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.

Abstract: A method includes (i) adding allantoin in a supersaturating amount to a protein preparation including a desired protein and at least one endotoxin as a contaminant, (ii) removing solids after the adding step to provide a sample for further purification by void exclusion chromatography on a packed particle bed of electropositive particles in a column, the packed particle bed having an interparticle volume, (iii) applying a sample volume to the packed particle bed, wherein the electropositive particles support void exclusion chromatography, and wherein the sample volume is not greater than the interparticle volume, and (iv) eluting a purified sample including the desired protein and a reduced amount of the endotoxin. The method is optionally carried out with only the allantoin treatment or only the void exclusion chromatography.

Abstract: Methods and apparatus for purification of biological molecules using combinations of tangential flow filtration subunits and adsorption sub-units in a single apparatus where the subunits may be operated independently or in series and where the apparatus and methods are suitable for use in a wide range of formats distinct from conditions required for chromatographic processes such as conducting process steps using adsorption subunits for purification of a biological molecule in a contaminated sample without prior buffer equilibration.

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: 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 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: 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: 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 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 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: 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 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: 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 includes (i) adding allantoin in a supersaturating amount to a protein preparation including a desired protein and at least one endotoxin as a contaminant, (ii) removing solids after the adding step to provide a sample for further purification by void exclusion chromatography on a packed particle bed of electropositive particles in a column, the packed particle bed having an interparticle volume, (iii) applying a sample volume to the packed particle bed, wherein the electropositive particles support void exclusion chromatography, and wherein the sample volume is not greater than the interparticle volume, and (iv) eluting a purified sample including the desired protein and a reduced amount of the endotoxin. The method is optionally carried out with only the allantoin treatment or only the void exclusion chromatography.

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: A composition for reducing the aggregate content of a protein preparation includes a first substrate having a first surface-bound ligand possessing a metal affinity functionality, the metal affmity functionality being substantially devoid of a metal, and an additional surface-bound ligand different from the first surface-bound ligand, the additional surface-bound ligand having an aggregate charge not opposite to that of the metal affinity functionality, optionally the additional surface-bound ligand is provided on an additional substrate such that the composition comprises a mixture of the first substrate and the additional substrate.

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 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 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.