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20 Minute Labs: Getting Rid of Germs

 20 Minute Labs hand wash logo | Yellow Scope


Yikes - germs?! GERMS | Yellow Scope

You probably know that germs are often what make people sick. Germs come many different forms including bacteria or viruses -  like the new Coronavirus that you've probably been hearing a lot about.

These tiny organisms can make us sick - but first they have to find a way to get inside our bodies! To do that, germs can often hitch a ride on our hands.

That's why washing our hands is so important. Washing your hands can kill the germs before they get inside our bodies AND before we can spread the germs to other people.

glowstick | Yellow Scope

Germs are so small that you can't see them with your eyes. Wouldn't it be great if they were lit up like a glow stick so we'd always know where they were?

Well, in this month's 20 Minute Lab experiment, we'll use something that acts a lot like germs but that we can see!

You'll be able to check your hand-washing skills to know that you're doing your best to fight the spread of germs!

NOTE: Here we used a special product called Glo Germ that you can order online, but we also are providing instructions for using oil and cinnamon instead - this alternative works great, it just doesn't glow under a light!

What You'll Need

20 Minute Labs hand wash ingredients | Yellow Scope

  • markers & glo germ | Yellow Scopecrayons or markers
  • paper
  • sink access
  • product that simulates germs on hands (Glo Germ, or cooking oil and cinnamon)
  • soap
  • black light (if using Glo Germ)
  • stop watch or app on a Smartphone
  • a helper to operate the stop watch and light for you, since your hands will be wet!
  • scrub brush
  • cloth napkin/towel

You can do the experiment twice and switch places with your helper if you want to practice both roles and see what happens!

Let's Get Started!

  1. First, using your markers or crayons, make a chart so you can record your results. It should have the following information:
    handwashing table | Yellow Scope
  2. Rub your Germ Gel on your hands. (Note: if you don't have Germ Gel, you can mix 1 tablespoon of cooking oil with 1 teaspoon of cinnamon and rub that mixture into your hands!) Make sure to spread it onto the back of your hands, between your fingers and under your fingernails as well! 
  3. 20 Minute Labs hand washing animation | Yellow ScopeLet dry for two minutes. While you wait, your helper can turn off the room lights and turn on the black light to see the 'germs'!
  4. After two minutes, your helper can start the stopwatch. 
  5. When the stop watch starts, wash your hands for 5 seconds, then stop!
  6. Have your helper shine the black light on your hands. (You will skip this part if you're using oil and cinnamon)
  7. Rate how 'dirty', or still covered in visible 'germs' you are. Maybe use Xs for dirty, and an O for clean! Here's an example:
    handwashing table filled out | Yellow Scope
  8. Repeat steps 5-7 until you get to 20 seconds. If you still aren't perfectly clean - use the scrub brush to get to those tough-to-clean areas like fingernails!
  9. Dry your hands with the towel.
20 Minute Labs hand wash results | Yellow Scope


What's going on?

How clean did your hands get at 5 seconds? 10 seconds? 20 seconds?

This point of this experiment is to give you a visual illustration of how well germs stick to the natural oils on our hands. Soap works to break up dirt and grease, so the germs get washed down the drain along with the water.

jenga | Yellow ScopeHow does this work? Soap molecules are made up of two different ends. One end loves water (hydrophilic), and the other end hates water (hydrophobic) but loves fat (like in oils).

The hydrophobic, fat-loving ends stick to the fats, surround them, and trap them. It's like a bunch of velcro sticking to the wood blocks of a Jenga tower, breaking it up and making it collapse!

While some alcohol-based hand sanitizers can kill germs and viruses on your hands, they're not as good at removing the natural oils that germs can attach to. 

In the case of the Coronavirus, soap not only breaks down the oils on our hands, but it also kills the virus itself! The Coronavirus has a coating that's a lot like oil - the soap wedges its fat-loving ends into the virus’s fatty shell. This breaks up the virus, and the inactive pieces can get washed down the drain!

This is why washing your hands with soap and water is the best way to make sure you're virus free!

To learn more about soap vs hand sanitizer, see the CDC website.


Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to We love getting your messages!

For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!

Chelsea Schuyler
Chelsea Schuyler