Patent ID: 7862998

Claim:
A method of detecting a target gene, comprising forming a signal probe polymer by contacting: a pair of first and second probes: the first probe having three nucleic acid regions, which includes a nucleic acid region X, a nucleic acid region Y, and a nucleic acid region Z in the stated order from the 5â€² end; the second probe having three nucleic acid regions, which includes a nucleic acid region Xâ€², a nucleic acid region Yâ€², and a nucleic acid region Zâ€² in the stated order from the 5â€² end; wherein the nucleic acid regions X and Xâ€², the nucleic acid regions Y and Yâ€², and the nucleic acid regions Z and Zâ€² are complementary regions capable of hybridizing with each other, respectively; an assist probe having a plurality of the same nucleic acid regions as in the first probe and a target region capable of hybridizing with a target gene; wherein the assist probe comprises the nucleic acid regions X, Y, and X, and the target region in the stated order from the 5â€² end, or comprises the target region, and the nucleic acid regions Z, Y, and Z in the stated order from the 5â€² end; and the target gene; wherein the nucleic acid regions X and Xâ€², the nucleic acid regions Y and Yâ€², and the nucleic acid regions Z and Zâ€² of the pair of first and second probes and the assist probe hybridize to each other and wherein the target gene is detected.