Methods of isothermally unlocking double-stranded DNA and preparing single stranded DNA

The invention belongs to the molecular biological technical field and provides a method of isothermally unlocking a double-stranded DNA and a method of preparing a single stranded DNA based on the method. According to the technical scheme of isothermally unlocking the double-stranded DNA, a compound is formed by recombinase combined with a single stranded DNA probe, and the compound recognizes sequences homologous to the single stranded DNA probe in the double-stranded DNA and invades the double-stranded DNA, so that isothermal unlocking of the double-stranded DNA is achieved; and then the single stranded DNA probe is in complementary pair with one of the double chains while a single stranded combined protein is combined with other chain to stabilize the chain opening structure. Based on the scheme and the characteristic that the 3'-tail end of the single stranded DNA probe can be recognized by ligase and polymerase and the like, the invention also provides a scheme of preparing the single stranded DNA and introduces a scheme of preparing the single stranded DNA by means of ligase and elongase. The technical schemes are accomplished in an isothermal condition without an ATP circulating system, or even ATP can be replaced by dATP. The used enzymes are wide in source and easy to obtain, and a universal platform is provided for an isothermal technology taking the double-stranded DNA as a research object.