The Effect of Sodium Dodecyl Sulfate on Skin Cells, Eye Cells, and Serratia marcescens

1. The Effect of Sodium Dodecyl Sulfate on Skin Cells, Eye Cells, and Serratiamarcescens Adrienne Williams March 17, 2012

2. Introduction • How many people in this room use shampoo, toothpaste, or bubble bath solution on a daily basis?

3. Background Information • Sodium Dodecyl Sulfate is an ingredient found in many toothpastes, shampoos, and other products.. • In previous research found in similar articles, Sodium Dodecyl Sulfate was tested on rabbit corneas and skin samples. • Irritation • Redness/bumps • Blindness • Vision impaired • Serratia marcescens

4. Purpose and Rationale • Purpose:The purpose of my project this year is to see the effect of Sodium Dodecyl Sulfate on Eye Cells, Skin Cells, and Serratia marcescens. Sodium Dodecyl Sulfate (SDS) is an ingredient found in many shampoos and soaps, that cause them to have a lathering effect. • Rationale: The rationale of this project is to see if this widely used ingredient has a detrimental effect on the human body. The human body was represented by the use of skin and eye cells in order to make the project applicable.

5. Research Hypothesis • The research hypothesis was that the SDS will impact both mammalian cell lines that it would encounter during bathing as well as the development of shower biofilms, specifically Serratia marcescens. • Sub-hypothesis: The highest concentration of SDS will cause defragmentation to the skin and eye cells. • Sub-hypothesis: The highest concentrations of SDS will reduce the amount of Serratia marcescens.

6. Procedures: Biofilm

7. Procedures: Cell Lines

8. Absorbance of Biofilm As treatment concentration increases, the average absorbance decreases, which was expected.

9. Skin Cell Viability Seen in the graph above, there is not a direct correlation between concentration and amount of cells, however it is believed that this is due to a source of error. However, the lowest number of cells is present in the highest concentration of SDS.

10. Eye Cell Viability As seen in the graph above, there is a direct correlation in amount of SDS and the number of viable eye cells. As concentration decreases, the number of cells increases.

11. Comparison of Cell Viability The above graph was created to see if there was a correlation between the two different mammalian cell lines. There is a correlation seen, in regards to the increasing number of cells, however it is interesting that the two lines equal out at the lowest concentration, when they started out with different initial counts. However, this could just mean that SDS kills many more skin cells than eye cells.

12. Statistical Analysis • ANOVA was used to calculate statistical significance. • Serratia marcescens: It also had a p-value of 0.645. Since this value is greater the .05. the data on this variable was not statistically significant based on treatment. • Skin Cells: It also had a p-value of 0.003. Since this value is much less than 0.05, the data was significantly significant based on treatment concentration of Sodium Dodecyl Sulfate. • Eye Cells: It also had a p-value of 0.014. Since this value is also less than 0.05, the data was significantly significant based on treatment concentration of Sodium Dodecyl Sulfate.

13. As a result of the data analysis the research hypothesis was accepted by the dependent variable Serratia marcescens, and the high and low concentrations added to the skin cells. • The null hypothesis was full accepted for the eye cells.

14. Future Research • Test actual products that have SDS • Find the optimal point • Quantitative analysis on skin irritation • Test more concentrations

15. The Effect of Sodium Dodecyl Sulfate on Skin Cells, Eye Cells, and Serratiamarcescens Questions?