Since the recognition property of the antibody could affect the detected minimum epitope distance of the analyte in the sandwich immunoassay, the recognition properties of 17 mAbs for model analytes were evaluated using ciELISA (Supplementary Tables and). For mAbs from haptens M3, M4, N3, and N4, a clear increase in mAb affinity for MN1-MN7 was observed as the epitope distance of the model analyte increased from 2.4 Å to 13.9 Å but decreased for MN8 and MN9 with longer epitope distances of 16.4 Å and 19.0 Å, respectively. The trends of mAbs 5A3, 10A9, and 4E1 from haptens N1 and N2 were not obvious, comparably recognizing all tested model analytes; however, mAbs 7F2, 1E2, and 2F5 from haptens N5 and N6