Insulin Saliva Collection
Fasting insulin levels in saliva correlate well with levels in serum. If fasting insulin levels are of interest, do not consume food or beverage within eight hours prior to saliva collection.
If insulin levels following a glucose challenge are of interest, please be advised that salivary insulin levels lag approximately 1 hour behind blood levels.
This analyte is sensitive to freeze-thaw degradation. Sample collection, storage, and handling should be carefully designed to minimize the impact of freeze-thaw cycles.
Consider documenting parameters to estimate saliva flow-rate (ie; time taken to collect and sample volume). Consistency in collection method is recommended to avoid introducing unsystematic error into your study data.
Saliva Collection Protocol
Before Sample Collection
- Avoid foods with high sugar, acidity, or caffeine immediately before sample collection.
- Document consumption of alcohol, caffeine, nicotine, and prescription/over-the-counter medications within the prior 12 hours.
- Document vigorous physical activity and the presence of oral disease, injury or inflammation.
- Do not brush teeth or eat a major meal within 60 minutes of sample collection.
- Rinse mouth with water to remove food residue and then wait at least 10 minutes before collecting saliva.
During Sample Collection
- Recommended Collection Volume: 100 µl*
- Use a collection device that has been validated for the measurement of this analyte.
- Follow your selected sample collection device/method protocol.
*Add 300 µl to the total volume of all tests for liquid handling
After Sample Collection
- Record the time and date of specimen collection.
- Refrigerate samples immediately (if possible) and freeze at or below -20°C (household freezer) as soon as possible (within 6 hours of sample collection)
- Samples visibly contaminated with blood should be recollected.
- Do not add preservatives to saliva samples unless it has been previously validated with the assay.
- Consider aliqouting samples to avoid multiple freeze-thaws.