Transcript Which Bathroom is the cleanest?

Which Bathroom is the
cleanest?
Katrina Sennett
4/23/10
Abstract
Which Bathroom is the Cleanest?
The purpose of this experiment was to find out
whether my bathroom at home, the bathroom at
Friendly’s, or the McDonald’s bathroom was
cleanest .I ordered petri dishes and agar online.
After preparing the petri dishes with the nutrition
agar, I swabbed bacteria samples from each
bathroom. I hypothesized that my bathroom
would be the cleanest of the three. At first, I
thought I was wrong and Friendly’s had been the
cleanest, for there was the least bacteria growing
in the Friendly’s petri dish. However, my
bathroom at home ended up being the most
bacteria-free, after watching and observing the
dishes for several days. I hypothesized correct
and my personal bathroom was the cleanest.
Planning
Procedure
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Gather Materials.
Prepare 6 Petri dishes with agar.
Roll the cotton swabs onto each toilet seat of McDonald’s,
Friendly’s, and your bathroom at home (2 cotton swabs
for each restroom).
Swab each cotton swab onto the agar in the 6 separate
Petri dishes.
Store the Petri dishes into a cool and dark place
Examine the growth of the bacteria.
Planning Continued
Materials
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Bag of agar
Water
Measuring cup
6 petri dishes
6 cotton swabs
Something that can be used for stirring, such
as a spoon
Data
• McDonald’s had the dirtiest bathrooms.
• Chunks and colonies of bacteria were all around the agar.
• A different kind of bacteria formed in the McDonald’s petri
dish than in the other dishes. It was small and redish in
color.
• Friendly’s bathrooms were the second cleanest.
• There were a lot of small colonies of bacteria in the
Friendly’s petri dish, but not as much as McDonald’s.
• One of the Friendly’s petri dish wasn’t clear as the other
ones. It was slightly foggy.
• In one of the petri dishes from my bathroom the bacteria
formed one big colony.
• The other petri dish from my bathroom had little bacteria
growth.
• My personal bathroom was the cleanest.
Conclusion
I hypothesized my bathroom would be cleanest.
My Hypothesis was correct. The order of
bathrooms from cleanest to dirtiest was Home,
Friendly’s, and McDonald’s. During this
experiment I’ve learned…
• My personal bathroom is the cleanest
of it, McDonald’s, and Friendly’s.
• McDonald’s is a very filthy bathroom!
• I’ve learned how to make agar using the agar
powder.
• How to use petri dishes.
Sources
• Bennett, Kathrine. "California State Science Fair
2007 Project Summary." . 2007. California State
Science Fair. 30 April. 2010
<http://www.usc.edu/CSSF/History/2007/Project
s/J1402.pdf>.
Acknowledgements
• I’d like to thank my parents for
taking me around to get samples,
buying and ordering the bacteria
growing kit, and assisting me with
my display board.