Nucleic acid detection and assay method by using mask oligonucleotide, and device for same

Through the present invention, a mask oligonucleotide is hybridized in regions on either side of a region in which an oligonucleotide probe is hybridized in a single-stranded region of a nucleic acid to be assayed, the region in which the probe is hybridized is thereby opened and the single-stranded region of the target nucleic acid is maintained in a stable state. By then subjecting the nucleic acid having such a single-stranded region to nucleic acid chromatography, the desired target nucleic acid is detected and quantified with high sensitivity by an extremely simple process.