Demonstrate the sticking power of germs and the necessity of good hand washing techniques! These experiments use Glo Germ™ gel, Glo Germ™ powder, and a blacklight. The Glo Germ™ products simulate the behavior of real germs, so you can see how they spread.
Watch our Glo Germ™ video and then try the experiments below:
Water Temperature – Gel Experiment #1:
- Try rubbing Glow Germ™ gel onto your hands, making sure to apply it to all areas, front, back, and around all the fingers.
- Rinse your hands in cold water. Rinse for 1 minute (don’t rub your hands against each other), and then observe the results in a dark room with the blacklight.
- Turn the water temperature up to warm, and stick your hands in for 60 more seconds without rubbing your hands together. What was the effect?
- Turn the water to hot (but not burning!), and stick your hands under the water for 60 seconds. Again, don’t rub your hands against each other.
Is the Glo Germ™ gel all gone? Which water temperature seemed to work best? (Wash your hands thoroughly with soap and water after the experiment is finished.)
Time or Temperature? – Gel Experiment #2:
- Put the gel on your hands and stick them under cold water for 60 seconds. You can rub your hands together, but do not use soap. What is the result? How do your hands look under the blacklight?
- Now, thoroughly wash your hands with soap and water until all the Glo Germs are gone. Reapply the gel, this time rinsing your hands in hot water (but not burning!) for 30 seconds.
- Look at your hands under the blacklight. Do they look as clean as when you washed them for longer with cold water?
Hot Water or Soap? – Gel Experiment #3:
Here’s another experiment you can try, but you’ll need two people to help you. Have one person use a timer to time the other two, who will be washing their hands.
- Put the same amount of gel in both participants’ hands. Give one person a bottle of liquid soap, and tell him to wash his hands, using only cold water. The second person will wash his hands in warm or hot water, but without using any soap. Set the timer for two minutes, then start washing!
- When the timer goes off, both of the hand-washers should turn off the water and stop washing their hands.
Whose hands show the most germs? Based on the other projects, what does this tell you about the importance of soap for removing germs?
Glo Germs’ Resistance to Different Types of Soap – Gel Experiment #4:
To test different hand soaps and see what affect antibacterial soap has on the Glo Germs (which simulate actual germs), you will need at least three kinds of soaps to compare. Try bar hand soap and several kinds of liquid hand soap (with lotion and without, antibacterial, and even a natural or organic liquid soap if you wish).
- Wash your hands with each kind of soap to see the effect on the Glo Germs. Make sure to record the results so you can compare them. Use a fresh application of gel for each test.
- Always use the same temperature of water and have a timer for 15 seconds set each time you wash your hands.
What were the results? Did you predict which soap would work the best, and was your prediction correct? Why do you think that particular soap worked best?
Head of Lettuce – Powder Experiment #1:
To show the way bacteria spreads by cross-contamination, use an unwashed head of lettuce and the bottle of Glo Germ™ powder to thoroughly coat the lettuce in ‘germs.”
- Sprinkle the powder onto the head of lettuce, getting in between the leaves and on the outside. Spread the powder around a little with your fingers, and look at the lettuce (and your hands) with the blacklight.
- Tear the lettuce leaves apart from the head. Rinse the lettuce like you would when making a salad. Use a dish towel to dry the lettuce.
- Cut or tear the lettuce into small pieces, and put them in a bowl. Now, turn on the blacklight, and take a look at the kitchen you made the salad in. Look at the sink, your hands, the lettuce, the bowl the lettuce is in, the towel, knife, and the cutting board.
There are little spots of glowing germs all over the objects you used to make the salad, spread from your hands and the lettuce. Not only is it important to wash your hands, it is important to wash fruits and vegetables carefully. Be sure to throw away the lettuce after the demonstration is done, and clean the entire area thoroughly with soap and water. If you do not want to do this experiment with a whole head of lettuce, try just a few leaves, or cut half a head. The experiment will still work using less lettuce; it just won’t be as dramatic.
Cutting Up Fruit – Powder Experiment #2:
Another experiment you can do with the simulated germ powder is to cut up a piece of fruit. Try cutting up a mango, apple, or pear. (Note: Make sure you have adult supervision!)
- Rub a small amount of Glo Germ™ powder over the surface of the fruit. Wash your hands thoroughly, then slice the fruit on a cutting board.
- Now, observe the cross-contamination of the germs, using the blacklight.
Where can you see spots of Glo Germ™? On the cutting board, the knife, and the fruit? How can this spread diseases? If someone did not properly wash fruits and vegetables, which touch kitchen utensils or other food, bacteria can spread. This is one way that food poisoning can happen. It is also very important to handle raw meat carefully. Never let meat drip blood on fruits or vegetables nearby. By keeping the kitchen clean and handling food properly, germs and disease can be limited.
Surface Cleaning – Powder Experiment #3:
See the behavior of germs on surfaces like a countertop, table, or cutting board.
- Spread a thin layer of powder of the area you wish to clean. Look at the powder under the blacklight.
- Now, take a wet rag and wipe the surface of the countertop or other object, cleaning off the white powder.
Look at the surface of the countertop again. Does it still glow? Now, use plenty of soap and water to clean off the surface. It is always important to use soap and water or another cleaner, not just wipe off a surface you are trying to clean, to thoroughly remove germs.