Representative binding curve of antibody to mammalian expressed human interferon alpha/beta R1 protein and to 1% BSA/PBS in a Direct Binding ELISA. High-binding polystyrene plates were coated with either 1 μg/ml of human interferon alpha/beta R1 protein or 1% BSA/PBS. Thereafter, titrations of the product were added to the wells. Goat anti-mouse IgG conjugated to HRP was used as the detection antibody. Colorimetric detection was performed using 3,3',5,5'-Tetramethylbenzidine (TMB) substrate. The HRP-TMB reaction was stopped using a diluted H₂SO₄/HCl solution.