This assay employs the competitive inhibition enzyme immunoassay technique. An antibody specific for fT4 has been pre-coated onto a microplate. Standards or samples and a biotin-conjugated antibody specific for fT4 are pipetted into the wells. A competitive inhibition reaction is launched between fT4 (Standards or samples) and biotin-conjugated fT4 with the pre-coated antibody specific for fT4. After washing, streptavidin conjugated Horseradish Peroxidase (HRP) is added
to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a
substrate solution is added to the wells and color develops in proportion to the
amount of fT4 bound in the initial step. The color development is stopped and the
intensity of the color is measured.
