Cortisol, Saliva, Human, BioAssay ELISA Kit

£943.00 96 Tests

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. It is increased under stress situations , physical exercise and external administration of ACTH. Measurement of cortisol levels in general 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 and albumin. The free cortisol, which is considered the active part of blood, is about 1-2%. In the absence of appreciable amounts of the cortisol binding proteins in saliva , salivary cortisol is considered to be free and shows a diurnal rhythm with the highest levels in the morning and the lowest levels at night.

Principle of the Test:
The assay is carried out following a typical competitive ELISA format. Competition occurs between an unlabeled antigen (present in standards, control and patient samples) and an enzyme-labeled antigen (conjugate) for a limited number of antibody binding sites on the microwell plate. 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.

SKU: USC7904-22 Categories: ,

Additional information

Intended Use

This kit is intended for the determination of cortisol in human saliva by competitive ELISA.

Detection Range





CV <11%


CV <10%

Kit Components

C7904-22A: Microtiter Strip, 1×96 wells. Coated with polyclonal antibody against cortisol.
C7904-22B: Cortisol (HRP), 50X, 1x300ul. Cortisol-HRP conjugate in a protein-based buffer with a non-mercury preservative. Preparation: Dilute 1:50 in assay buffer before use (eg. 40ul of HRP in 2 ml of assay buffer). If the whole plate is to be used dilute 240ul of HRP in 12ml of assay buffer. Discard any that is left over.
*C7904-22C1: Low Control, 11.1(7.7-12.8ng/ml) 1x600ul
*C7904-22C2: High Control, 54.4(38-63.3ng/ml)1x600ul
Cortisol in a protein-based buffer with a non-mercury preservative. Prepared by spiking buffer with a defined quantity of cortisol. Refer to vial label for expected value and acceptable range. Stability: Once opened, the control should be used within 14 days or aliquoted and stored frozen. Avoid multiple freezing and thawing cycles.
*C7904-22D1: Calibrator A, 0ng/ml cortisol, 1x2ml
*C7904-22D2: Calibrator B, 1ng/ml cortisol, 1x600ul
*C7904-22D3: Calibrator C, 3ng/ml cortisol, 1x600ul
*C7904-22D4: Calibrator D, 10ng/ml cortisol,1x600ul
*C7904-22D5: Calibrator E, 30ng/ml cortisol, 1x600ul
*C7904-22D6: Calibrator F, 100ng/ml cortisol, 1x600ul
Note: Once opened, the calibrators should be used within 14 days or aliquoted and stored frozen. Avoid multiple freezing and thawing cycles.
C7904-22E: Wash Buffer, 10X, 1x50ml
Preparation: Dilute 1:10 in distilled or deionized water before use. If the whole plate is to be used dilute 50ml of the wash buffer concentrate in 450ml of water.
C7904-22F: Assay Buffer, 1x15ml. Ready to use. Protein-based buffer with a non-mercury preservative.
C7904-22G: TMB Substrate, 1x16ml. Ready to use. Tetramethylbenzidine and hydrogen peroxide in a non-DMF or DMSO containing buffer.
C7904-22H: Stop Solution, 1x6ml. Ready to use. 1M sulfuric acid. Caution: Corrosive!

Storage and Stability

Store *C7904-22C and *C7904-22D at 4°C until opened. Once opened aliquot and store at -20°C. Store other components at 4°C. Stable for 6 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.

Shipping Temperature

On Dry Ice

Shelf Life

6 Months