The invention relates to a Protein A chromatography step of a purification process for a therapeutic protein, wherein a load solution including the therapeutic protein is applied onto a Protein A chromatography medium. According to the invention, a solution comprising CaCl.sub.2 is used as a wash solution for the Protein A chromatography medium for enhancing the removal of lipases, in particular phospholipase B-like 2 (PLBL2). The invention is of particular interest for the purification of CHO-expressed antibodies, such as tanezumab.

The present disclosure provides an analysis method for measuring the content of light chain-exchanged molecules in a composition containing a multi-specific antigen-binding molecule. The analysis method of the present disclosure includes the steps of: treating a composition comprising a multi-specific antigen-binding molecule and preparing a plurality of types of F(ab) fragments; and measuring the F(ab) fragments by a separation method based on electric charge or hydrophobic interactions and determining the content (content ratio) of each fragment.

Described is a method for preparing an Immunoglobulin G (IgG) enriched fraction from a C1-INH depleted plasma supernatant. Isolation of Immunoglobulin G (IgG) enriched fraction from a C1-INH depleted plasma supernatant provided an alternative starting material for the manufacturing process. In the present invention, C1-INH depleted plasma supernatant is treated with heparin before further processing.

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

Molecules, including antibodies and antigen-binding fragments thereof that specifically bind to a linker peptide, and methods of producing and using the described antibodies and antigen-binding fragments are presented herein. Also presented herein methods of generating antibodies that specifically bind to an immunorecessive epitope.

A hybridoma cell line of secreting cyproheptadine monoclonal antibodies with a preservation number of CGMCC No. 14699 belongs to the field of food safety immunological detection. BALB/c mice are immunized through one time immunization with complete freund's adjuvant, three times of booster immunization with incomplete freund's adjuvant and one time of rush immunization with cyproheptadine complete antigen without adjuvant; the spleen cells from BALB/C mice immunized with high potency and low value of IC50 are fused with murine myeloma cells; and then the hybridoma cell line is obtained through indirect competitive ELISA screening and three sub-clones. The monoclonal antibody secreted by this cell line has good specificity and detection sensitivity to cyproheptadine (value of IC50 is 0.37 ng/ml), being suitable for detection of cyproheptadine in food.

The present disclosure relates to an improved method for the manufacture of polypeptides comprising at least three or at least four immunoglobulin single variable domains (ISVDs). More specifically, an improved method is provided of producing, purifying and isolating polypeptides comprising at least three or at least four ISVDs in which an undesired product-related conformational variant is reduced or absent.

Methods and reagents to obtaining a sample enriched in peptides comprising the third complementarity-determining region of the heavy chain (CDRH3) of immunoglobulins, such as IgGs, are described. These methods are based on the use of targeted protease digestion of immunoglobulins and affinity purification of CDRH3 peptides using specific antibodies. Such methods and reagents are useful for analyzing the immunoglobulin repertoire.

The present disclosure relates to a method for the purification of a human IgG-CH1 domain comprising molecule using an antigen-binding protein that is capable of binding to an epitope that is comprised in the CH1 domain of each of human IgG1, human IgG2, human IgG3 and human IgG4. The disclosure further relates to the antigen-binding proteins that can be used in the method of the disclosure. The frame-work regions of the antigen-binding proteins of the invention preferably correspond to those of antibodies that naturally are devoid of light chains as may e.g. be found in camelids. The disclosure further relates to nucleic acids that encode such antigen-binding proteins, to immunoadsorbent materials that comprise such proteins, and to the uses of such immunoadsorbent materials for the purification of IgG-CH1 domain containing molecules from a variety of species.

A method for refolding an antibody, a process for producing a refolded antibody, a refolded antibody, and uses thereof are provided. A method for refolding an antibody in a liquid phase comprises the steps of denaturing an inactive antibody binding directly or through a linker to a peptide, the peptide having an isoelectric point lower than the isoelectric point of the inactive antibody, and dispersing in a liquid phase the peptide-binding inactive antibody denatured in the step above. Also provided is a process for producing a refolded antibody.