Disclosed are methods by which compounds/molecules capable of binding antigens, for example antibody type compounds/molecules, can be purified, extracted and/or selected. The methods may be used to purify, extract or select a specific type (or types) of binding agent from a mixed composition. The methods may be used to extract or purify specific binding agents from mixed compositions, which compositions comprise other agents capable of binding other antigens. The methods may find particular application as methods for the purification of blood group antigen antibodies.

Compositions and methods are provided that simplify isolation of proteins of interest from serum or plasma. Finely divided silica or a similar lipid/lipoprotein binding solid is used in combination with a protein precipitating agent to generate a solution that includes the protein of interest and that can be applied to chromatography media without resulting in significant fouling of the media. The method is particularly suitable for isolation of immunoglobulin G.

A process for the preparation of pharmaceutically acceptable immunoglobulin compositions from plasma-derived immunoglobulin fractions which allows the parallel preparation of immunoglobulin compositions enriched in IgG, IgM and IgA. In this process, immunoglobulin contained in Cohn fraction I/II/III or Kistler Nitschmann fraction A+I is resolubilized at conductivities of at least 1 mS/cm, and following removal of contaminating protein the resolubilized immunoglobulin is subjected to anion exchange chromatography to obtain IgG- and IgM/IgA-enriched immunoglobulin compositions. The IgG-enriched immunoglobulin composition is further subjected to treatment with a cation exchange material to obtain an immunoglobulin composition having a reduced properdin content.

The invention relates to a method of isolating an immunoglobulin, comprising the steps of: a) providing a separation matrix comprising multimers of immunoglobulin-binding alkali-stabilized Protein A domains covalently coupled to a porous support: b) contacting a liquid sample comprising an immunoglobulin with the separation matrix; c) washing said separation matrix with a washing liquid; d) eluting the immunoglobulin from the separation matrix with an elution liquid, and e) cleaning the separation matrix with a cleaning liquid, wherein the alkali-stabilized Protein A domains comprise mutants of a parental Fc-binding domain of Staphylococcus Protein A (SpA).

Methods of sequencing a protein using a novel digestion-on-emitter technology are provided.

Purified recombinant polypeptides isolated from Chinese hamster ovary host cells, including antibodies, such as therapeutic antibodies, and methods of making and using such polypeptides are provided.

The invention relates to means and methods of producing at least two antibodies. Methods may include providing cells with nucleic acid that encodes the antibodies; culturing said cells; collecting the antibodies from the culture; and separating produced antibodies from half antibodies by ion exchange chromatography (IEX). In some embodiments the antibodies exhibit IEX retention times that that deviate by 10% or less from the average of the retention times of the individual antibodies under the IEX conditions used. The invention also relates to compositions of antibodies thus produced. In some aspects the invention relates to compositions comprising 2-10 recombinant antibodies characterized in that the IEX retention times of at least two of said antibodies deviate by 10% or less from the average of the retention times of the individual antibodies under the IEX conditions. It also relates to compositions comprising 2-10 recombinant antibodies characterized in that the pI of at least two of said antibodies differ by 0.4 units or less from the average pI of said at least two antibodies.

The present invention relates to a Streptococcus pneumoniae antiserum without cross-reactivity and method for producing the same, more specifically, it relates to a method for producing a S. pneumoniae antiserum comprising the step of removing cross-reactivity using S. pneumoniae and a S. pneumoniae antiserum prepared by the method. The Streptococcus pneumoniae antiserum prepared according to the method of the present invention has very high specificity for a particular serotype, since the cross-reactivity with S. pneumoniae of serotypes expressing capsular polysaccharides of similar structure is removed. Therefore, it can be very useful in the related art that requires accurate quantification of S. pneumoniae capsular polysaccharide.

The invention discloses a separation matrix which comprises a plurality of separation ligands, defined by the formula R.sub.1-L.sub.1-N(R.sub.3)-L.sub.2-R, immobilized on a support, wherein R.sub.1 is a five- or six-membered, substituted or non-substituted ring structure or a hydroxyethyl or hydroxypropyl group; L.sub.1 is either a methylene group or a covalent bond; R.sub.2 is a five- or six-membered, substituted or non-substituted ring structure; L.sub.2 is either a methylene group or a covalent bond; R.sub.3 is a methyl group; and wherein if R.sub.1 is a hydroxyethyl group and L.sub.1 is a covalent bond, R.sub.2 is a substituted aromatic ring structure or a substituted or non-substituted aliphatic ring structure.

D2C7-(scdsFv)-PE38KDEL (D2C7-IT) is a recombinant Pseudomonas exotoxin A-based immunotoxin (IT), targeting both wild-type epidermal growth factor receptor (EGFRwt) and mutant EGFR variant III (EGFRvIII) proteins overexpressed in glioblastomas. A good laboratory practice (GLP) manufacturing process was developed to produce sufficient material for a Phase I/II clinical trial. D2C7-IT was expressed under the control of the T7 promoter in Escherichia coli BLR (λ DE31). D2C7-IT was produced by a 10 L batch fermentation process and was then purified from inclusion bodies using anion exchange, size exclusion, and an endotoxin removal process that achieved a yield of over 300 mg of purified protein.