131 results about "Aqueous buffer" patented technology

Compositions and methods are provided for performing capillary electrophoresis using a composition comprising in combination in an aqueous buffered medium a coating polymer and a sieving polymer, where the sieving polymer is more hydrophilic than the coating polymer and is present in greater amount. Of particular interest are uncrosslinked acrylamide polymer mixtures for coating plastic channels and providing sieving for performing DNA separations in microfluidic devices. Polyacrylamide or N,N-dimethyl acrylamide is used with a N,N-dialkyl acrylamide copolymer, either separately or together for sieving and coating, serving as the medium in capillary electrophoresis DNA separations.

A method for purification of a nucleic acid comprising the steps of (a) adsorbing on a substrate the nucleic acid from a composition containing (i) an aqueous buffer, (ii) salts in a high concentration, (iii) a water-miscible, non-acidic organic compound, and (iv) the nucleic acid; ( b) optionally washing with a washing solution the substrate with the adsorbed nucleic acid; (c) contacting the substrate with the adsorbed nucleic acid with a solution containing salts in a lower concentration compared to the composition of step (a), thereby desorbing the nucleic acid from the substrate; (d) separating the solution with the desorbed nucleic acid from the substrate, thereby purifying the nucleic acid; and optionally (e) precipitating the desorbed nucleic acid from the solution of step (d) and isolating the precipitated nucleic acid, thereby further purifying the nucleic acid.

A multiparticulate dosage form formulated to make misuse more difficult containing least one active substance with potential for misuse (A), at least one synthetic or natural polymer (C), optionally at least one natural, semi-synthetic or synthetic wax (D), at least one disintegrant (E) and optionally one or more additional physiologically compatible excipients (B), wherein the individual particles of the dosage form display a breaking strength of at least 500 N and a release of active substance of at least 75% after 45 minutes measured according to Ph.Eur. in the paddle mixer with sinker in 600 ml of aqueous buffer solution with a pH value of 1.2 at 37° C. and 75 rpm.

Compositions and methods are provided for performing capillary electrophoresis using a composition comprising in combination in an aqueous buffered medium a coating polymer and a sieving polymer, where the sieving polymer is more hydrophilic than the coating polymer and is present in greater amount. Of particular interest are uncrosslinked acrylamide polymer mixtures for coating plastic channels and providing sieving for performing DNA separations in microfluidic devices. Polyacrylamide or N,N-dimethyl acrylamide is used with a N,N-dialkyl acrylamide copolymer, either separately or together for sieving and coating, serving as the medium in capillary electrophoresis DNA separations.

This invention is related to an adhesive composition which may be used to bond or seal tissue in vivo. The adhesive composition is readily formed from a two component mixture which includes a first part of a protein, preferably a serum albumin protein, in an aqueous buffer having a pH in the range of about 8.0-11.0 and a second part of a water-compatible or water-soluble bifunctional crosslinking agent. When the two parts of the mixture are combined, the mixture is initially a liquid which cures in vivo on the surface of tissue in less than about one minute to give a strong, flexible, pliant substantive composition which bonds to the tissue and is absorbed in about four to sixty days. The adhesive composition may be used either to bond tissue, to seal tissue or to prevent tissue adhesions caused by surgery.

A multiparticulate dosage form formulated to make misuse more difficult containing least one active substance with potential for misuse (A), at least one synthetic or natural polymer (C), optionally at least one natural, semi-synthetic or synthetic wax (D), at least one disintegrant (E) and optionally one or more additional physiologically compatible excipients (B), wherein the individual particles of the dosage form display a breaking strength of at least 500 N and a release of active substance of at least 75% after 45 minutes measured according to Ph.Eur. in the paddle mixer with sinker in 600 ml of aqueous buffer solution with a pH value of 1.2 at 37° C. and 75 rpm.

This invention is related to an adhesive composition which may be used to bond or seal tissue in vivo. The adhesive composition is readily formed from a two component mixture which includes a first part of a protein, preferably a serum albumin protein, in an aqueous buffer having a pH in the range of about 8.0-11.0 and a second part of a water-compatible or water-soluble bifunctional crosslinking agent. When the two parts of the mixture are combined, the mixture is initially a liquid which cures in vivo on the surface of tissue in less than about one minute to give a strong, flexible, pliant substantive composition which bonds to the tissue and is absorbed in about four to sixty days. The adhesive composition may be used either to bond tissue, to seal tissue or to prevent tissue adhesions caused by surgery.

