Abstract: The invention relates to a stabilizer for L-012 or a salt thereof, a stabilization method for L-012 or a salt thereof, coexisting with the stabilizer and L-012 or a salt thereof, and the like. The stabilizer is represented by Formula [1]: wherein p pieces of M1 each independently represent a hydrogen atom or an alkali metal atom, q pieces of R1 each independently represent a hydroxy group or a sulfonic acid group, m represents 0 or 1, p represents an integer of 1 to 3, q represents an integer of 0 to 4, Y represents a nitrogen atom or a CH group (a methine group), and Z represents an aryl group having a specific structure or a pyrazolyl group having a specific structure.

Abstract: The invention relates to a stabilizer for L-012 or a salt thereof, a stabilization method for L-012 or a salt thereof, coexisting with the stabilizer and L-012 or a salt thereof, and the like. The stabilizer is represented by Formula [1]: wherein p pieces of M1 each independently represent a hydrogen atom or an alkali metal atom, q pieces of R1 each independently represent a hydroxy group or a sulfonic acid group, m represents 0 or 1, p represents an integer of 1 to 3, q represents an integer of 0 to 4, Y represents a nitrogen atom or a CH group (a methine group), and Z represents an aryl group having a specific structure or a pyrazolyl group having a specific structure.

Abstract: This invention provides methods and compositions, e.g., to reduce interference from non-specific binding sample constituents in a migration shift assay. Interference due to non-specific binding of sample constituents to an affinity substance (e.g., an affinity molecule or a conjugate of an affinity molecule and a charged carrier molecule) is prevented by, e.g., binding the constituents to charged polymers such as heparin sulfate. The present invention also provides methods to concentrate an analyte of interest with high concentration and to detect the analyte with high sensitivity, and further to optimize the reaction conditions for easily concentrating the analyte. Such objects of the present invention are attained, for example, by concentrating a complex of the analyte and a conjugate which is formed by contacting the analyte in a sample with an affinity molecule bound to a charged carrier molecule such as DNA.

Abstract: The present invention addresses the problem of providing a chelate color former which can measure the concentration of iron with high sensitivity and with low blank values when measuring the concentration of iron, and an iron concentration measurement method and kit that use this chelate color former. The present invention relates to: a compound represented by following formula [1] or a salt thereof wherein, R1 and R2 each independently represent —SO3H or —CO2H; an iron concentration measurement method in which the compound is used as a chelate color former, the compound is brought into contact with iron in a sample, and the concentration of iron in the sample is measured on the basis of the degree of resulting color development; and a kit to be used therein.

Abstract: The present invention addresses the problem of providing a chelate color former which can measure the concentration of iron with high sensitivity and with low blank values when measuring the concentration of iron, and an iron concentration measurement method and kit that use this chelate color former. The present invention relates to: a compound represented by following formula [1] or a salt thereof wherein, R1 and R2 each independently represent —SO3H or —CO2H; an iron concentration measurement method in which the compound is used as a chelate color former, the compound is brought into contact with iron in a sample, and the concentration of iron in the sample is measured on the basis of the degree of resulting color development; and a kit to be used therein.

Abstract: This invention provides methods and compositions, e.g., to reduce interference from non-specific binding sample constituents in a migration shift assay. Interference due to non-specific binding of sample constituents to an affinity substance (e.g., an affinity molecule or a conjugate of an affinity molecule and a charged carrier molecule) is prevented by, e.g., binding the constituents to charged polymers such as heparin sulfate. The present invention also provides methods to concentrate an analyte of interest with high concentration and to detect the analyte with high sensitivity, and further to optimize the reaction conditions for easily concentrating the analyte. Such objects of the present invention are attained, for example, by concentrating a complex of the analyte and a conjugate which is formed by contacting the analyte in a sample with an affinity molecule bound to a charged carrier molecule such as DNA.