Provided is a high-loading and alkali-resistant protein A magnetic bead. The magnetic bead can maintain chemical stability under pH 2-14 and has an immunoglobulin G (IgG) binding capacity greater than 50 mg/mL. Further provided is a method for purifying and/or detecting an immunoglobulin, comprising a step of contacting a sample containing the immunoglobulin with the high-loading and alkali-resistant protein A magnetic bead. The alkali-resistant protein A magnetic bead can realize rapid purification of immunoglobulin, saving about 80% of treatment time and reducing total purification costs by 50%. In addition, the alkali-resistant protein A magnetic bead has high alkali resistance. An alkaline method for in situ cleaning can be performed to regenerate the magnetic bead after use. The magnetic bead has rapid magnetic response and good dispersiveness, realizing rapid magnetic bead enrichment, cleaning, and elution. The magnetic bead facilitates automated, high-throughput, and large volume purification of a sample.

The present invention concerns a method of storing a separation matrix comprising multimers of immunoglobulin-binding alkali-stabilized Protein A domains covalently coupled to a porous support. The method comprises the steps of: a) providing a storage liquid comprising at least 50% by volume of an aqueous alkali metal hydroxide solution; b) permeating the separation matrix with the storage liquid; and c) storing the storage liquid-permeated separation matrix for a storage time of at least days. The alkali-stabilized Protein A domains comprise mutants of a parental Fc-binding domain of Staphylococcus Protein A (SpA), as defined by, or having at least 80% such as at least 90%, 95% or 98% identity to, SEQ ID NO 51 or SEQ ID NO 52, wherein the amino acid residues at positions 13 and 44 of SEQ ID NO 51 or 52 are asparagines and wherein at least the asparagine residue at position 3 of SEQ ID NO 51 or 52 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.

The present invention relates to a chromatography ligand, which comprises Domain C from Staphylococcus protein A (SpA), or a functional fragment or variant thereof. The chromatography ligand presents an advantageous capability of withstanding harsh cleaning in place (CIF) conditions, and is capable of binding Fab fragments of antibodies. The ligand may be provided with a terminal coupling group, such as arginine or cysteine, to facilitate its coupling to an insoluble carrier such as beads or a membrane. The invention also relates process of using the ligand in isolation of antibodies, and to a purification protocol which may include washing steps and/or regeneration with alkali.

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:8, SEQ ID NO 26 or SEQ ID NO 27, wherein at least the alanine residue at the position corresponding to position 42 in SEQ ID NO:4-7 has been mutated to arginine and/or wherein at least the aspartic acid residue at the position corresponding to position 37 in SEQ ID NO:4-7 has been mutated to glutamic acid.

A mixed mode affinity chromatography carrier includes a substrate, a hydrophilic polymer, an antibody-binding cyclic peptide, and a cation exchange group.

Compositions and methods are described for self-assembled polymer materials having at least one of macro, meso, or micro pores.

A composition and a method for culturing cells. The composition includes a plurality of buoyant hollow particles, the buoyant hollow particles comprising a siliceous surface; and a plurality of mammalian cells attached to the siliceous surface of the buoyant hollow particles; wherein the buoyant hollow particles are less dense than a media; and wherein the average seeding density is 3-50 adherent cells/buoyant hollow particle.

The present invention relates to a method and/or device for improving the separation behaviors and performance of aqueous two-phase system (ATPS) for the isolation and/or concentration of one or more target analytes from a sample. In one embodiment, the present method and device comprise ATPS components within a porous material and one or more phase separation behavior modifying agents that improve the separation behavior and performance characteristics of ATPS, including but not limited to the increasing the stability or reducing fluctuations of ATPS thought the adjustment of total volume of a sample solution that undergoes phase separation, volume ratio of the two phases of the ATPS, fluid flow rates, and concentrations of ATPS components.

The present invention provides a lectin-magnetic carrier coupling complex for separating glycosylated exosomes from a clinical sample. The lectin-magnetic carrier coupling complex comprises a magnetic carrier and lectins coupled to the outer side of the magnetic carrier. The lectin-magnetic carrier coupling complex provided by the present invention may rapidly, accurately, and automatically separate glycosylated exosomes from a clinical sample with a high separation efficiency; and the separated exosomes are intact in morphology without rupturing or cracking, may be directly used for liquid detection of glycosylated exosomes, or directly used for immunology-related detection, or directly used for nucleotide sequence detection and analysis after extracting nucleic acids from the exosomes.

A separation matrix comprising porous particles to which antibody-binding protein ligands have been covalently immobilized, wherein the density of said ligands is above 5 mg/ml, the volume-weighted median diameter of said porous particles is at least 10 and below 30 μm and the said porous particles have a gel phase distribution coefficient, expressed as K.sub.D for dextran of molecular weight 110 kDa, of 0.5-0.9.