Immuno-electron microscopy of BV particles carrying scFvE2/p17 (BV-E2/p17). Samples of baculovirus progeny recovered from the culture medium of Sf9 cells infected with BV-E2/p17 and harvested at 72 h pi were deposited on grids and negatively stained with uranyl acetate. Specimens were reacted with anti-HA tag monoclonal antibody, followed by anti-mouse IgG antibody coupled to 20-nm colloidal gold grains. Different fields are presented in panels (a) to (f). Arrow in (a) points to a gold grain associated with a BV particle (BV). In (f), two gold grains are seen associated with one BV particle.