Patent ID: 7250257

Claim:
A method of detecting a mismatching region, comprising the steps of: i) subjecting a labeled polynucleotide, which has been labeled with a labeling substance, to hybridization with a plurality of oligonucleotide probes, wherein said oligonucleotide probes have been fixed respectively to a plurality of regions on a supporting material, ii) causing a first enzyme to act upon a single-stranded moiety of the labeled polynucleotide, which moiety has failed to form a double strand with each of the plurality of the oligonucleotide probes having been respectively fixed to the plurality of the regions on the supporting material, wherein the first enzyme decomposes a single-stranded polynucleotide from a terminal of the labeled polynucleotide, the single-stranded moiety of the labeled polynucleotide being thereby separated from a double strand, which has been formed by the labeled polynucleotide and each of the oligonucleotide probes, iii) detecting a signal, which is obtained from the labeling substance of the labeled polynucleotide, with respect to each of the regions on the supporting material after the single-stranded moiety of the labeled polynucleotide has been separated from the double strand, which has been formed by the labeled polynucleotide and each of the oligonucleotide probes, first detection data being obtained from the signal detection, iv) causing a second enzyme to act upon a mismatching moiety, at which the labeled polynucleotide and a certain oligonucleotide probe among the plurality of the oligonucleotide probes having been respectively fixed to the plurality of the regions on the supporting material have undergone a mismatch binding with each other, after the first detection data has been obtained, wherein the second enzyme cuts off the mismatching moiety, at which the labeled polynucleotide and the certain oligonucleotide probe have undergone the mismatch binding with each other, being thereby separated from a region on the supporting material, to which region the mismatch polynucleotide has been bound, v) detecting a signal, which is obtained from the labeling substance of the labeled polynucleotide, with respect to each of the regions on the supporting material after the mismatching moiety has been separated from the region on the supporting material, to which region the certain oligonucleotide probe has been fixed, second detection data being obtained from the signal detection, vi) making a comparison between the first detection data and the second detection data, and vii) specifying the region on the supporting material, to which region the mismatch polynucleotide was bound, in accordance with results of the comparison, thereby detecting a mismatching region.