The present invention is directed to a novel process for purifying a recombinant polypeptide from a solution comprising one or more impurities, wherein the process is a chromatography process which uses saccharin. The present invention also provides the use of saccharin in a process for purifying a recombinant polypeptide from a solution comprising one or more impurities, wherein the process is a chromatography process. The invention further provides a wash buffer for purifying using chromatography a recombinant polypeptide from a solution comprising one or more impurities, wherein the wash buffer comprises saccharin.

Disclosed herein are, inter alia, methods and compositions useful for detecting and/or quantifying host cell proteins during the production of a product, e.g., a recombinant protein, e.g., an antibody.

The present disclosure relates to methods of modifying the isoelectric point of an antibody. The method includes providing an antibody comprising a first polypeptide comprising a heavy chain variable region and a second polypeptide comprising heavy chain variable region and substituting, in at least one of the first and second polypeptides of the antibody, one or more amino acid residues of the heavy chain variable region (V.sub.H) at positions 7, 9, 11, 14, 41, 70, 74, 82a, 84, and 113, according to the Kabat numbering system, wherein the substituting increases or decreases the isoelectric point of the antibody.

Systems and methods for characterizing low molecular weight (LMW) protein drug product impurities are provided. One embodiment uses hydrophilic interaction chromatography (HILIC) coupled to mass spectrometry analysis. After removal of the N-linked glycans from the protein drug product, for example an antibody drug product, the elution of LMW impurities from the HILIC column was determined by the size of the molecular weight species. In some embodiments, the HILIC separation is performed under denaturing conditions, making the detection of LMW forms using this method highly comparable to both SDS-PAGE and CE-SDS methods. LMW drug product impurities include, but are not limited to light chain, half antibody, H2L, H2, HL, HC, peptide backbone-truncated species, and combinations thereof.

Provided herein are, inter alia, biological manufacturing and downstream purification processes.

The invention provides methods for using and compositions of humanized antibodies that bind tau protein that is phosphorylated at the serine at position 413.

The disclosure relates to chromatography ligands, e.g., chromatography ligands comprising at least two binding units and at least one spacer domain, wherein each binding unit comprises one or two immunoglobulin binding domains.

The present disclosure relates to proteins comprising a target-binding domain for detection of a target of interest, methods, compositions and kits thereof.

The present invention relates to a new and improved method for preparing a highly concentrated immunoglobulin composition from pooled plasma for subcutaneous injection. A composition comprising 20% or more immunoglobulin suitable for subcutaneous use is also described.

Chromatography resins having mixed mode ligands and methods of using such resins are provided.