Abstract: To provide a method and kit for measurement of a target substance with high detection sensitivity, provided is a method of measuring at least any one of the presence or absence, and a concentration, of a target substance in a sample liquid, the method including the steps of: (a) preparing a first particle that specifically binds to the target substance and contains a rare earth complex, and a second particle that has a larger average particle diameter than that of the first particle and specifically binds to the target substance; (b) mixing the sample liquid, the first particle, and the second particle to provide a mixed liquid; and (c) determining at least any one of the presence or absence, and the concentration, of the target substance from polarization anisotropy of the mixed liquid obtained in the step (b).

Abstract: Provided is a particle having high detection sensitivity in the detection of a substance to be measured, such as an antigen or an antibody, from a body. The particle includes a rare earth complex, wherein the particle has a particle size distribution of 0.1 or less in terms of polydispersity index (pdi) measured by dynamic light scattering, and wherein the particle has a hydrophilic polymer on a surface thereof.

Abstract: A silica aggregate includes primary silica particles aggregated, the primary silica particles having an average particle size of 1 nm or more and less than 10 nm, the primary silica particles being crosslinked to each other by a bond containing a siloxane bond.

Abstract: A particle including a polymer which has a repeating unit derived from a vinyl-based monomer. The particle has a specific structure containing a carboxy group, and a surface of the particle contains a water-soluble polymer.

Abstract: Provided are a reagent and a measurement method for enabling a specimen test based on polarization anisotropy to be performed with high sensitivity and within a short period of time. Specifically, provided is an analysis method including measuring a value (R) for polarization anisotropy through use of a luminescent reagent that binds with a target substance, the analysis method including: a reaction step including mixing a sample containing the target substance with the luminescent reagent and a sensitizer, and subjecting the mixture to a reaction to obtain a reaction liquid; and a measurement step of measuring the R of the reaction liquid, the luminescent reagent including a luminescent particle substrate and a hydrophilic layer arranged on an outside of the luminescent particle substrate, the sensitizer containing a hydrophilic polymer.

Abstract: To perform measurement based on polarization anisotropy in which a reaction between a target substance and a luminescent reagent is performed within a short period of time, and in which high-sensitivity measurement can be performed, provided is an analysis method including measuring a value (R) for polarization anisotropy through use of a luminescent reagent that reacts with a target substance, to thereby determine at least any one of the presence or absence of the target substance and a concentration of the target substance, the analysis method including: a reaction step of mixing a sample containing the target substance with the luminescent reagent, and subjecting the mixture to a reaction to obtain a reaction liquid; a dilution step of diluting the reaction liquid to obtain a diluted liquid; and a measurement step of measuring the R of the diluted liquid, the luminescent reagent including luminescent particles.

Abstract: Provided are a method of recovering cells cultured on a substrate, the method including: a step 1 of adding a cell detachment solution containing a metal ion chelating agent to the substrate having the cells adhering thereto to bring the cells into contact with the cell detachment solution; a step 2 of applying ultrasonic vibration to the substrate and the cells to detach the cells from the substrate; and a step 3 of obtaining the cells singulated from the cells detached in the step 2, and a cell recovery apparatus capable of implementing the method of recovering cells.

Abstract: A DNA complex includes a carrier and DNA immobilized on the carrier. 80% or more by mass of the DNA is single-stranded DNA, the DNA has an average molecular weight of 500,000 or less, and the DNA content is more than 15% by mass and 50% or less by mass of the DNA complex. The carrier contains an inorganic material. The DNA complex has an average particle size of 10 ?m or more.

Abstract: Provided are a latex agglutination reagent containing polyoxazoline that is preferable for use in a latex agglutination reaction and has a high sensitization action of sensitivity while a non-specific reaction can be suppressed, and a method for measuring a target substance in a specimen by a latex agglutination method. A latex agglutination reagent used in a method for measuring a target substance in a specimen by a latex agglutination method using an insoluble carrier that carries an antibody or an antigen contains polyoxazoline having a repeating unit represented by the following General Formula (in Formula (1), R represents a hydrogen atom or a methyl group, an ethyl group, or a propyl group, and n is an integer of 100 or greater).

Abstract: To provide a method for producing a particle that can suppress non-specific adsorption without using BSA. A method for producing a particle, including: a first step of mixing a radically polymerizable monomer, an organic silane compound having a silicon atom to which an alkoxy group is bonded and having radical polymerizability, a radical polymerization initiator, a water-soluble polymer, and an aqueous medium to prepare an emulsion; and a second step of adding a specific reactive compound after the first step.

