FIG. 5.

Particles released into the media upon coexpression of SV5 proteins resemble authentic SV5 virions. (A) MDBK cells were infected with rSV5, and virions were purified on sucrose gradients as described in Materials and Methods. (B to F) 293T cells were cotransfected with plasmids encoding the SV5 M, NP, and HN proteins (B to D) or M, NP, and F proteins (E and F). VLPs were pelleted from the culture media through 35% sucrose cushions. Virions and VLPs were adsorbed onto carbon-coated grids, negatively stained, and visualized by electron microscopy. Arrowheads indicate nucleocapsid-like structures that were occasionally observed in VLP preparations.