FIG. 3.

(A) Total hemolytic complement activity of NHS, NHS depleted of C1q (C1q depleted), and C1q-depleted serum reconstituted with C1q (C1q depleted+C1q). EA were incubated with serum and the percentage of EA lysed was determined. (B) gC1-null and gC2-null viruses are neutralized by the classical complement pathway. Neutralization experiments were performed with 20% NHS that was C1q depleted or reconstituted. Results shown represent mean titers ± standard deviations of three independent experiments. P < 0.02, comparing heat-inactivated NHS and either NHS or C1q-restored serum for NS-gC1null and G-gC2null. In contrast, values are not significant, P = 0.23 and 0.86, comparing heat-inactivated NHS with C1q-depleted serum for NS-gC1null and G-gC2null, respectively.