The present disclosure provides methods, compositions, and kits for the rapid release, labeling, and detection of O-glycans present on a glycoconjugate, such as a glycoprotein, glycopeptide, peptidoglycan, or proteoglycan of interest. The compositions and methods allow the released O-glycans to be subjected to high-throughput analysis.

Disclosed herein are glyco-decoy acceptor compositions that sidetrack or inhibit the activity of biosynthetic enzymes participating in synthesis of ligands binding at selectin, galectin and siglecs receptors; methods of their preparation and uses in drug discovery and in treatments of diseases.

The invention relates to methods for the quantification of glycoproteins in a sample, comprising quantifying said glycoproteins by comparison with an internal standard, wherein said internal standard comprises variant forms of said glycoproteins, wherein said variant forms contain only core Asn-linked GlcNAc moieties.

Predicting recurrence of hepatocellular carcinoma (HCC) after liver transplantation. The disclosure indeed discloses a set of biomarkers present in a serum sample taken from a HCC patient before liver transplantation, which can be used to assess recurrence of HCC after liver transplantation. More specifically, the disclosure discloses a process to predict the recurrence of HCC after liver transplantation via determining the amount of at least four specific N-glycans in a serum sample.

The invention relates to the analysis of carbohydrates, such as N-glycans and O-glycans found on proteins. The invention relates, in part, to glycan labeling with formulas/compounds enhancing their detection and/or analysis by methods such as capillary electrophoresis, liquid chromatography and mass spectrometry. These detection methods may be useful in studying glycosylation patterns of biological or medical samples, or for assessing protein production, protein quality/purity, for comparing innovator and biosimilar glycosylated proteins, or for selecting proteins with the desired glycosylation.

The invention provides methods and tools, for example, glycan arrays, for the analysis of glycans and anti-glycan antibodies. Embodiments of the invention may be used to detect proteins, antibodies, diseases and/or pathogenic agents. In other embodiments, methods of the invention are used to develop or optimize arrays and antibodies.

Described herein are methods for diagnosing high-risk cancer in a subject by detecting PolySialic Acid (polySia) in a biological sample obtained from the subject, or by detecting polySia and one or more tissue-specific markers in a biological sample obtained from the subject.

Mass spectrometry (MS) active, fluorescent rapid tagging reagent is provided having three substituent groups: (a) a tertiary amino group or other MS active atom; (b) a highly fluorescent moiety; and (c) a reactive group that can react with an amine. The reactive group provides rapid tagging of desired bio-molecules. The fluorescent moiety provides the fluorescent signal. The tertiary amino group provides the MS signal.

The present teachings relate to methods, systems, and kits for the preparation, purification and/or analysis of a glycan or glycoconjugate, and specifically to a magnetic bead based sample preparation protocol. In some aspects, the sample preparation protocol can provide for glycoconjugate capture, glycan release, fluorescent derivatization, and glycan purification for subsequent capillary electrophoresis, liquid chromatography, or other glycoanalytical method using magnetic beads containing negatively charged carboxyl groups extending from the surface of the magnetic beads.

Disclosed herein are glyco-decoy acceptor compositions that sidetrack or inhibit the activity of biosynthetic enzymes participating in synthesis of ligands binding at selectin, galectin and siglecs receptors; methods of their preparation and uses in drug discovery and in treatments of diseases.