Patent ID: 7482122

Claim:
A method of enhancing detection signal for measurement of nucleic acid sequences comprising the steps of: (a) providing a solid capture support comprising an immobilized capture sequence complementary to a capture-binding segment of a single strand nucleic acid target sequence of interest; (b) hybridizing said capture-binding segment of said target sequence from a sample with said capture support to form a target-capture complex; (c) removing unhybridized target sequence; (d) providing a T- or L-primary probe comprising a target-binding segment and an enhancer linker segment; and hybridizing said target-binding segment of said primary probe with a probe-binding segment of said target sequence to form a capture-target-primary probe complex; (e) removing unhybridized T- or L-primary probe; (f) providing a first enhancement probe comprising a first annealing segment complementary to said enhancer linker segment of said primary probe, a second annealing segment and a chemical label; and hybridizing said first annealing segment of said first enhancement probe with said enhancer linker segment of said primary probe; (g) providing a second enhancement probe comprising a first annealing segment complementary to said second annealing segment of said first enhancement probe, a second annealing segment complementary to said first annealing segment of said first enhancement probe, and said chemical label, wherein each of said first and said second enhancement probes consists of a single molecule; and hybridizing said second enhancement probe with said first enhancement probe, thereby multiple said first and second enhancement probes annealing with each other in a pattern that said first annealing segment of said second enhancement probe anneals with said second annealing segment of said first enhancement probe, said first annealing segment of said first enhancement probe anneals with said second anneal segment of said second enhancement probe, thereby linking multiple said first and second enhancement probes alternately into a staggered chain extending from said enhancer linker segment of said primary probe, and forming a final complex containing multiple said chemical labels; (h) removing unhybridized said first and second enhancement probes; (i) detecting said chemical labels in said final complex; and (j) determining the presence of said target sequence in said sample.