Enzyme immunoassay for the quantitative determination of Cortisol in human serum and plasma. For research use only. Not for use in clinical diagnostic procedures.
Solid phase enzyme-linked immunosorbent assay (ELISA) based on the competition principle. An unknown amount of antigen present in the sample and a fixed amount of enzyme labelled antigen compete for the binding sites of the antibodies coated onto the wells. After incubation the wells are washed to stop the competition reaction. After the substrate reaction the intensity of the developed colour is inversely proportional to the amount of the antigen in the sample. Results of samples can be determined directly using the standard curve.
Cortisol (hydrocortisone, compound F) is the main glucocorticoid in humans and is produced in the zona fasciculata of the adrenal cortex. 90 % of the circulating cortisol are bound to corticoid binding globulin (CBG, Transcortin), ca. 7 % are bound to albumin and only 1–3 % are unbound. Only the latter part represents the active form of cortisol. In humans there is a physiological fluctuation of cortisol achieving the highest level in the morning and the lowest during midnight. This fluctuation of cortisol plasma level is reflected in saliva normally with a peak in the first 90 minutes after wake up.
For concrete data please consult the Instruction for Use in the download box on the right side.