Fig. 4.

RVG incorporation into recombinant virus particles. (A) SDS-PAGE of recombinant and vector virus particles. rL and rL-RVG were propagated in eggs and purified by differential centrifugation and sedimentation through 40%-to-60% (wt/vol) sucrose gradients. Viral proteins were analyzed by using SDS-PAGE with 10% gels under reducing conditions (I) and were subjected to Western blot analyses with mouse serum against RV (II). (B) Electron microscopy of recombinant and vector virus particles. rL or rL-RVG propagated in eggs was prepared and partially purified by centrifugation through 20% sucrose. Viruses were stained with IgG purified from mouse naïve serum (ab, antibody), mouse serum against NDV, or mouse serum against RV and with goat anti-mouse IgG conjugated with colloidal gold and then negatively stained.