One scientific experiment is to look at the effectiveness of each brand or type. For this experiment, compare sanitizers that contain alcohol against nonalcoholic sanitizers. Also, for comparison, use sanitizers that offer different amounts of alcohol in their products; most alcohol-based sanitizers use between 60 to 90 percent alcohol. For this experiment, you need five brands of hand sanitizer, five test subjects, cotton swabs, ten agar petri dishes and an incubator.
On your test subjects, take a control swab before applying any sanitizer. Apply to agar, and mark each dish as "Control" with the subjects' names. Then have each test subject clean his hands as directed by the sanitizers being tested. Swab again, and apply to the remaining petri dishes. Make sure each dish is marked with the appropriate sanitizer's name as well as the subject's name. Incubate for 48 hours. Count the number of bacterial colonies on all dishes. Compare the control and experimental groups to determine the percentage of decrease for bacterial colonies for each hand sanitizer.