Figure 2

Infection of MDCK cells by different influenza A virus strains. Immunocytometric detection of cells stained with antibodies against influenza A virus M1 and NP. (I): uninfected cells; (II): cells infected with equine influenza A virus H3N8 (18 h p.i.); (III): cells infected with porcine influenza A virus H1N5 (18 h p.i.); (IV): cells infected with human influenza A virus H1N1 (18 h p.i.).