US Patent 9845495 Method and kit for detecting target nucleic acid

[Problem] To provide a method for detecting a nucleic acid (such as DNA and RNA) under isothermal conditions, in particular a method by which a short-chain nucleic acid can be directly detected. [Solution] A method for detecting a target nucleic acid in a sample of the present invention comprises: (a) a step of preparing a first oligonucleotide which comprises, in the direction from 5′ to 3′, a first arbitrary sequence, an endonuclease recognition site that is used in a nicking reaction, and a sequence complementary to the target nucleic acid; (b) a step of carrying out a nucleic acid amplification reaction using the target nucleic acid contained in the sample as a primer in the presence of an endonuclease which recognizes the endonuclease recognition site that is used in a nicking reaction; and (c) a step of detecting an oligonucleotide which is obtained by the nucleic acid amplification reaction and comprises a sequence complementary to the first arbitrary sequence.