Nucleic acid sequence measurement method and nucleic acid sequence measurement kit

A nucleic acid sequence measurement method for measuring a target having a specific nucleic acid sequence included in a sample by hybridization, comprising:

• (a) a step of adding a label molecule A into a sample solution including the target;
• (b) a step of subjecting the target and the label molecule A to a hybridization reaction to form a complex of the target and the label molecule A in the sample solution;
• (c) a step of adding a label molecule B to the sample solution;
• (d) a step of supplying the sample solution to a solid-phase surface of a substrate on which a detection probe is fixed;
• (e) a step of subjecting the complex of the target and the label molecule A to a hybridization reaction with the label molecule B and the detection probe;
• (f) a step of separating an aggregate consisting of the target not binding to the detection probe, the label molecule A, and the label molecule B, and an aggregate consisting of the label molecule A and the label molecule B from the solid-phase surface;
• and
• (g) a step of irradiating the solid-phase surface with excitation light and measuring a quantity of fluorescence emitted from the solid-phase surface;
• wherein the detection probe has a detection part that is a sequence complementary to the nucleic acid sequence of the target,
• the label molecule A has a nucleic acid sequence complementary to the nucleic acid sequence of the target and different from the nucleic acid sequence of the detection part,
• the label molecule B has a nucleic acid sequence complementary to the nucleic acid sequence of the label molecule A,
• the label molecule A and the label molecule B bind to each other at at least two or more sites, and
• a fluorescent molecule is attached to a predetermined position of both of the label molecule A and the label molecule B,
• wherein the label molecule A has a part x near the 3′ end, a part y near the 5′ end, and a part z that is a nucleic acid sequence complementary to the nucleic acid sequence of the target and different from the nucleic acid sequence of the detection part,
• the label molecule B has a part X near the 3′ end and a part Y near the 5′ end,
• the nucleic acid sequence of the part x is complementary to the nucleic acid sequence of the part X and the nucleic acid sequence of the part y is complementary to the nucleic acid sequence of the part Y, and
• two or more of either one or both of the parts x and the parts y are provided in the label molecule A and two or more of either one or both of the parts X and the parts Y are provided in the label molecule B.