Re: How do we keep germs alive in our petri dishes?

Dear Ms. Shipman's Class -

I'm glad to hear you won 1st place, and that you did it with the help of bacteria.. :)

You can store your Petrie plates in a refrigerator at 4-degrees Celcius, and they will keep for some time. We often use this method in the lab to store bacterial stocks for periods up to a few months. I would strongly recomend that you *not* store them in a refrigerator that others use to store food. Doing so creates a significant health hazard.

Otherwise, place them upside down (agar half of the plate on top) in a container. Any moisture that collects within the plate will fall to the empty lid, and not onto the agar surface, where it may smear your colonies around. You might also wrap the plates in saran wrap to limit the moisture that escapes. You don't want the plates to dry out while they're being stored.

Hope this helps..

-L. Bry, MadSci Admin