This disclosure relates to a method which involves the steps of: (a) providing an aqueous solution comprising a protein and a polyalkoxy fatty acyl surfactant of general formula I

##STR00001##

wherein R.sup.1—C(═O) is a fatty acyl group, R.sup.2 is H or a substituted or unsubstituted hydrocarbyl group, X.sup.1 is S, O or NH, X.sup.2 is S, O or NH, n is 0 or an integer of 1-5, R.sup.3 is a polymeric group comprising polymerized units of general formula II and III

##STR00002##

(b) contacting the aqueous solution with a separation membrane, and (c) subjecting the aqueous solution to a diafiltration step and/or to an ultrafiltration step to produce a retentate product which is an aqueous solution comprising the protein, whereby the compound of formula I reduces aggregation of the protein in method steps (a)-(c) and whereby the compound of formula I passes through the separation membrane in step (c).

The present invention relates to an improved method of purifying an immunoglobulin, and more particularly to a method of purifying an immunoglobulin which is capable of sufficiently removing impurities from an immunoglobulin-containing plasma protein sample through a simple process, comprising a single anion-exchange chromatography and a single cation-exchange chromatography.

The present invention relates to an improved method of purifying an immunoglobulin, and more particularly to a method of purifying an immunoglobulin which is capable of sufficiently removing impurities from an immunoglobulin-containing plasma protein sample through a simple process, comprising a single anion-exchange chromatography and a single cation-exchange chromatography.

Method and system for purifying a sample comprising a biomolecule of interest and impurities, comprising expressing said biomolecule of interest in a bioreactor to form a product sample comprising said biomolecule of interest and impurities; subjecting said product sample to filtration to form a clarified product sample; subjecting said clarified product sample to affinity chromatography to remove impurities; subsequently subjecting said product sample to diafiltration followed by virus filtration and optional concentration. The buffer used during the diafiltration step (and thus in the virus filtration step) is the buffer desired for the final formulation of the product.

Method and system for purifying a sample comprising a biomolecule of interest and impurities, comprising expressing said biomolecule of interest in a bioreactor to form a product sample comprising said biomolecule of interest and impurities; subjecting said product sample to filtration to form a clarified product sample; subjecting said clarified product sample to affinity chromatography to remove impurities; subsequently subjecting said product sample to diafiltration followed by virus filtration and optional concentration. The buffer used during the diafiltration step (and thus in the virus filtration step) is the buffer desired for the final formulation of the product.

Methods of producing multiple protein products from blood-based materials including alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins are described herein. The inventive methods include steps of fractionation that utilize a combination of salt and organic solvent. Advantageously, the inventive methods are simple and produce alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins in high yields. The sequence of process steps can be selected to obtain multiple products from various in-process materials, such as supernatants, pastes, chromatography flow-though, and chromatography washes.

Methods of producing multiple protein products from blood-based materials including alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins are described herein. The inventive methods include steps of fractionation that utilize a combination of salt and organic solvent. Advantageously, the inventive methods are simple and produce alpha-1-proteinase inhibitor, gamma globulin, albumin, and other proteins in high yields. The sequence of process steps can be selected to obtain multiple products from various in-process materials, such as supernatants, pastes, chromatography flow-though, and chromatography washes.

The present disclosure provides a downstream manufacturing method for the production of bispecific antigen-binding molecule products, which comprise at least two different binding domains. The process comprises at least one filtration step, wherein the filtration is ultrafiltration/diafiltration (UF/DF), and/or viral filtration (VF), wherein a β-cyclodextrin is applied in the process either in a buffer applied in the filtration step or added to the filtration pool after the UF/DF filtration step wherein the buffer or the pool have a concentration of about 0.1 to 3% (m/v) of a (3-cyclodextrin, to preferably keep the product in a non-aggregated form.

The present disclosure provides a downstream manufacturing method for the production of bispecific antigen-binding molecule products, which comprise at least two different binding domains. The process comprises at least one filtration step, wherein the filtration is ultrafiltration/diafiltration (UF/DF), and/or viral filtration (VF), wherein a β-cyclodextrin is applied in the process either in a buffer applied in the filtration step or added to the filtration pool after the UF/DF filtration step wherein the buffer or the pool have a concentration of about 0.1 to 3% (m/v) of a (3-cyclodextrin, to preferably keep the product in a non-aggregated form.

The disclosure describes methods for the purification of protein-enriched extracts to provide concentrates and isolates and methods for incorporation of such materials into products. The purification methods are adapted for removal of, e.g., chlorophyll and may thus provide lightening the color of the protein-enriched extracts. The methods generally include treatment with peracetic acid or hydrogen peroxide and filtrations. A protein composition in the form of a concentrate or isolate is provided, the protein composition including RuBisCO, F2 fraction proteins, or combination thereof extracted from a plant material.