A universal mismatch-directed signal amplification platform for ultra-selective and sensitive DNA detection under mild isothermal conditions

We describe a novel mismatch-directed signal amplification method which can be performed easily under mild isothermal conditions for the ultra-selective and sensitive detection of any DNA sequence of interest. By taking advantage of the unique discrimination properties of an endonuclease IV and lambda exonuclease coupling system in cleavage reactions of DNA duplexes containing apurinic/apyrimidinic sites with different adjacent mismatched bases, the established assay enables sensitive detection of 1.0 fmol of target strand and selective differentiation of 0.5% target strand from single-base different sequences at 37 °C without the need for temperature adjustment.