Introduction to Microbiology

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Introduction to Microbiology
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Where do Microorganisms come from?

• EVERYWHERE!!!!
• They are all around us, in this lab we will
  examine various microorganisms in the environment
  around us.

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Part I-Test Tube

• Obtain a test tube
• Fill 1/4 full with soil
• Add water to test tube until it is about 1/3
  full. Cap test tube and shake.
• Place your names on the label.

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Part I- Petri Dish

• Obtain a petri dish and place your names on the
  label.
• Pour a layer of hot, melted agar into the petri
  dish. Fill your petri dish about 1/4th full.
• Recover your petri dish.
• Allow the agar to harden for about 5 minutes.

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• Locate a sterile transfer loop.
• Place the plate in front of you.
• Dip the loop end of the transfer loop into the
  soil water and transfer the soil water to the
  agar plate.
• Gently rub the surface of the agar with loop.
  Dont push too hard.
• Transfer two more loopsful of soil water in the
  same manner.
• Observe your plate and make a drawing of what you
  see.

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Part II- Fungi

• Obtain another petri plate, and put a label with
  your names.
• Add a thin layer of tomato soup to the bottom of
  the plate.
• Grind up a small sample of dirt in your fingers.
• Sprinkle a few specks of dirt on the soup and
  cover the plate.
• Observe your plate and make a drawing of what you
  see.

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Part III- Yeast test tube

• Obtain a culture tube, and label with your names.
  
• Add yeast growth medium to the tube until it is
  2/3 full.
• Locate the packet of dry yeast.
• Add one of the small particles of yeast to the
  tube.
• Shake the tube with the top on until you cant
  see the particles of yeast any longer.

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Part III- Yeast Slide

• Obtain a sterile loop.
• Dip the end of the loop into the yeast liquid in
  the tube.
• Transfer a small amount of liquid onto a clean
  glass slide.
• Repeat this 4 more times so you have a drop of
  the yeast growth medium on the slide.
• Add a cover slip and observe the yeast under high
  power on a microscope.
• Count the number of cells you see in the field.

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Part IV- Algae and Protozoa

• Locate the large plastic bottle filled with pond
  water.
• Obtain a clear glass slide and a cover slip.
• Place a drop of pond water on the slide using a
  pipette.
• Place cover slip on slide.
• Observe under low and medium power.
• Make drawings.

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Part V- Soil Culture

• Obtain your original tube containing the soil and
  water after about 4 days.
• Obtain a clear glass slide, a cover slip, and the
  bottle of methylene blue stain.
• Transfer a drop of soil water to the slide.
• Spread the water around on the slide.
• After the water has dried, add a drop of the
  methylene blue stain, and let it dry for 1 minute
  on the slide.
• Carefully blot the slide dry with a paper towel.
• Observe the slide under high and low power.
• Make drawings of what you see.