Demonstrate the sticking power of germs and the necessity of good hand
washing techniques! These experiments use
Glo Germô gel, Glo Germô powder,
and a blacklight. The Glo Germô products simulate the behavior of real germs, so you can see how they spread.
Watch our Glo Germô video and then try the experiments below:
Water Temperature -
Gel Experiment #1:
Try rubbing Glow Germô 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 Germô 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: Is the amount of time you wash
your hands for or is the temperature of the water more important?
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
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
Whose hands show
the most germs? Based on the other projects, what does this tell you about the
importance of soap for removing 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
Always use the
same temperature of water and have a timer for 15 seconds set each time you wash
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 Germô powder to thoroughly coat the lettuce in "germs.''
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
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
Rub a small
amount of Glo Germô 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 Germô? 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
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.