Anti-DENV-2 mAbs were generated according to previously described procedures [28, 29] . Female 4-to 6-week-old BALB/c mice were immunized with 10 7 plaque-forming units (pfu) of DENV-2 (16681). The DENV-2 was purified from viral culture supernatant using 4G2 (an anti-E protein mAb)-coupled protein G-Sepharose 4 Fast Flow gel. After four inoculations with the same concentration of antigens, the splenocytes from the immunized mouse spleen were harvested and then fused with mouse myeloma NS-1 cells. Fused cells were cultured in DMEM supplemented with 15% FBS, HAT medium and hybridoma cloning factor (Roche) in 96-well tissue culture plates. Two weeks after fusion, culture supernatants were screened by ELISA. Selected clones were subcloned by limiting dilutions. Hybridoma clones were isotyped using a commercially isotyping kit (Southern Biotech) by ELISA. Ascites fluids were produced in pristine-primed BALB/c mice. mAbs were affinity-purified by standard protein G-Sepharose 4 Fast Flow (GE Healthcare Bio-Sciences) according to manufacturer's directions.