Try rinsing your mouth out with a bit of warm water. You can also try smelling a lemon, or picture sour or savory foods to get your saliva pooling. We want to collect what is called “passive drool” (unstimulated saliva). Just relax and let it pool in your mouth for a while before attempting to spit in the tube. It may take several minutes for you to fill the tube to the required amount. Remember, bubbles don’t count.