Handwashing is the best way to kill influenza and corona viruses, but it’s easy to make your own hand sanitzer for those times when you can’t get to a sink.

To make sanitizer, you’ll need 91% or 99% rubbing alcohol (isopropanol) and the kind of aloe vera gel used for sunburn treatment, which may have a little bit of water and alcohol mixed in already. Both are available over the counter at most stores.

Mix 3/4 cup 91% alcohol with 1/4 cup aloe vera gel, or mix 2/3 cup 99% alcohol with 1/3 cup aloe vera gel. (You need at least 60% alcohol in the final product.) Add to a dispenser or bottle and keep out of the reach of children, unless applying it to their hands!

Does hand-washing really get rid of germs?  Yes! Scrubbing your hands with soap and water for the length of time it takes you to recite the ABC’s will get rid of the majority of harmful microbes on your hands.

Image from “Kitchen Science Lab for Kids” (Quarto Books 2016)

Here’s a video on how to make Petri plates for a hand-washing experiment, where you touch labeled sections of the plates with your fingertips before washing, after washing with water alone, and after scrubbing with soap or hand sanitizer. You can also use the plates to swab and grow microbes from around your house or school!

Find the recipe for Petri Plates in my book Kitchen Science Lab for Kids, or click here for a link to the recipe on my original blog post, where you can also read more about the science!

Homemade Petri Plates from “Kitchen Science Lab for Kids” (Quarto Books 2016)

Today on WCCO MidMorning, I’ll be talking microbiology! According to the CDC, hand washing is the best way to remove microbes from your hands.

You can see what bacteria and fungi are hanging out on your fingertips by touching homemade petri plates to grow colonies. Test your fingers before and after washing with water alone, soap and water, and finally hand sanitizer. You can find the experiment in my book, Kitchen Science Lab for Kids, and here on my website. The video below shows you how to make plates.