251results about "Chromatographic anion exchangers" patented technology

The present invention relates to a method for protein purification that involves the combination of non-affinity chromatography with HPTFF.

The present invention provides a positively charged microporous membrane having a protein binding capacity about 25 mg / ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

A method for adsorption of a substance from a liquid sample on a fluidized bead or stirred suspension, in which the beads used comprise a base matrix and exhibit a structure having affinity to the substance, characterized in that the structure is covalently bound to the base matrix via an extender. Populations of beads in which the beads contain a filler incorporated in a base matrix and an extender are also described.

PCT No. PCT / SE97 / 00237 Sec. 371 Date Dec. 29, 1998 Sec. 102(e) Date Dec. 29, 1998 PCT Filed Feb. 14, 1997 PCT Pub. No. WO97 / 29825 PCT Pub. Date Aug. 21, 1997Process for separating off a peptide or a nucleic acid by an anion exchanger (I) characterized in that a) the anion exchanger (I) exhibits ligands, which (i) contain a primary, secondary or tertiary amino group and (ii) are covalently bound to an organic polymer (matrix), b) there on a carbon atom at a distance of 2 or 3 atoms away from an amino nitrogen in the ligands is a hydroxyl group or a primary, secondary or tertiary amino group, and c) the maximum elution ionic strength in the pH range 2-14 for at least one of the proteins transferrin, ovalbumin 1, ovalbumin 2, beta -lactoglobulin 1 and beta -lactoglobulin 2 on the anion exchanger is higher than the elution ionic strength required for a quaternary comparative ion exchanger.

The present invention relates to a method of separating antibodies from other compound(s) in a liquid sample, wherein a mobile phase comprising said sample is contacted with a multi-modal separation matrix to adsorb undesired compounds while the antibodies remain free in the liquid, wherein the multi-modal separation matrix comprises first groups, which are capable of interacting with negatively charged sites of the target compounds, and second groups, which are capable of at least one interaction other than charge-charge interaction with said target compounds. The invention also relates to a chromatography column packed with the above-described multi-modal separation matrix and a filter having such multi-modal groups adsorbed to its surface.

Novel material for chromatographic separations, processes for its preparation, and separations devices containing the chromatographic material. In particular, the disclosure describes porous inorganic / organic hybrid particles having a chromatographically-enhancing pore geometry, which desirably may be surface modified, and that offer more efficient chromatographic separations than that known in the art.

A method for the removal of a substance carrying a negative charge and being present in an aqueous liquid (I). The method comprises the steps of: (i) contacting the liquid with a matrix carrying a plurality of ligands comprising a positively charged structure and a hydrophobic structure, and (ii) desorbing the substance. The characterizing feature is that (I) each of said ligands together with a spacer has the formula: -SP-[Ar-R1-N<+>(R2R3R4)] where (A) [Ar-R1-N<+>(R2R3R4)] represents a ligand a) Ar is an aromatic ring, b) R1 is [(L)nR'1]m where n and m are integers selected amongst zero or 1; L is amino nitrogen, ether oxygen or thioether sulphur; R'1 is a linker selected among 1) hydrocarbon groups; 2) -C(=NH)-; c) R2-4 are selected among hydrogen and alkyls; (B) SP is a spacer providing a carbon or a heteroatom directly attached to Ar-R1-N<+>(R2R3R4); (C)-represents that SP replaces a hydrogen in (Ar-R1-N<+>(R2R3R4); (D)-represents binding to the matrix; and (II) desorption. There is also described (a) anion-exchangers having high breakthrough capacities, (b) a screening method and (c) a desalting protocol.

The present invention provides a positively charged microporous membrane having a protein binding capacity of about 25 mg / ml or greater comprising a hydrophilic porous substrate and a crosslinked coating that provides a fixed positive charge to the membrane. The present invention further provides a positively charged microporous membrane comprising a porous substrate and a crosslinked coating comprising pendant cationic groups. The membranes of the present invention find use in a variety of applications including ion-exchange chromatography, macromolecular transfer, as well as detection, filtration and purification of biomolecules such as proteins, nucleic acids, endotoxins, and the like.

A novel sorbent suitable for use as a stationary phase in a chromatography column, the core of which consists of an organic polymer of synthetic or natural origin. Further, the carrier exhibits a plurality of covalently bonded non-aromatic zwitterionic groups on its surface. Additionally, the invention also relates to a method for purifying a particular biological macromolecule, such as a protein or a nucleic acid, by zwitterionic ion exchange chromatography as well as an ion exchange column suitable for use in the zwitterionic ion exchange chromatography.

