Protein C
In the beginning, protein C inhibitor(PCI) was originally identified in human plasma by Griffin and Marlar and first isolation was performed by Suzuki et al. Protein C inhibitor (PCI) can be isolated from human plasma using an ordinary chromatographic procedure consisting of barium citrate adsorption, polyethylene glycol fractionation, DEAE-Sepharose CL-6B treatment, ammonium sulfate fractionation, dextran sulfate-agarose chromatography, gel filtration on ACA-44, and DEAE-Sephacel chromatography.