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Experiment #1

Scott 4/16/97

Purpose: This experiment will determine how much washing hands really counts. Procedure: What I did is wash both hands at 8:04 P.M., then be myself for 15 minutes, (then had one hand washed, put tape on each hand, then wiped the tape across agar gel.

Hypothesis: I expect the washed hand will have some bacteria, but not as much as the unwashed hand.

Observations: There was no activity for 4 days. On the 5th day, the unwashed hand had little specks, about 28 individual specks. The washed hand had about 15 specks. I checked another dish of agar, which had not been touched, and noticed some fuzzy little growths. On the 6th day, the specks grew largely on the unwashed hand. The washed hand had doubled. 1 also noticed an odor that was very unpleasant. On day 7, the little specks became bigger on the unwashed hand. There were wet looking splotches, dry blotches, and little wet dots. The washed hand had the same type of bacteria that the untouched agar had. By day eight the unwashed hand had orange dots, a few little green ring worm like things, and blotches. The washed continued to grow.

Conclusions: The unwashed hand had about 3 times as much growth as the washed hand. This means that there were about 3 times as much germs on the unwashed hand as the washed hand. Day 5 of each experiment for the washed hand each had about the same amount of growth. Day 6 of each experiment for the washed hand also had about the same amount of growth. However, there is much more growth for experiment #2 than #1 for the unwashed hand for day 5 and day 6. Clearly, washing your hands really helps kill bacteria.

Experiment#2

4/17/97

Purpose: This experiment will determine how much washing hands really counts.

Procedure: What I did is wash both hands at 7:05 A.M., then be myself for 9 hours and 40 minutes. I then had one hand washed, put tape on each hand, then wiped the tape across the agar gel.

Hypothesis: I expect the washed hand to have some bacteria, and the unwashed hand will have a lot more bacteria.

Observations: There was no activity for 3 days. On the 4th day I noticed tiny puddles on the agar for the unwashed hand. On the washed hand there were fuzzy little growths in the agar. I checked another dish of agar, which had not been touched, and noticed some similar growth. On the 5th day, those puddles from the unwashed hand had grown, and I saw little lines and dry-looking blotches in the agar. I also noticed an odor. The agar for the washed hand continued to grow those little fuzzy growths, and had 2 or 3 little puddles, such as I had seen from the unwashed hand. On the 6th day, the unwashed hand had big blotches, some orange spots, and one black dot There were also some pimple like growths. The washed hand had some tiny new growths. The agar which had not been touched had a very small amount of growth. On day 7 the bacteria from the unwashed hand is looking really gross. It has a big black dot, orange specks, puddles, smaller puddles, pimple like things, and smaller bacteria growths. The washed hand bacteria continued to grow.

Conclusions: The agar from the unwashed hand has about 10 times Gust my estimate) as much growth as the agar from the washed hand. This means that the unwashed hand has about 10 times as much germs on it as the washed hand. I also found out that there is bacteria in the air, and what it looks like when it grows. It is obvious that the longer you go without washing your hands, the more bacteria you pick up on your hands. Clearly, washing your hands really does help kill bacteria.

New Questions

  1. Will using a different kind of soap vary the outcome? Will using different brands of soap and anti-bacterial soap have different results? Do different types of soap encourage the growth of different types of bacteria?
  2. Do different activities result in different levels of germs?
  3. What difference will the length of time spent washing hands have on the amount of germs? For example, is 1 minute more efffective than 15 seconds? Be sure to wash hands for a certain amount of time-this is a variable.
  4. How much bacteria is in the air? Use a control to test this.
  5. Where does all this bacteria come from? How does it get on my hands?
  6. How can I team to identify bacteria?


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