Abstract: A method for depletion or removal of endotoxins from a known or suspected endotoxin-containing source by virtue of a solid phase extraction material in an essentially aqueous system comprising the steps of—providing a known or suspected endotoxin-containing source, —contacting the known or suspected endotoxin-containing source with a positively charged solid phase material having a surface on which ferric iron is immobilised, wherein the solid phase extraction material has immobilised the ferric iron by (2-aminoethyl)amine (TREN) ligand—incubating the known or suspected endotoxin-containing source for a period of time sufficient to bind endotoxin to the porous solid phase material, —separating the solid phase material from the essentially aqueous system, —optionally isolating the essentially aqueous system freed or depleted from endotoxin.

Abstract: This application describes compositions, kits, and methods for removing contaminants from a protein preparation, for example a cell culture harvest comprising a recombinant protein. The methods described herein can enhance the performance of a later applied chromatographic purification step. The method generally involves contacting a protein preparation comprising a desired protein with a combination of allantoin, a cationic polymer, and a fatty acid, thereby causing the formation of solids and removal of the solids using a suitable process. Further treatment by contacting the treated sample with a chemically reactive surface further enhances results achieved by the first purification step.

Abstract: This application describes compositions, kits, and methods for removing contaminants from a protein preparation, for example a cell culture harvest comprising a recombinant protein. The methods described herein can enhance the performance of a later applied chromatographic purification step. The method generally involves contacting a protein preparation comprising a desired protein with a combination of allantoin, a cationic polymer, and a fatty acid, thereby causing the formation of solids and removal of the solids using a suitable process. Further treatment by contacting the treated sample with a chemically reactive surface further enhances results achieved by the first purification step.

Abstract: Provided herein is a novel method of purifying an IgG antibody from a preparation by use of an electropositive membrane having a defined porosity.

Abstract: A method of reducing the aggregate content in a preparation having a target protein includes contacting the preparation with an aryl anion to form a mixture and contacting the mixture with at least one electropositive solid to remove excess aryl anion.

Abstract: Methods are provided for enhancing reduction of virus and viral DNA levels in protein preparations.

Abstract: Methods are provided for extracting DNA-compaction proteins from biological samples.

Abstract: A method of purifying a desired protein from a preparation includes providing the preparation in a form having less than about 5% of the chromatin residing in the original production medium, contacting the preparation with a nonionic organic polymer in an amount sufficient to cause the desired protein to precipitate or adsorb on a nonionic hydrophilic surface, and adjusting a salt concentration before or during the contacting step, the adjusting step providing a sufficient salt concentration to produce a conductivity greater than physiological conductivity.

Abstract: A method of purifying a target protein includes contacting a cell culture harvest or a protein preparation including at least one target protein with at least one fatty acid having 8 to 10 carbon atoms to form a mixture, contacting the mixture with one or more solids to form a mixture, the one or more solids comprise a cationic functional group, a metal binding functional group, or both, the metal binding functional group including a nitrogen-containing moiety selected from (1) a polyamine, (2) an imine, (3) an N-heterocycle, (4) an amino acid, (5) an N-hydroxyamide, (6), an arylamine, and combinations thereof, and separating solid materials after contacting the mixture with the one or more solids to provide a solution comprising the target protein.

Abstract: A method of purifying a target antibody includes contacting a cell culture harvest or a protein preparation including at least one target antibody with at least one fatty acid having 7 to 10 carbon atoms to form a mixture, contacting this mixture with allantoin, and then separating solid materials to provide a solution comprising the target antibody. Solid materials can be removed by filtration, sedimentation or centrifugation, and the fatty acids can be enanthic, caprylic, pelargonic, nonenoic or capric acid. The invention is also directed to kits used to facilitate this method of antibody purification.

