Universal nucleic acid probe set and method for utilization thereof

An oligonucleotide probe comprising nucleotide units including (a′) a nucleotide unit labeled with (h) a labeling substance, a part or all of said nucleotide units being an artificial nucleotide unit or units having a function to raise a dissociation temperature of the oligonucleotide probe from a complementary strand, said dissociation temperature of the oligonucleotide probe from the complementary strand being 100° C. or higher under normal pressure conditions.

A nucleic acid probe set comprising (A) one fluorescent probe, which is formed of an oligonucleotide including (a) a nucleotide unit labeled with (d) a fluorescent substance, and (B) one binding probe formed of an oligonucleotide having (b1) one fluorescent probe binding region, which can hybridize to the fluorescent probe (A), and (b2) one target nucleic acid binding region, which can hybridize to a target nucleic acid sequence (C), wherein the fluorescent substance (d) is a fluorescent substance which changes in fluorescent character upon interaction with guanine, the nucleotide unit (a) is a 3′-terminal nucleotide unit of the fluorescent probe (A), and the target nucleic acid binding region (b2) is located on a side of a 5′-end of the binding probe (B).