26 results about "Isoelectric focusing" patented technology

Provided herein are bispecific antibodies having modifications that enable greater developability and manufacturability. In certain instances, such bispecific antibodies comprise common light chain bispecific antibodies that bind CD38 and CD19, having reduced isoelectric focusing, improved hydrophobic interaction chromatography retention, and effective targeting of cells expressing CD19 and CD38. Also provided are methods of reducing an experimental isoelectric point of bispecific antibodies that bind CD19 and CD38.

The invention discloses a method for detecting a charge variant of a monoclonal antibody. The method comprises the following steps: preparing a monoclonal antibody to be detected into a test solution; the test solution comprises a monoclonal antibody to be detected, a methylcellulose solution, urea, amino acid, an ampholyte carrier and an isoelectric point marker; detecting the test solution by adopting a full-column imaging capillary isoelectric focusing method, and determining the content percentage of the charge variant of the monoclonal antibody to be detected according to an isoelectric focusing map; wherein the isoelectric point of the amino acid is similar to the boundary isoelectric point of a main peak and an alkali peak in an isoelectric focusing map of the monoclonal antibody to be detected. According to the method, the separation degree between the main peak and the alkali peak of the to-be-detected sample can be remarkably improved. The sensitivity is good, the precision is high, and while the separation degree of a main peak and an alkali peak is improved in a targeted manner, the separation degree and proportion of an acid peak and the main peak, the isoelectric point of a sample and the like are basically not influenced.

Multispecific antibodies with reduced isoelectric focusing points are described herein.

This paper provides a method for detecting low concentrations of amphoteric compounds in a sample, comprising: (a) preparing an analytical sample mixture for capillary isoelectric focusing (CIEF) detection using the sample; and (b) detecting the analytical sample mixture using a fluorescence detector via a CIEF system; wherein the concentration of the low concentration amphoteric compound in the analytical sample mixture is less than 0.5 μg / μL. This method is more resistant to background noise interference and can sensitively detect and accurately quantify low concentrations of amphoteric compounds present in the sample.

The present disclosure provides icIEF sample matrices that enable icIEF analysis of PEGylated proteins in their real conjugated states. The sample matrices of the present disclosure can include glycine, which enables the separation of co-migrated PEGylated protein charge variants. The sample matrices can also include taurine, which further improves icIEF assay by depleting matrix induced baseline interferences. Accordingly, a sample matrix of the present disclosure including a combination of glycine and taurine enables icIEF separation of acidic and basic species from the main peak for PEGylated proteins, allowing the identification / separation, characterization and quantification of discrete PEGylated protein species. By using the sample matrices of the present disclosure to characterize PEGylated proteins by icIEF, repeatability, linearity, accuracy, sample stability, and method robustness are achieved.

The present disclosure relates to fluidic systems and devices for processing, extracting, or purifying one or more analytes. These systems and devices can be used to process samples and extract nucleic acids, for example, by isoelectric focusing. In particular, the systems and related methods can allow for the extraction of nucleic acids, including non-crosslinked nucleic acids, from samples such as tissues or cells. The systems and devices can also be used for multiplexed parallel sample processing.

The invention discloses a method for separating and enriching exosomes by using paper-based isoelectric focusing equipment and adopting paper-based isoelectric focusing. The method comprises the following steps: carrying out step-by-step centrifugation and ultrafiltration on an exosome solution to obtain a purified exosome solution, incubating the purified exosome solution and carbon quantum dots at a certain temperature to obtain a fluorescent exosome solution adsorbed with the carbon quantum dots, and respectively taking a glycine-hydrochloric acid solution and a glycine-sodium hydroxide solution as positive and negative electrode solutions of paper-based isoelectric focusing equipment, so as to obtain the fluorescent exosome. And performing isoelectric focusing on the paper-based material fully soaked with the fluorescent exosome solution, and finally recovering different focused exosomes. The invention provides a carrier-free ampholyte focusing platform which is convenient, easy to obtain, environment-friendly, low in cost, small in sample loading amount, low in detection limit, easy for sample enrichment and recovery, and compatible with other subsequent detection methods.

The presently claimed and described technology is directed to an acidic high polymer composition comprising about 1.0% (w / v) polymer and about 4% (v / v) carboxylic acid. The acid high polymer composition may be used as a neutral capillary storage or conditioning solution or in a method of improving capillary isoelectric focusing (cIEF) robustness or performance. The technology is also directed to a kit comprising an acidic high polymer composition, at least one stabilizer, an anolyte, and a catholyte.

The disclosure relates to methods of characterizing ampholyte compositions suitable for downstream applications such as capillary isoelectric focusing using liquid-chromatography-mass spectrometry.

