Anti xrn1

A549 cells grown on Millicell EZ glass slide (Millipore) at 80% confluence were infected with WSN at an MOI of 2 for 4 to 8 h.p.i. or were transfected with 2 μg of the WSN NS1 clone. The cells were fixed in phosphate-buffered saline (PBS) containing 4% formaldehyde, permeated with 0.3% Triton X-100, blocked with 5% normal donkey serum for 1 h at 25°C, and then stained with anti-XRN1 (diluted 1:20; Santa Cruz), anti-WSN NS1 (diluted 1:100; NUS, anti-DCP1A (diluted 1:20; Santa Cruz), or anti-FLAG (diluted 1:100; Sigma) antibodies for 2 h at 37°C. Subsequently, the cells were stained with fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG (diluted 1:200; green, Invitrogen), goat anti-rabbit IgG (diluted 1:200; red, Invitrogen), or donkey anti-goat IgG (diluted 1:200; purple, Invitrogen) for 1 h at 25°C. The cells were washed three times with PBS and mounted in Vectashield antifade mounting medium with 4′,6′-diamidino-2-phenylindole (DAPI) (Vector Laboratories). Confocal images were obtained with a confocal laser-scanning microscope (Zeiss; LSM 700).