The present invention is directed to certain fluorinated surfactants, and use thereof in acid etch solutions, such as in aqueous buffered acid etch solutions. The etch solutions are used with a wide variety of substrates, for example, in the etching of silicon oxide-containing substrates.

The present invention is generally directed to novel polymeric mateirals for use in the electrophoretic separation of nucleic acids. In particular, the novel polymer materials are sparsely crosslinked nanogels, dissolved in an aqueous buffer to form solutions with moderate to high viscosity. The present invention further provides methods for generating such novel polymers, and related methods of their use.

The present embodiments provide systems, kits and methods suitable for performing dry or substantially dry electro-blotting analyses on immobilized protein or nucleic acid samples. Electro-blotting performed according to the presently described embodiments may include a step whereby detection of one or more immobilized proteins or nucleic acids is electrophoretically accelerated. Methods for performing electro-blotting of immobilized proteins or nucleic acids may include applying an electric voltage to one or more reagents typically used in protein or nucleic acid blotting procedure. The one or more reagents may be absorbed on a suitable carrier matrix. Electro-blotting performed in accordance with the systems and methods described herein may be performed under substantially dry conditions (i.e., with little or no aqueous buffers).

Environmental samples typically include impurities that interfere with PCR amplification and DNA quantitation. Samples of soil, river water, and aerosol were taken from the environment and added to an aqueous buffer (with or without detergent). Cells from the sample are lysed, releasing their DNA into the buffer. After removing insoluble cell components, the remaining soluble DNA-containing extract is treated with N-phenacylthiazolium bromide, which causes rapid precipitation of impurities. Centrifugation provides a supernatant that can be used or diluted for PCR amplification of DNA, or further purified. The method may provide a DNA-containing extract sufficiently pure for PCR amplification within 5–10 minutes.

A method for purification of a nucleic acid comprising the steps of (a) adsorbing on a substrate the nucleic acid from a composition containing (i) an aqueous buffer, (ii) salts in a high concentration, (iii) a water-miscible, non-acidic organic compound, and (iv) the nucleic acid; (b) optionally washing with a washing solution the substrate with the adsorbed nucleic acid; (c) contacting the substrate with the adsorbed nucleic acid with a solution containing salts in a lower concentration compared to the composition of step (a), thereby desorbing the nucleic acid from the substrate; (d) separating the solution with the desorbed nucleic acid from the substrate, thereby purifying the nucleic acid; and optionally (e) precipitating the desorbed nucleic acid from the solution of step (d) and isolating the precipitated nucleic acid, thereby further purifying the nucleic acid.

The invention relates to a biological preparation method of (S)-4-chloro-3-hydroxybutyrate ethyl, which uses 4-chloro-3-carbonyl ethyl butyrate as a substrate and enables the substrate to be subjected to asymmetric reduction reaction in the presence of a biological catalyst, a cofactor and a hydrogen donor to produce the (S)-4-chloro-3-hydroxybutyrate ethyl, wherein the biological catalyst is recombinant ketone reductase and the hydrogen donor is isopropyl alcohol; the asymmetric reduction reaction is carried out in a hybrid system of aqueous buffer solution and toluene with pH of 7.0-9.0, and the volume ratio of the aqueous buffer solution to the toluene is 4-20:1. The method provided by the invention solves the problems of requirement of additional coenzyme system, too much added organic solvent, low efficiency of catalyst and high cost in the traditional biological preparation method. The method provided by the invention has the advantages of mild reaction condition, high reaction efficiency and simple operation, and the concentration of the substrate can be increased to 40%, thus improving the preparation efficiency of (S)-4-chloro-3-hydroxybutyrate ethyl and reducing the reaction cost greatly.

Disclosed herein are novel peptide amphiphile molecules and compositions discovered to possess improved solubility in aqueous buffers which, in turn, facilitates purification required for pharmaceutical applications, particularly for in vivo administration to human patients. In addition, gels of such peptide amphiphile compositions are shown herein to possess unexpectedly superior gelation kinetics and rheological properties, including an increased mechanical stiffness, which better mimics the mechanical properties of natural central nervous system tissues.