The present invention relates to mixed-modal anion-exchange materials composed of a support on which a ligand is immobilized. The ligand combines at least one basic domain based on cyclic monobasic derivatives with two or more rings as anion-exchange domain and at least one non-ionic binding domain. The basic domain is ionized under the conditions of use and may contain secondary, tertiary, or quaternary nitrogen forming a weakly (WAX) or strongly (SAX) basic anionic exchange domains. The non-ionic binding domain allows adjustment of the overall hydrophobicity / hydrophilicity of the material and represents a second binding site for the solute to be separated. Binding to this second binding site is based on reversed phase (RP), hydrophobic interaction (HIC) or hydrophilic interaction (HILIC). Linker sites, which can be represented by a chemical bond or by hydrophobic moieties like alkyl(ene) chains or hydrophilic moieties like amide structures connect the support to the binding domains and the binding domains to each other.

A method for making an ion exchange coating (e.g., a chromatographic medium) on a substrate comprising (a) reacting at least a first amine compound comprising amino groups, with at least a first polyfunctional compound, in the presence of a substrate to form a first condensation polymer reaction product, with a first unreacted excess of either at least said first amino group or polyfunctional compound functional moieties, irreversibly attached to the substrate, and (b) reacting at least a second amine compound or at least a second polyfunctional compound with unreacted excess in the first condensation polymer reaction product to form a second condensation polymer reaction product, and repeating the steps to produce the desired coating. A coated ion exchange substrate so made.

The present invention relates to a method of separating sugars and sugar alcohols from each other. More particularly the present invention relates to the use of a weakly basic anion exchange resin in a chromatographic separation process. The advantage of the present invention compared with the prior art is that it is especially suitable for separating reducing sugars in acidic conditions as well as for example in weakly acidic conditions. The method using chromatographic separation comprises at least one step where a weakly basic anion exchange resin is used in a chromatographic column or in a part of a column.

The present invention relates to a chromatography ligand defined by the following formula (I) R1—R2—N(R3)—R4—R5 wherein R1 is a substituted or non-substituted phenyl group; R2 is a hydrocarbon chain comprising 0-4 carbon atoms; R3 is a hydrocarbon chain comprising 1-3 carbon atoms; R4 is a hydrocarbon chain comprising 1-5 carbon atoms; and R5 is OH or H. The invention also comprises a separation matrix, comprising the described ligands coupled to a porous support, such as particles or a membrane. The ligand and matrix according to the invention is useful for purification of biomolecules or organic compounds, such as proteins, polypeptides, DNA etc. An advantageous use according to the invention is the purification of antibodies.

The present invention provides novel and improved protein purification processes which incorporate certain types of carbonaceous materials and result in effective and selective removal of certain undesirable impurities without adversely effecting the yield of the desired protein product.

A method for making an ion exchange coating (e.g., a chromatographic medium) on a substrate comprising (a) reacting at least a first amine compound comprising amino groups, with at least a first polyfunctional compound, in the presence of a substrate to form a first condensation polymer reaction product, with a first unreacted excess of either at least said first amino group or polyfunctional compound functional moieties, irreversibly attached to the substrate, and (b) reacting at least a second amine compound or at least a second polyfunctional compound with unreacted excess in the first condensation polymer reaction product to form a second condensation polymer reaction product, and repeating the steps to produce the desired coating. A coated ion exchange substrate so made.

To provide chromatographic packings whereby biological components, etc. which cannot be separated by either ion-exchange chromatography or reversed phase chromatography employed alone can be efficiently separated without deteriorating their activities. Use is made of a packing which contains a charged copolymer and makes it possible to change the effective charge density on the surface of a stationary phase by a physical stimulus while fixing a mobile phase to an aqueous system.

Permeable polymeric monolithic materials are prepared in a plastic column casing. In one embodiment, the permeable polymeric monolithic materials are polymerized by the application of heat from an external source starting at a low temperature such as 40 degrees centigrade, depending on the mixture and size of the column, and continuing at a higher temperature, such as 60 degrees centigrade. The temperature at the start of the polymerization is low enough so as not to cause exothermal run-away conditions and to avoid high heat of reaction that would prevent a substantially constant temperature across the cross-section of the column. The higher temperature is used after sufficient monomer depletion has occurred and steric interference has increased so the polymerization reaction is sufficiently slow to avoid heat of reaction generation high enough to cause significant reduction in the homogeneousness of the pore sizes.

Embodiments of the present invention are directed to porous materials for use in solid phase extractions and chromatography. The materials feature at least one hydrophobic component, at least one hydrophilic component and at least one ion-exchange functional group. The materials exhibit superior wetting and ion-exchange performance.

