An Fc-binding polypeptide of improved alkali stability, comprising a mutant of an Fc-binding domain of Staphylococcus Protein A (SpA), as defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:22, SEQ ID NO 51 or SEQ ID NO 52 wherein at least the asparagine or serine residue at the position corresponding to position 11 in SEQ ID NO:4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.

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.

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

The current invention reports a method for purifying an immunoglobulin, wherein the method comprises applying an aqueous, buffered solution comprising an immunoglobulin in monomeric and in aggregated form to a cation exchange material under conditions whereby the immunoglobulin in monomeric form does not bind to the cation exchange material, and recovering the immunoglobulin in monomeric form from the solution after the contact with the cation exchange material.

The present application relates to antibodies that bind to small molecules such as cyclophosphamide, ifosfamide, and analogs thereof, and immunological assays for determining the presence and/or quantifying the amount of cyclophosphamide and/or ifosfamide in a sample. By way of example, such immunological assays can be used for environmental testing.

The present disclosure provides modified proteins that are capable of being cleaved by the protease OmpT1. The proteins can be modified in an exposed surface motif to incorporate OmpT1 cleavage sites. Also provided are nucleic acids encoding the modified proteins, bacterial cells that express the modified proteins, and cell free synthesis systems containing modified RF1. The disclosure further provides methods for reducing the deleterious activity of a modified protein in a cell free synthesis system by contacting the modified protein with OmpT1. Also provided are methods for reducing RF1 competition at an amber codon in the cell free synthesis system, and methods for expressing a protein in the cell free synthesis system. The modified proteins of the invention can be used to increase the yield of proteins having non-natural amino acids incorporated at an amber codon.

The invention provides a process of purification of antibody or fusion protein from protein mixture comprising product and process related impurities. The process provides the use of hydroxyapatite chromatography for the separation of low molecular weight impurities and basic variants. In addition, invention further provides a scalable purification process to remove product and process related impurities.

A process for purification of antibody or fusion protein through anion exchange chromatography to produce an antibody or fusion protein which is substantially free of at least one of the product-related impurities.

A process for purification of antibody or fusion protein by affinity chromatography wherein the elution is performed with high salt concentration which reduce turbidity in protein mixture during neutralization steps. The present invention provides an improved process of purifying antibodies through affinity chromatography using high salt-based elution.

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