This assay employs the quantitative sandwich enzyme immunoassay technique. Antibody specific for SERPINB4 has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any SERPINB4 present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for SERPINB4 is added to the wells. After washing, avidin 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 SERPINB4 bound in the initial step. The color development is stopped and the intensity of the color is measured.