RP-HPLC analysis of pooled fractions from the Q Sepharose FF chromatography step (see Fig 1). The pooled top fractions, T and t, from the patient sample (upper panel) and the normal sample (lower panel), respectively, were applied to a C-4 column, eluted with a linear gradient of acetonitrile (dotted line), and the effluent monitored as the absorbance at 214 nm (data not shown) and 280 nm. Fractions were collected and analyzed for protein C(immunological). The fractions containing protein C (indicated by vertical arrows) were pooled and used for further studies.