Paper Towel Bacterial Studies
Problem:
Will using an automatic paper towel dispenser be the most effective and efficient way of reducing the spread of bacteria by eliminating direct contact with the paper towel dispenser?
Will using an automatic paper towel dispenser be the most effective and efficient way of reducing the spread of bacteria by eliminating direct contact with the paper towel dispenser?
- Hypothesis:
If direct contact is eliminated from the use of the paper towel dispenser, then the spread of bacteria will be reduced.
Materials:
1. paper towel dispenser
2. tissues
3. hand sanitizer
4. paper
5. pencil/pen
6. masking tape
7. petri dishes
8. agar
9. Q-tips- 10. clipboard
11. erlenmeyer flask
12. alcohol
13. rubber stopper
14. cotton balls
Procedure:
1. Locate the paper towel dispenser in Room 305.
2. At the start of the day, pour a little alcohol into a beaker (one that has a skinny neck toward the top).
3. Quickly slide a rubber stopper on top of the beaker (alcohol can evaporate when exposed to air for too long).
4. When ready, take off the rubber stopper and replace it with a cotton ball (hold it on the top).
5. Turn the beaker upside down so the cotton ball is soaking in alcohol.
6. Quickly take the cotton ball off and replace it with the rubber stopper like in Step 3.
7. Thoroughly scrub the paper towel knob with the cotton ball. Make sure to reach all sides, grooves, etc.
8. Discard the swab.
9. Put up a clipboard next to the paper towel dispenser saying to make a tally every time someone uses it on there.
10. Open up a fresh package of sterile petri dishes and take out one.
11. Pour a small bottle of agar solution into the dish.
12. Leave it somewhere safe for the agar to dry and become a gel.
13. At the beginning of the next day, take a Q-tip and wipe it thoroughly all around the knob.
14. Swipe the Q-tip in a serpentine pattern lightly across the petri dish prepared in Steps 10-12 (it is extremely important not to break the gel).
15. Close the lid quickly (the petri dish must remain sterile).
16. Put a piece of masking tape across the petri dish on the bottom and write on it “Control #1” and the date.
17. Repeat steps 4-15 for the next two days, labeling the petri dishes Control #2 and Control #3 (and the date to keep track). Bacteria should start to form after 3 days sitting in the petri dish. Make sure to examine under a microscope after a week.
18. The control group has been completed. Now, place the box of tissues next to the sink and leave a sign to use the tissues. Keep the sign for making a tally after using it. Make sure the tallies are organized, otherwise, there will be a bunch of random lines and nobody will know what day they belong to.
19. Repeat steps 4-15 for 3 days for the tissues, labeling the petri dishes Tissues #1, Tissues #2, and Tissues #3 and their dates.
20.Repeat steps 4-15 for 3 days for the hand sanitizer, labeling the petri dishes Hand Sanitizer #1, Hand Sanitizer #2, and Hand Sanitizer #3.
21. Compare the results.
Observations
Control #1: (Grew on swiped area) Irregular, flat, undulate
Other colony: Punctuate, raised, entire
Other colony: Irregular, raised, entire
Other part: filamentous, flat, filiform
Control #2: (Grew in colony) Irregular, raised, multicolored, entire
Other colony: Punctuate, flat, entire
Other colony: Irregular, flat, undulate
Control #3: (Grew in colony) Irregular, flat, entire
Other colony: Filamentous, flat, filiform
Tissues #1: (Grew in huge colony) Giant white cloud, white flurries, raised, grew extremely rapidly, and looks like shredded cotton. Around Day 20, the bacteria began rising up the sides of the petri dish.
Tissues #2: (Grew in colonies) Punctuate, orange, raised
Other colony: 1 white stalk (only stalk in all of the petri dishes), punctuate
Other colony: Entire, brown/black, looks like flower, although very veiny (looks like spilled soda)
Tissues #3: (Grew in colonies) Entire, flat, smooth, scarlet
Other colony: Yellow, raised, irregular
Other colony: Irregular, light yellow, smooth
Other colony: Punctuate, beige, raised
Other colony: Irregular, brown, light brown, white, flat
Hand Sanitizer #1: (Grew in scattered dots) Raised white dots
Other colony: Punctuate, white
Hand Sanitizer #2: (Grew in scattered dots) Raised yellow dots
Hand Sanitizer #3: (Grew in colony) Punctuate, raised, yellow
Other colony: Punctuate, white, raised
Other colony: Circular, raised, white
Other colony: Fluffy, brown bacteria: center is concentrated and spreads out - Dying Bacteria
- - All bacteria samples began dying at around Day 30
- - Agar cracked when bacteria was dying
- - Control bacteria faded when dying out
- - Tissues Trial 1 sagged in and cracked when dying
- - Tissues Trials 2 and 3 faded away when dying out
- - Hand Sanitizer samples have not yet startec to die out yet because they have not reached Day 30.
