Activities & Days Out / 18 February, 2019 / Nanny Anita

Germ Experiment: What’s Growing On Your Hands?

Something suddenly hit me the other day while I was getting ready. And it was a possible reason as to why children don’t care about washing their hands. It occurred to me that YC and EC don’t seem to have a problem with washing their hands if they can see or feel the dirt on them. However after going to loo or after they have coughed/sneezed into them is a different matter. The reason that occurred to me was this – out of sight, out of mind. If they can’t see the dirt, then why should they wash it. Because of this idea, I thought it would be a good idea to do a germ experiment and see just how “dirty” their hands are.

Make sure you follow my science board on Pinterest for more ideas. Don’t forget to save the pin for later.

For this germ experiment you will need:

• Paper cups
• Cling film
• Gelatine powder
• Sugar
• Hot water
• Ear buds

Before you start your actually experiment you will need to prep your culture dishes. Now I don’t know about you but I don’t have any Petri dishes or agar solution lying around at home to use. Thankfully you can make it yourself.

This part needs to be kept as sterile as possible as you don’t want to contaminate the solution or dishes. To make up your own agar solution dissolve 2 tsp of sugar and 2 tsp of powdered gelatine in ¼ cup of boiling water. Pour about 1cm into each of your cups and cover them immediately with cling film. Place them into the fridge for 24 hrs to set.

When your dishes are ready use the ear buds to swab the surfaces that you want to test. We ended up swabbing EC’s hands, YC’s hands, BB’s hands, Andy’s hands, the loo, and BB’s indoor climbing frame.

Gently brush each swab other the surface of your makeshift Petri dish and cover again with the cling film. Make sure that you label each dish with where the sample came from. And of course only use one sample per dish.

Store your dish in a warm and dark place for at least 5 days.

*MAKE SURE YOU DO NOT REMOVE THE CLING FILM ONCE THE GERMS HAVE GROWN* This is really important. You have no idea what you might have actually grown, so it is best to keep them sealed. Once you have finished with the experiment place them in a bag and throw them away. Personally I would then remove the bin bag and take it out of the house. I am sure nothing would happen, but just to be sure.

I asked everyone which ones would have the most growth. EC said it would be his hands with the most, then Andy’s, then the loo. YC said it would be EC’s first, then the loo, and then the climbing frame. I said EC’s first, then Andy’s, and then YC’s hands. I didn’t let anyone wash their hands before I swabbed them. It would have been interesting to do one swab before they washed their hands, then one after they had.

After a week (I left it slightly longer) the results were both surprising and absolutely disgusting. The ones with the most growth were YC’s, Andy’s, and the loo. EC’s had more variety of things growing, but because I actually kept checking his to see if the experiment was working, I may have disturbing the growth. Either way they were all yucky. Except for BB ‘s hands, but that was because I had only just washed them.

If you enjoyed my germ experiment be sure to check out my lava lamps and straw bridges experiment.

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