A new method of purifying fibrinogen with both biological and immunological activity from human plasma

Using a combination of Cohn ethanol fractionation, virus inactivation, glycine and sodium chloride precipitation, and lysine-Sepharose affinity chromatography, a unique and rapid simplified method was developed to obtain highly purified fibrinogen for diagnostic use with both biological (Clauss method) and immunological (Jacobsson method) activity. Yield was 0.66 g of fibrinogen per liter of starting pooled plasma, and the purified product showed good agreement in activity with the starting material. The purified fibrinogen solution contained over 95% clottable protein and had a clear appearance. No degradation was observed after urokinase treatment and the preparation provided good precision in fibrinogen measurement compared to pooled plasma. The simplified method was, thus, shown to result in a high-purity fibrinogen preparation, suitable for in vitro diagnostic use, as well as for use to prepare a fibrinogen reference material and to perform fibrinogen quality control using an automated coagulation analyzer.