Methods for peptide and/or protein quantification by mass spectrometry using labeled peptides, wherein multiple labels lead to distinct fragments for the labeled peptides and their unlabeled variant, thus facilitating data analysis and enhancing the potential for quantification. Methods for selecting the label and label position are further given, as well as sets of labeled peptides resulting from or for use in the above-mentioned methods. The methods and substances are especially useful for data-independent or multiplexed parallel reaction monitoring proteomics applications involving peptide quantification.

The invention relates to a method of determining glycan moiety on a recombinant glycoprotein using condensation nucleation light scattering detection.

Immunoglobulin light chain proteins are used to generate synthetic fibrils in vitro. The fibrils are mixed with immunoglobulin light chain proteins from a biological sample. In either a direct binding assay, competition assay, or dilution-based competition assay, a signal is detected from the mixture. The intensity of the detectable signal relates to the level of binding between the immunoglobulin light chain proteins to the fibrils and can thus be used to identify amyloidogenic immunoglobulin light chain proteins in a biological sample of the subject and to assess amyloidogenic risk to a subject. For example, the signal intensities from the assays can be used in a comparison to one or more threshold (control) values derived from samples of known light chain types or in the absence of light chains. The comparisons permit identification of amyloidogenic proteins, assessment of amyloidogenic risk, and categorization of the subject into an appropriate “at risk” group.

The present disclosure provides a group of diagnostic biomarkers usable for diagnosis of colorectal cancer or colorectal adenoma. A method for detecting colorectal cancer or colorectal adenoma using the group of diagnostic biomarkers is also provided. For example, the method provided by the present disclosure is a non-invasive approach that may utilize serum samples for detecting colorectal cancer. Moreover, the method for detecting colorectal cancer may detect colorectal cancer of different stages (e.g., pre-cancer stage, early stage, middle stage, late stage).

The disclosure relates to methods of analyzing a post-translationally modified protein of interest using electrophoresis, the methods comprising deglycosylating the protein of interest after labeling.

Some embodiments relate to nanoparticle probes for the detection of disease states in a patient or for tissue engineering. In some embodiments, the nanoparticle probe comprises one or more slip bonds that bind to a cell surface structure. In some embodiments, the binding of the nanoparticle probe is selective. In some embodiments, the nanoparticle probe binds to cells having a certain maximum glycocalyx thickness.

A method for simultaneously detecting an exosome membrane protein and mRNA is provided. The method can perform simultaneous detection on exosomes separated and purified from the same sample by labeling an exosome membrane protein with a fluorescent antibody and labeling a target gene mRNA with a molecular beacon, wherein labeling the exosome with the molecular beacon is specifically performed by means of an in-situ exosome capture well plate or chip, and each well or chip in the in-situ exosome capture well plate includes a fluorescein-labeled molecular beacon; and the molecular beacon is a specific DNA probe for detecting the target gene mRNA. The present invention utilizes an in-situ exosome capture well plate or chip technology to detect a biomarker gene mRNA contained in an exosome of a biological sample.

Provided herein are methods, systems, and kits for improving success rates in assisted reproductive technologies such as in vitro fertilization, frozen embryo transfer, and intrauterine insemination. These methods, systems, and kits rely on levels of protein, metabolite, and microRNA markers determined herein to be linked to uterine toxicity and embryo implantation failure.

Methods for preparing labeled glycosylamines from a complex matrix are provided. The methodology includes the steps of: denaturing glycoproteins in a complex matrix to form a denatured complex matrix mixture; loading the denatured complex matrix mixture onto a MWCO filtration device; adding a glycosidase enzymatic solution onto the MWCO filtration device to form a deglycosylated complex matrix mixture comprising glycosylamines; collecting glycosylamines released from the MWCO filtration device; and derivatizing glycosylamines with a rapid tagging reagent to form a plurality of labeled glycosylamines suitable for detection in various liquid chromatography systems and detectors.

The present invention provides compositions comprising chimeric polypeptides that bind to free ubiquitin proteins or free ubiquitin-like proteins with high affinity, as well as chimeric polypeptides that bind to both free and conjugated ubiquitin proteins or free and conjugated ubiquitin-like proteins, and methods of using the chimeric polypeptides to determine the amount of free or total ubiquitin or free or total ubiquitin-like proteins in various types of samples.