Abstract: The present invention provides a GG-specific mismatch endonuclease variant, a TT-specific mismatch endonuclease variant, and a GT/TG-specific mismatch endonuclease variant. The present invention also provides a mismatch specific cleaving reaction using said variant, a method for removing errors in a nucleic acid amplification reaction using a mismatch nuclease, a method for suppressing amplification of a nucleic acid having a specific base sequence during a nucleic acid amplification reaction, and a method for detecting a nucleic acid having a single base polymorphic mutation using said suppression method.

Abstract: A polypeptide having a mismatch endonuclease activity of recognizing a mismatch and cleaving the mismatch; a mismatch-specific cleavage reaction using the polypeptide; a method for removing an error in a nucleic acid amplification reaction utilizing the polypeptide; a method for inhibiting the amplification of a nucleic acid comprising a specific nucleotide sequence during a nucleic acid amplification reaction; and a method for detecting a nucleic acid having a single-nucleotide polymorphism mutation utilizing the inhibition method.

Abstract: A polypeptide having a mismatch endonuclease activity of recognizing a mismatch and cleaving the mismatch; a mismatch-specific cleavage reaction using the polypeptide; a method for removing an error in a nucleic acid amplification reaction utilizing the polypeptide; a method for inhibiting the amplification of a nucleic acid comprising a specific nucleotide sequence during a nucleic acid amplification reaction; and a method for detecting a nucleic acid having a single-nucleotide polymorphism mutation utilizing the inhibition method.

Abstract: An ink, which contains DNA and is hardly decomposed by an external stimulus such as ultraviolet light, heat, an acid or an alkali, is provided. A method of easily analyzing a DNA in an ink composition is also provided. An ink composition containing a DNA and having a water-tolerance at a certain level or higher is prepared. The DNA in a print that is produced by using the above ink composition is quickly extracted with water or an aqueous solution and analyzed. Furthermore, a DNA in a print that is produced by using an oil- and water-based ink composition containing the DNA is quickly extracted with water or an aqueous solution and analyzed.