A mixture of 100 μL of normal or serpin-free human plasma and increasing concentrations of sulfated polysaccharide were incubated with 100 μL of APTT reagent. After 2 min of incubation at 37°C, 100 μL of 25 mM CaCl2 was added to the mixtures, and the clotting time was recorded. The results are expressed as ratios of clotting time in the presence (T1) and in the absence (T0) of sulfated polysaccharide. The panels show mean±SD, n=3. (A) *p < 0,05 for ▲, ■ or ○ vs. ●; (B) *p < 0,05 for ■ vs. ●; (C) NS, not significant (p > 0,05).