Patent ID: 7820387

Claim:
A method for characterizing a nucleic acid comprising: a) providing: i. a sample suspected of containing a target nucleic acid; ii. oligonucleotides capable of hybridizing to said target nucleic acid to form an invasive cleavage structure, wherein said oligonucleotides comprise first and second oligonucleotides, said first oligonucleotide comprising a portion complementary to a first region of said target nucleic acid and said second oligonucleotide comprising a 3′ portion and a 5′ portion, said 5′ portion complementary to a second region of said target nucleic acid downstream of and contiguous to said first portion of said target nucleic acid; iii. a solid support, wherein one or more of said oligonucleotides is attached to said solid support; and iv. an archaeal FEN-1 endonuclease active at 55° C. and above for detecting the presence of an invasive cleavage structure; b) exposing said sample to said oligonucleotides and said FEN-1 endonuclease, wherein said exposing said sample to said oligonucleotides and said FEN-1 endonuclease comprises exposing said sample to said oligonucleotides and said FEN-1 endonuclease under conditions wherein an invasive cleavage structure is formed between a target nucleic acid and said oligonucleotides if said target nucleic acid is present in said sample; and c) detecting said invasive cleavage structure.