PROBES FOR IMPROVED MELT DISCRIMINATION AND MULTIPLEXING IN NUCLEIC ACID ASSAYS

摘要

Methods and compositions for the detection and quantification of nucleic acids are provided. In certain embodiments, methods involve the use of cleavable probes that comprise a ribonucleotide position that is susceptible to endoribonuclease (e.g., RNase H) cleavage in the presence of target nucleic acid molecules. Probes of the embodiments may also comprise non-natural nucleotide linked to a reporter and/or quenching moiety.

主权项

1. A method for detecting the presence of a target nucleic acid comprising:
(a) contacting a sample with a first cleavable probe, said probe comprising, from 5′ to 3′, (i) a first sequence region comprising at least one non-natural nucleotide labeled with a first member of a reporter-quencher pair; (ii) a second sequence region; (iii) a sequence that is the reverse complement of the second sequence region; and (iv) a sequence comprising one or more ribonucleotide base that is complimentary to a first region on a first strand of the target nucleic acid; (b) contacting the cleavable probe with an endoribonuclease, thereby cleaving probe that is hybridized with target nucleic acid to form a truncated cleavable probe; (c) allowing the truncated cleavable probe to hybridize to itself to form a hairpin probe; (d) extending the hairpin probe in the presence of a non-natural nucleotide labeled with a second member of a reporter-quencher pair that is capable of base-pairing with the at least one non-natural nucleotide of the first sequence region; and (e) detecting the target nucleic acid by detecting a change: signal from the label on the cleavable probe and the hairpin probe.