A method of making a therapeutic composition, as well as the therapeutic composition so made, is disclosed. The method comprises mixing a hydrophobic drug with an aqueous buffer solution and adding a surfactant to the aqueous buffer solution to form the therapeutic composition. A implantable medical device with the therapeutic composition and a method of making a coating for an implantable medical device containing the therapeutic composition is also disclosed.

The invention provides a therapeutic composition comprising an aqueous buffer, and a therapeutic agent that improves the functioning of a diseased heart by decreasing left ventricular end-diastolic pressure and simultaneously increasing left ventricular ejection without affecting the blood pressure or heart rate.

A method for removing an organic solute from a solution comprises contacting the solution with a polymer formed by copolymerizing one or more hydrophobic monomers and one or more hydrophilic monomers, whereby the solute is adsorbed onto the polymer. The solution can comprise a polar solvent such as a polar organic solvent or water or an aqueous buffer. The hydrophobic monomer can be, for example, divinylbenzene. The hydrophilic monomer can be, for example, a heterocyclic monomer, such as a vinylpyridine or N-vinylpyrrolidone.

Disclosed are an enzymatic batchwise or continuous process for the production of fatty acid alkyl esters for use in the biofuels, food and detergent industries and a system therefor. The process utilizes enzymes immobilized on a hydrophobic resin mixed with a fatty acid source and an alcohol or alcohol donor in the presence of an alkaline or mild alkaline aqueous buffer, or in the presence of water or aqueous solution. The production process for fatty acid alkyl esters is carried out by transesterification or esterification simultaneously or sequentially. The biocatalyst activity is maintained with no significant activity losses in multiple uses and also avoids the accumulation of glycerol and water by-products or other hydrophilic compounds on the biocatalyst.

This invention relates to aqueous buffered compositions and methods for lowering vaginal pH and reducing the level of self-perceived vaginal odor. Such compositions may be applied to the vaginal area to lower vaginal pH and assist in maintaining such pH over a period of time.

The present invention is generally directed to novel polymeric mateirals for use in the electrophoretic separation of nucleic acids. In particular, the novel polymer materials are sparsely crosslinked nanogels, dissolved in an aqueous buffer to form solutions with moderate to high viscosity. The present invention further provides methods for generating such novel polymers, and related methods of their use.

Apparatus and methods for performing small angle X-ray scattering (SAXS) at low (cryogenic) temperatures for determining the structure of and changes in the structure of proteins, DNA, RNA, and other biological molecules and biomolecular assemblies and structures. A cryogenic, small angle X-ray scattering (SAXS) application sample holder, includes a sample cell including a base portion and at least two parallel walls disposed on the base, wherein the sample cell has a liquid volume capacity defined by the walls and the base portion of 0.001 to 10 microliters. A method for performing cryogenic SAXS on a sample includes the steps of providing a sample biomolecule solution containing an aqueous buffer, a biomolecule, and a cryoprotectant agent, wherein the cryoprotectant agent comprises up to 60% (w / w) of the biomolecule solution, and other known components as necessary to solubilize and stabilize the biomolecule, in a sample holder of claim 1 or 18, cryogenically cooling the sample solution in the sample holder at a rate equal to or greater than 100 K / sec without ice formation, and examining the cooled sample using small angle X-ray scattering by passing a beam of X-rays through the sample.

This invention relates to aqueous buffered compositions and methods for lowering vaginal pH and reducing the level of self-perceived vaginal odor. Such compositions may be applied to the vaginal area to lower vaginal pH and assist in maintaining such pH over a period of time.

