This assay employs a two-site sandwich ELISA to quantitate INHA in samples. An antibody specific for INHA has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any INHA present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for INHA is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-