FIG. 8.

The AdC68 R1 mutant resists neutralization by polyclonal antisera. Particles (6 × 10⁷) of GFP-expressing wild-type (black circles) or CDQ mutant (black squares) virus or Ad5 control virus (white squares) (0.5 to 0.6 infectious units per cell) were incubated with serial dilutions of rabbit (A) or rhesus macaque (B) anti-AdC68 polyclonal antiserum for 1 h at 37°C then added to HEK-293 cells. After 48 h, cells expressing GFP were counted in a flow cytometer. Arrows indicate the 50% neutralization point in each experiment.