Patent ID: 7482127

Claim:
A method of detecting the presence of absence of a target sequence in a sample comprising; a) providing; i) first and second nucleic acid molecules, wherein said first and second nucleic acid molecules are configured to form a first invasive cleavage structure with a target sequence, and wherein said first and second nucleic acid molecules are also able to form a second invasive cleavage structure with an interfering sequence, ii) a sample comprising: A) a target region suspected of containing said target sequence, and B) an interfering region comprising said interfering sequence, iii) a cleavage agent, and iv) blocker oligonucleotides configured to at least partially hybridize with said interfering region such that formation of said second invasive cleavage structure is at least partially inhibited; b) contacting said sample with said first and second nucleic acid molecules, said cleavage agent, and said blocker oligonucleotides, and c) detecting the presence or absence of said target sequence in said sample.