FIG. 3.

Electron microscopy of TGEV pseudoparticles. Particles secreted from RK13 cells coexpressing the M and E genes were purified by a procedure similar to that used for TGEV virions (see Materials and Methods). Particles were viewed after immunogold labeling with an anti-M ectodomain antibody and negative staining. The insert shows two pseudoparticles at a twofold-higher magnification.