soap vs. sanitizer laboratory experiment. why wash your hands? hand are the most frequent...
TRANSCRIPT
Soap vs. Sanitizer
Laboratory Experiment
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.
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
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.
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.
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
Methods Label your Petri dish
Group #Treatment Before/After
Before After
Gro
up
1
Contro
l
Methods How to sample:
Methods Apply treatment for 30 seconds
Analysis # Before - # After = Difference Difference ÷ # Before = Reduction Reduction x 100 = % Reduction
TREATMENT
Number of Bacterial Colonies
Before After Difference%
ReductionControl 1
Control 2
Control Average:
Soap 1
Soap 2
Soap Average:
Sanitizer 1
Sanitizer 2
Sanitizer Average:
Analysis Sample results:
TREATMENT
Number of Bacterial Colonies
Before After Difference%
Reduction
Control 1 119 500 -381 -320%
Control 2 198 32 166 83.8%
Control Average: -118%
Soap 1 100 68 32 32%
Soap 2 6 90 -84 -1400%
Soap Average: -684%
Sanitizer 1 7 1 6 85.7%
Sanitizer 2 23 2 21 91.3%
Sanitizer Average: 88.5%
Expected ≈ 0
Expected > 0