Methods for detection of a target nucleic acid by capture

A method of detecting or measuring a target nucleic acid comprising the steps of:

• forming a cleavage structure by incubating a sample containing a target nucleic acid with a probe comprising a binding moiety and a secondary structure that changes upon binding of said probe to said target nucleic acid, wherein said binding moiety comprises a region of said probe that is released upon cleavage of said probe with a nuclease and binds to a capture element,
• cleaving said cleavage structure with said nuclease at a cleavage temperature to release a nucleic acid fragment, wherein said secondary structure of said probe is stable at or below said cleaving temperature when not bound to said target nucleic acid;
• and
• detecting and/or measuring the amount of said fragment captured by binding of said binding moiety to a capture element on a solid support as an indication of the presence of the target sequence in the sample.

A method of forming a cleavage structure comprising the steps of:

• (a) providing a target nucleic acid,
• (b) providing an upstream nucleic acid complementary to said target nucleic acid,
• (c) providing a downstream probe having a secondary structure that changes upon binding of said probe to said target nucleic acid and said probe further comprises a binding moiety, wherein said binding moiety comprises a region of said probe that is released upon cleavage of said probe with a nuclease and binds to a capture element, and
• (d) annealing said target nucleic acid, said upstream nucleic acid and said downstream probe;
• and
• wherein said cleavage structure can be cleaved with said nuclease at a cleaving temperature, and said secondary structure of said probe is stable at or below said cleaving temperature when not bound to said target nucleic acid.

A method of generating a signal indicative of the presence of a target nucleic acid in a sample, comprising

• forming a cleavage structure by incubating a sample comprising a target nucleic acid with a probe comprising a binding moiety and a secondary structure that changes upon binding of said probe to said target nucleic acid, wherein said binding moiety comprises a tag that binds to a capture element, and
• cleaving said cleavage structure with said nuclease at a cleaving temperature to release a nucleic acid fragment and generate a signal, wherein said secondary structure of said probe is stable at or below said cleaving temperature when not bound to said target nucleic acid, and generation of said signal is indicative of the presence of a target nucleic acid in said sample;
• and
• detecting and/or measuring said signal.

A method of detecting or measuring a target nucleic acid comprising the steps of:

• forming a cleavage structure by incubating a sample containing a target nucleic acid with a probe comprising a binding moiety and a secondary structure that changes upon binding of said probe to said target nucleic acid, wherein said binding moiety comprises a tag that binds to a capture element,
• cleaving said cleavage structure with said nuclease at a cleavage temperature to release a nucleic acid fragment, wherein said secondary structure of said probe is stable at or below said cleaving temperature when not bound to said target nucleic acid;
• and
• detecting and/or measuring the amount of said fragment captured by binding of said binding moiety to a capture element on a solid support as an indication of the presence of the target sequence in the sample.