- CAN:
- EU:
- USA: For research use only. Not for use in diagnostic procedures.
The Free Estriol (also referred to as unconjugated estriol or uE3 in the literature) ELISA is a competitive immunoassay. Competition occurs between Estriol present in calibrators, controls and patient samples and an enzyme-labelled antigen (conjugate) for a limiting number of anti-Estriol antibody binding sites on the microplate wells. After a washing step that removes unbound materials, the enzyme substrate is added, and approximately 15–20 minutes later the enzymatic reaction is terminated by addition of stopping solution. The resulting optical density (OD), measured with a microplate reader, is inversely proportional to the concentration of Estriol in the sample. A calibrator curve is plotted with a provided set of calibrators to calculate directly the concentration of estriol in patient samples and controls.
Serum and salivary assays follow the same procedure except that the volume of the calibrators, controls and samples dispensed into the microplate wells is 10 μL for serum assays and 20 μL for salivary assays.