Figure 2

Selection of complement source. 176 strain was tested for survival at different baby rabbit or guinea pig serum concentrations (12.5%, 25%, 50%) for 60 min. Bacteria without complement and bacteria with heat-inactivated complement (dilution factor 50%) were used as negative control. The results are expressed as % survival at 60 min. The means and standard errors from 3 independent experiments are shown. Error bars represent the SD.