Expert: Walter Hintz - 1/17/2010

Question
Hi, I need help with my science fair project. I am doing whose mouth is cleaner a dog mouth or a humans mouth and i read that I need to take a sample of dog and humans spit and stick them in gelatin then wait for about 2 weeks. Am i doing this right? Please type back ASAP!!!

Answer
Hi Sumar
You do not stick saliva in gelatin. Dissolve the gelatin an add a little beef broth and let it set in a closed container then gently put the saliva on the gelatin and keep it in a warm.  You do not need two weeks.  Bacteria will grown in 24-48 hours.  Be careful and do not touch the colonies after they grow