The Cortisol Quantitative Test is based on a widely used immunoassay technique. A sample (serum / plasma / urine) containing an unknown amount of cortisol to be assayed (unlabeled antigen) is added to a standard amount of a labeled derivative of the same substance (labeled antigen). The labeled and unlabeled antigens are then allowed to compete for high affinity binding sites on a limited number of antibodies coated on to the plate. After washing away the free antigen, the amount of labeled antigen in the sample is reversibly proportional to the concentration of the unlabeled antigen. The actual concentrations in unknown samples are obtained by means of a standard curve based on known concentrations of unlabeled antigen analyzed in parallel with the unknowns. In this kit an enzyme label is used. The biospecfic reaction takes place during 1 hour incubation. After washing away, substrate solution is added and the enzyme allowed to react for a fixed time before the reaction is terminated. Absorbencies are measured at 450 nm using ELISA plate reader. A standard curve is produced using values from 6 standards from which absorbency values for blank tubes have been subtracted. Results for unknown may be read directly from this standard curve using either manual calculation or by a suitable computer program.
This kit is suitable for the direct measurement of cortisol in serum/plasma/urine samples. It may also be used following an extraction procedure for assaying urinary cortisol (call for details of the procedure). Note: The cortisol levels should be established in your laboratory using your own set of samples and standards and good laboratory practice should be employed where applicable.
< Sensitivity >
The minimum detectable concentration of cortisol by this assay is estimated to be 2 ng/ml
1. Microtiter wells coated with cortisol specific antibody.
2. Enzyme labeled (HRP) Cortisol solution, 12mL.
3. TMB Color Reagent (One-step ready to use), 12 mL
4. Stop Solution (2N HCl), 6 mL
5. 20x Wash Buffer, 25 mL.
6. Sample diluent, 25mL
7. Cortisol Standards, 1 Set. (Contains 0, 5, 10,30,100,300,600 ng/mL).