To provide systems that are configured to perform multiple types of analysis, such as electrophoretic mobility and isoelectric electrophoresis within a single device, and that are automated so that multiple samples are analyzed simultaneously or in rapid succession with ease and robustness while consuming minimal volumes of expensive reagents and disposables.SOLUTION: A system includes: a housing; a cartridge retainer disposed within the housing; a detection assembly disposed within the housing; and a reagent tray holder movably disposed within the housing. The detection assembly is configured to transition between a first configuration, in which a first detector detects a first output of at least one emitter, and a second configuration, in which a second detector detects a second output of the at least one emitter. The reagent tray holder is configured to move relative to the cartridge retainer to place the capillary of a capillary cartridge in fluid communication with a reagent volume.SELECTED DRAWING: Figure 6

Systems and methods for calibrating compound markers in mass spectrometry (MS) detection are disclosed. The systems and methods automatically identify a plurality of isoelectric point (pI) markers in a sample, generate a calibration curve correlating pI with time, and convert the time scale to a pI scale. Based on the established correlation between time and pI, the system further associates pI with intensity values, enabling presentation to an operator for analysis.

The invention relates to the field of collagen isoelectric point detection, in particular to a collagen isoelectric point detection method. The collagen isoelectric point detection method provided by the invention comprises the following seven steps: S1, solution preparation; S2, gel preparation; S3, sample pretreatment; S4, sample application; wherein in the step of sample pretreatment in the step S3, centrifugation is segmented, and a urea solution is added before each segment of centrifugation, so that the collagen sample is not easy to gather, and formation of a normal strip by subsequent isoelectric focusing is facilitated. The electrophoresis condition is controlled in the step S5 of isoelectric focusing electrophoresis, so that the formed strip is clear, condensed and not loose, and the isoelectric point of the collagen sample can be accurately measured by utilizing a trace amount of the collagen sample.

The invention relates to a method for determining isoelectric points of proteins and polypeptides, which is characterized in that a capillary isoelectric focusing electrophoresis method or a full-column imaging capillary isoelectric focusing electrophoresis method is used for determining according to a 214nm absorption peak. The method provided by the invention solves the problem that the isoelectric point of the protein or polypeptide which does not contain a benzene ring structure cannot be measured by a capillary isoelectric focusing electrophoresis method because the protein or polypeptide does not have ultraviolet absorption under the wavelength of 280 nm.

A method for detecting a by-product in a sample of a target asymmetric bispecific antibody (AsBsAb) is provided, comprising subjecting the sample to capillary isoelectric focusing to separate the by-product from the target AsBsAb based on a difference in their pi. In particular, the AsBsAb comprises two half antibodies, and the pi of the first half antibody is different from the pi of the second half antibody.

A method for detecting byproducts in a sample of a target asymmetric bispecific antibody (AsBsAb), comprising subjecting the sample to capillary isoelectric focusing to separate the byproducts from the target AsBsAb based on their pI differences. Specifically, the AsBsAb comprises two half-antibodies, and the pI of the first half-antibody is different from that of the second half-antibody.

The disclosure relates to methods of characterizing ampholyte compositions suitable for downstream applications such as capillary isoelectric focusing using liquid-chromatography-mass spectrometry.

The present invention generally pertains to methods of characterizing charge variants of a protein of interest. In particular, the present invention pertains to the use of desalting size exclusion chromatography-reduced peptide mapping mass spectrometry to identify charge variants separated by capillary isolectric focusing.

The invention discloses a circulating type free flow isoelectric focusing electrophoresis device and method.The circulating type free flow isoelectric focusing electrophoresis device is mainly composed of a gas-liquid buffer chamber, liquid storage pipes, a separation chamber, a collecting pipe, a cooling device and a driving pump, liquid inlets of the separation chambers are connected with liquid storage pipes in the gas-liquid buffer chambers in a one-to-one correspondence manner through switches, liquid outlets of the separation chambers are connected with a collecting pipe through a three-way valve, another outlet of the three-way valve corresponds to the liquid storage pipes in the gas-liquid buffer chambers in a one-to-one correspondence manner, and a switch is connected between the three-way valve and the liquid storage pipes. According to the device and the method, required reagents are low in price, a constant flow pump is adopted to replace a multi-channel driving pump, the effect of infinite plate length can be achieved under continuous circulation, heat dissipation is facilitated, and a solution without a sample can be recycled in a pipeline with the corresponding pH value.

