Purpose:
The purpose of
this experiment is to test the effectiveness of washing and drying hands
on the number of bacteria on the hands. This experiment will basically
test whether bacteria are better cleaned using soap, drying with paper
towels, air drying, or using chemicals like hydrogen peroxide or alcohol
Hypothesis:
It is the hypothesis
of this experiment that bacteria will be best cleaned off when they are
washed with chemicals like soap or hydrogen peroxide and the hands are
then drying on a sanitary object like clean paper towels.
Equipment:
Used in this experiment
was Dirt (as a source of bacteria) Soap, Hydrogen peroxide, alcohol, Paper
towels, bath towels, 2 agar plates, an incubator, a pen and paper.
Procedure:
The first step is to divide each agar
plate into 8 sections and number them 1-16. On sections 1-4 place hands
in dirt. The place left thumb on section 1 and again on section 2. Place
the right thumb once down on section 3 and then clean with the Alcohol
and place on section 4. repeat in a similar manner for sections 5-8 and
on the 8th section use Hydrogen peroxide. For sections 9-12, place dirt
on thumb and wash hands without using soap. On section 9, air dry the thumb
before placing. Section 10 dry on paper towels, on section 11 use the bath
towel and section 12 dry hands on pants. Use similar drying techniques
for sections 13-16 however, this time use soap while washing hands. Record
the relative growth on each section between 1-5 (5 being most growth) after
5 days of incubation.
Results:
| Section # |
|
Relative amount of Bacteria |
| 1 | Dirty Thumb Pressed once (Left Thumb) | * * * * * |
| 2 | Dirty Thumb Pressed Twice (left thumb) | * * * |
| 3 | Dirty Thumb Pressed once (Right Thumb) | * * * * * |
| 4 | Dirty Thumb cleaned with Rubbing Alcohol (right thumb) | * * |
| 5 | Dirty Thumb Pressed once (left Thumb) | * * * |
| 6 | Dirty thumb pressed Twice (left Thumb) | * * * |
| 7 | Dirty Thumb Pressed once (right thumb) | * * * * |
| 8 | Dirty Thumb Cleaned with Hydrogen Peroxide | * |
| 9 | Washed (no Soap) Air dried | * * * * |
| 10 | Washed (no Soap) Paper Towel dried | * * |
| 11 | Washed (no Soap) Bath Towel dried | * * |
| 12 | Washed (no Soap) hands dried on pants | * * * * |
| 13 | Washed (with Soap) air dried | * * * |
| 14 | Washed (with Soap) Dried with paper towels | * |
| 15 | Washed (with Soap) dried with Bath towel | * |
| 16 | Washed (with Soap) dried on pants | * * * |