Concentrations of cortisol in saliva correlate with the amount of unbound (free) cortisol in serum or plasma (r > 0.90). Free cortisol is considered to be the biologically active fraction.

Saliva is easily collected into an absorbent cotton roll placed between the cheek and gum. Gently chewing the roll stimulates saliva flow and 0.5 – 1 ml can be collected in less than a minute.

Assay features ;
Elisa format with anti-cortisol coated solid-phase (96 well plate).
Enzyme (peroxidase) conjugate as label.
Colour developed using TMB as substrate and read at 450 nm in plate reader.

Antibody specificity, relative to cortisol as 100%;