Science Buddies: "Ask an Expert"

It matters if you are testing toothpaste or mouth wash. E coli is an intestinal bacterium. You want to use mouth bacteria for the test. Better make sure there's not some rule against using them in your science project.

Hi Sybee,

Sorry for getting back to you so late. I cannot use mouth bacteria, my teacher said that I should use E. coli. He said that the experiment should work except we cannot find a retailer for tetrasodium pyrophosphate (Na4P2O7). Do you know anyone that sells this chemical?

Hi,

Sigma-Aldrich Chemical Co. sells tetrasodium pyrophosphate: https://www.sigmaaldrich.com/catalog/se ... us=product

Your school will have to order it because they do not sell to individuals.

Sybee