Salivary Cortisol ELISA Kit

Sample

Saliva

Species Reactivity

Universal

Detection Method

cELISA

Intended Use

The Cortisol Enzyme Immunoassay Kit is a competitive immunoassay specifically designed and validated for the quantitative measurement of salivary Cortisol. It is not intended for diagnostic use. It is intended only for research use in humans and some animals. CD has not validated this kit for serum or plasma samples.

Note:Please read the complete kit insert before performing this assay. Failure to follow kit procedure and recommendations for saliva collection and sample handling may result in unreliable values.

Storage

All unopened components of this kit are stable at 2-8°C until the kit's expiration date.

Precision

The intra-assay precision was determined from the mean of 20 replicates each.

The inter-assay precision was determined from the mean of average duplicates for 20 separate runs.

Sensitivity

Analytical Sensitivity
The lower limit of sensitivity was determined by interpolating the mean optical density minus 2 SDs of 10 sets of duplicates at the 0 μg/dL level. The minimal concentration of Cortisol that can be distinguished from 0 is 0.007 μg/dL.
Functional Sensitivity
The functional sensitivity was determined by assaying 60 saliva samples at a concentration level resulting in a CV of approximately 20%. The functional sensitivity of the salivary Cortisol ELISA is 0.018 μg/dL.
Correlation with Serum
The correlation between serum and saliva Cortisol was determined by assaying 49 matched samples using the Diagnostic Systems Laboratories Serum Cortisol EIA and the CD HS Salivary Cortisol EIA.
The correlation between saliva and serum was highly significant, r (47) = 0.91, p < 0.0001.

General Description

Cortisol (hydrocortisone, Compound F) is the major glucocorticoid produced in the adrenal cortex. Cortisol production has a circadian rhythm, with levels peaking in the early morning and dropping to lowest values at night. Levels rise independently of circadian rhythm in response to stress. In blood, only about 5-10% of Cortisol is in its unbound or biologically active form. The remaining Cortisol is bound to serum proteins. Unbound serum Cortisol enters saliva via intracellular mechanisms; in saliva, the majority of Cortisol remains unbound to protein. Salivary Cortisol levels are unaffected by salivary flow rate and are relatively resistant to degradation from enzymes or freeze-thaw cycles. Studies consistently report high correlations between serum and salivary Cortisol, indicating that salivary Cortisol levels reliably estimate serum Cortisol levels).

Internal CD Data, n=26. Time of Cortisol peak will vary in individuals relative to their normal wake-up time.