1. Soap vs. Sanitizer Laboratory Experiment

2. Why wash your hands?  Hand are the most frequent transmission route for many types of infections.  Pathogens may enter through the mouth, nose, or eyes.  Proper hand hygiene is the easiest way to reduce infections.

3. How do you wash properly?  Scrub your hands with soap and warm water for 20 seconds to 2 minutes.  Scrubbing your hands physically removes dirt and grease, which wash away with the water

4. What about hand sanitizer?  When water is not available, hand sanitizer can be an effective alternative.  The alcohol in hand sanitizer disrupts the coating on bacteria and viruses.  Use enough sanitizer to keep your hands wet while you rub for at least 30 seconds.

5. Soap vs. Sanitizer Experiment  Problem/Question:  Which is more effective at reducing the amount of bacteria on hands: washing with soap or antibacterial sanitizer?  Hypothesis & Prediction:  If washing with soap and water is more effective at reducing the amount of bacteria on hands, then the soap treatment will show a greater reduction in bacterial growth than the sanitizer treatment.

6. Experimental Design  Independent/Manipulated Variable:  Cleanser/Chemical  Dependent/Responding Variable:  Bacterial growth  Treatments:  Soap  Sanitizer  Control:  No soap or sanitizer  Analysis:  Compare percent reduction in bacterial growth

7. Methods  Label your Petri dish  Group  #Treatment  Before/After Before After Group 1 Control

8. Methods  How to sample:

9. Methods  Apply treatment for 30 seconds

10. Analysis  # Before - # After = Difference  Difference ÷ # Before = Reduction  Reduction x 100 = % Reduction TREATMENT Number of Bacterial Colonies BeforeAfterDifference% Reduction Control 1 Control 2 Control Average: Soap 1 Soap 2 Soap Average: Sanitizer 1 Sanitizer 2 Sanitizer Average:

11. Analysis  Sample results: TREATMENT Number of Bacterial Colonies BeforeAfterDifference% Reduction Control 1 119500-381-320% Control 2 1983216683.8% Control Average: -118% Soap 1 100683232% Soap 2 690-84-1400% Soap Average: -684% Sanitizer 1 71685.7% Sanitizer 2 2322191.3% Sanitizer Average: 88.5% Expected ≈ 0Expected > 0