A method for filtering a protein-containing liquid containing protein at a concentration of 20 mg/mL or more and 100 mg/mL or less, the method including a prefiltration step of filtering the protein-containing liquid by a prefilter having a pore size of 0.08 μm to 0.25 μm and including a hydrophobic resin, and a virus removal step of filtering the protein-containing liquid by a virus removal membrane including a synthetic polymer, after the prefiltration step, wherein the protein-containing liquid before conducting the prefiltration step includes 0.25 g or more of a trimer or higher multimer of the proteins having an average diameter of less than 100 nm, per 1 m.sup.2 of the virus removal membrane.

An objective is to provide an Fc-modified antibody or the like having a long serum half-life according to a CCAP method, more specifically, an antibody or the like where IgBP is bound to only one site, based on findings of the inventors. Provided is an objective antibody or the like by purification and production of an Fc-modified antibody or the like with a column bound to an Fc region of an antibody. Specifically, an antibody where only one of two binding sites of Fc is selectively modified is provided by allowing an IgBP-bound antibody produced by a CCAP method to adsorb to a carrier of an IgBP-immobilized column, or forming a state where only one Fc of an antibody is bound to an IgBP binding column and then adding a peptide reagent for CCAP to the column to perform a reaction of a CCAP method in the column.

This invention relates to the general field of recombinant expression of polypeptides in animal cell culture. More specifically, the invention concerns improved selection of cells transfected with recombinantly engineered vectors designed to express polypeptides, in particular heteromultimeric polypeptides.

The present invention relates to a method of purifying a recombinant polypeptide from Host Cell Proteins (HCP), the method comprising: (a) applying a solution comprising the recombinant polypeptide and HCP to a superantigen chromatography solid support, (b) washing the superantigen chromatography solid support with a wash buffer comprising caprylate and arginine; and (c) eluting the recombinant polypeptide from the superantigen chromatography solid support.

In certain embodiments, the present invention provides novel antibody purification methods and systems using a potentially simple and cost-efficient means. In some embodiments, customized Z-33 derived from Staphylococcus aureus Protein A is used to construct immuno-amphiphile molecules which can assemble into immunofibers in aqueous solution with bioactive epitopes on the surface and have IgG binding ability.

The invention describes a method of generating antibodies to a mixture of peptidogenic proteins wherein the peptidogenic protein has altered conformational dynamics as compared to a starting protein and wherein the peptidogenic protein has a similar conformation to the starting protein. The peptidogenic proteins can be used to induce an immune response, which can lead to the generation of antibodies and/or can be used to vaccinate a mammal.

The present disclosure relates to, inter alia, a method of quantitating an amount of an antibody molecule from a mixture comprising two or more antibody molecules, comprising separating each of the two or more antibody molecules from the mixture by hydrophobic interaction chromatography high performance liquid chromatography (HIC-HPLC) and quantitating an amount of each antibody molecule, wherein the molecular weight of each antibody molecule is within 15 kDa of any other antibody molecule in the mixture and either each antibody molecule is different from another antibody molecule in the mixture by more than about 0.25 unit on the Kyte & Doolittle hydropathy scale or each of the antibody molecules when nm alone on HIC-HPLC elutes at distinct run time with little overlap from the other antibody molecules in the mixture, or both.

The present invention is directed to methods for using particles (e.g, microparticulate, nanoparticulate; magnetic, non-magnetic) comprising surfaces comprising capture moieties as described herein, to remove an interference as described herein, or enrich biomarkers, especially antibodies, prior to a diagnostic test, or to be isolated and used for prophylactic or therapeutic purposes.

The invention provides a method for producing a host cell protein-(HCP) reduced antibody preparation from a mixture comprising an antibody and at least one HCP, comprising an ion exchange separation step wherein the mixture is subjected to a first ion exchange material, such that the HCP-reduced antibody preparation is obtained.

There is provided, inter alia, an aqueous solution comprising (i) an antibody protein; and (ii) a antibody protein stabilizing mixture of arginine, methionine, and a C3 polyol.