Patent ID: 7914989
Filing Date: 2011-03-29
Classification: C12Q

Abstract:
1. A method of detecting a target nucleic acid sequence in a sample, the method comprising: (a) combining the sample under a defined set of conditions with a unimolecular probe comprising, (i) a first nucleic acid sequence complementary to the target nucleic acid sequence and comprising a first portion and a second portion, (ii) a second nucleic acid sequence complementary to the first portion of the first nucleic acid sequence and capable of hybridizing therewith to form a first intramolecular duplex comprising a first hairpin structure under the defined set of conditions, the first intramolecular duplex including a portion of the first nucleic acid sequence, wherein the portion of the first nucleic acid sequence of the first intramolecular duplex is capable of hybridizing to the target nucleic acid sequence, and (iii) third and fourth nucleic acid sequences being complementary to each other and linked to each other so as to hybridize to form a second intramolecular duplex comprising a second hairpin structure under said set of conditions, wherein the second portion of the first nucleic acid sequence comprises a single stranded region covalently attached to the third nucleic acid sequence and is located between the first and second intramolecular duplexes; (b) permitting the target nucleic acid sequence, if present in the sample, to hybridize with the first nucleic acid sequence under the defined set of conditions thereby disrupting the first intramolecular duplex and forming an intermolecular duplex comprising the target nucleic acid sequence and the first nucleic acid sequence; and (c) detecting the presence of the intermolecular duplex, wherein the presence of the intermolecular duplex is indicative of the presence of the target nucleic acid sequence in the sample.