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The Challenge: Make an Antibacterial Cream



Where do we get the bacteria from?

Bacteria can be found both in and on our bodies but one of the most accessible and populated areas is the mouth. By wiping sterile swabs around the inside of the mouth, placing the saliva into a small bottle of enrichment media (the nutrient broth), and incubating them at body temperature for an hour, the colony will begin to grow. Just a small drop of this enrichment culture spread on the surface of some nutrient agar in a Petri dish will produce colonies of bacteria if they are kept in an insulated box.

What do you think you would see if you had the ideal concentration of bacteria?
Rollover the dishes below to find out.