Detection of nucleic acids by fluorescence quenching
First Claim
1. A method for detecting presence of a nucleic acid target sequence comprising:
- a) hybridizing to the target sequence a detector nucleic acid comprisingi) a first oligonucleotide hybridized to a second oligonucleotide which is shorter than the first oligonucleotide such that the detector nucleic acid comprises an intermolecularly base-paired portion and a single-stranded target binding sequence, and;
ii) a first dye linked to the first oligonucleotide and a second dye linked to the second oligonucleotide which together form a fluorescent donor/acceptor dye pair linked to the detector nucleic acid such that fluorescence of the first or the second dye is quenched;
b) extending the target sequence on the first oligonucleotide, thereby displacing the second oligonucleotide from the first oligonucleotide and producing a change in a fluorescence parameter, and;
c) detecting the change in the fluorescence parameter as an indication of the presence of the target sequence.
1 Assignment
0 Petitions
Accused Products
Abstract
Detector nucleic acids are employed for detection of nucleic acid target sequences by fluorescence quenching mechanisms. The detector nucleic acid comprises at least two oligonucleotides and is partially single-stranded and partially double-stranded. One of the two dyes of a donor/acceptor dye pair is linked to the first oligonucleotide and the other is linked to a second oligonucleotide such that they are in close spatial proximity when the first and second oligonucleotides are base-paired and donor fluorescence is quenched. A single second oligonucleotide may be hybridized to the first oligonucleotide or multiple second oligonucleotides may be hybridized to the first oligonucleotide and to each other, forming a junction structure comprising multiple donor/acceptor dye pairs. The detector oligonucleotide retains its partially single-stranded and partially double-stranded conformation in the absence of target. In the presence of target, however, the second oligonucleotide(s) of the detector nucleic acid is/are completely or partially displaced from the first, increasing the distance between the donor and acceptor dyes and causing a change in fluorescence which may be detected as an indication of the presence of the target sequence.
105 Citations
47 Claims
-
1. A method for detecting presence of a nucleic acid target sequence comprising:
-
a) hybridizing to the target sequence a detector nucleic acid comprising i) a first oligonucleotide hybridized to a second oligonucleotide which is shorter than the first oligonucleotide such that the detector nucleic acid comprises an intermolecularly base-paired portion and a single-stranded target binding sequence, and; ii) a first dye linked to the first oligonucleotide and a second dye linked to the second oligonucleotide which together form a fluorescent donor/acceptor dye pair linked to the detector nucleic acid such that fluorescence of the first or the second dye is quenched; b) extending the target sequence on the first oligonucleotide, thereby displacing the second oligonucleotide from the first oligonucleotide and producing a change in a fluorescence parameter, and; c) detecting the change in the fluorescence parameter as an indication of the presence of the target sequence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A method for detecting amplification of a target sequence comprising, in an amplification reaction:
-
a) hybridizing to the target sequence a detector nucleic acid comprising i) a first oligonucleotide hybridized to a second oligonucleotide which is shorter than the first oligonucleotide such that the detector nucleic acid comprises an intermolecularly base-paired portion and a single-stranded target binding sequence, and; ii) a first dye linked to the first oligonucleotide and a second dye linked to the second oligonucleotide which together form a fluorescent donor/acceptor dye pair linked to the detector nucleic acid such that fluorescence of the first or the second dye is quenched; b) extending the first oligonucleotide of the detector nucleic acid on the target sequence with a polymerase to produce a detector nucleic acid extension product and separating the detector nucleic acid extension product from the target sequence; c) hybridizing a primer to the extended first oligonucleotide of the detector nucleic acid extension product and extending the primer with the polymerase, thereby displacing the second oligonucleotide from the extended first oligonucleotide and producing a change in a fluorescence parameter, and; d) detecting the change in the fluorescence parameter as an indication of amplification of the target sequence. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 45, 46, 47)
-
-
25. A method for detecting a target sequence comprising:
-
a) providing a detector nucleic acid comprising i) a first oligonucleotide hybridized to a second oligonucleotide which is shorter than the first oligonucleotide such that the detector nucleic acid comprises an intermolecularly base-paired portion and a single-stranded target binding sequence, and; ii) a first dye linked to the first oligonucleotide and a second dye linked to the second oligonucleotide which together form a fluorescent donor/acceptor dye pair linked to the detector nucleic acid such that fluorescence of the first or the second dye is quenched; b) hybridizing the detector nucleic acid to the target sequence by means of the single-stranded target binding sequence, thereby reducing quenching of the first or the second dye and producing a change in a fluorescence parameter, and; c) detecting the change in the fluorescence parameter as an indication of the presence of the target sequence. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34)
-
-
35. A detector nucleic acid comprising:
-
a) a first oligonucleotide hybridized to a second oligonucleotide which is shorter than the first oligonucleotide such that the detector nucleic acid comprises an intermolecularly base-paired portion and single-stranded target binding sequence, wherein at least a portion of the intermolecularly base-paired portion is not complementary to a selected target, and; b) a first dye linked to the first oligonucleotide and a second dye linked to the second oligonucleotide which together form a fluorescent donor/acceptor dye pair linked to the detector nucleic acid such that fluorescence of the first or the second dye is quenched and dissociation of the detector nucleic acid reduces quenching of the first or second dye. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44)
-
Specification