FIG. 4.

Growth kinetics and expression of NS2-3 and NS3 after infection with CSFV strains CP G1 and Alfort-p447. (A) Growth curves of cp CSFV CP G1 and noncp CSFV Alfort-p447 determined on SK6 cells infected at a multiplicity of infection (MOI) of 0.3. The titers of released virus were determined at the indicated time points over a 3-day period. (B) Immunoblot analysis of SK6 cells infected with CP G1 or Alfort-p447 at an MOI of 0.3. Cells were lysed 24 hpi. The samples were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions, transferred to a nitrocellulose membrane, and analyzed by using an anti-NS3 monoclonal antibody. Note the large amount of NS3 derived from cells infected with CP G1. Marker proteins are indicated in kilodaltons (kDa) on the left. The positions of NS2-3 and NS3 are marked with arrows. n.i., noninfected SK6 cells.