Methods of sequencing a protein using a novel digestion-on-emitter technology are provided.

The field of this invention relates to immunohistochemistry (IHC) and in situ hybridization (ISH) for the targeted detection and mapping of biomolecules (e.g., proteins and miRNAs) in tissues or cells for example, for research use and for clinical use such by pathologists (e.g., biomarker analyses of a resected tumor or tumor biopsy). In particular, the use of mass spectrometric imaging (MSI) as a mode to detect and map the biomolecules in tissues or cells for example. More specifically, the field of this invention relates to photocleavable mass-tag reagents which are attached to probes such as antibodies and nucleic acids and used to achieve multiplex immunohistochemistry and in situ hybridization, with MSI as the mode of detection/readout. Probe types other than antibodies and nucleic acids are also covered in the field of invention, including but not limited to carbohydrate-binding proteins (e.g., lectins), receptors and ligands. Finally, the field of the invention also encompasses multi-omic MSI procedures, where MSI of photocleavable mass-tag probes is combined with other modes of MSI, such as direct label-free MSI of endogenous biomolecules from the biospecimen (e.g., tissue), whereby said biomolecules can be intact or digested (e.g., chemically digested or by enzyme).

A system and method is provided for validating the manufacturing process for the production of complex biological compositions, and particularly for providing process validation information for evaluation by a federal regulatory agency. The system and method continuously and chronologically assess the concentration of proteoforms within the biological composition as it is being produced in a fermentor. Samples from the fermentor are analyzed in a pre-selected array of analysis columns, with data generated by the columns being accumulated and evaluated, and particularly compared with data from previous stages in the production process. A continuous process validation system includes top-down and bottom-up analysis sectors, each including a plurality of different analysis columns that can be selected by the controller for a particular biological composition and a particular production process.

The present disclosure discloses a mass spectrometry based method for detecting serum metabolite, and relates to the technical field of mass spectrometric detection. The method includes: analyzing detection matching values of detection personnels receiving a detection task, and selecting a detection personnel with the largest detection matching value as a selected detection personnel; firstly performing position matching, then performing configuration to obtain a serum sample, and performing mass spectrometric detection on the serum sample after the selected detection personnel reaches a detection position; verifying a fingerprint of the selected detection personnel before the selected detection personnel uploads mass spectrometric result data; and stamping the mass spectrometric result data with a time mark and uploading the mass spectrometric result data to a detection platform for storage by the selected detection personnel through a mobile phone terminal after the fingerprint verification is passed, ensuring the authenticity and safety of the data.

Provided herein are peptide formulations comprising polymers as stabilizing agents. The peptide formulations can be more stable for prolonged periods of time at temperatures higher than room temperature when formulated with the polymers. The polymers used in the present invention can decrease the degradation of the constituent peptides of the peptide formulations.

The present invention centers upon a novel “molecular amplification spike,” which is an admixture of two components, namely, an aliquot of a quantity of a molecule, composition, compound or element of interest (an “analyte”) in its natural isotopic state and an aliquot of an isotopically enriched form of the same molecule, composition, compound or element. The molecular amplification spike contains 20% natural-abundance isotope, balance enriched isotope. The molecular amplification spike may optionally contain more than 20% natural-abundance isotope, with concomitantly reduced balance of enriched isotope. Such an admixed spike, when added to a sample prior to mass spectrometric analysis of that sample, creates new and significantly improved percentage of errors and quantification or confirmation of the absence of the molecule, composition, compound or element of interest in the sample.

Tryptophan degradation is a key metabolic pathway controlling immune reactions and evidence suggests that during cancer progression generation of tryptophan metabolites may be fundamental for immune escape promoting the malignant phenotype of cancer cells in an autocrine fashion. The present invention relates to methods of measuring mass tag labelled tryptophan and metabolites thereof and methods using the labelled molecules for monitoring in a subject the effectiveness of a treatment and of disease recurrence after treatment, for stratifying patients and for diagnosing suppression of an immune response in a subject.

A magnetic bead is respectively modified by two functional molecular layers from the inside out, termed as the polyethylene glycol (PEG) passivation layer and the photo-affinity peptide probe layer, respectively; PEG passivation layer is introduced at the surface of a magnetic bead, forming a PEG-modified magnetic bead, and the photo-affinity peptide probe layer is a molecular layer of peptide whose N-terminal end is modified with the thiol group and the diazirine group; the PEG passivation layer on the capture magnetic bead is used to reduce non-specific interaction of protein molecules, while the photo-affinity peptide probe layer can specifically recognize and capture target proteins; the weak interaction between the photo-affinity peptide probe and target proteins is converted to covalent linkage under the UV irradiation, thus achieving specific and efficient capture and magnetic separation of interacted proteins.

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.

A separation time of an isomer of one or more isomers of a sialylated glycopeptide of a sample is calculated from a peak of a precursor XIC. Product ion intensities of the first group are summed at the separation time producing a first sum and product ion intensities of the second group are summed at the separation time producing a second sum using XICs of the first and second groups. A ratio of the first sum to the second sum is calculated. The ratio at the separation time is compared to predetermined ratio ranges that each corresponds to a combination of a selection from a set of the first linkage and the second linkage taken one or more times. One or more linkages of the sialic acid to the glycan of the isomer are identified from a combination found to match the ratio in the comparison.