Antiseptics and Bacteria

A lab report for freshman biology modeling the effects of different antiseptics on peppercorn bacteria.


To determine the antibacterial effectiveness of rubbing alcohol, peroxide, and bactine in relation to each other.


Will any of the three products (rubbing alcohol, peroxide, and bactine) kill bacteria, and if so, which is the most effective?

Background Information:

Bacteria are single celled prokaryotes, organisms with no nucleus, of the kingdom monera. Bacteria may either be coccus (circular), bacillus (rod-shaped), or spirillium (spiraled), and form in streptococcus chains, or staphylococcus clusters. Contrary to popular belief, a very small percentage of bacteria are pathogenic, and many are actually beneficial, some even necessary for our existence. As with all living things, bacteria require nutrition, water, heat, ect. to survive, and are classified as either aerobic, requiring oxygen, or anaerobic, not requiring oxygen. When you look more closely at the structure of bacteria, you see that they are made up of a cell wall and capsule containing organelles such as ribosomes and mesosomes, and a strand of DNA, but lacking membrane bound organelles.

Antibiotics, antiseptics, and disinfectants are substances than kill microorganisms like bacteria. Antibiotics kill bacteria inside the body, while antiseptics destroy bacteria on skin and tissue, and disinfectants fight bacteria on non-living materials. Some antiseptics include rubbing alcohol, peroxide, and bactine, the antibacterial solutions that I plan to test in this lab. Different antiseptics can be made up of many different ingredients, but the active ingredient in most is alcohol based, chlorine based, peroxide based, iodine based, or acid based. The only function of an antiseptic is to eliminate bacteria regardless of the bacteria’s nature.

Antiseptics are used by applying to the different skin or tissue they are designed for and either being left to work then evaporate, or are washed off after a certain amount of time. Different antiseptics work by targeting a specific bacteria or group of bacteria, and altering the pH level of their environment to a more basic or acidic level that the targeted bacteria can’t live or grow in. Different antiseptics with different antibacterial components differ in their ability to fight bacteria. The effectiveness of one antiseptic can be measured by the zone of inhibition it creates. The zone of inhibition is the area around an antibacterial solution in which bacterial growth is inhibited, or stopped. The difference in the sizes of zones of inhibition are used to compare the effectiveness off different antibacterial solutions.

Based on all of this information, I believe it is safe to say that the purpose of antibiotics, antiseptics, and disinfectants is to remove bacteria. In most cases, these substances are effective and completing their purpose. Other times, bacteria are not killed by the substances they are supposed too. This may be due to a lack of the antibacterial solution. More often than not though, it is because the bacteria have formed a resistance to the substance. Bacteria form these immunities when they are exposed to an antibacterial solution, but by some coincidence a few aren’t destroyed. These surviving cells then come in contact with other bacteria, and pass on the immunity through bacterial conjugation. In this process, bacterial DNA gets passed on to other bacteria. Therefore, overuse of antibacterial products will save bacteria rather than eliminate them.

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10 Responses to “Antiseptics and Bacteria”
  1. Jessica Says...

    On November 10, 2008 at 8:13 pm

    THANKS! :) i needed a science project lol

  2. Julie Says...

    On December 2, 2008 at 12:13 pm

    This was a good paper; hope you did well on it!

  3. Jonathan Says...

    On April 19, 2009 at 9:33 pm

    Very good, but better if the information in were added a lot

  4. nottellingyou Says...

    On August 18, 2009 at 12:25 am

    Hey, yeah its good but you need to work on your spelling and grammar!!
    Just giving some constructive criticism…

  5. Amanda Says...

    On March 24, 2010 at 3:31 pm

    This really helped me with my Biology bacterical lab.
    Thanks! :D

  6. AJIT SINGH(ajju) Says...

    On September 3, 2010 at 3:29 am

    just on time i get this for biotect,,,i.e both bio n chem…
    thanks alot

  7. margy Says...

    On February 15, 2011 at 4:56 am

    saved me from a failed science assignment, cheers :D

  8. Ashika Says...

    On September 30, 2011 at 2:39 am

    hey this is amazing!
    im doing a similar experiment but with differant bacteria.. and different antseptcs.. can ur way of cultivating the bacteria be used for all bacterium? and was it all in liquid medium.. please reply asap! :) thank you

  9. RONNEL Says...

    On September 18, 2012 at 8:57 pm


  10. avery Says...

    On February 24, 2013 at 5:01 pm

    wow this is awsome! i just won an award for it! talk about science!

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