Self-priming hairpin-mediated isothermal amplification

A hairpin probe comprising the following components and having a self-priming structure for detecting target nucleic acids:

• (i) a PS1 region disposed at a 5′ end of the hairpin probe, the PS1 region modified with phosphorothioate DNA, the PS1 region having a sequence complementary to a PS1′ region:
• (ii) an X region linked to the PS1 region, the X region disposed on a stem of the hairpin probe including a sequence complementary to a target nucleic acid;
• (iii) the PS1′ region disposed in a loop of the hairpin probe, the PS1′ region linked to the X region, the PS1′ region having a sequence complementary to the target nucleic acid following the sequence complementary to the target nucleic acid of the X region, the PS1′ region modified with phosphorothioate DNA;
• (iv) an L region linked to the PS1′ region, the L region having a sequence complementary to the target nucleic acid following the sequence complementary to the target nucleic acid of the PS1′ region, the L region disposed in the loop of the hairpin probe;
• (v) an a region of a self-priming hairpin, linked to the L region, the a region including a sequence complementary to a part of the X region to form a stem of the hairpin probe;
• (vi) a b region of the self-priming hairpin, linked to the a region of the self-priming hairpin, the b region including a sequence complementary to a part of the X region to form the stem of the hairpin probe;
• and
• (vii) an a′ region of the self-priming hairpin, disposed at a 3′ end of the hairpin probe, the a′ region linked to the b region of the self-priming hairpin, the a′ region including a sequence complementary to the a region of the self-priming hairpin.