The Anti-Dengue virus NS3 antibody detects the viral non-structural protein 3 (NS3) of all four DENV serotypes. While the DENV viral caspid, premembrane, envelope and NS1 proteins are secreted, the NS3 protease/helicase is cytoplasmically localized and does not enter the secretory pathway. Thus the anti-dengue virus NS3 antibody can be used to label DENV-infected cells but not uninfected cells that bind viral particles.