The Effect of Different Cleaning Procedures on the Hygiene of

Hands By: Chelsea Guan

Pd. 10

Problem Statement and HypothesisWhat is the most effective way to remove

bacteria from hands?If hands are washed with soap and water,

then there will be fewer bacteria left than if hand sanitizer or water were used.

Basic ConceptsPathogenAsepticAgarIncubation

ProcedureGather materials (buy Agar Plates, soap,

hand sanitizer) Find 9-12 people to volunteer for the test

(no sex or age requirement) Divide the volunteers into 3 groupsLabel each plate with the words left and

right, the name of the volunteer, and which group the plate belongs to

Each volunteer will then lightly press their left hand in an Agar Plate

Procedure (Continued)They will then wash both their hands with

soap, hand sanitizer, or water respectively. (For soap and water, hands must covered in soap and rinsed under warm water for 20 seconds. For hand sanitizer, a dime sized drop of hand sanitizer will be placed on the left palm. Hands will then be rubbed together for 20 seconds. For water alone, hands will be rinsed under warm water for 20 seconds.)

Each volunteer will then press their right hand in the same plate respectively

Procedure (Continued)Seal plates using parafilm and tapeThe plates will then be incubated for 2

days inside an incubator inside of conditions (temperature around 20-23 degrees C)

Each plate will then be taken out (PLATES ARE NOT TO BE OPENED), and bacteria colonies on the Agar Plates will be counted

To prevent spread of possible pathogen, plates will be disposed after autoclaved.

Design DiagramLevels Soap and

WaterWater Hand

SanitizerNone

Trials 3 3 3 9

DataLevels Soap and

WaterWater Hand

SanitizerNone

Trials 0 4 1 2

2 1 1 3

0 2 2 36

1 0

1

0

0

0

4

4

2

6

Analyzed ResultsSoap and Water

Water Hand Sanitizer

None

Observed .75 2.33 1.33 4.833

Expected 2.3125 2.3125 2.3125 2.3125

Total 1.06 .00013 .42 2.75

P value: 4.23

Photo Documentation

Graphs of Data

Series10

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

SoapWaterHand SanitizerNone

Nu

mb

er

of

Colo

nie

s

Method of Cleaning

ConclusionSources of errorImprovementsExtensionsApplications

Special thanks to…Mrs. PietrangeloMy parentsAll my volunteers

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