- Conclusion:
- The hand sanitizer worked much better than the tissues. There was a definite decrease in amount of bacteria on the petri dish from when the tissues were tested to when the hand sanitizer was tested. Control Day 1 was 1/3 (33%) covered by bacteria. Control day 2 was 3/4 (75%) covered in bacteria. Control day 3 was 1/4 (25%) covered in bacteria. Tissues day 1, 2, and 3 were 4/4 (100%),1/12 (8.33...%), and 1/6 (16.66...%) covered in bacteria. Hand sanitizer days 1,2, and 3 were 1/20 (5%), 2/25 (8%), and 1/5 (20%) covered in bacteria. Also, an interesting fact is that out of 52 people, only 2 washed their hands for the correct amount of time which is the amount of time it takes to sing Happy Birthday twice. Another thing we monitored was that we did monitor how many children used the dispenser. The amount of people that used it for control 1, 2, and 3 were 33, 42, and 20. The amount of people that used the paper towel dispenser for tissues 1,2, and 3 was 44, 38, and 53. The number of people that used it for hand sanitizer 1, 2, and 3, were 21, 38, and 40. Their were many problems encountered throughout the course of the experiment. Some of them included:
- - Hurricane Sandy got in the way of the observations and experiment.
- - There was no way to observe or take photos of the bacteria on weekends.
- - The conditions and climate in which the bacteria grew was not the same.
- - It is not known if the supplies were actually used.
- - Some students may have washed their hands prior to getting the dispenser.
- - One of the reasons the Tissues group of bacteria grew excessively was because of the amount of people that used the dispenser, compared to the amount of people using the paper towel dispenser during the Hand Sanitizer group. There was no way to make sure people used the paper towel dispenser the same amount of times every trial, every day unless we forced use of the paper towel dispenser.
- If the experiment was to be done again, the bacteria would be kept in a place where at least one group member could observe them each day. This place would be temperature monitored. Also, we would have somebody constantly supervising the paper towel dispenser when in use. This way, we would be able to guarantee that people are using the supplies, and washing their hands after getting the paper towel dispenser.
- This experiment formed many questions including:
- - Would wipes be a more effective way of preventing the spread of germs than tissues? What about hand sanitizer?
- - What kind of sanitizer would work best?
- - How much do the effectiveness of hand sanitizer vary (from brand to brand)?
- - Do alcohol-free hand sanitizers have the same effectiveness as regular hand sanitizer?
- This experiment was useful because it showed that because of direct contact, many germs were on the knob, therefore meaning that the spread of germs just from the paper towel knob was high, even with using the supplies. So, the experiment proves that sensor hand paper towel dispensers would make a dramatic decrease in the spread of germs meaning there would be less illnesses throughout the school. This information can be shared with many schools, and can drastically decrease the amount of germs spread throughout the year.
- Misc.:
Independent Variable - - Hand Sanitizer
- - Tissues
- Dependent Variable - The amount of bacteria growth
Qualitative Observation - Part #1 of Control #1 grew in an irregular, flat, undulate colony and was yellow.
Quantitative Observation - Tissues #3 took up about 16.7% of the bottom of the petri dish.
Inference- Hand sanitizer killed the most germs because it is designed to be a germ-killing substance and also contains rubbing alcohol.
Control Group - Taking the swab after a normal day with no physical barrier or germ-killing substance
Experimental Group - - - Using tissues when using paper towel dispenser
- Using hand sanitizer when using paper towel dispenser
Constants:
- Way bacteria was introduced to the petri dish - - Paper towel dispenser
- - Swab
- - Petri dishes
- - Agar
- - Rubbing Alcohol
- - Amount of days bacteria got to grow
- - Where the bacteria grew