If you are having difficulty collecting saliva, we have a few recommendations:
Note: Too many bubbles are often caused by spitting too frequently into the tube. To avoid bubbles, try pooling saliva in your mouth for several minutes before spitting. If your sample contains a large percentage of bubbles, cap the tube and tap it on a hard surface to disperse bubbles into liquid.
Drink extra water the day/night before collection to encourage the production of more saliva.
If your mouth is dry, try pressing the tip of your tongue against your teeth or the roof of your mouth. Smelling (not eating) a lemon or other foods can also produce saliva flow.
Allow saliva to pool in the mouth before collecting.
Chewing gum (even sugarless) is not advised as it may contaminate the sample.
If you are still unable to collect enough saliva in one day, cap the tube, place it in the refrigerator or freezer, and add more saliva at the same time the next day until the tube is at least half full. You may continue collecting in this way for up to 3 days.