(this will show how washing hands can significantly reduce the spread of bacteria)

Idea Behind the Experiment

Bacteria is a fact of life. It is all around us every single day. That is why washing our hands is so important. This experiment is designed to use bread (and the speed that it molds to demonstrate this point). Washing your hands or using hand sanitizer will greatly reduce the spread of bacteria in day to day life.

What you are Going to Need

4 Slices of white bread (white bread makes the mold growth extremely apparent)
4 zip lock bags (large enough to hold a single slice)
Hand Sanitizer
Rubber gloves
Anti-bacterial hand soap
Poster board
Paper towels

Procedure

It is important that you start this experiment with soiled hands, there is no need to get them especially dirty though. Just make sure that you have not washed your hands in a few hours. Or perhaps you could make it a point to handle something such as dirty dishes or something that is touched routinely by other people but not cleaned.

Using dirty hands, take one of the slices of bread and handle it. Try not to crush the bread but make sure it comes into contact with your hands in multiple spots
Place it in the zip lock bag and seal it
Make sure you label the bag as “dirty hands” or something similar
Wash your hands with anti-bacterial soap and dry them with clean paper towels.
Repeat step one making sure to handle the bread thoroughly
Seal the bag and label it as before
Next you are going to want to use the hand sanitizer and repeat the process
Finally, we want to use the rubber gloves. To handle the final piece of bread then to seal it in the zip lock bag

 

Now you should pin each bag to your poster board. Make sure to label each bag with the date that you are starting your experiment. Over the following days and weeks, you are going to want to monitor your bread slices for mold growth. As soon as you see any mold make sure to label it with the date.

What to Expect

Over the course of the experiment (1-2 weeks) you will start to see some seriously gross results. The bread that you handled with dirty hands should mold first and the rate of mold growth will be rapid. In some cases, by the end of the experiment the bread that was touched with dirty hands will be unrecognizable. While the bread that was handled after using some form of disinfecting will mold at a much slower rate. This shows that while the soap and hand sanitizer doesn’t completely eliminate bacterial it greatly reduces the amount present.

Finally, the bread that was handled with new/sterile rubber gloves will have little to no mold at all. This demonstrates that when bacteria are not present at all the mold growth is significantly reduced.

 

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