Patent ID: 7381532

Claim:
A method for detecting the presence of a target nucleic acid, wherein the method comprises: a) providing: a target nucleic acid, which comprises in the 3′ to 5′ order a first hybridization site and a second hybridization site; an upstream oligonucleotide that is complementary to the first hybridization site and wherein the upstream oligonucleotide has a blocked 3′ end, and a downstream probe comprising a 5′ region and a 3′ region, wherein the 3′ region is complementary to the second hybridization site and the 5′ region forms a non-complementary 5′ flap when the downstream probe is annealed to the target; b) annealing the upstream oligonucleotide and the downstream probe to the target nucleic acid to form a cleavage structure; c) cleaving the cleavage structure with a nuclease to release the non-complementary 5′ flap; and d) detecting the released non-complementary 5′ flap, wherein the released non-complementary 5′ flap is indicative of the presence of the target nucleic acid in the sample.