Abstract: The present invention is intended to provide a novel fluorescent labeled single-stranded nucleic acid, by which the background of an exciton oligomer can be further reduced and the novel use thereof. The present invention relates to a labeled single-stranded nucleic acid having at least two fluorescent atomic group pairs that exhibit an exciton effect. The labeled single-stranded nucleic acid is characterized in that the emission peak wavelength of one of the fluorescent atomic group pairs (fluorescent atomic group pair A) is shorter than the excitation peak wavelength of the other fluorescent atomic group pair (fluorescent atomic group pair B), and the fluorescent atomic group pairs A and B have a Förster resonance energy transfer (FRET) effect. This fluorescent labeled single-stranded nucleic acid is usable as a primer for amplifying a target nucleic acid or a probe to be hybridized with a target nucleic acid.

Abstract: A method for detecting a target nucleic acid molecule of the present invention includes a step of associating a first and third probes labeled with a first fluorescent substance which is an energy donor with a second probe labeled with a second fluorescent substance which is an energy acceptor to form an associate in a nucleic acid molecule; and a step of emitting light with an excitation wavelength of the first fluorescent substance to the associate to detect the target nucleic acid molecule using fluorescence released from the second fluorescent substance in the associate as an indicator, wherein a region associating with the second probe is between a region associating with the first probe and a region associating with the third probe in the target nucleic acid molecule.

Abstract: The present invention provides a compound represented by the following chemical formula (I); a tautomer or stereoisomer of the compound; or a salt of the compound, the tautomer, or the stereoisomer. In the chemical formula (I), R1 and R2 are each a Group 1 element or a protecting group of an amino group and may be identical to or different from each other, or alternatively, R1 and R2 together may form a protecting group of an amino group. R3 is a Group 1 element or a protecting group of a hydroxy group. R4 is a Group 1 element or —PR5R6R7R8 (R5, R6, R7, and R8 are each a Group 1 element, a lone electron pair, a Group 16 element, a Group 17 element, or a protecting group of a phosphorus atom, and may be identical to or different from each other). J is a hydrogen atom or an arbitrary atomic group, A is a hydrogen atom, a hydroxy group, an alkyl group, an aralkyl group, an alkoxy group, an electron-withdrawing group, a silylene group, or a sulfide group, or alternatively, J and A together may form a linker.

Abstract: The present invention provides a nucleic acid probe that can achieve high detection sensitivity and high specificity in mutation detection, mismatch detection, etc. by the PCR method, a method for designing such a nucleic acid probe, and a method for detecting a target sequence. The nucleic acid probe includes a nucleic acid molecule, and the nucleic acid molecule includes a plurality of fluorescent dye moieties that exhibit an excitonic effect. At least two of the fluorescent dye moieties that exhibit an excitonic effect are bound to the same base or two adjacent bases in the nucleic acid molecule with each fluorescent dye moiety being bound via a linker (a linking atom or a linking atomic group). The extension-side end of the nucleic acid molecule is chemically modified, thereby preventing an extension reaction of the nucleic acid molecule.

Abstract: The present invention is intended to provide a novel fluorescent labeled single-stranded nucleic acid, by which the background of an exciton oligomer can be further reduced and the novel use thereof. The present invention relates to a labeled single-stranded nucleic acid having at least two fluorescent atomic group pairs that exhibit an exciton effect. The labeled single-stranded nucleic acid is characterized in that the emission peak wavelength of one of the fluorescent atomic group pairs (fluorescent atomic group pair A) is shorter than the excitation peak wavelength of the other fluorescent atomic group pair (fluorescent atomic group pair B), and the fluorescent atomic group pairs A and B have a Förster resonance energy transfer (FRET) effect. This fluorescent labeled single-stranded nucleic acid is usable as a primer for amplifying a target nucleic acid or a probe to be hybridized with a target nucleic acid.

Abstract: The present invention provides a compound represented by the following chemical formula (I); a tautomer or stereoisomer of the compound; or a salt of the compound, the tautomer, or the stereoisomer. In the chemical formula (I), R1 and R2 are each a Group 1 element or a protecting group of an amino group and may be identical to or different from each other, or alternatively, R1 and R2 together may form a protecting group of an amino group. R3 is a Group 1 element or a protecting group of a hydroxy group. R4 is a Group 1 element or —PR5R6R7R8 (R5, R6, R7, and R8 are each a Group 1 element, a lone electron pair, a Group 16 element, a Group 17 element, or a protecting group of a phosphorus atom, and may be identical to or different from each other). J is a hydrogen atom or an arbitrary atomic group, A is a hydrogen atom, a hydroxy group, an alkyl group, an aralkyl group, an alkoxy group, an electron-withdrawing group, a silylene group, or a sulfide group, or alternatively, J and A together may form a linker.

Abstract: The present invention provides a nucleic acid probe that can achieve high detection sensitivity and high specificity in mutation detection, mismatch detection, etc. by the PCR method, a method for designing such a nucleic acid probe, and a method for detecting a target sequence. The nucleic acid probe includes a nucleic acid molecule, and the nucleic acid molecule includes a plurality of fluorescent dye moieties that exhibit an excitonic effect. At least two of the fluorescent dye moieties that exhibit an excitonic effect are bound to the same base or two adjacent bases in the nucleic acid molecule with each fluorescent dye moiety being bound via a linker (a linking atom or a linking atomic group). The extension-side end of the nucleic acid molecule is chemically modified, thereby preventing an extension reaction of the nucleic acid molecule.