Abstract: The nucleic acid probe of the invention is a nucleic acid probe for detecting a trace amount of target nucleic acid highly sensitively, highly accurately, and highly quickly, and is designed so that the nucleic acid probe undergoes a conformational change after hybridization to the target nucleic acid and that the nucleic acid probe, which underwent the conformational change, has a decreased binding strength of hybridization and dissociates from the target nucleic acid, where the conformational change comprises forming a self-cleaving nucleic acid enzyme intramolecularly and the self-cleaving nucleic acid enzyme has cleavage activity toward a cleavage portion within the nucleic acid probe's own molecule.

Abstract: A method of forming a self-connective structure (a hairpin structure, a four-stranded structure, etc.) of a single-stranded oligonucleotide chain by forming a mimetic base pair of a mismatch base pair failing to form any normal base pair among base pairs of the single-stranded oligonucleotide chain with the use of a compounds represented by the following general formula (I): A-L-B (I) wherein A represents a chemical structural moiety capable of forming a pair with one base of a base pair failing to form any normal base pair; B represents a chemical structural moiety capable of forming a pair with the other base of the base pair failing to form any normal base pair; and L represents a linker structure by which the chemical structures A and B are linked to each other; and a method of inhibiting the activity of enzyme according to the previous method.

Abstract: A method of forming a self-connective structure (a hairpin structure, a four-stranded structure, etc.) of a single-stranded oligonucleotide chain by forming a mimetic base pair of a mismatch base pair failing to form any normal base pair among base pairs of the single-stranded oligonucleotide chain with the use of a compounds represented by the following general formula (I): A—L—B (I) wherein A represents a chemical structural moiety capable of forming a pair with one base of a base pair failing to form any normal base pair; B represents a chemical structural moiety capable of forming a pair with the other base of the base pair failing to form any normal base pair; and L represents a linker structure by which the chemical structures A and B are linked to each other; and a method of inhibiting the activity of enzyme according to the previous method.

Abstract: A method whereby a mismatched base pair in a nucleic acid such as DNA or RNA can be conveniently and highly sensitively detected; and detection reagents therefor.