Germ Killing Science Fair Projects

Surface Microbiology

Surface microbiology looks at the organisms that are too small to see with the naked eye. This field of science requires a microscope and good observation skills. It is important to keep your work space clean when working on surface microbiology science fair projects because your samples can be easily contaminated.

PURPOSE

The purpose of this experiment was to determine which type of waterless hand sanitizer would kill germs most effectively.

I became interested in this idea when I learned about diseases caused by E.coli and wondered what people should use to help prevent such diseases caused by dirty hands.

The information gained from this experiment may be used by all people, especially parents of young children, so that they know the best type of waterless hand cleansers to use to help prevent diseases.

HYPOTHESIS

My hypothesis is that the hand sanitizers with highest percentage of ethyl, or isopropyl alcohol will be more effective killing bacteria on average. Based on this information, I think that the Lysol brand will be the most effective on killing germs because of the higher percentage of alcohol.

I base my hypothesis on a July 2000, hospital infection control article which states that "the higher amounts of alcohol up to 70%, the better the hand cleanser kills bacteria."(John M. Boyce)

EXPERIMENT DESIGN

The constants in this study were:

• Amount of water used (none)
• New bottle of each type of hand cleanser.
• The amount of hand sanitizer on the hands (1 ml.)
• The place on the hands you wash
• Amount of time spent washing the hands (ten seconds)
• The motion used washing the hand
• The method of judging the amount of germs on the hands after they’re washed
• The amount of time after you’re hands are washed before taking the sample
• Size of the area you wash determined by template
• The type of swab used to collect the germs
• The motion and method of collecting the germs
• The time spent taking the sample (ten seconds)
• The shape of the area you take the sample
• The type of material of the template
• The type of agar and size of plate used to grow the bacteria in
• Method of applying germs to agar
• The area the germs are spread on the agar plate
• The same subject before and after use of gel
• The time the germs grow in the incubator

The responding variable was the percentage of bacteria still living after using the hand gel.

To measure the responding variable will count the number of living bacteria in the past experiment, and compare it with the number of living bacteria in the pre experiment. I will do this with all brands of gel, to see which one killed the most bacteria.

MATERIALS

Germ killing science fair projects continue at antigerm science fair projects.

See other bacteria experiments here...