A method of ionising a sample is disclosed comprising nebulising a sample which includes monoclonal antibody (“mAb”) molecules. A stream of monoclonal antibody droplets or charged droplets is directed so as to impact upon a target or electrode so as to form intact parent monoclonal antibody ions, intact minus light chain parent monoclonal antibody ions or light chain (“LC”) fragment monoclonal antibody ions.

The present invention provides photo-cleavable anionic surfactants, particularly 4-hexylphenylazosulfonate (Azo) and sodium 4-hexylphenylazosulfonate derivatives, which can be rapidly degraded upon UV irradiation, for top-down and bottom-up proteomics. These surfactants can effectively solubilize proteins and peptide fragments with performance comparable to sodium dodecyl sulfate (SDS) and are compatible with mass spectrometry analysis of the solubilized proteins and peptide fragments. Top-down proteomic studies using the present photo-cleavable anionic surfactants has allowed the detection of 100-fold more unique proteoforms as compared to controls and has enabled the solubilization of membrane proteins for comprehensive characterization of protein post-translational modifications. In addition, the present photo-cleavable anionic surfactants are also suitable for dissolving polypeptides in bottom-up proteomic experiments including extracellular matrix proteomics, and are suitable as a substitute for SDS in gel electrophoresis.

A method for the identification and localization of small molecule species in a histologic thin tissue section comprises the steps of: a) acquiring a mass/mobility image of the tissue section and generating a mass/mobility map of the small molecule species of interest for each pixel of the image; b) providing a second sample of the same tissue and extracting the small molecules of interest, separating them, and acquiring mass and ion mobility spectra from the separated small molecules; c) identifying the small molecules of interest using corresponding reference databases; and d) assigning identified small molecules to entries in the mass/mobility maps of the first tissue section by comparison of ion masses and mobilities of the identified species to those of the second thin tissue section.

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.

This disclosure provides a novel label-free N-glycan analysis method to detect and quantify N-glycans and N-linked glycosylation profiles without using a label, such as a fluorescent label. This method allows for reduced sample preparation and chromatographic separation times, and can be used for product batch release.

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.

The present invention relates to a method of characterizing the binding characteristics between a peptide of interest and MHC molecules of a given cell type, the method comprising the steps of: (i) Providing two or more cells characterized by displaying, on their surface, MHC molecules, (ii) dispensing the two or more cells in two or more vessels, so that each vessel comprises one or more cells, (iii) adding, to the different vessels, different variants of a peptide of interest, wherein the variants of said peptide are labeled and have the same amino acid sequence, yet differ from one another in the type of labeling and their concentration, and exposing the cells thereto so as to form, in the different vessels, peptide-MHC complexes on the surface of the cells, (iv) isolating the thus formed peptide-MHC complexes and (v) determining the concentration of the different peptide-MHC complexes formed (FIG. 1).

Disclosed herein are methods for the direct readout of proteoforms and complexes thereof, such as immunoglobulins. The method may comprise ionizing a sample with an ionizer, wherein the sample comprises a mixture of different proteoforms or complexes thereof; detecting a multiplicity of ions generated by the ionization of the sample with a current detector; determining ion masses for each of the multiplicity of ions detected with the current detector with a mass analyzer; generating a mass-domain spectrum from the ion masses with the mass analyzer. The method may also comprise determining one or more metrics capturing the heterogeneity or relative abundance of proteoforms.

A method for identifying by mass spectrometry an unknown microorganism subgroup among a set of reference subgroups, including a step of constructing one knowledgebase and one classifying model per associated subgroup on the basis of the acquisition of at least one set of learning spectra of microorganisms identified as belonging to the subgroups of a group and including: constructing an adjusting model allowing mass-to-charge offsets of the acquired spectra to be corrected on the basis of reference masses-to-charges that are common to the various subgroups; adjusting the masses-to-charges of all of the lists of peaks of the learning spectra and constructing one classifying model per subgroup and the associated knowledgebase on the basis of the adjusted learning spectra.

Provided herein are methods and biomarkers useful for detecting and diagnosing osteoarthritis and predicting the progression of osteoarthritis in subjects. The diagnoses and predictions of prognosis may be used to develop treatment plans for subjects. Also included are methods of treating subjects and administering pharmaceuticals based on the diagnosis and prognosis predictions.