Figure 1.

Electron micrographs of control (A) and biotinylated adenovirus (B). AdLuc was incubated with 100 μg/ml photoactivatable biotin and irradiated at a wavelength of 350 nm for 5 min; control virus was treated identically except for the addition of photoactivatable biotin. After incubation with colloidal gold-streptavidin, negative-stain immunoelectron microscopy was performed and photographs were taken at ×135,000.