The present invention is a surface-modified base matrix comprised of a porous polymeric base matrix onto which branched hydrophilic polyhydroxy-functional polymers have been covalently attached, wherein the polyhydroxy-functional polymers are hyperbranched polymers presenting a degree of branching (DB) of at least about 0.2 and each polymer is tethered to the base matrix at two or more points. The present matrix can for example be a cross-linked carbohydrate material, such as agarose, and the hyperbranched hydrophilic polymer can e.g. be a copolymer of epichlorohydrin and a sugar. The invention also relates to a method of surface-modification of a porous base matrix by activating functional hydroxy groups thereon and contacting the activated matrix with a hydrophilic hyperbranched hydroxy-functional polymer.

The present invention relates to a method of separating antibodies from other compound(s) in a liquid sample, wherein a mobile phase comprising said sample is contacted with a multi-modal separation matrix to adsorb undesired compounds while the antibodies remain free in the liquid, wherein the multi-modal separation matrix comprises first groups, which are capable of interacting with negatively charged sites of the target compounds, and second groups, which are capable of at least one interaction other than charge-charge interaction with said target compounds. The invention also relates to a chromatography column packed with the above-described multi-modal separation matrix and a filter having such multi-modal groups adsorbed to its surface

The present invention provides a new design for high capacity stationary phases for dianion selective ion chromatography. The stationary phases include one or more layers which are products of condensation polymerization. Multiple components are of use in forming the first polymer layer and the condensation polymer structure, thereby providing a stationary phase that can be engineered to have a desired property such as ion capacity, ion selectivity, and the like. Exemplary condensation polymers are formed by the reaction of at least one polyfunctional compound with at least one compound of complimentary reactivity, e.g., a nucleophilic polyfunctional compound reacting with an electrophilic compound.

Treatment of anion exchange materials containing hydroxyl containing moieties in the beta position relative to the quaternary center in the hydroxide form with glycidol substantially alters the selectivity of the anion exchange material. Furthermore, sequential treatments of first a hydroxide containing solution to put the anion exchange material in the hydroxide form followed by treatment with glycidol in an alternating sequence progressively changes selectivity in a predictable manner allowing facile manipulation of selectivity. Unique to the selectivities achievable with this chemistry is the ability to reverse the elution order of sulfate and carbonate. With all other known systems, carbonate elutes ahead of sulfate and sometimes compromises the ability to quantitate sulfate. With glycidol treatment, carbonate can be moved after sulfate which eliminates interference issues for samples containing significantly more carbonate than sulfate. This modification is useful for columns operated with a hydroxide or carbonate eluent system.

An exemplary multimodal chromatographic medium of the invention includes one or more strong anion exchange, weak anion exchange, strong cation exchange and / or weak cation exchange binding sites in combination with one or more reverse phase and / or hydrophilic interaction chromatography binding site. In an exemplary embodiment, the sites interact with one or more glycans in a mixture of glycans in a manner that allows separation of glycans in the mixture and analysis of the glycan mixture. The media are incorporated into devices and systems for chromatographic analysis. Also provided are methods of using the multimodal media of the invention to analyze glycans.

The invention provides novel materials for chromatography and chromatography columns. The invention provides a monofunctional silane chemically bonded to a substrate, the monofunctional silane has two groups, R, and R′, the monofunctional silane being of the form: where the R groups are independently selected from the group consisting of alkenyl, alkynyl, and phenyl, R′ is selected form the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, aryl, substituted aryl, alkylamine, amide, ether, alcohol, cabamate, ester, an anion exchanger, and a cation exchange. Methods for manufacture and design of the columns are also provided and disclosed.

Described are composite materials and methods of using them for mixed-mode chromatography. In certain embodiments, the composite material comprises a support member, comprising a plurality of pores extending through the support member; and a multi-functional cross-linked gel. The multi-functional cross-linked gel possesses at least two of the following functions or characteristics: cationic, anionic, hydrophobic, hydrophilic, thiophilic, hydrogen bond donating, hydrogen bond accepting, pi-pi bond donating, pi-pi bond accepting, or metal chelating. The composite materials may be used in the separation or purification of a biological molecule or biological ion.

A liquid chromatography agglomerated bed comprising component A comprising (a) substrate particles and polymer chains (e.g. a condensation polymer) bound to the substrate particles and projecting therefrom, and (b) component B comprising substrate particles having external surfaces of opposite charge to that of the charged polymer chains, components A and B being bound at least in part by electrostatic forces between the component A charged polymer chains and the component B external surfaces to form in composite an agglomerated bed of ion exchange particles packed in a chromatography column.