Effect of anti-C5 and anti-C5a on bacterial killing in whole blood. Bacterial counts on blood-agar plates 24 hours after seeding 100 μL whole blood incubated for different time intervals with live log-phase N meningitidis H44/76 in the absence or presence of anti-C5 (clone 137-76), anti-C5a (clone 137-26), and isotype control antibody. Median results of duplicate experiments with 2 different donors are presented.