Petri Dish Experiments

What you need:

4 Petri Dishes

Gelatin

Q-tips

dirty objects

The kids and I had a fun time recently doing some petri dish experiments. We filled four petri dishes with gelatin mix and let it get firm. About two hours later we took Q-tips and swiped objects we thought would have bacteria growing on them.

Michael picked his own mouth and dirt. Maura picked the dog's mouth and the toaster. We saw growth in about four days, but after two weeks the thing were so nasty we didn't even want to look at them!

We learned that mold grows in feathery clusters, but bacteria grows more in dots.Isabelle's mouth was all bacteria, but much less than Michael's. Both the dirt and the toaster had red mold and some bacteria spots.

Neat little scientist projects! Next: hear how we made flatulence with a zip lock bag, soggy bread and yeast! :-P