FIGURE 2.

Influenza A viruses (IAV)-antigen detection and β-tubulin staining of MOC of Pekin duck (Du) and turkey (Tu) (Experiments 1 and 3). MOC were infected with H9N2, pH1N1 or H6N8 [10⁴ focus forming assay (FFU)/MOC] and collected at 12, 24, and 48 hours post infection (hpi). MOC sections were stained for IAV-nucleoprotein (FITC, green), β-tubulin (Cy3, red), and cell nuclei (DAPI, blue) and analyzed by fluorescence microscopy. Presented is a merge of three colors: red, green, and blue. IAV nucleoprotein was detected with mouse monoclonal antibodies which were visualized by secondary Alexa fluor^® 488 goat anti-mouse antibodies. Negative virus-negative controls consist of non-infected MOC-Ch. A representative picture of each species is shown.