Abstract: The particle is a particle including, in a surface layer thereof, a copolymer having a repeating unit A having a side chain A having, at a terminal thereof, a carboxy group to be bonded to a ligand and a repeating unit B having a side chain B having a hydroxy group at a terminal thereof, wherein when the particle is dispersed in ion-exchanged water, the surface layer of the particle is hydrated to form a swollen layer, wherein the density of the carboxy groups to be incorporated into the swollen layer satisfies a value of from 0.04 group/nm3 to 0.15 group/nm3, and wherein the ratio of a particle diameter in water to be measured when the particle is dispersed in ion-exchanged water to a dry particle diameter to be measured when the particle is dried satisfies a value of from 1.10 to 1.40.

Abstract: Provided is a magnetic particle excellent in detection speed when a substance to be measured, such as an antigen or an antibody, is detected from a specimen. The particle includes a magnetic particle containing a magnetic material, wherein the magnetic particle has a resin on a surface, wherein the particle has a volume average particle diameter of 0.4 ?m or more and 1.5 ?m or less, wherein the particle has a density of 5.1 g/cm3 or more and 10.0 g/cm3 or less, and wherein the resin has a functional group capable of binding a ligand.

Abstract: To provide a polymer having a high tumor/blood ratio. The present invention provides a polymer represented by the following formula (P1): wherein in the formula (P1), R0 represents any of a residue or a functional group derived from a cationic polymerization initiator; L represents a linker and L may not be present; n represents an integer of 1 or more; D represents a dye backbone of a dye having absorption in the near-infrared region.

Abstract: A particle includes a copolymer including a repeating unit A having, in a side chain, a sulfide group or a secondary amine, and three or more hydroxy groups, and a repeating unit B having, in a side chain, at least one reactive functional group for binding a ligand, in which nonspecific adsorption is suppressed.

Abstract: The present disclosure provides a particle showing a small non-specific adsorption, having a reactive functional group for chemically bonding a ligand thereto, and being suitable for an agglutination method; a particle for the agglutination method having a ligand chemically bonded to the particle; a reagent, a kit and a method for detecting a target substance, each for in vitro diagnosis, each of which contains the particle. The particle includes a polymer having a unit having a linker A in a side chain, wherein when both terminals of the linker A are represented by X1 and X2, the linker A has a reactive functional group for chemically bonding a ligand thereto in one of X1 and X2; one of X1 and X2 includes an ester structure; and a sum of bonds between atoms linearly connecting X1 and X2 is 18 to 24 and the X1 and X2 contain CH2 or CH.

Abstract: The present invention provides a particle that shows a small non-specific adsorption, has a reactive functional group for chemically bonding a ligand thereto, and is suitable for an agglutination method. The particle includes a polymer having a unit having a side chain A and a unit having a side chain B, wherein the side chain A has a carboxyl group at a terminal thereof, and has an ester bond and an amide bond in a molecular structure thereof; the side chain B has an alkyl group at a terminal thereof; and a zeta potential at the time when the particles are dispersed in water is minus 40 mV or higher and minus 5 mV or lower.

Abstract: An object is to provide a polymer having a high tumor/blood ratio. The present invention provides a polymer represented by the following formula (P1): wherein in the formula (P1), R represents any of a residue derived from a polymerization initiator, or a functional group; A may not be present, and when present, A represents any of a low-molecular compound, a dye, a reporter molecule, a target-binding molecule, a polymer or D; L represents a linker and L may not be present; n1 represents an integer of 1 or more; and D represents a dye backbone of a dye having absorption in the near-infrared region.

Abstract: A silica aggregate includes primary silica particles aggregated, the primary silica particles having an average particle size of 1 nm or more and less than 10 nm, the primary silica particles being crosslinked to each other by a bond containing a siloxane bond.

Abstract: A DNA complex includes a carrier and DNA immobilized on the carrier. 80% or more by mass of the DNA is single-stranded DNA, the DNA has an average molecular weight of 500,000 or less, and the DNA content is more than 15% by mass and 50% or less by mass of the DNA complex. The carrier contains an inorganic material. The DNA complex has an average particle size of 10 ?m or more.

Abstract: A novel near-infrared dye-bound transferrin exhibiting a high absorption coefficient in the near-infrared wavelength region, a high tumor accumulation property, a high tumor/blood ratio and a high imaging contrast, and a contrast agent for photoacoustic imaging, including the same are provided. A compound is provided in which transferrin and an organic dye having a specified structure that absorbs light in the near-infrared wavelength region are covalently bound.