Screening of mAbs against DENV1-4 by ELISA C6/36 cells at 80% confluency in 96-well plates were infected with DENV-1 to -4 to produce viral antigens. These cells were then harvested 5-7 days after infection. One mg/ml mAbs was added to the plates and incubated at room temperature (RT) for 1 h. After washing with PBS, horseradish peroxidase (HRP)-conjugated antimouse IgG (Jackson ImmunoResearch Laboratories) was incubated at RT for 1 h. Finally, plates were incubated with peroxidase substrate o-phenylenediamine dihydrochloride (OPD; Sigma-Aldrich). Reaction was stopped with 3N HCl and optical density was measured using a microplate reader set at 490 nm.