Abstract: Relative quantification of metabolites by Electrospray Ionization Mass Spectrometry (ESI-MS) requiring a mechanism for simultaneous analysis of multiple analytes in two or more samples. Labeling reagents that are reactive to particular compound classes and differ only in their isotopic kit facilitating relative quantification and providing tangible evidence for the existence of specific functional groups. Heavy and light isotopic forms of methylacetimidate were synthesized and used as labeling reagents for quantification of amine-containing molecules, such as biological samples. Heavy and light isotopic forms of formaldehyde and cholamine were also synthesized and used independently as labeling reagents for quantification of amine-containing and carboxylic acid-containing molecules, such as found in biological samples. Advantageously, the labeled end-products are positively charged under normal acidic conditions involving conventional Liquid Chromatography Mass Spectrometry (LC/MS) applications.

Abstract: Disclosed are a method and a corresponding composition of matter for detecting single nucleotide polymorphisms. The composition of matter includes a metal substrate, a probe oligonucleotide immobilized on the substrate; and an upstream oligonucleotide either immobilized on the substrate or in a solution in contact with the substrate. The probe oligonucleotide and the upstream oligonucleotide participate cooperatively in an invasive cleavage reaction when the substrate is contacted with a cleavage agent and a target nucleic acid. Under proper reactions conditions, the probe oligonucleotide, the upstream oligonucleotide, the target nucleotide, and the cleavage agent cooperative result in the formation of a cleavage product at or near the location of a single nucleotide polymorphism of interest.

Abstract: A high-throughput method of distinguishing at least one molecule individually in a sample comprising multiple molecules, which method comprises: subjecting a sample comprising multiple molecules, at least one molecule of which is detectably labeled, to electrophoresis; imaging the electrophoretic mobility of each detectably labeled molecule over time by detecting the position of the detectable label of each detectably labeled molecule over time, and, optionally, at the same time, dispersing the imaging by a transmission grating for spectroscopic analysis, and determining the electrophoretic mobility of each detectably labeled molecule and, optionally, determining the molecular spectrum of each detectably labeled molecule, thereby distinguishing at least one molecule individually in a sample comprising multiple molecules, and a system for use in such a method.