FIG. 4.

Replication in BHK-21 cells of FMDV clones unable to bind heparin. p100c10 and p100RGG denote FMDV C-S8c1p100c10 and C-S8c1p100RGG, respectively; their origins are described in Materials and Methods. The five clones selected for the inability to bind heparin, termed hs-c1 through hs-c5, were selected as detailed in the text (3). Infections of BHK-21 cell monolayers were carried out at a multiplicity of infection of 5 PFU per cell. Procedures for infection in liquid culture and titration of infectivity are described in Materials and Methods. One representative experiment of three is shown for the parental p100c10 and p100RGG viruses.