The present invention provides matched antibody pairs for the specific detection of one or more of the four dengue virus serotypes in a biological sample that may contain one or more of such dengue virus serotypes. Each matched antibody pair is capable of detecting not more than one serotype of dengue virus NS1 protein that may be present in the sample and will not cross react with other serotypes that may be present in the sample. Multiple matched pairs may be used to detect one or more dengue virus serotypes that may be present in a sample. Such matched pair antibodies, facilitate the development of confirmatory in vitro diagnostic tests such as sandwich immunoassays, that detect and distinguish the presence of one or more dengue virus serotypes in a biological sample, preferably a sample derived from human subject. The invention also provides kits comprising the matched antibody pairs of the invention and methods for using the kits for immunoassays for the specific detection of one or more serotypes of dengue virus in a patient population. The present invention also provides monoclonal antibodies specific for the NS1 protein of dengue virus and therapeutic compositions and methods for treating dengue virus infection.