One place where bacteria can be found is on your teeth. This is why it’s so important to brush well. Don’t believe me? Then this experiment is for you. You’ll need to gather your materials and make sure you have a toothbrush and microscope nearby.
This is important because prokaryotes are incredibly common and have a huge impact on our lives. You may already know some of the ways bacteria can be harmful to you, and this is certainly important information. Scientists have used knowledge of prokaryotes to create medications, vaccines, and healthy living habits that have led to a healthier life for billions of people.
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Materials:
- water
- toothbrush
- microscope with coverslips and slides
Experiment:
- Place a drop of water on a microscope slide.
- Gently brush your toothbrush against your teeth and then apply the saliva from the brush to the slide.
- Add a cover slip, and observe under the microscope. Draw what you see.
Here’s a short video on a real bacterial colonization of the mouth after only 8 hours of having a cleaning done at the dentist:
If you’ve ever gone to the store to buy toothpaste, you know there many brands. Do any actually do a better job of getting rid of bacteria on your teeth? This is a great question for the scientific method. Here’s what you do:
- Brush your teeth really well.
- Swab your teeth with a cotton ball and apply to a petrie dish of agar.The next day, brush with a different brand of toothpaste, and again, swab and apply to a different dish.
- Repeat for five days with five different brands. Record the growth of bacteria on each dish for each day.
- Remember that “day 1” for the first dish will be different than “day 1” for the second dish, and so on.
- Which brand left the fewest bacteria? Could there be factors that caused the difference besides toothpaste brand? (Hint: Do you eat the same thing every day?)
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