title: Fluorescent antibody techniques applied to the identification of dengue virus in infected tissue.
abstract: We evaluated an indirect fluorescent antibody (FA) method for the detection of dengue virus antigen in infected mouse tissues. The biotin-avidin system [unlabeled antiviral antibody, biotinyl-anti-IgG and fluorescein conjugated avidin D(biotin-avidin system)] theoretically enhances the sensitivity of the FA method by amplifying the number of fluorescein particles attached indirectly to antigen. Using antibody endpoint titers in dengue-infected suckling mouse brain as an assay for sensitivity, we compared this three-step technique with the standard direct and two-step indirect FA techniques. Comparative tests were done on frozen sections of mouse brains with infectivity titers between 4.5 and 8.3 log10 LLC-MK2 cell PFU/g. Antibody endpoint titers with the biotin-avidin system were 2- to 8-fold higher than those obtained with the indirect and direct fluorescent antibody systems. The biotin-avidin system may be useful for rapid postmortem diagnosis of some fatal dengue hemorrhagic fever-dengue shock syndrome cases and perhaps also for early diagnosis of dengue by examination of leukocytes or biopsy material.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis*; D001360:Avidin / Q000276:immunology; D001710:Biotin / Q000276:immunology; D003715:Dengue / Q000382:microbiology*; D003716:Dengue Virus / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D007074:Immunoglobulin G / Q000032:analysis; D051379:Mice
chemical_list: D000956:Antigens, Viral; D007074:Immunoglobulin G; D001360:Avidin; D001710:Biotin