The invention provides methods for making porous devices from substantially monodisperse populations of substantially spherical particles of polyarylketone polymers or of thio-analogues of such polymers, of selected sizes. The porous devices allow greater control of porosity than previously available porous devices. In some embodiments, the porous devices are frits, filters, membranes or monoliths.

Compositions and methods for analyzing disulfide bonds are provided. An exemplary method includes preparing peptide standards having no disulfide bonds, scrambled disulfide bond peptide standards, and native disulfide bond peptide standards according to the sequence of the region of the protein drug product that includes the disulfide bond, digesting a sample of protein drug product into peptides, separating the protein drug product peptides, analyzing the protein drug product peptides and the peptide standards, identifying scrambled and native disulfide bond peptides by retention time, and quantifying the level of scrambled disulfide bond peptides.

The present invention provides a method for quantifying a monoclonal (M-) protein in a sample of a subject, the method comprising the steps of:—subjecting a serum sample of a subject to serum protein electrophoresis (SPE) in a gel, preferably serum protein electrophoresis in an agarose gel, to separate serum proteins into different serum protein fractions, optionally followed by immunofixation electrophoresis (IFE) and further optionally involving immunostaining of the gel;—excising from said gel a gel part comprising, or suspected of comprising, a M-protein;—performing an enzymatic digestion of proteins present in said gel part in order to provide a peptide digest comprising at least one M-protein peptide;—subjecting said peptide digest comprising said at least one M-protein peptide to liquid chromatography-mass spectrometry (LC-MS) to determine a quantity of said at least one M-protein peptide, thereby quantifying said M-protein in said sample.

The present invention relates to the field of protein characterization, and in particular to methods for identifying critical quality attributes of therapeutic proteins expressed in host cells by implementing a workflow including using a competitive binding assay with insufficient antigen followed by SCX-MS.

Methods, devices, and systems for improving the quality of electrospray ionization mass spectrometer (ESI-MS) data are described, as are methods, devices, and systems for achieving improved correlation between chemical separation data and mass spectrometry data.

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.

Provided herein are methods of identifying a protein capable of binding a ligand, the method comprising: (a) contacting the ligand with two or more samples comprising a plurality of proteins in a solution; (b) separating the proteins bound to the ligand (“bound proteins”) from the proteins that are not bound to the ligand (“unbound proteins”) in each sample; (c) denaturing and digesting the bound proteins to form a plurality of peptides in each sample; (d) quantifying a plurality of molecular features contained in the plurality of peptides in each sample, wherein the molecular features are defined as having a mass to charge ratio, retention time, and peak intensity as measured by mass spectrometry; and (e) ranking the molecular features that exhibit a statistically significant difference in quantity between the samples contacted with the ligand and a sample that is not contacted with the ligand (“statistically significant molecular feature”).

A microwave microstrip resonator apparatus including a housing; a resonator within the housing; an output conductor within the housing and spaced apart from the resonator so as to define a capacitive gap therebetween; a reaction vessel configured to reside with the capacitive gap; and a power supply coupled to the resonator whereby contents within the reaction vessel are heated when energy is supplied to the resonator by the power supply. A mass spectrometer may also be coupled to an outlet end of the reaction vessel such that the contents within the reaction vessel are, simultaneously, delivered to the mass spectrometer for analysis.

The present invention generally pertains to methods of quantitating therapeutic proteins co-administered to a subject using LC-MRM-MS. In particular, the present invention pertains to the use of dual enzymatic digestion to generate unique surrogate peptides allowing for the accurate quantitation of co-administered therapeutic proteins using LC-MRM-MS.

A chromatography device having a housing having an inlet and an outlet. At least two layers of media disposed between the inlet and the outlet inside of the housing forming a media stack, and wherein at least one of the layers comprises a functionalized layer. A spacer ring disposed between at the least two layers of media forming an air gap between them.