How Much Bacteria Is On A Dollar Bill

How much bacteria is on dollar bills? Dollar bills will have a lot of bacteria because they sit in people's pockets, purses, and in other peoples' hands. My first step is to get my materials, agar plates, $1-$20, cotton swabs, tape. My second step is to make a control. My third step is put agar plates in fridge. My fourth is to rub back and forth with swabs on money. Then take out agar plates. My sixth step is to put the bacteria from the money in the agar plate. After that I will tape the label of each dollar to the agar plates. My eighth is to close the lids and wait. My last step is to count the bacteria colonies by color. I found disgusting and colorful bacteria colonies. The highest dollar with bacteria was dollar was surprisingly the control with 32 different bacteria colonies. The lowest was control #2 with 0. My project was inaccurate though because my control should not have any bacteria. This was most likely because I used a dirty cotton swab or because I used old cotton swabs instead of new ones.

How Much Bacteria Does Money Have?

Everybody knows money has lots of bacteria. My question was to find out how much bacteria does money have? My hypothesis is that money will have lots of bacteria. I decided to choose this project because I know someone who is a germophobe but I thought to myself, “ If this person hates germs then why do they deal with paper money? I then decided my project would be about how much bacteria is on money. Later on I decided that since money is in people’s purses, pockets, wallets, and hands that money must have lots of bacteria.

I first put on all the safety equipment needed which was goggles, gloves, and and apron. The first step to my experiment was to wet my cotton swab. Then I rubbed the cotton swab gently across the dollar, I rubbed the front of the dollar for a minute and the back for another minute. After that I rubbed the dirty swab gently in the agar plate. For my final step I taped the lid to the agar plate and then labeled on the agar plate the dollar’s year and number. I did that for around 7 different dollars. The plates were placed under a homemade incubator for 3 days to let the bacteria grow. After three days I counted the bacteria colonies on each plate. Every dollar bill was from 2009, but one which is from 2013. I also did two controls.

My project needed many observations to see the bacteria grow. I went to Mr.Fritz’s room and took pictures on two different days. The first day was when the bacteria just started to grow. On the second day I took pictures of them when they were done growing. They were very disgusting on the second day. The bacteria had many different colors like black, yellow, gold, white, and orange. On the first day of pictures there was not many different colors and not as much bacteria on the second day. It turns out the control had the most bacteria.Dollar #5 has the least with 15 different bacteria colonies. I also found out dollar #2 and dollar #4 both had a total of 19 bacteria colonies. There were 38 blacks bacteria, 35 yellow bacteria, 30 orange bacteria, and 42 white bacteria.

In the end this project taught me that money has lots of colorful and gross bacteria. My hypothesis was that money would have lots of bacteria. My hypothesis was correct because I found many different kinds of bacteria with each dollar. All the dollars combined I ended up finding 119 different bacteria colonies. With my experiment I saw many cases of error such as I used old cotton swabs instead of new cotton swabs. When I was doing my control it ended up with bacteria, so my project is inaccurate.

Now here are my graphs