Have you ever wondered if there is a difference in the brands of mouthwash you use? Is the generic brand as good as Listerine? Luke wondered that same thing and decided to put his query to the test in this years science fair. After acquiring some petri dishes, he went to work growing bacteria and testing mouthwash. He first swabbed his mouth and put the swab in sterile water, this created a bacteria solution. He poured the water into the petri dishes, poured off any excess, and then placed a disk that had been submerged in mouthwash in the center of the dish. After sealing the dishes, placing them in a warm place, and waiting a few days, he measured the "kill zone" of each mouthwash. As he peeled off the tape and opened the lids to measure the kill zone, I'm not ashamed to say that we both felt queasy and itchy as we examined the bacteria. I think we both took showers after we were finished. The results were very clear that Listerine does kill 99.9% of the germs (or at least 99.9% more than the other brands). For those of you who were wondering if the generic brand is just a effective. . . it's not! In this study it didn't kill any of the bacteria, in fact, there was a bacteria colony growing right on the disk. Keep in mind that this a fifth grade science project, so take it for what it's worth, but this family will be using Listerine from now on!
Luke really enjoyed working on this project and was very excited to participate in the fair. He woke up extra early the morning of the fair, got his project in order and put on his suit. I found out later he was the only boy who wore a suit but Luke's friends reported to me that all the judges were very complimentary on Luke's appearance. The results of the fair have yet to come in, but I was very proud of Luke and how hard he worked on his project.
