An object of the present invention is to provide a kit, a method, and a reagent which prevent the problem of false positive due to nonspecific adsorption, suppress the increase in noise to be generated, and are capable of achieving high-precision measurement of a measurement target substance in a wide concentration range from a low concentration to a high concentration. According to the present invention, there is provided a kit for measuring a measurement target substance, the kit including: a first particle having a label and modified with a first binding substance; a second particle having no label and modified with a second binding substance; a flow channel for flowing the first particle and the second particle; and a substrate having a third binding substance capable of specifically binding to the measurement target substance or a substance capable of binding to the first binding substance, in which the first particle having a label is a luminescent labeled particle containing at least one kind of compound represented by Formula (1) and a particle. ##STR00001## Each symbol in Formula (1) has the meaning described in the present specification.

A method for screening secretion-producing cells is provided, in which a cell that produces a secretion of interest is subjected to screening from a plurality of cells. The method includes capturing the cell and at least one detection particle that is allowed to capture the secretion of interest in each of a plurality of wells having a bottom section with a through-hole sized such that the cell does not pass through, causing the cell captured in each of the plurality of wells to produce a secretion, detecting the secretion of interest captured by the at least one detection particle, and identifying, based on a result of the detection as an index, a well in which a cell producing the secretion of interest is captured from the plurality of wells. Each of the wells has a size allowing the cell to be captured in one cell unit in a state in which one or more detection particles are captured.

Described herein are systems and methods for the discrete detection and quantification of target analytes in a sample based on their binding by two or more particles to form analyte-linked particle complexes. The analyte-linked particle complexes can be differentiated and enumerated versus unbound singlet particles based on the unique physical characteristics of the particles utilized. In some embodiments of the current invention, this may involve one type of analyte, while in other embodiments it may involve multiple different types of analytes, either individually or in analyte complexes.

Provided herein are structures and methods for detecting one or more analyte molecules present in a sample. In some embodiments, the one or more analyte molecules form a complex in solution with a supramolecular structure. The supramolecular structures of the complex may be detectable such that binding of the analyte molecule to a binding site of an array is detectable via one or more features of the supramolecular structure. A binding site of an array includes capture molecules to capture bound complexes to facilitate detection.

The present application relates to detection units and methods for detecting one or more target analytes in a sample using a complex formed by a target and first and second probes, wherein the complex comprises an elongated region, a particle that is coupled to the first probe, and a solid support that is coupled to the second probe. Specific binding of a target analyte can be distinguished from non-specific binding of the particle by measuring the displacement of the particle.

Provided herein are aptamers for binding lipoproteins, systems for binding lipoproteins, and methods of detecting lipoproteins in a sample. The aptamers are useful for detecting the levels of lipoproteins in a biological sample and selectively detecting LDL particles in the presence of HDL particles. The aptamers can also be used as therapeutic agents against various diseases.

Methods and devices are provided herein for identifying a cell population comprising an effector cell that exerts an extracellular effect. In one embodiment the method comprises retaining in a microreactor a cell population comprising one or more effector cells, wherein the contents of the microreactor further comprise a readout particle population comprising one or more readout particles, incubating the cell population and the readout particle population within the microreactor, assaying the cell population for the presence of the extracellular effect, wherein the readout particle population or subpopulation thereof provides a direct or indirect readout of the extracellular effect, and determining, based on the results of the assaying step, whether one or more effector cells within the cell population exerts the extracellular effect on the readout particle. If an extracellular effect is measured, the cell population is recovered for further analysis to determine the cell or cells responsible for the effect.

The disclosure provides compositions comprising at least one assembly comprising a peptide and a major histocompatibility complex (MHC), wherein the peptide is an integral component of the MHC, wherein the peptide is attached to a surface at its C-terminus through a linker and wherein the peptide is synthesized on the surface. In certain embodiments, the compositions comprise a plurality of assemblies in a spatially-ordered array. The disclosure provides methods for making and using these compositions.

The present application relates to detection units and methods for detecting one or more target analytes in a sample using a complex formed by a target and first and second probes, wherein the complex comprises an elongated region, a particle that is coupled to the first probe, and a solid support that is coupled to the second probe. Specific binding of a target analyte can be distinguished from non-specific binding of the particle by measuring the displacement of the particle.

Provided are an additive and a surface treatment agent capable of suppressing agglutination of latex particles contained in a reagent for a latex agglutination reaction during storage of the reagent although a synthetic polymer is contained as an active component. An additive is to be added to latex particles used in a reagent for a latex agglutination reaction. The latex particles have not been subjected to blocking treatment. The additive includes a polymer containing more than 60% by mass and 99% by mass or less of hydrophilic repeating units (A) relative to all repeating units and 1% by mass or more and less than 40% by mass of hydrophobic repeating units (B) relative to all repeating units, and having a weight average molecular weight of 3,000 or more.