Novel application of -inoculated chorioallantoic membrane to characterize a NP-specific monoclonal antibody for immunohistochemistry assaying.

Monoclonal antibodies (MAbs) are widely applied in disease diagnoses. Herein, we report a MAb, WF-4, against nucleoprotein (NP), its broad response with , and its application in an immunohistochemistry (IHC) assay. WF-4 was screened by immunofluorescence assay (IFA). The results showed that its reactivity with baculovirus-expressed full-length recombinant NP (rNP) in Western blot (WB), indicating its IHC applicability. Fifteen (reference subtypes H1 to H15) infected chicken embryonated chorioallantoic membranes (CAM), fixed by formalin, were all detectable in the WF-4-based IHC assay. Also, the reactivity of the IHC test with NP from experimentally inoculated H6N1 and from all recent outbreaks of H5 subtype avian (AIV) field cases in Taiwan showed positive results. Our data indicate that CAM, a by-product of preparation, is helpful for -specific MAb characterization, and that the WF-4 MAb recognizes conserved and linear epitopes of NP. Therefore, WF-4 is capable of detecting NP antigens via IHC and may be suitable for developing various tests for diagnosis of and, especially, AIV infection.