Crosslinking compounds for effective and efficient cross-linking and identification of intermolecular and intramolecular interactions of proteins, peptides and nucleic acids.

The present disclosure provides a method for measuring post-translational modifications in proteins such as antibodies. In particular, the method may be used to quantify C-terminal truncation in antibodies that incorporates heavy isotopic standards for both the unprocessed C-terminal K peptide and the truncated C-terminal K peptide to build a calibration curve and quantify this PTM using mass spectrometry. Quantification of post-translational modifications may occur in a single liquid chromatography tandem mass spectrometry (LC-MS.sup.2) run.

Aspects of the present application relate to techniques of diagnosing whether a pathogen (e.g., SARS-CoV-2) is present in a subject using infrared (IR) spectroscopy and machine learning techniques. The techniques use spectral data obtained from performing IR spectroscopy on a biological sample (e.g., saliva or nasal sample, or genetic material extracted therefrom) to generate a set of feature values. The feature values are provided as input to a machine learning model to obtain output indicating whether the pathogen is present in the biological sample. The output of the machine learning model may be used to determine a diagnosis result for a subject.

A method of isotope-labelling a microbiota sample. It involves providing a first microbiota sample that was obtained from a given source; exposing the first microbiota sample to an isotope enriched medium; and culturing the exposed first microbiota sample in the isotope enriched medium to obtain an isotope-labelled microbiota sample, wherein the isotope labelled metaproteome of the isotope-labelled microbiota sample is taxon specific for taxa present in the first microbiota sample when initially obtained from the given source.

A highly-sensitive-allergen-measurement method is provided. A method for detecting an allergen in a sample comprises treating the sample with a protease, and detecting the presence or absence of an allergen-derived polypeptide in the enzymatically treated sample by a chromatographic separation analysis, wherein the allergen is one or more members selected from the group consisting of buckwheat, crustacean, milk, egg and peanut.

An embodiment provides a method for identifying Covid-19 in a body fluid of a patient, including: removing the body fluid from a patient; applying a treatment to the body fluid, wherein the treatment comprises an antibody that joins with a Covid-19 targeted antigen (TA) in the body fluid to form an antibody-TA complex, wherein the antibody comprises a light functional antibody; identifying the antibody-TA complex, using a spectroscopic technique, from the body fluid using a light source; and returning the body fluid to the patient. Other aspects are described and claimed.

Process for in vitro diagnosis and/or monitoring and/or prognosis and/or theranosis of hepatic disorders from a biological sample originating from a subject, in which process the presence and/or the concentration of the marker ADH1B (SEQ ID NO.2) and/or the presence and/or the concentration of the combination of the markers ADH1B (SEQ ID NO.2) and ADH1A (SEQ ID NO.1) is determined.

The invention relates to a method to evaluate mass spectrometry data for the analysis of peptides from biological samples, particularly MALDI-TOF mass spectrometry data, comprising the following steps: a) provide expected mass defects; b) determine measured mass defects, i.e. the mass defects resulting from the mass spectrometry data; c) compare the measured mass defects with the expected mass defects.

The present disclosure provides a rapid, scalable, and high-throughput method of identifying the precise regions in a receptor protein which are involved in binding of a molecule of interest. The method of the instant disclosure is useful where the crystal structure of a protein of interest is not available. Also provided are surface display libraries, and methods of making the same.

The invention relates to the quantitative measurement of steroidal compounds by mass spectrometry. In a particular aspect, the invention relates to methods for quantitative measurement of steroidal compounds from multiple samples by mass spectrometry.