Objective     To assess functional affinity of rhEndoglin conjugated eptide in order to identify the affinity.      Methods     We measured the functional affinity of rhEndoglin conjugated eptide with non-competitive ELISA method. After coating the peptide by BSA binding with glutaral couple

affirming the best concentration

best time of peptide to coat the plate and the coating coefficient

and the proper binding time of peptide to Endoglin to reach an equilibrium

we plotted the standard curve of the binding reaction of peptide and Endoglin.      Results     The affinity constant of peptide and anti-hEndoglin IgG is respectively (2.956±0.749)×10

6

mol/L and (7.403±10.76) ×10

8

mol/L.      Conclusion     The peptide we got from the peptide liberary can strongly bind to Endoglin

providing a theoretical basis for its clinical use.