Methods of analyzing a ligand-drug conjugate using acid-mediated cleavage and for implementing the methods are provided herein. Further provided include various application of the methods for analysis and development of a ligand-drug conjugate.

Methods are provided for detecting the amount of one or more HRT panel analytes (i.e., estrone (E1), estrone sulfate (E1s), 17-estradiol (E2a), 17-estradiol (E2b), estradiol sulfate (E2s), estriol (E3), equilin (EQ), 17-dihydroequilin (EQa), 17-dihydroequilin (EQb), Equilenin (EN), 17-dihydroequilenin (ENa), 17-dihydroequilenin (ENb), and 8,9-dehydroestrone (dE1)) in a sample by mass spectrometry. The methods generally involve ionizing one or more HRT panel analytes in a sample and quantifying the generated ions to determine the amount of one or more HRT panel analytes in the sample. In methods where amounts of multiple HRT panel analytes are detected, the amounts of multiple analytes are detected in the same sample injection.

Provided herein are methods for identifying new biomarkers for various diseases using proteomics, peptidomics, metabolics, proteoglycomics, glvcomics, mass spectrometry and machine learning. The present disclosure also provides glycopeptides as biomarkers for various diseases such as cancer and autoimmune diseases.

Systems, and methods that facilitate the performance of an assay of a sample substantially in real-time. Thus, the assay can be performed, and the desired result obtained, much more quickly than allowed by conventional systems and methods.

The present invention is related to a method for differential diagnosis of hereditary angioedema, wherein the method comprises determining the level of C4 protein, C1-INH protein and C1q protein in a sample from a subject, wherein the sample is a dried blood spot sample and wherein the level is determined by mass spectrometry.

Provided is a method for identifying proteins capable of increasing the number of identified proteins contained in a target sample derived from blood. A protein contained in the target sample derived from blood is fragmented, and a protein contained in an having less bias in a quantity ratio of proteins than the target sample is fragmented, and the fragmented proteins are mixed (Steps S101 to S103). In this manner, the mixed sample in which the bias in a quantity ratio of proteins is less than that of the target sample is generated. By performing MS/MS measurement using the generated mixed sample (Step S107), an MS/MS spectrum of a peak derived from a protein contained in a small amount in the target sample can be prevented from being missed. Accordingly, the number of identified proteins contained in the target sample derived from blood can be increased.

Described are dual mass-spectrometry-cleavable cross-linkers that can be cleaved selectively using two differential tandem mass-spectrometric techniques such as collision induced dissociation (CID) or electron transfer dissociation (ETD), i.e., a dual cleavable crosslinking technology (DUCCT) cross-linker. When used to cross-link a macromolecule, such as a peptide, MS/MS fragmentation produces two signature complementary mass spectra of same cross-linked peptides, the analysis of which gives rise to high confidence in characterizing the structures of the cross-linked macromolecules as well as sites of interactions. Also described, are methods of making and using DUCCT cross-linkers.

Methods, compositions and kits useful in the detection, assessment, diagnosis, prognosis and/or treatment of neurological injury or disease or brain injury, such as traumatic brain injury (TBI), are provided in which certain newly discovered protein biomarkers are detected in a biological sample of a subject undergoing testing or evaluation. The methods allow for detection of changes in levels, amounts, or concentrations of the protein biomarkers in a subject compared with those of controls. Detection of the protein biomarkers, and/or levels thereof, provides an indication of biological and biochemical events, e.g., at a cellular level, that are occurring in the subject who is undergoing testing or analysis for the neurological injury or brain injury.

This disclosure relates to the field of mass spectrometry analysis. In some embodiments, the disclosure relates to compositions and methods for detecting and quantifying proteins in the RAS-RAF-MAPK pathway by immunoprecipitation enrichment followed by mass spectrometry analysis.

There is provided a method of evaluating a liver condition of a subject, the method includes computing a fluctuation parameter from a liver breath test based on at least one of a percentage dose recovery (PDR) curve and a delta over baseline (DOB) curve of an isotope labeled methacetin, or a salt or a derivative thereof, and evaluating at least one liver condition of the subject, based at least on the fluctuation parameter. There is provided herein a method of evaluating a liver condition of a subject, the method includes computing a hepatic impairment score based at least on a breath test related parameter and on a demographic parameter.