Science Buddies: "Ask an Expert"

Is plaque considered a aqueous solution, or is it possible to logically test plaque on litmus paper?

jeb wrote:Is plaque considered a aqueous solution, or is it possible to logically test plaque on litmus paper?

I think plaque is a sticky film of bacteria. I don't think it is an aqueous solution, but it may dissolve sufficiently in water that you could test for pH changes by dissolving the plaque in a specific, standard amount of water, i.e., 10 mls, and then testing the pH of that water.

If it does not dissolve in water, you will not see any effect on pH. If you see no effect on pH you will need to check if plaque is soluble in water.