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US5312728A Expired / Lapsed US ⏱️ 0.0 years remaining

Assays and kits incorporating nucleic acid probes containing improved molecular switch

Assignee: Salk Institute for Biological Studies
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Filing: 1992-05-04
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Granted: 1994-05-17
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Expires: 2012-05-04
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Abstract

Abstract A probe for the detection of a nucleic acid target sequence containing a molecular switch comprising three essential elements: a probe sequence of 20-60 nucleotides surrounded by switch sequences of 10-40 nucleotides which are complementary to each other, wherein the state of the switch is useful for selectively generating a detectable signal if the probe is hybridized to a target; also, assays and kits utilizing such probes.

Inventors

  • 👤 Paul M. Lizardi
  • 👤 Fred R. Kramer
  • 👤 Sanjay Tyagi
  • 👤 Cesar E. Guerra
  • 👤 Hilda M. L. Buyoli
  • 👤 Barbara C. Chu
  • 👤 Gerald F. Joyce
  • 👤 Leslie E. Orgel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 00:20
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/68; C12Q1/6844; C12Q1/6867; C12Q1/6813; C12Q1/6816; C12Q1/682; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 255 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid and comprising the steps of: a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotide sequences: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence only when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal when the probe sequence is hybridized with said target sequence, b) specifically hybridizing probes with said target sequence, c) destroying the ability of probes which did not hybridize specifically with said target sequence in step b to generate a signal, d) generating a signal from probes which did hybridize specifically with said target sequence in step b, and e) detecting the signal in order to detect the predetermined nucleic acid target sequence.
Claim 2
Independent Claim 255 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid and comprising the steps of: a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotide sequences: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence only when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal when the probe sequence is hybridized with said target sequence, b) specifically hybridizing probes with said target sequence, c) destroying the ability of probes which did not hybridize specifically with said target sequence in step b to generate a signal, d) generating a signal from probes which did hybridize specifically with said target sequence in step b, and e) detecting the signal in order to detect the predetermined nucleic acid target sequence.
Claim 3
Dependent Claim 13 words
A method according to claim 1 wherein said probe is a replicatable RNA.
Claim 4
Dependent Claim 43 words
A method according to claim 2 wherein step c comprises destroying with a ribonuclease the replicability of probes which did not hybridize specifically with said target sequence and wherein step d comprises exponentially replicating probes which did hybridize specifically with said target sequence.
Claim 5
Dependent Claim 31 words
A method according to claim 2 wherein probes hybridized specifically with said target sequence in step b are separated from probes which did not so hybridize prior to performing step d.
Claim 6
Dependent Claim 91 words
A method according to claim 1 comprising a quantitative determination of the amount of said target sequence in said sample, wherein the amount of probe added in step a substantially exceeds the maximum number of target sequences expected in said samples, wherein step b proceeds until virtually all target sequences hybridize with probes, wherein step c the replicability of virtually all of the probes which did not hybridize specifically with said target sequence is destroyed, wherein step d is carried out for a predetermined time, and wherein step e is quantitative.
Claim 7
Dependent Claim 22 words
A method according to claim 5 additionally comprising performing a parallel assay on a sample which does not contain said target sequence.
Claim 8
Independent Claim 232 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid comprising the steps of a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotide sequence: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence only when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal when the probe sequence is hybridized with said target sequence, said detectable signal resulting from exponential replication of replicable RNA, b) specifically hybridizing probes with said target sequence, c) exponentially replicating the replicatable RNA, and d) detecting the replication products in order to detect the predetermined nucleic acid target sequence.
Claim 9
Independent Claim 232 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid comprising the steps of a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotide sequence: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence only when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal when the probe sequence is hybridized with said target sequence, said detectable signal resulting from exponential replication of replicable RNA, b) specifically hybridizing probes with said target sequence, c) exponentially replicating the replicatable RNA, and d) detecting the replication products in order to detect the predetermined nucleic acid target sequence.
Claim 10
Dependent Claim 47 words
