Figure 1

mAb-PN9cx3 recognizes heterogeneous isolates of both PRRSV-1 and PRRSV-2 species in immunofluorescence assays. MARC-145 cells were infected with PRRSVs at an MOI of 1 for 24 h, fixed in 4% paraformaldehyde and permeabilized with 0.5% Triton X-100 prior to incubation with a cocktail containing mAb-PN9cx3 hybridoma supernatant and PBS-diluted PRRSV convalescent swine serum (1:200 dilution). After a 1-h incubation, the interactions between the primary antibodies and targets were revealed by the binding of Alexa Fluor®555-labelled goat anti-mouse IgG (H + L) (red) and FITC-labelled goat anti-swine IgG (green). Uninfected MARC-145 cells (MOCK) served as a negative control. The PRRSV strains used for infection included three HP-PRRSV isolates (SD16, Accession No. JX087437.1; JXA1, GenBank Accession No. EF112445.1; and GD-HD, Accession No. KP793736.1), a PRRSV-2 prototype strain (VR2332, GenBank Accession No. EF536003.1), the NADC30-like Chinese isolate HNhx (GenBank: KX766379), and a Chinese PRRSV-1 isolate (GZ11, GenBank Accession No. KF001144.1).