Epitope binning is a process of in vitro mAb characterization where a pair of mAbs are assessed for their differential binding site on an antigen. For anti-IDs, epitope binning was performed using an Octet Red 384 instrument. Therapeutic antibody was immobilized onto human IgG Fc sensors at 2 µg/mL for 180 seconds. Next, the biosensors were dipped into wells containing the 1 st saturation anti-ID (200 nM) with an association phase of 240 seconds. Then the biosensors were dipped into wells containing the competing antibody, also known as the 2 nd anti-ID at a concentration of 200 nM. If the second antibody binds, then it belongs to a different bin. The antibody interaction was reported as the percentage of binding response, comparing the antibody binding signal against the buffer only signal.