The purpose of this experiment was to determine whether Neutrogen Deep Clean, Johnso & Johnson's Clean & Clear, or Oxy Balance Facial Wash killed Corynebacterium xerosis the best. This experiment was preformed by soaking sterilized disks in four containers. Three of these containers contained a separate cleanser, and the fourth container contained the control, which was water. The disks soaked in these containers over night and they were then placed in petri dishes that were growing Corynebacterium xerosis. The petri dishes were then placed into an incubator over night at 37 degrees Celcius. The next day, they were taken out of the incubator and the zone of inhibitions around each of the disks were recorded. This procedure was repeated 20 times for each type of cleanser.
After completing this project, it was found that Neutrogena Deep Clean worked best at killing Corynebacterium xerosis because its average zone of inhibition was 4.05 mm. Oxy balance Facial Wash worked second best with an average zone of inhibition of 3.225 mm. Johnson & Johnson's Clean & Clear killed Corynebacterium xerosis third best with an average zone of inhibition of 2.875 mm. The control was the least effective in killing the bacteris because it only had an average zone of inhibition of .6 mm. These results accured due to several factors. One factor was because Neutrogena contains salicylic acid and beta alpha hydroxy acid. Another factor was the pH level of the products. The pH level measures the mildness of the cleaners. Usually cleansers that have an alkaline pH are more harsh than the cleansers with a neutral or acid pH. The pH of the skin ranges from 5.5 to 6. The acid helps protect the skin, and the cleansers that have a neutral or acid balance do not disrupt the acid mantal. The pH level of neutrogena ranges from 3.8 to 4.6 which means that it is acidic and it will not disrupt the acid mantal of the skin.