of three separate petri dishes with damp paper
towel. Place a few grains of rice in one, a few small (1 cm x 0.5 cm) pieces
of potato in another, and a few small pieces of bread in the third. Cover
the dish and seal it with tape to prevent drying out. Place the culture
in a cool, dark location for 4-5 days.
2. Obtain a sample of bread mold from your culture and prepare a wet
mount. Make a detailed drawing showing both the hyphae and sporangia. You
should be able to locate spores, cell walls and nuclei.
3. Do the same for the fungus growing on potato and rice.