Cortisol ELISA Assay Kit


The Eagle Biosciences Cortisol ELISA Assay Kit (enzyme-linked immunoassay kit) is intended for the quantitative determination of Cortisol in human serum by an enzyme immunoassay. The Cortisol ELISA Assay Kit is for research use only and not to be used in diagnostic procedures.

SKU: COR31-K01 Categories: , ,

Cortisol ELISA Assay Kit

For Research Use Only

Size: 1×96 wells
Sensitivity: 0.4 μg/dL
Dynamic Range: 0.5–60 μg/dL
Incubation Time: 65 minutes
Sample Type: Serum
Sample Size: 20 µL

Controls Included

Additional Information

Assay Background

Cortisol is the most abundant circulating steroid and the major glucocorticoid secreted by the adrenal cortex. Cortisol is physiologically effective in blood pressure maintenance and anti-inflammatory activity. It is also involved in calcium absorption, gluconeogenesis as well as the secretion of gastric acid and pepsin. Measurement of blood cortisol levels can be used as an indicator of adrenal function and the differential diagnosis of Addison’s and Cushing’s diseases as well as adrenal hyperplasia and carcinoma. Most circulating cortisol is bound to cortisol binding globulin or transcortin. Therefore, the free cortisol concentration excreted in the urine is very small, and the 24-hour collection of urine is a must in order to obtain an accurate measurement of urinary cortisol. Cortisol in blood shows a diurnal rhythm with the highest levels in the morning and the lowest levels at night.

Assay Principle

The principle of the following enzyme immunoassay test follows the typical competitive binding scenario. Competition occurs between an unlabelled antigen (present in standards, controls and patient samples) and an enzyme-labelled antigen (conjugate) for a limited number of antibody binding sites on the microplate. The washing and decanting procedures remove unbound materials. After the washing step, the enzyme substrate is added. The enzymatic reaction is terminated by addition of the stopping solution. The absorbance is measured on a microtiter plate reader. The intensity of the colour formed is inversely proportional to the concentration of cortisol in the sample. A set of standards is used to plot a standard curve from which the amount of cortisol in patient samples and controls can be directly read.

Typical Standard Curve


Product Manual



Elliott, Alexandra Lauren (2019) The Upright Go Wearable Posture Device: An Evaluation of Postural Health, Improvement of Posture, and Salivary Cortisol Fluctuations in College Students. Undergraduate thesis, under the direction of Carol Britson from Biological Sciences, University of Mississippi.