Which Antiseptic Most Effectively Reduces the Amount of Bacteria?

Researched by Kyle A.
1999-2000 

 

PURPOSE


 






The purpose of this experiment was to determine which antiseptic most effectively kills bacteria. 

I became interested in this idea when I was watching television, and saw many commercials about cleaners, or medicines that kill bacteria.

The information gained from this experiment may aid people, hospitals, nursing homes, restaurants, and families in keeping their homes, or areas clean.


 
 



HYPOTHESIS


 






My hypothesis is that iodine will reduce the amount of bacteria most effectively.

I base my hypothesis on the fact that this is a common antiseptic within many houses, and is widely used in hospitals, and medical centers.


 
 



EXPERIMENT DESIGN


 













The constants in this study were:

  •  The type of bacteria used
  •  The petri dish used
  •  The microscope used
  •  The same amount of antiseptics used
  •  The incubator used
  •  The test tubes used
  •  The amount of bacteria used
  • The type and amount of agar used
The manipulated variable was the type of antiseptics used to reduce the amount of bacteria.

The responding variable was the amount of bacteria that grow after treated with the antiseptics. 

To measure the responding variable, I will examine the bacteria after treated, and count the colonies that have grown, or are left.


 
 


MATERIALS

QUANTITY ITEM  DESCRIPTION
1 Culture of bacteria
.2 ml hydrogen peroxide
12 test tubes
.2 ml iodine
.2 ml isopropyl alcohol
1 incubator

 
 

PROCEDURES


 






1. Gather all needed materials that were sterilized according to hospital procedures.
2. Gather twelve test tubes and label them 1 through 6, A and B.
3. Fill the test tubes 1 through 3 A and B with 1.8 ml of saline to dilute the disinfectant. 
4. Fill the test tubes 4 through 6 A and B with .8 ml of saline to create a stronger concentration of disinfectant.
5. Also label one control; do not treat this one with any antiseptics.
6. Start the stopwatch.
7. With a swab transfer bacteria from the petri dish to test tube 1A.
8. Make sure the test tubes are adjusted to a density of a McFarlane standard.
9. After two minutes use a loop to transfer a sample of the test tube 1A to a petri dish, covering the whole plate, and label it 1A    2minutes.
10. Repeat step 8 for all test tubes A and B labeling the petri dishes according to the label on the test tube the sample was taken from.
11. After 15 minutes repeat steps 8 through 9 labeling the test tubes the same except labeling them at 15 minutes.
12. Put the all of the petri dishes into the incubator set at 35 degrees Celsius.
13. After 24 hours take the petri dishes out of the incubator.
14. Examine the petri dishes and determine if they are no growth, light growth, moderate growth, or heavy growth, compare them to the control, this will be the heavy growth. 


 
 


RESULTS


 






The original purpose of this experiment was to determine which antiseptic would most effectively reduce the amount of bacteria.
 
 

The results of the experiment were that there was no growth at all of bacteria on the plate that had been treated with iodine. There was a moderate growth for hydrogen peroxide as well as isopropyl.
 
 

See the table and graph below.
 


 
 

CONCLUSION


 






My hypothesis was that iodine would kill the most amount of bacteria.

The results indicate that this hypothesis should be accepted, because the iodine effectively killed all of the bacteria.

Because of the results of this experiment, I would want to treat different bacteria with different antiseptics, as well as different substances like wine or vinegar.

If I were to conduct this project again I would have many more trials, so that I could get a more accurate reading. I would also use a different species of bacteria to see if the results would be the same.


 
 
 
 
 
RESEARCH REPORT
 

Introduction


 


 Bacteria have been around much before the dinosaurs. They have caused diseases and sickness long before man has ever walked on earth. These tiny, microscopic creatures cause great plagues, kill millions of people, and help make the cheese on your pizza.
 
 


Bacteria


 


Bacteria were first discovered in 1683 by Anthony Van Leeuwenhoek. When they were first discovered he called them animalcules, although he did not understand them or know what they were his discovery was called the foundation of microbiology. The significance of bacteria was not fully understood until nearly two hundred years later. Bacteria are usually single celled organisms that are classified with blue-green algae under the kingdom Monera. 
Bacteria are divided into three basic groups, their names are based on their shapes; coccus are spherical or round, bacillus are rod like, and spirilum are usually spiral shaped. Bacteria are usually measured in microns, it takes 1,000 microns to make a millimeter, and bacteria are from 1 to 5 microns. 
Bacteria reproduce by dividing, or splitting into two. The bacteria mainly reproduce the same as any cell. They must create enough protein for two cells, and they also create two nuclei before dividing. Different bacteria divide at different times, they can divide many times, not just once, and their offspring also will divide, and so on. First they must reach maturity, then they too divide. They can divide every fifteen minutes making millions in twenty-four hours.
People usually only hear about the harmful things bacteria do, like spoiling food or causing sickness, but many others help humans in many ways. Bacteria make different foods or chemicals. They make vinegar and wine, and different beverages that have yeast in them. Bacteria can cause fatal diseases, minor stomachaches, or a skin irritation. They can cause fatigues, or just an infection within a household, or just one person.
 
 




Antiseptics


 


  People have used been using wine and vinegar to treat their wounds for more than 2,500 years, long before the germ was discovered.  Many hundreds of years ago, surgeons discovered that battle wounds that were left untreated soon smelled like rotting flesh. To stop or prevent the smell, they treated the flesh with different chemicals, and powders that later became known as antiseptics.
 Many antiseptics are in first aid kits, but physicians say that it is just as effective to wash with soap and hot water. Antiseptics are used for many different purposes. They are used to disinfect the skin of a patient before surgery, to treat a wound so that it does not get infected, or to clean an area or materials for an experiment, or operation. 
 
 


SUMMARY
Many people think that bacteria do not belong in this world, and try to get rid of them all together. They say that they are responsible for many deaths, but without them, there would be no animal or plant life on earth.


BIBLIOGRAPHY

 






"Antiseptics" Compton’s Interactive Encyclopedia 1995"
"Antiseptic" Encarta Reference Suite  2000 
"Antiseptic" World Encyclopedia  1999 Volume 1 
"Bacteria" Compton’s Interactive Encyclopedia  1995
"Bacteria" Encarta Reference Suite  2000

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