METHOD FOR DETECTING DNA POLYMORPHISM WITH TRIPLE- STRANDED DNA FORMATION TECHNIQUE APPLIED THERETO

摘要

PROBLEM TO BE SOLVED: To provide a method for efficiently detecting DNA polymorphism in high sensitivity without the need of a long DNA searching region. SOLUTION: It has been known that RecA as a homologous recombinant protein forms a partially three-stranded DNA from a targeted double-stranded DNA and the complementary oligonucleotide probe, and the three-stranded DNA stably maintains its three-stranded DNA structure even after removing the RecA protein. This method for efficiently detecting DNA polymorphism in a targeted DNA is based on the finding that the thermal stability of the three-stranded DNA structure changes significantly when a polymorphism exists in a target DNA and a mismatch with an oligonucleotide probe is formed, thus comprises the steps of heat-treating a three-stranded DNA formed by a homologous recombinant protein by making use of the above-mentioned thermal stability change, and investigating whether an oligonucleotide probe is liberated and the three-stranded DNA is dissociated or not.