How to See Germs on Your Hands

Bacteria -- plain old germs, if you will -- are all around us. What's more, they're all ON us. And in us. And coming out of us with every sneeze and sniffle. So, when you put you nice clean hands on a doorknob, just how many new germs are you picking up? Here's a way to visualize what's going on.

Instructions

Difficulty: Moderate

Things You’ll Need:

• Agar plates. These can be found in most high school biology labs. You can also order them directly from science supply houses.

1. click to enlarge Prepare agar plates. Press fingers into plates as shown, to transfer bacteria from hands to the plates.
2. click to enlarge An unwashed hand will grow dense growths of bacteria from each finger.
3. click to enlarge A cold water rinse of the hands will reduce the overall growth, though bacteria are still plentiful.
4. click to enlarge Washing the hands with soap and hot water will reduce bacterial growth even further.
5. click to enlarge Washing hands with a hand sanitizer like Purell virtually eliminates all growth of germs on the hands.
6. For more detailed information, see the resource links, directly below.