The invention provides a preparation method of a liposome vesicle based on a microfluidic device. The preparation method comprises the steps of: preparing a microfluidic chip by a soft lithography method; preparing a precursor solution for preparing the liposome vesicle; and using a constant-pressure injection pump to inject the precursor solution into a ''Y''-shaped chip through different injection ports, setting a total flow rate, adjusting the flow ratio of a buffer solution to a phospholipid molecular alcohol solution, and collecting a product at an outlet, wherein the product is the prepared liposome vesicle. The microfluidic chip selected by the invention is a ''Y''-shaped microfluidic chip with a serpentine mixing channel of a square structure, and the chip is prepared by the soft lithography method. By using the chip, based on the principle of self-assembly on an interface, by adjusting the total flow rate and the flow rate ratio of the aqueous buffer solution to the phospholipid molecule ethanol solution, regulation of the size of the liposome vesicle and control on the dimensional uniformity are achieved, and an efficient low-cost method is provided for preparation of artificial cells with uniform properties as well as drug carriers.

A sensor platform for use in sample analysis comprises a substrate (30) of refractive index m and a thin, optically transparent layer (32) of refractive index (n2) on the substrate, where n2 is greater than n1. The platform includes one of more sensing areas each for one or more capture elements. The platform also includes an immersion fluid with a refractive index n3 greater than an aqueous buffer but less than n2 to enhance the fluorescent signal of an affinity reaction. Also disclosed are an apparatus incorporating the platform and a method of using the platform.

The present invention refers to a pharmaceutical formulation for injection comprising fluorescent nanoparticles as in vivo diagnostics. The present invention relates to an injectable pharmaceutical formulation for human medicine and / or veterinary use, comprising 17% to 20% per weight of poloxamer 407 and 3%-15% per weight of poloxamer 188, 0.10 nM to 10.0 μM fluorescent nanoparticles and water or an aqueous buffer, wherein the pharmaceutical formulation is liquid at 4° C.-32° C. and forms a gel at about 37° C., their use as an in vivo marker and methods of their preparation. The inventive formulation is useful for local control and prevention of spreading / diffusion of nanoparticles, and thus allows full utilization of their quantum physics properties for example as a tool to enable surgical precision of tumor removal; even without tumor specific epitope binding antibodies.

Disclosed herein are novel peptide amphiphile molecules and compositions discovered to possess improved solubility in aqueous buffers which, in turn, facilitates purification required for pharmaceutical applications, particularly for in vivo administration to human patients. In addition, gels of such peptide amphiphile compositions are shown herein to possess unexpectedly superior gelation kinetics and rheological properties, including an increased mechanical stiffness, which better mimics the mechanical properties of natural central nervous system tissues.

Carbon monoxide (CO) is a member of the gasotransmitter family that includes NO and H2S and is implicated in a variety of pathological and physiological conditions. Whereas exogenous therapeutic additions of CO to tissues and whole animals have been well studied, the real-time spatial and temporal tracking of CO at the cellular level remains an open challenge. We now report a new type of turn-on fluorescent probe for selective CO detection by exploiting palladium-mediated carbonylation reactivity. The compounds of the invention are capable of detecting CO both in aqueous buffer and in live cells with high selectivity over a range of biologically relevant reactive small molecules, providing a potentially powerful approach for interrogating its chemistry in biological systems.

Solid controlled-release oral dosage forms comprising a therapeutically effective amount of an opioid analgesic or a salt thereof which provide an extended duration of pain relief of about 24 hours, have a dissolution rate in-vitro of the dosage form, when measured by the USP Paddle Method at 100 rpm at 900 ml aqueous buffer (pH between 1.6 and 7.2) at 37° C. of from about 12.5% to about 42.5% (by wt) opioid released after 1 hour, from about 25% to about 65% (by wt) opioid released after 2 hours, from about 45% to about 85% (by wt) opioid released after 4 hours, and greater than about 60% (by wt) opioid released after 8 hours, the in-vitro release rate being substantially independent of pH and chosen such that the peak plasma level of said opioid analgesic obtained in-vivo occurs from about 2 to about 8 hours after administration of the dosage form.

Dewaxing buffers containing a water-soluble organic solvent, methods for use thereof, and kits incorporating dewaxing buffers. The dewaxing buffers contain a water soluble organic solvent that has a boiling point of at least 80° C. The dewaxing buffers described herein can be used to quickly and efficiently remove embedding paraffin from slide-mounted tissue sections in an aqueous buffer solution at elevated temperature without fear of paraffin redeposition of the slides. In addition, the dewaxing buffers described herein can be used to perform dewaxing and HIER in a single step, which can substantially reduce protocol time and lower the risk of sample loss or damage.