Separation of fibrinogen from plasma proteases

A method of purifying fibrinogen, the method comprising:

• (a) extracting fibrinogen from a Fraction I precipitate by admixing the Fraction I precipitate with an extraction buffer such that fibrinogen is solubilised in the extraction buffer, wherein the extraction buffer comprises salt at a concentration of at least 0.1M;
• (b) precipitating the fibrinogen;
• and
• (c) solubilising the fibrinogen in a solution comprising at least one ω-amino acid at a concentration of at least 100 mM.

A method for purifying fibrinogen, which method comprises:

• (a) extracting fibrinogen from a fibrinogen containing material by admixing the material with an extraction buffer such that fibrinogen is solubilised in the extraction buffer, wherein the extraction buffer comprises at least one ω-amino acid at a concentration of at least 5 mM;
• (b) applying the extraction buffer from step (a) to an ion exchange matrix under conditions such that fibrinogen binds to the matrix;
• (c) eluting the fibrinogen from the matrix;
• and
• (d) optionally recovering the fibrinogen from the eluate.

A method of purifying fibrinogen from a fibrinogen containing solution, the method comprising:

• (a) applying the solution to an ion exchange matrix, under conditions such that fibrinogen binds to the matrix;
• (b) washing the ion exchange matrix with a solution comprising at least one ω-amino acid;
• (c) eluting the fibrinogen from the matrix;
• and
• (d) optionally recovering the fibrinogen from the eluate.