Murine and humanized DB32-6 mAbs affinity analysis for E-DIII of DENV-2 was performed by surface plasmon resonance (BIAcore X, Biacore, Inc). Purified E-DIII (50 mg/ml) was immobilized on a CM5 sensor chip (Biacore, Inc) and injected at a flow rate of 10 ml/min. The mAbs were diluted to 4, 2, 1, 0.5, 0.25 and 0 nM in HBS-EP buffer (Biacore, Inc). mAbs were injected at a flow rate of 30 ml/min for 3 min and then allowed to dissociate over 1.5 min. Regeneration of the surface was achieved with an injection of 10 mM glycine HCl/0.2 M NaCl (pH 3.0) before each mAb injection. The data were analyzed by the BIAevaluation software with a global fit 1:1 binding model.