Part 1: Isolating Unknowns

***Your students will need to be familiar with the asceptic technique of transferring bacteria before attempting this activity.
 

You will need the following materials:

1. Prepared nutrient agar plates (these can be ordered from any biological supply company or make your own)
2. Innoculating loop
3. Bunsen burner
4. Sediment sample from Winogradsky Column ( top layer works the best, lower layers need to be grown in an anaerobic apparatus- email me for directions)
5. Wet paper towel
6. Zip-lock bag

 

 

Procedure:
 

7. Using the asceptic technique, streak a small amount of wet sediment across the surface of the agar.  Flame the loop and continue to spread the culture across the agar.
8. Turn plate over, and place in the zip-lock bag with the paper towel.  Allow this to remain undisturbed for 48 hours.
9. After 48 hours, observe plates for separate colonies.  Have students select one colony and again using the asceptic technique transfer this colony to a new agar plate.  Place new plates in zip-lock bags with paper towels.  Allow this to remain for another 48 hours.  Destroy theold plates using either an autoclave or soaking the plates in a 10% bleach solution.