Petri dish experiments

There is something about the microscopic side of diseases and invisible-to-us bacteria that fascinates me.  So, with homeschooling, I get to force my curiosities on the boys.  : )

We finally used our petri dish experiment bought courtesy of the investment my mom makes to their education.  

First, you get to dissolve the agar (a nutrient for bacteria) in some boiling water.

The instructions for measuring were for 1 dish at a time.  I don't know who would even do that.  That's not exciting at all.  How are you going to put your toilet seat sample next to the remote control sample and compare.  Sheesh.   

You pour a little in each dish.

You spray a mist of water on a q-tip, then swab some things you might think are disgusting.  You let the squeamish students take pictures.   

We swabbed some money.

Then the swab is introduced to the petri dish filled with agar.

Joel apparently thinks the swab from his flip flop is kind of gross.

We waited about 10 days and got a mixed result.  The boys either had better swabbing method than I did, or their swabbing objects were all that much dirtier.

The dishes with the most visible colonies.

And they weren't too visible, really.  I'm kind of glad they weren't worse, because the samples were from our home, but I'm kind of disappointed we didn't get to see a lot of awesomely disgusting growths.  : )  I am keeping them around a bit longer in case they need more time to grow.  I have some doubts that my agar mixture was correct because it seemed like it should have been more wet.