Abstract: Provided are techniques by which a mutant gene in a gene group comprising a large number of wild-type genes can be detected with high sensitivity and in a rapid and simple way. Provided is a method for measuring a nucleic acid for the purpose of specifically detecting a genotype as an examination target from subjects which are genes or specimens likely to have a plurality of genetic polymorphisms, wherein the measurement method comprises hybridizing a fluorescent dye-labeled oligonucleotide with a genotype other than the examination target to suppress the gene amplification of such genotype while at the same time, hybridizing the same fluorescence-labeled oligo as described above with an amplification product derived from the genotype of the examination target amplified in the same gene amplification step as described above, and specifically detecting the genotype of the examination target based on a change in the fluorescence intensity of the fluorescent dye before and after the hybridization.

Abstract: [Problems] To provide a novel mixture for assaying a target nucleic acid, characterized by enabling a nucleic acid assay while: 1) requiring no step of diluting the target nucleic acid; 2) requiring no procedure of changing a probe concentration depending on a concentration of the target nucleic acid. [Means for Solving Problems] 1) A mixture which comprises one internal standard nucleic acid and two nucleic acid probes labeled with a fluorescent dye; 2) a mixture for measuring Km value which comprises one internal standard nucleic acid having a partial mutation and one nucleic acid probe labeled with a fluorescent dye; 3) a mixture which comprises one internal standard nucleic acid and one double nucleic acid probe labeled with two fluorescent dyes; and a method for assaying a nucleic acid by making use thereof.

Abstract: Objects are to provide nucleic acid probes, which in the detection of target nucleic acids with fluorescent quenching probes, can assay a greater variety of target nucleic acids at the same time while suppressing increases in assay labor and cost, and also a method for assaying target nucleic acids by using the nucleic acid probes. Provided is a nucleic acid probe having a base sequence hybridizable with a target nucleic acid sequence in a target nucleic acid.

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.