FIG. 4.

Vaccinia virus virions bind to the heparin-Sepharose beads in vitro. Different amounts of purified vaccinia virus virions, as indicated at the bottom of the figure, were incubated with heparin-Sepharose beads at 4°C for 60 min as described in Materials and Methods. The unbound virions were collected in the supernatant, and the titers were determined. The data shown on the y axis were obtained by the following formula % Bound = [1-(PFU_supernatant/PFU_input)] × 100.