To ascertain the binding specificity of D29 Fab-IgG, direct binding ELISA against dengue virus was performed using standard ELISA methods. Briefly, 2610 5 pfu/well purified DENV1-4 was coated on Maxisorb plate followed by blocking using 5% SM. Following incubation with 1 mg/ml dengue-specific antibodies, plates were probed with HRP-conjugated anti-human IgG-Fc secondary antibody or anti-mouse IgG-Fc secondary antibody (Pierce). Detection steps in subsequent ELISAs followed this method unless otherwise stated. To determine the binding affinity of D29 Fab-IgG direct binding ELISA was performed with serially diluted D29 Fab-IgG. Results were fitted to a one-site binding hyperbola using Prism 5.03 (GraphPad, San Diego, USA).