The present invention relates to a method of measuring at least one product quality attributes, including critical quality attributes (e.g., oxidation, C-terminal lysine, aggregation, N-terminal glutamine cyclization.) by an online liquid chromatography system, wherein the liquid chromatography system is running a hydrophobic interaction chromatography (HIC) method.

Methods for determining the relative abundance of intact adeno-associated virus (AAV) capsid components in a sample of recombinant AAV particles are disclosed. In embodiments, the methods include a system regeneration process that minimizes or eliminates the presence of ghost peaks to maximize analytical accuracy and ensure product quality and consistency.

The present invention generally pertains to methods of characterizing antibodies and related products. In particular, the present invention pertains to the use of immunoprecipitation and native strong cation exchange chromatography-mass spectrometry to specifically and sensitively detected and quantitate antibodies and related products in a sample.

The present invention generally pertains to methods of characterizing charge variants of a protein. In particular, the present invention pertains to the use of anion exchange chromatography-mass spectrometry (AEX-MS) methods using a salt-gradient. The present invention is particularly useful for charge variant analysis of IgG4 subclasses.

The present disclosure discusses a method of separating and/or purifying acidic peptides by the use of a mobile phase having a pH greater than or about equal to the isoelectric point of one or more of the metal oxides in the flow path.

Systems and methods are provided for microbial identification using cleavable tags. Control information is sent to a mass spectrometer to fragment one or more nucleic acid primers labeled with a first tag and monitor for an intensity of the first tag in a mass spectrometry (MS) method. An ion source provides a beam of ions from a polymerase chain reaction amplified sample that includes one or more nucleic acid primers labeled with the first tag. The first tag binds to one or more nucleic acid primers of a known microbe and is cleaved from the nucleic acid primers during the MS method. The mass spectrometer receives the beam of ions and is adapted to perform the MS method on the beam of ions. If the intensity of the first tag received from the mass spectrometer exceeds a threshold value, the known microbe is identified in the sample.

Disclosed is a method for evaluating in vivo protein nutrition based on an LC-MS-MS technique, including the following steps: (1) collecting contents from different intestinal segments, and extracting and isolating protein ingredients; (2) determining the concentration of proteins; (3) treating before carrying out mass spectrometry: including digestion and desalting of a whole protein solution; (4) LC-MS-MS analysis; (5) database searching; and (6) data processing. Proteomic technology is used to identify proteins in the contents of different intestinal segments and digestive products thereof, and the source of the proteins in the contents of different intestinal segments and the contents thereof can be determined therefrom. Through bioinformatic analysis, the function of differential proteins in the body can be further understood, where the gene expression of enzymes related to protein digestion and metabolism may be different, thereby providing a scientific basis for further scientific evaluation of protein digestion and utilization.

An analytical method for detecting presence of oxidizing substances by measuring degradation of peptides may include preparing a test preparation that includes a peptide and a sample. The peptide degrades in the presence of oxidizing substances. The method may include detecting impurities of the peptide in the test preparation in which detected impurities indicate presence of oxidizing substances in the sample. Examples include using high performance liquid chromatography to detect, identify, and quantify impurities of the peptide indicating presence of oxidizing substances in the sample. Exemplary oxidizing substances include peroxide-containing, chlorine-containing compounds, and bromine-containing compounds. Exemplary peptides include vasopressin.

The present invention provides reagents for instrumentation quality control and methods of use thereof. In particular, sets of peptides or other molecules are provided for evaluating the performance of instruments with mass spectrometry (MS) and/or liquid chromatography (LC) functionalities.

The present invention provides a snake venom thrombin marker peptide of Agkistrodon Halys Pallas and an application of the snake venom thrombin-like enzyme in identifying species of Hemocoagulase for Injection. The application includes the following steps of: dissolving a to-be-detected sample and a reference substance of the marker peptide respectively to prepare a test solution and a reference solution, and conducting alkylation reduction on the test solution and the reference solution with dithiothreitol and iodoacetamide; after diluting products with an ammonium bicarbonate solution, adding enzyme for hydrolysis; and after enzymolysis is finished, conducting centrifugation at a high speed, and injecting a supernatan into a liquid chromatography-mass spectrometer for analysis. This method is simple, convenient and rapid, is strong in specificity, fills the gap in identifying the source of species of the snake venom thrombin-like enzyme of Agkistrodon Halys Pallas and improves the quality control level.