The invention provides processes for producing preparations (e.g., plasma preparations or fibrinogen (Fg)-depleted preparations) containing one or more proteins (e.g., plasma proteins). Processes of the invention can be used to obtain enriched preparations of one or more proteins (e.g., Fg, immunoglobulin (Ig； e.g., IgG), alpha-1 proteinase inhibitor (A1 PI), albumin, plasminogen, prothrombin complex, and/or other plasma proteins). Multiple enriched preparations can be obtained from a single sample (e.g., a whole blood or plasma sample) using the processes of the invention.
