Immunofluorescence assay (IFA) BHK-21 cells at 80% confluency were infected at a multiplicity of infection (MOI) of 0.5 with DENV-2 (16681). After 2 days infection, the cells were fixed with 1:1 methanol/acetone for 10 min at 220uC. Cells were blocked using PBS supplemented with 1% BSA for 1 h at RT. Primary anti-DENV antibodies or control antibodies (normal mouse IgG, Jackson ImmunoResearch Laboratories) were diluted (1:250) in block solution for 1 h at RT. Secondary antibody, FITC-conjugated goat anti-mouse IgG