A method according to claim 7, wherein said probe is a first DNA strand, comprising the additional step of hybridizing to the second switch sequence of said probe a second DNA strand which is a template for the transcription of a replicatable RNA prior to step c.
Claim 11
Dependent Claim 53 words
A method according to claim 7, wherein said probe is a replicatable recombinant RNA, comprising the additional step of separating probes which hybridized with target sequence in step b from probes which did not so hybridize prior to step c, and wherein the replicatable RNA of step c is said replicatable recombinant RNA.
Claim 12
Dependent Claim 62 words
A method according to claim 7 wherein said probe is an RNA strand comprising a replicatable RNA sequence extending from said second switch sequence, comprising the additional step of selectively cleaving said replicatable RNA sequence from probes which hybridized with target sequences in step b prior to step c, and wherein the replicatable RNA of step c is said replicatable RNA sequence.
Claim 13
Dependent Claim 14 words
A method according to claim 10 wherein the step of cleaving involves ribozyme cleavage.
Claim 14
Dependent Claim 18 words
A method according to claim 10 wherein the step of cleaving includes adding a ribonuclease to the sample.
Claim 15
Dependent Claim 68 words
A method according to claim 7 comprising a quantitative determination of the amount of said target sequence in said sample, wherein the amount of probe added in step a substantially exceeds the maximum number of target sequences expected in said sample, wherein step b proceeds until virtually all target hybridize with probes, wherein step c is carried out for a predetermined time, and wherein step d is quantitative.
Claim 16
Dependent Claim 22 words
A method according to claim 13 additionally comprising performing a parallel assay on a sample which does not contain said target sequence.
Claim 17
Independent Claim 251 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid comprising the steps of a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotides sequences: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence being when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal from an RNA signal generator sequence of said hybridization probe when the probe sequence is hybridized with said target sequence, b) specifically hybridizing probes with said target sequence, c) cleaving said RNA-signal generator sequence from probes which hybridized with target sequences in step b, d) generating an amplified signal using said RNA-signal generator, and e) detecting said amplified signal in order to detect the predetermined nucleic acid target sequence.
Claim 18
Independent Claim 251 words
A method for the detection of at least one predetermined nucleic acid target sequence in a sample containing nucleic acid comprising the steps of a) adding to the sample hybridization probes comprising a molecular switch consisting essentially of three oligonucleotides sequences: i) a probe sequence of from about 20 to about 60 nucleotides, having a 5' side and a 3' side, which probe sequence is complementary to said target sequence, ii) a 5' sequence of from about 10 to about 40 nucleotides, including a first switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 5' side of the probe sequence, and iii) a 3' sequence of from about 10 to about 40 nucleotides, including a second switch sequence of at least about 10 nucleotides, immediately adjacent to and linked to the 3' side of the probe sequence, said second switch sequence being hybridized with said first switch sequence being when said probe sequence is not hybridized to said target sequence, wherein said molecular switch includes a preselected nucleic acid sequence for selectively generating a detectable signal from an RNA signal generator sequence of said hybridization probe when the probe sequence is hybridized with said target sequence, b) specifically hybridizing probes with said target sequence, c) cleaving said RNA-signal generator sequence from probes which hybridized with target sequences in step b, d) generating an amplified signal using said RNA-signal generator, and e) detecting said amplified signal in order to detect the predetermined nucleic acid target sequence.
Claim 19
Dependent Claim 18 words
A method according to claim 15 wherein said RNA-signal generator includes an enzyme which generates a color signal.
Claim 20
Dependent Claim 22 words
A test kit for performing an assay according to claim 1 comprising a quantity of said probes and an appropriate RNA replicase.
Claim 21
Dependent Claim 22 words
A test kit for performing an assay according to claim 7 comprising a quantity of said probes and an appropriate RNA replicase.
Claim 22
Dependent Claim 11 words
The method of claim 8 wherein the replicatable RNA is MDV-poly-RNA.
Claim 23
Dependent Claim 20 words
The method of claim 8 wherein the second DNA strand includes a promoter sequence for a DNA directed RNA polymerase.
Claim 24
Dependent Claim 17 words
The method of claim 20 wherein the exponential replication of step (c) is performed with Q-beta replicase.
Claim 25
Dependent Claim 14 words
The method of claim 9 wherein the predetermined target sequence is a gene segment.
Claim 26
Dependent Claim 13 words
The method of claim 20 wherein the promoter is for T7 RNA polymerase.

References Cited (Backward Citations)

US4551433A Cited
US4710464A Cited
US4683202A Cited
US4683202B1 Cited
US4725537A Cited
EP0224126A2 Cited
WO1987006270A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-05-16 1997-11-15 1998-05-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-05-16 2001-11-15 2002-05-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-05-16 2005-11-15 2006-05-17 $7700.00 Window Closed / Lapsed

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