Method and kit for concentrating target double-stranded nucleic acid molecules using a pyrrole-imidazole-containing polyamide

A method of separating a target double-stranded nucleic acid molecule from a sample, comprising:

• mixing a sample, a first PI polyamide, a first carrier, a second PI polyamide, and a second carrier such that a mixed solution comprising the sample, the first PI polyamide, the first carrier, the second PI polyamide, and the second carrier is obtained;
• forming a complex A by binding the first carrier to the first PI polyamide with which a target double-stranded nucleic acid molecule in the sample is bound in the mixed solution and a complex B by binding the second carrier to the second PI polyamide with which a non-target double-stranded nucleic acid molecule in the sample is bound in the mixed solution;
• removing the complex B from the mixed solution;
• and
• separating the complex A from the mixed solution,
• wherein the first PI polyamide is a pyrrole-imidazole-containing polyamide which is modified with a first linker molecule, includes a plurality of β-alanine moieties such that the pyrrole-imidazole-containing polyamide has at least one β-alanine moiety in every two residues or three residues in a sequence of the pyrrole-imidazole-containing polyamide, and specifically binds to a sequence of the target double-stranded nucleic acid molecule, the first carrier is modified with a first ligand molecule which specifically binds or adsorbs to the first linker molecule, the second PI polyamide is a pyrrole-imidazole-containing polyamide which is modified with a second linker molecule and specifically binds to a sequence of the non-target double-stranded nucleic acid molecule, the second carrier is modified with a second ligand molecule which specifically binds or adsorbs to the second linker molecule, and a content of the target double-stranded nucleic acid molecule for separating the target double-stranded nucleic acid molecule from the sample is less than 1% in the sample.