FIG 3 .

Binding of Fabs to live meningococci as measured by flow cytometry. The test strain was serogroup B strain H44/76 with FHbp ID 1 in variant group 1. (A) Binding of Fabs 1A (solid line) and 3C (dashed line) at 10 µg/ml. (B) Binding of the same Fabs at 2 µg/ml. (C) Binding of control chimeric human-mouse Fabs JAR 5 (solid line) and Fab 502 (dashed line) at 2 µg/ml. Bound Fab was detected with (Fab-specific) biotinylated goat anti-human IgG and streptavidin conjugated to phycoerythrin. Shaded gray histogram, bacteria without FH or Fab.