Abstract: A nucleic acid probe set includes (A) a fluorescent probe and (B) a binding probe. The fluorescent probe (A) is formed of an oligonucleotide, which includes (a) a nucleotide unit labeled with (d) a fluorescent substance. The binding probe (B) is formed of an oligonucleotide having (b1) a fluorescent probe binding region, which can hybridize to the fluorescent probe (A), and (b2) a target nucleic acid binding region, which can hybridize to a target nucleic acid sequence (C). The fluorescent substance (d) is a fluorescent substance which changes in fluorescent character upon interaction with guanine. At least one of nucleotide units which constitute the fluorescent probe (A) is an artificial nucleotide unit having a function to raise a dissociation temperature between the probe (A) and the fluorescent probe binding region (b1). The nucleic acid probe is provided with an improved fluorescence quenching efficiency.

Abstract: A nucleic acid probe set includes (A) a fluorescent probe and (B) a binding probe. The fluorescent probe (A) is formed of an oligonucleotide including (a) a nucleotide labeled with a fluorescent substance. The binding probe (B) is formed of an oligonucleotide having (b1) a fluorescent probe binding region, to which the fluorescent probe (A) can hybridize, and (b2) a target nucleic acid binding region, which can hybridize to a target nucleic acid (C). The nucleic acid probe set is designed such that, when the fluorescent probe (A) hybridizes to the fluorescent probe binding region (b1) and the target nucleic acid (C) hybridizes to the target nucleic acid binding region (b2), guanine in the target nucleic acid (C) and the fluorescent substance (d) labeled on the nucleotide (a) interact with each other to change a fluorescent character of the fluorescent substance (d).