FIG. 2.
CCHFV growth in the absence (−) of SKI-1/S1P or S2P. SRD12B cells (top, SKI-1/S1P−) or M19 cells (bottom, S2P−) were infected with CCHFV strain IbAr10200 at a multiplicity of infection of 0.5. Cells were fixed with 4% paraformaldehyde at the indicated times postinfection and irradiated with 2 × 106 rads. Fixed cells were permeabilized with 0.5% Triton X-100 and processed by IFA with CCHFV hyperimmune mouse ascitic fluid developed against CCHFV IbAr10200, as described earlier (22), and anti-mouse Alexa 594 antibody (Invitrogen). Images were acquired with a 20× objective.