General Safety Guidelines
Microbiology Safety Guidelines

Materials and Apparatus

You will need the following for each team participating in the activity:

• Erlenmeyer flasks, 250 ml (7)
  
• Glass tubing (7-8 mm diameter), 30 cm long (2) for curved tubing, Flasks #6 & #7
  
• Glass tubing (7-8 mm diameter), 8-10 cm long for straight tubing, Flask #5
  
• Bunsen burner and wing tip for bending glass
  
• Rubber stoppers to fit flasks- 3 with one hole, 2 without holes.
  
• Bouillon cube; 750-1000 ml beaker
  
• Paraffin or sealing wax (clean soup can for melting wax)
  
• Autoclave or pressure cooker
  
• Hot plate or microwave for heating broth.
  
• Filter apparatus – paper, funnel, and funnel holder (largest capacity)
  
• Graduated cylinders, 100 ml (2)
  
• Microscopes, glass slides, and coverslips if students want to examine samples of the broth that turns cloudy.
  

Advance Preparation

1. Bouillon can be prepared in advance. Dissolve one cube in 500 ml of warm water. When cool, filter to produce a very clear medium. Peptone (8 grams) can be used in place of the bouillon. Filtering would not then be required.

2. Glass tubing that needs to be bent should be prepared for students. Make sure the ends are fire polished. When inserting the tubes into the stoppers, use some glycerin on the end of the tubing that is to be inserted. Wear protective gloves when inserting the tubing.

3. Students should NOT operate the autoclave or pressure cooker.

4. Sealing the flasks could be done after class by some students if class time for the setups is limited.

Relevant National Science Education Standards

Unifying Concepts and Processes — The activity is concerned with evidence, models, and explanations and also with change, constancy, and measurement.

Science as Inquiry — The activity is concerned with the abilities necessary to do scientific inquiry and also with scientific inquiry.

Physical Science — The activity is concerned with the structure and properties of matter and is also concerned with chemical reactions.

Life Science — The activity is concerned with the behavior of organisms.

History and Nature of Science — The activity is concerned with science as a human endeavor and the nature of scienctific knowledge and provides a historical perspective.

Relevant New Jersey State Science Education Standards

5.1	The activity involves conducting systematic observations, interpreting and analyzing data, drawing conclusions, and communicating results.
5.2	The activity deals with the history and people behind the science involved.
5.5	The activity requires understanding of the basic characteristics of living organisms.
5.6	The activity investigates the behavior of matter in biological systems.

1. Conant, J.B., ed. Harvard Case Histories in Experimental Science. Cambridge, MA: Harvard University Press, 1957.

2. Gabriel, M.L. and Fogel S., eds. Great Experiments in Biology. Englewood Cliffs, NJ: Prentice-Hall, 1955, pp 105-118.

3. Brock, T.D., ed. Milestones in Microbiology. Englewood Cliffs, NJ: Prentice-Hall, 1961.