Abstract: 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.

Abstract: 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 isoelectric focusing.

Abstract: Methods and system for identification of dimer species using online chromatography and electrospray ionization mass spectrometry are provided. Also provided are methods and system for quantitation of heterodimer species using immunoprecipitation and liquid chromatography-mass spectrometry.

Abstract: The present invention provides rapid, sensitive high-throughput methods and systems for characterizing peptides or proteins using hydrophobic interaction chromatography-coupled native mass spectrometry to improve manufacturing process of biopharmaceutical products, such as identifying impurities during antibody purification, monitoring post-translational modification variants during production, or characterizing drug-to-antibody ratio of antibody-drug conjugates. The separation profiles of the peptides or proteins are generated and compared to identify or qualify the peptides or proteins.

Abstract: Systems and methods to characterize dimerization interfaces at the subdomain level of a protein are provided. An exemplary method includes digesting a protein dimer sample into subdomains, labeling the digested protein sample, isolating labeled dimeric and monomeric subdomain fragments, and peptide mapping the labeled sample to determine where the dimer fragments are labeled and where the dimer fragments are not labeled. Regions that show decreased labeling extents in the dimer fraction than that in the monomer fraction are likely involved or in close proximity to the dimerization interface.

Abstract: Methods and system for identifying and quantifying antibody fragments and identifying the site of fragmentation on an antibody are provided herein.

Abstract: Methods and system for identifying and/or quantifying a protein are provided herein.

Abstract: Methods and system for identifying and/or quantifying a protein are provided herein.

Abstract: Methods and system for identifying and/or quantifying a protein are provided herein.

Abstract: Liquid chromatography-free methods for quantitating a target protein in a sample are provided.

Abstract: Disclosed are native liquid chromatography-mass spectrometry systems and methods of use. A native liquid chromatography-mass spectrometry system can include a liquid chromatography system capable of separating a sample; and an electrospray ionization mass spectrometry (ESI-MS) system in fluid communication with the liquid chromatography system, wherein the ESI-MS system comprises a multi-nozzle electrospray ionization emitter and a system for modifying a desolvation gas and a mass spectrometer, wherein the mass spectrometer is configured to receive ions and characterize mass to charge ratio of ions.

Abstract: The present invention provides rapid, sensitive high-throughput methods and systems for characterizing peptides or proteins using hydrophobic interaction chromatography-coupled native mass spectrometry to improve manufacturing process of biopharmaceutical products, such as identifying impurities during antibody purification, monitoring post-translational modification variants during production, or characterizing drug-to-antibody ratio of antibody-drug conjugates. The separation profiles of the peptides or proteins are generated and compared to identify or qualify the peptides or proteins.

Abstract: Systems and methods to characterize dimerization interfaces at the subdomain level of a protein are provided. An exemplary method includes digesting a protein dimer sample into subdomains, labeling the digested protein sample, isolating labeled dimeric and monomeric subdomain fragments, and peptide mapping the labeled sample to determine where the dimer fragments are labeled and where the dimer fragments are not labeled. Regions that show decreased labeling extents in the dimer fraction than that in the monomer fraction are likely involved or in close proximity to the dimerization interface.

Abstract: Methods and system for identification of dimer species using online chromatography and electrospray ionization mass spectrometry are provided. Also provided are methods and system for quantitation of heterodimer species using immunoprecipitation and liquid chromatography-mass spectrometry.

Abstract: Systems and methods to characterize dimerization interfaces at the subdomain level of a protein are provided. An exemplary method includes digesting a protein dimer sample into subdomains, labeling the digested protein sample, isolating labeled dimeric and monomeric subdomain fragments, and peptide mapping the labeled sample to determine where the dimer fragments are labeled and where the dimer fragments are not labeled. Regions that show decreased labeling extents in the dimer fraction than that in the monomer fraction are likely involved or in close proximity to the dimerization interface.

Abstract: Methods and system for identifying and quantifying antibody fragments and identifying the site of fragmentation on an antibody are provided herein.

Abstract: Methods and system for identifying and/or quantifying a protein are provided herein.

Abstract: Systems and methods to characterize dimerization interfaces at the subdomain level of a protein are provided. An exemplary method includes digesting a protein dimer sample into subdomains, labeling the digested protein sample, isolating labeled dimeric and monomeric subdomain fragments, and peptide mapping the labeled sample to determine where the dimer fragments are labeled and where the dimer fragments are not labeled. Regions that show decreased labeling extents in the dimer fraction than that in the monomer fraction are likely involved or in close proximity to the dimerization interface.

Abstract: A fire sprinkler has an inlet pipe and a water nozzle body. The water nozzle body has a water nozzle cover and a water mouth component. A stop valve core, the upper end of which is a stop valve, is mounted inside the water nozzle body. A supporting rack is mounted at a water nozzle lower end. A glass heat sensitive element is vertically mounted in the supporting rack. A stop valve core which is supported via the glass heat sensitive element drops to bias the stop valve from the water inlet, which is situated at the lower end of the induction pipe. A force rotates the water nozzle body on the ball bearing. The centrifugal force from nozzle body rotation provides a parabolic water spray shape for achieving larger area fire extinguishing effect.