The present disclosure relates to a method for detecting the contents of whey protein and casein, and/or the ratio thereof in milk powder by liquid chromatography-mass spectrometry. According to the method of the present disclosure, the characteristic peptide segments of whey protein and casein are selected and used for correction, and thus the accuracy and stability of detection of peptide segments by mass spectrometry using external standards are improved; in addition, the method of the present disclosure has the following advantages: easy to pretreat samples, low cost, a wide range of applicability, enable to perform quantitative detection of whey protein at one time, not affected by protein denaturation in the production process, no need to synthesize isotope internal standard, and avoiding influence of ionization efficiency and matrix in mass spectrometry detection by means of their own multiple characteristic peptide segment ratios.

The present invention relates to the field of protein characterization, and in particular to methods for characterizing high molecular weight species of a therapeutic protein by implementing a workflow including using a post-column denaturation-assisted SEC-MS method that allows highly specific, sensitive, and comprehensive characterization of high molecular weight species.

Methods and systems are provided to improve consistency and robustness in chromatography, for example, in operations of multi-column chromatography systems.

The present disclosure relates to the determination of analytes in a sample using chromatography. The present disclosure provides methods of separating an analyte from a sample. A mobile phase is flowed through a chromatography column. The mobile phase includes about 0.005% (v/v) to about 2.50% (v/v) difluoroacetic acid and less than about 100 ppb of any individual impurity, especially metal impurities. A sample including the analyte is injected into the mobile phase. The analyte is separated from the sample.

The present disclosure provides, in some embodiments, devices, methods, and kits for purifying extracellular vesicles (EVs) using size exclusion chromatography in tandem with cation exchange chromatography, which can be referred to as dual-mode chromatography (DMC).

Provided is a method by which the disaccharides derived from glycosaminoglycans can be analyzed in a stable and highly reproduceable manner. A method for analyzing a glycosaminoglycan according to the present invention includes: a first process for producing a plurality of kinds of disaccharides derived from a glycosaminoglycan in a biological sample by adding a plurality of kinds of glycosaminoglycan-specific enzymes to the biological sample: and a second process for separating and analyzing the plurality of kinds of disaccharides by a liquid chromatography-mass spectrometry method, where a column used for liquid chromatography in the liquid chromatography-mass spectrometry method is a column packed with a stationary-phase support to which an amide group as a functional group is bound, or a column packed with a stationary-phase support to which an adamantyl group as a functional group is bound.

Provided are methods for quantifying peanut proteins in food products using a matrix-specific calibration curve. Methods provided include exposing a food sample comprising a matrix and one or more peanut proteins to an extractant to extract the one or more peanut proteins from the food sample; heating the food sample to reduce protein interference in the food sample; digesting one or more peanut proteins in the food sample to form one or more peanut peptides; determining a relative response value of the one or more peanut peptides in the food sample by analyzing the food sample using liquid chromatography with tandem mass spectrometry; and determining an amount of the one or more peanut proteins by comparing the determined relative response value of the one or more peanut peptides in the food sample to a matrix-specific calibration curve.

The present disclosure provides novel methods to purify and quantify extracellular vesicles (EVs) in biological samples, e.g plasma or cerebrospinal fluid (CSF).

Methods for performing multiple omics analysis in parallel are provided, the methods can include: dividing the mixture of cells or cell components into at least a first portion and a second portion; performing a first analysis on the first portion to acquire a first set of analytical data; performing a second analysis on the second portion to acquire a second set of analytical data. Methods for forming mixtures of analytes into first and second portions are also provided. The methods can include aligning the first and second plates to engage the first exposed surface with the second exposed surface, wherein the engaging is sufficient to convey at least some of the first analytes into the second solution to form a second mixture of the first analytes.

The present disclosure describes a computer implemented method, a system, and a computer program product of measuring quality attributes of a virus sample. In an embodiment, the method, system, and computer program product include (1) receiving light scattering (LS) data from a light scattering detector analyzing separations of a virus sample, dRI data, and UV data, (2) receiving a molecular weight of a protein component of the sample, Mprotein (expected), a refractive index increment of the protein component, (dn/dc)protein, a refractive index increment of a DNA component of the sample, (dn/dc)DNA, and an extinction coefficient of the protein component, εprotein, (3) calculating a protein fraction of the sample, xprotein, with respect to the LS data, the dRI data, the Mprotein (expected), the (dn/dc)protein, the (dn/dc)DNA, and an optical constant, K, (4) calculating a DNA extinction coefficient of the sample, εDNA, and (5) calculating quality attribute values of the sample.