Let's Talk Microbes at Family Housing!

Let's Talk Science volunteers visited the community group at Family Housing for a super fun activity about Microbes last week! We learned why it is important to wash our hands properly...

Unwashed hands

Rinsed hands (dirtier than unwashed!! Maybe this is because I touched the tap?)

Washed hands - although not perfect, they are much cleaner than before!

And then we tested our handwashing technique using a special powder and a black light!

Then we had the chance to build our own microbes, based on some freaky photos!

Finally, everyone used a nutritious medium (agar) to see what kind of microbes grew from the playground!

If you want to make petri plates like these at home for a science project, they are actually very easy to make with the help of an adult! Here is what you need:

- 7.5 g agar agar (I got 20 g from the Asian market downtown for about $2)

- 1 tsp Marmite / Vegemite (available from any grocery store, often near the baking supplies, about $2 for a small jar.. it's also good on toast!) OR 2 beef stock cubes

- a large pot

- 0.5 L water

- a large Pyrex measuring cup (for pouring your melted agar)

- petri plates OR tinfoil tart cups and plastic wrap

- permanent marker

- tape

1. With the help of an adult, combine the water, the agar agar, and the Marmite, Vegemite, or stock cubes in the large pot.  Heat until boiling, and continue to boil for 30 minutes to sterilize.

2. While the agar is boiling, prepare your petri plates or tart cups.  If you are using the tart cups, set them out on a baking sheet so that you can move them around! 

3. When the mixture has been boiling for 30 minutes, rinse the measuring cup with boiling water to sterilize.  Ask an adult to CAREFULLY pour the melted agar into the measuring cup, and then to pour your melted agar into the petri plates or tart cups.  This recipe will fill about 25 petri plates. Please be VERY careful because this agar is hot enough to burn! 

4. When you have poured your plates, lightly cover the whole tray with plastic wrap, and leave undisturbed for 2 hours to cool and harden.

5. Your petri plates are now ready to use! Try testing things like doorknobs, spoiled food, your shoes, etc. Once you have placed the item you want to test on your agar, seal the dish with either the lid of the petri plate or plastic wrap.  Tape the lid on and DO NOT OPEN AGAIN!! Label the plate with a marker.  Keep the plates in a warm place (such as on top of the refrigerator). Bacteria and fungi (if present) should be visible after about 3 days.

To see all of the amazing things that grew, please click "read more"..

Finally, what you all came here to see: everyone had the chance to learn about the microbes that are all around us by seeing what kinds of freaky bacteria and fungi grew from things in the playground! We shouldn't be surprised or scared to find that there are microbes all around us: they are a normal (and important!) part of our environment! However, this does go to show how important it is to wash your hands very well before eating, or before touching your eyes or face, especially if you have a cut! Here are all of the plates prepared by the scientists at the activity on Thursday: