For many years, saliva has been used as a biological fluid for the detection of different biomarkers – for instance electrolytes, hormones, drugs and antibodies – in both human and veterinary medicine.
Saliva sample collection is non-invasive, painless and very convenient, particularly for the patient. Collecting a saliva sample is possible at any time, day or night, anywhere. Saliva collection can be undertaken in circumstances where blood collection is difficult or inadvisable.
The ability to evaluate a pooled saliva sample from multiple collections makes it possible to get a reliable assessment of the hormone concentration even when distinct diurnal fluctuations occur. Steroid hormone assessment from saliva allows for the specific determination of the biologically active or “free” fraction of the target hormone. Assays for salivary steroid determination must be extremely sensitive as the concentration of the biologically active, free fraction is significantly lower than the concentration of the total steroid in the serum.