Thrombin enhances hemolytic activity of C5b,6 in serum-based assay. C5b,6 (200nM) was incubated alone or with either thrombin (500nM) or trypsin (500nM; as control) at 37°C for the indicated times. At the indicated time, an aliquot was prepared for SDS-PAGE analysis or diluted (2000-fold) to quantify residual C5b,6 activity using the serum-based hemolytic assay. C5b,6 alone (after 10 minutes of incubation) resulted in 23.8% ± 2.7% lysis and was arbitrarily given an activity of 1.0. Heat-denatured C5b,6 (10 minutes at 95°C) is shown as an additional control. Data are mean ± SD of 3 independent experiments each performed in quadruplicate. *P < .05.