RESUMO
A panel of hybridomas producing monoclonal antibodies (MAbs) to nucleocapsid protein (NP) of avian influenza A virus was obtained. On the basis of 2 MAbs, the authors designed an antigen-bound ELISA (sandwich ELISA), in which NP3 MAbs were used as antigen-bound antibodies and NP MAbs conjugated with horse radish peroxidase as antigen detection antibodies. The specificity of the test system to avian influenza virus was determined. The developed test system was ascertained to specifically detect influenza A virus of all study subtypes and to yield no cross reactions with other tested virus pathogens. The sensitivity of the sandwich ELISA was 30 ng/ml of NP in the urine-treated virus preparations. The assay was tested on experimental H5N1-infected mice. The findings positively correlated with the results of postmortem studies and with the virus isolation method in the chick embryos. The developed test system may be used to detect avian influenza A virus as an alternative or supplement to other diagnostic techniques.