Abstract: A method of purifying a desired protein from a preparation includes (a) providing the preparation in a form having less than about 5% of chromatin residing in an original production medium, (b) contacting the preparation with a nonionic organic polymer and a salt, a concentration of nonionic organic polymer being sufficient to precipitate the desired protein or cause its accretion on a hydrophilic surface, or maintain it in a precipitated state or accreted on the hydrophilic surface, the salt concentration being sufficient to produce greater than physiological conductivity, and (c) contacting the preparation with at least one electropositive surface, optionally in the presence of a salt concentration sufficient to produce greater than physiological conductivity, the desired protein does not substantially adsorb to the at least one electropositive surface while not preventing adsorption of acidic contaminants to the at least one electropositive surface.

Abstract: Methods for reduction of aggregate levels in antibody and other protein preparations comprising the steps of treatment with an organic multivalent cation (e.g., ethacridine, chlorhexidine, or polyethylenimine) and treatment with a composition having a combination of surfaces bearing electronegative chemical moieties and surfaces bearing electropositive chemical moieties.

Abstract: A method of reducing aggregate content in a preparation having a target protein includes contacting the preparation with an alkyl cation to form a mixture, and contacting the mixture with at least one functionalized solid to remove excess alkyl cation.

Abstract: Methods for the improved purification of antibodies and other proteins from protein preparations including the steps of conditioning the protein preparation by contacting it with multivalent organic ions, then applying the conditioned preparation to an adsorptive chromatography medium.

Abstract: A method for the purification of a desired protein from a protein preparation includes conditioning the protein preparation by treatment with soluble organic multivalent ions, immobilized organic multivalent ions, or both, optionally in the presence of supersaturated allantoin, thereby removing at least 90% of chromatin, then (1) precipitating the desired protein with a nonionic organic polymer in the presence of non-protein-precipitating salts at greater than physiological concentration to provide a precipitate of the desired protein; or (2) precipitating the desired protein with a nonionic organic polymer in the absence of non-precipitating salts at greater than physiological concentration to provide a precipitate and subsequently washing the precipitate with a nonionic organic polymer in the presence of non-protein-precipitating salts at greater than physiological concentration.

Abstract: A method of reducing the aggregate content in a protein preparation having a target protein includes contacting the protein preparation with a thio-heterocyclic cation to form a mixture, contacting the mixture with at least one functionalized solid to remove excess thio-heterocyclic cations; and optionally contacting the mixture, simultaneously or sequentially, with at least one further functionalized solid to further reduce aggregate content of the protein preparation.

Abstract: A method of reducing aggregate and product-contaminant complex content in a protein preparation including a desired protein includes (i) contacting the protein preparation with at least one solid surface comprising at least one surface-bound ligand capable of binding a metal, the surface-bound ligand being capable of binding a metal is initially substantially devoid of a metal, the operating conditions are selected to substantially prevent the binding of the desired protein to the at least one solid surface and (ii) separating the protein preparation from the surface-bound ligand, such that when more than one surface-bound ligand is present, each surface-bound ligand is independently either of the same net charge or charge neutral.

Abstract: A method of isolating exosomes includes conducting at least one purification step in the presence of an organic zwitterion having a molecular weight of less than about 350 Daltons, a buffering pK of a negatively charged portion of the organic zwitterion is at least one full pH unit below an operating pH at which the at least one purification step is conducted, and a buffering pK of the positively charged portion of the organic zwitterion is at least one full pH unit above the operating pH.

Abstract: A method of purifying a sample that includes a desired virus includes the steps of (i) providing a packed chromatographic column having negatively charged porous particles, (ii) equilibrating the column to the conditions to which the desired virus in the sample is to elute, (iii) contacting the sample with the packed chromatographic column such that the sample volume applied to the packed chromatographic column is less than or equal to the interparticle space of the negatively charged porous particles within the packed chromatographic column, (iv) eluting the desired virus from the packed chromatographic column, where the desired virus is in a purer state and in the conditions to which the packed chromatographic column was equilibrated.

Abstract: Materials and methods for use of constrained cohydration agents in the purification of biological materials such as antibodies, viruses, cells, and cellular organelles in connection with convective chromatography, fluidized bed or co-precipitation applications.