What Soap Will Kill the Most Germs?

Question: What soap will kill the most germs?

Hypothesis: I think that hand sanitizer will ill the most germs because of the amount of alcohol in it.

Procedure:

I will order the Nutrient Agar Plates
I will rub my hand without anything done to them.
Then I will wash my hand with each liquid that I plan to use then put it in the dish.
Then I will watch each thing grow and see which ones grow the most germs.
Next, I will culture the bacteria in a warm place for two days.
Finally, I will count the bacteria colonies.

Data Table:

Graph:

Conclusion:

In this experiment, I tested different cleansers to see which one kills the most germs. The cleansers that I tested were antibacterial soap, regular soap, hand sanitizer, and a water rinse. I found that antibacterial soap grew the least amount of bacteria colonies. In my hypothesis, I thought that hand sanitizer would kill the most germs because of the content of alcohol in it. As it turns out, antibacterial soap killed the most germs. Antibacterial soap had an average of thirty-four bacteria colonies, whereas hand sanitizer had an average of fifty-five bacteria colonies. Therefore, antibacterial soap clearly killed the most germs. I thought that my results were pretty interesting and accurate. To make my project better, I could have ran more than two tests, but for time's sake, I had no other choice.

Abstract:

What Type of Soap Will Kill the Most Germs?

For my science fair project, I wanted to see which type of soap would kill the most germs. I always wanted to know the difference between regular soap, antibacterial soap, and hand sanitizer. I predicted that hand sanitizer would kill the most germs. This is because of the amount of alcohol in it.

I tested three different soaps - antibacterial soap, regular soap, and hand sanitizer. I also tested some different controls - plain water, no wash at all, and distilled water (to prove that the plates were clean from the start). First, I rubbed my hands on the hallway floor to get them dirty. Then, I washed my hands with one of the liquids for twenty seconds. Next, I swabbed my wet hands and rubbed the swab onto the plate. I then sealed the plate, labeled it, and repeated this for each of the liquids. Then, once my first batch was done, I left it in the lab with a heat lamp on them for three days. I checked them after the third day. I counted each bacteria colony on each plate. I repeated the same process for the second batch except this time I tested hand sanitizer, antibacterial soap, regular soap, and plain water for a second time.

In my results, I have found that antibacterial soap kills the most germs. I know this because it grew the least amount of bacteria colonies. It had an average of thirty-four colonies total, whereas regular soap(the one that grew the most colonies) had an average of seventy-two. The ones in between were hand sanitizer, which had an average of fifty-five colonies and regular water, which had thirty-six colonies. It did come pretty close, but antibacterial soap clearly won.

By doing this project, I have learned that antibacterial soap kills the most germs. This surprised me because I hypothesized that hand sanitizer would kill the most because of the amount of alcohol in it. My hypothesis was obviously wrong because hand sanitizer had an average of fifty-five, but antibacterial soap grew less colonies with an average of thirty-four. I thought that I had pretty accurate results because I made sure that when I tested each soap I did the same thing each time. I would rub my hands in the hallway for about a minute and then wash my hands with one of the soaps for twenty seconds. I did this every time. It could have been even more accurate if I had tested each soap more than two times each. If I had more time, I would have tested each one five times. All in all, I feel that I conducted a successful science project.