Isolating from the Winogradsky Column
and Testing Unknown Bacteria
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:
Back to main page
Prepared nutrient agar plates (these can be ordered from any biological
supply company or make your own)
Sediment sample from Winogradsky Column ( top layer works the best, lower
layers need to be grown in an anaerobic apparatus- email me for directions)
Wet paper towel
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.
Turn plate over, and place in the zip-lock bag with the paper towel.
Allow this to remain undisturbed for 48 hours.
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%
Woodrow Wilson National Fellowship Foundation
CN 5281, Princeton NJ 08543-5281 - Tel:(609)452-7007
Technical contact: email@example.com