Shoe Science!

This was the scene last week at the museum where I work:

Those beautiful golden shoes are mine (of course!), but what exactly am I doing?  I am swabbing the underside of my shoe for any microbes that might be hiding there, to give to the Science Cheerleader!  Darlene is a former professional cheerleader who now uses her cheering skills to bring science to everyone.  The microbes from my shoe (as well as from a few places around my museum) have a chance of making it to the International Space Station as a part of Project MERCCURI!

You can still contact them about getting involved, but if you just want to try it at home and see what you might have on there, pick up a bacteria growing kit, like this one from Steve Spangler Science:

It comes with six large (4 inch) diameter Petri dishes, six cotton swabs, five grams of Nutrient Agar, one 600 mL plastic beaker, and one activity guide-- all for fifteen bucks!  Do your work shoes, walking shoes, or gym shoes have the most bacteria?   Here is how Steve Spangler recommends you find out:

• In making the agar solution, mix ½ tsp of agar (about 1.2 grams) with ¼ cup (60 mL) of hot water and stir. Bring this mixture to a boil for one minute to dissolve the agar completely. The mixture should be clear with no particles floating around in the solution. Cool the solution for several minutes.
• Prepare three Petri dishes for the first part of the experiment. Fill the bottom half of the dishes with the solution, loosely cover them with the lids so the moisture can escape, and allow the agar to cool and harden for a couple of hours or overnight.
• Choose three shoes to test.
• Follow this germ-collecting process for each step of your experiment:
1. Wash your hands.
2. Slightly wet the end of a clean Q-Tip and swab the shoes.
3. Lightly run the wet/germy Q-Tip over the surface of the agar.
4. Throw away the Q-Tip.
5. Close the Petri dish, tape the dish shut, seal it in a Ziploc bag, and label it.
6. Wash your hands.
• Once the germs are collected, place the Petri dishes in a warm dark place to grow (anything up to about 98 degrees F should be fine). All dishes should be in the same place and observed for the same number of days to standardize the conditions.
• Most bacteria collected in the environment will not be harmful. However, once they multiply into millions of colonies in a Petri dish they become more of a hazard. Be sure to protect open cuts with rubber gloves and never ingest or breathe in growing bacteria. Keep your Petri dishes sealed in the Ziploc bags for the entire experiment. When you're finished with the experiment, some people recommend placing the Petri dish bag in a larger Ziploc bag along with a few drops of bleach. Seal the larger bag and dispose of it in the trash.
• You're likely to have a huge variety of colors, shapes, and smells in your Petri dishes. Count the number of colonies in the dishes, note the differences in color, shape, and other properties. Getting bacteria to grow can be a little tricky, so don't get discouraged if you have to make more than one attempt. Allow enough time for the germs to grow, too. You need millions of them in one place just to see them at all.

If you’re not interested in seeing what’s growing, I can’t say I blame you.  Maybe just enjoy these Periodic Table sneakers instead!

This pair of hand-painted shoes has everything you might need to cheat on your high school chemistry test: elemental symbol, atomic number, even the metals and non-metals, all color-coded!  Yours for $50 from Etsy seller Stolle Creations.

Happy science!