The application provides a preparation method of a mineralized collagen scaffold material with a biomimetic structure, and belongs to the field of biomedical engineering.The preparation method comprises the following steps: preparing a polyacrylic acid-stabilized amorphous calcium phosphate solution, wherein the molar ratio of Ca element to P element in the amorphous calcium phosphate solution is 1.67:1; preparing a collagen solution containing norepinephrine; performing isoelectric focusing treatment on the collagen solution under a constant voltage to form a dense film, then stretching the dense film to produce a deformation of 120% to 200%, and obtaining a collagen film with a biomimetic structure; soaking the collagen film in the amorphous calcium phosphate solution, and then performing freeze-drying to obtain a norepinephrine-mineralized collagen scaffold material.The mineralized collagen scaffold material prepared by the method has excellent biocompatibility, osteogenic induction and sufficient mechanical strength, can effectively promote bone tissue defect repair, and has a good application prospect in the field of bone tissue engineering.The application further provides a mineralized collagen scaffold material with a biomimetic structure and an application thereof.

This application discloses a method for detecting charge variants of monoclonal antibodies. The method includes preparing a test solution of the monoclonal antibody to be tested; the test solution includes the monoclonal antibody to be tested, methylcellulose solution, urea, amino acids, an amphoteric electrolyte carrier, and an isoelectric point marker; the test solution is detected using whole-column imaging capillary isoelectric focusing, and the percentage of charge variants of the monoclonal antibody to be tested is determined based on the isoelectric focusing spectrum; wherein the isoelectric point of the amino acid is similar to the isoelectric point of the boundary between the main peak and the base peak in the isoelectric focusing spectrum of the monoclonal antibody to be tested. This method can significantly improve the separation between the main peak and the base peak of the sample. It also exhibits good sensitivity and high precision, while specifically improving the separation between the main peak and the base peak, with minimal impact on the separation and ratio of the acid peak and the main peak, as well as the isoelectric point of the sample.

The utility model discloses a protein free flow isoelectric focusing electrophoretic separation device which comprises a cold liquid plate, a silica gel heat conduction pad is arranged at the top of the cold liquid plate, an electrophoretic separation chamber is arranged at the top of the silica gel heat conduction pad, the electrophoretic separation chamber comprises a separation chamber lower plate, the separation chamber lower plate is connected with the silica gel heat conduction pad, and a separation chamber upper plate is arranged above the separation chamber lower plate. The top of the separation chamber upper plate is connected with a pair of symmetrical electrode chambers, carbon rods are connected in the electrode chambers in a penetrating mode, and rectangular holes of the same size are formed in the bottoms of the electrode chambers and the top of the separation chamber upper plate. An anion exchange membrane and a cation exchange membrane which are used for isolating an electrode solution from an operation buffer solution are respectively adhered to the positions, corresponding to the rectangular holes, of the bottom of the separation chamber upper plate, a silica gel gasket is arranged between the separation chamber upper plate and the separation chamber lower plate, and the separation chamber upper plate and the separation chamber lower plate are connected through a clamp; a plurality of separation chamber liquid inlets and separation chamber liquid outlets are respectively formed in two sides of the short edge of the separation chamber upper plate.

The present invention describes methods, devices, and systems for performing isoelectric focusing reactions. The systems or devices disclosed herein can include a holder having a membrane. In some cases, the disclosed devices can be designed to perform isoelectric focusing or other separation reactions and subsequently further characterize the separated analytes using mass spectrometry. Two or more isoelectric focusing reactions can be performed in parallel. The disclosed methods, devices, and systems provide rapid and accurate separation and characterization of protein analyte mixtures or other biomolecules by their isoelectric points.

Methods, devices, and systems for performing isoelectric focusing reactions are described. The systems or devices disclosed herein may comprise fixtures that have a membrane. In some instances, the disclosed devices may be designed to perform isoelectric focusing or other separation reactions followed by further characterization of the separated analytes using mass spectrometry. Two or more isoelectric focusing reactions may be performed in parallel. The disclosed methods, devices, and systems provide for fast, accurate separation and characterization of protein analyte mixtures or other biological molecules by isoelectric point.

In some embodiments, the present disclosure provides an icIEF sample matrix that enables icIEF analysis of a pegylated protein in its actual conjugated state. Sample matrices of the present disclosure can include glycine that enables the isolation of co-migrated PEGylated protein charge variants. The sample matrix can also include taurine that further improves the icIEF assay by eliminating the matrix-caused baseline interference. Thus, the sample matrix of the present disclosure comprising a combination of glycine and taurine enables icIEF separation of acidic and basic species of PEGylated proteins from the main peak, allowing for identification / isolation, characterization and quantification of discrete PEGylated protein species. By characterizing PEGylated proteins via icIEF using a sample matrix of the present disclosure, repeatability, linearity, accuracy, sample stability, and method robustness are achieved.