Re: Mouthwash and Bacteria

Hi Anna,

To study the effect of mouthwash on killing mouth bacteria you will need to grow bacteria and then expose them to mouthwash to see if the mouthwash inhibits the growth of the bacteria. To perform such an experiment you will need certain supplies. You will need different mouthwashes and you will require supplies and a means to culture bacteria that will be exposed to the mouthwash. The first part is easy, the second will require you to be resourceful. Does Hamden have a college or university that has a microbiology course? If so, you could try contacting the microbiology lab instructor to see if they could supply some nutrient agar plates (food for the bacteria) and an incubator in which you can cultivate the bacteria. If there are no such educational resources available you could try other places that use microbiological techniques, such as, Hamden's sewage treatment plant, or a regional hospital. Perhaps your teacher could help you contact such organizations.

Once you are ready to cultivate the bacteria you must decide which bacteria are appropriate to use. Since you are investigating mouthwashes you will want to use bacteria that live in the mouth. We all have bacteria living in our mouths, so why not use the bacteria living in your mouth. If you have access to a sterile swab (such as ones used in a doctor's office) you can swab your mouth and then use the swab to streak a nutrient agar plate. After incubating the plate at 37 Celcius (our body temperature) the bacterial colonies that appear originated from your mouth. You can then expose these bacteria to different mouthwashes to see which mouthwashes inhibit the bacterial growth the best.

You have chosen a very interesting science project and you will learn a lot about the very fascinating world of microbiology. I have used some terminology that you may be unfamiliar with but I am sure your library will have books on basic microbiology, also this URL MadSci Microbiology links provides links to some excellent microbiology sites.

I have only given you advice on how to get started. I hope it helps and if you need further assistance down the road please don't hesitate to email me. I wish you lots of luck with your project and above all enjoy exploring the world of microbes!

Chris