Summer Research Program for Science Teachers
Washington Irving High School
How To Culture Bacteria in the Laboratory
MATERIALS : plates, flasks, weighing balance, agar, trptone, Nacl, yeast extract, ampicillin, graduated cylinder
METHOD : take 15ml of water, dissolve the following compounds in the weighted amount :
NaCl (granular) 0.075g
Yeast extract 0.075g
Stir the mixture and autoclave for 25minutes at a temperature of 120 C
Pour solution into plate and allow to cool for 15 minutes. What do you observe?
Take a sample of dust (may be near the window) with the stick provided.
Streak by drawing a thin, zigzag, light line on the LB medium until the plate is covered with the lines containing the dust. Cover the plate. Place the plate in an incubator set at 37 C and leave overnight.
Prepare another LB medium in the same way as described and in addition add about ½ ml of the prepared ampicillin to the LB in the flask.
Then transfer the solution on to the plate, allow to cool for about 15 minutes and streak with dust as described. Incubate and leave overnight. This is your control.
After 24hours record your observation. What happened to the plate containing ampicillin? [Content Standard Unifying Concepts- Change, constancy, and measurement]
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