Fig. 3.

Characterization of E protein expressed by baculovirus. A Lysates of Sf9 cells infected by Bac-EGP64 (EG) were ultracentrifuged on a 15%–65% sucrose gradient, Bac-GP64 (WT) was used as a negative control. Two distinct bands were taken from top to bottom and assayed. B Western blot of a ZIKV E protein specific monoclonal antibody. C TEM of purified EG negatively stained with 1% phosphotungstic acid (a, scale bar = 1 μm; b, scale bar = 200 nm). D Immune Electron Microscopy (IEM) detection of purified baculovirus EG and WT by anti-E monoclonal antibodies. Gold particles are displayed on the surface of EG (a), and no gold particles are displayed on the surface of WT (b).