Patent ID: 8460869

Claim:
A method of detecting the presence of a target nucleic acid in a sample comprising the steps of: (a) providing a sample containing a target nucleic acid, (b) mixing the sample with a soluble nucleic acid capture probe that is configured as 5′-capture region-target complementary sequence-terminal region-3′ or as 5′-terminal region-target complementary sequence-capture region-3′, and that forms under hybridizing conditions, a partially double-stranded hairpin structure wherein the capture region and the terminal region bind intramolecularly to form a double stranded stem, wherein the target-complementary region forms a single-stranded loop portion of the partially double stranded hairpin structure, and wherein the capture region and the terminal region are configured to not hybridize to the target nucleic acids under stringent hybridization conditions, (c) specifically hybridizing the target-complementary sequence of the capture probe to a target sequence in the target nucleic acid, such that the target complementary sequence and the target sequence are in a double stranded form, and wherein the capture region and the terminal region are not intramolecularly bound one to the other, such that the capture region and the terminal region are each in a single stranded form, (d) binding the single-stranded capture region to an immobilized probe attached to a capture support by binding together members of a specific binding pair, thereby forming a capture hybrid made up of the capture support, the immobilized probe, the nucleic acid capture probe and the target nucleic acid, (e) separating the capture hybrid attached to the capture support from sample components, (f) releasing the target nucleic acid from the capture hybrid, wherein releasing the target nucleic acid from the capture hybrid further releases the capture probe from the immobilized probe and the released the capture probe reforms the partially double-stranded hairpin structure, (g) hybridizing a detection probe to the target nucleic acid to form a detection hybrid, wherein the detection probe hybridizes specifically to a target sequence that overlaps or is the same as the target sequence that hybridizes to the target-complementary sequence of the capture probe, wherein said detection probe hybridization is performed in the presence of the capture probe, and wherein the reformation of the capture probe's partially double-stranded hairpin structure prevents or minimizes competition between the capture probe and the detection probe, and (h) detecting a signal produced from the detection hybrid to indicate the presence of the target nucleic acid in the sample.