摘要:
Disclosed are compositions and a method for of amplifying nucleic acid sequences useful for detecting the presence of molecules of interest. The method is useful for detecting specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of a DNA ligation operation, an amplification operation, and a detection operation. The DNA ligation operation circularizes a specially designed nucleic acid probe molecule. This operation is dependent on hybridization of the probe to a target sequence and forms circular probe molecules in proportion to the amount of target sequence present in a sample. The amplification operation is rolling circle replication of the circularized probe. A single round of amplification using rolling circle replication results in a large amplification of the circularized probe sequences. Following rolling circle replication, the amplified probe sequences are detected and quantified using any of the conventional detection systems for nucleic acids such as detection of fluorescent labels, enzyme-linked detection systems, antibody-mediated label detection, and detection of radioactive labels. Because, the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that the ligation step can be manipulated to obtain allelic discrimination, the DNA replication step is isothermal, and signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme. In multiplex assays, the primer oligonucleotide used for the DNA polymerase reaction can be the same for all probes. Also described are modes of the method in which additional amplification is obtained using a cascade of strand displacement reactions.
摘要:
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.
摘要:
An improved method and device for nucleic acid hybridization assay employing combined direct an alternating field electrophoresis are disclosed. In the method of the present invention, a sample is hybridized with nucleic acid probe and is contacted with a support medium where direct and alternating electric fields are applied. Under the influence of the electric fields, hybrid separates from non-specifically bound nucleic acid probe. The hybrid may be measured on the support medium itself as on a paper strip or in a cartridge containing support medium or may be blotted on an inert surface and then measured. The method an device are useful in the diagnosis of diseases. Kits are provided for assay of a large number of diseases.
摘要:
Disclosed are compositions and a method for of amplifying nucleic acid sequences useful for detecting the presence of molecules of interest. The method is useful for detecting specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of a DNA ligation operation, an amplification operation, and a detection operation. The DNA ligation operation circularizes a specially designed nucleic acid probe molecule. This operation is dependent on hybridization of the probe to a target sequence and forms circular probe molecules in proportion to the amount of target sequence present in a sample. The amplification operation is rolling circle replication of the circularized probe. A single round of amplification using rolling circle replication results in a large amplification of the circularized probe sequences. Following rolling circle replication, the amplified probe sequences are detected and quantified using any of the conventional detection systems for nucleic acids such as detection of fluorescent labels, enzyme-linked detection systems, antibody-mediated label detection, and detection of radioactive labels. Because, the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that the ligation step can be manipulated to obtain allelic discrimination, the DNA replication step is isothermal, and signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme. In multiplex assays, the primer oligonucleotide used for the DNA polymerase reaction can be the same for all probes. Also described are modes of the method in which additional amplification is obtained using a cascade of strand displacement reactions.
摘要:
Disclosed are compositions and methods for sensitive detection of one or multiple analytes. In general, the methods involve the use of special label components, referred to as reporter signals, that can be associated with, incorporated into, or otherwise linked to the analytes. In some embodiments, the reporter signals can be altered such that the altered forms of different reporter signals can be distinguished from each other. In some embodiments, sets of reporter signals can be used where two or more of the reporter signals in a set have one or more common properties that allow the reporter signals having the common property to be distinguished and/or separated from other molecules lacking the common property. In other embodiments, sets of reporter signal/analyte conjugates can be used where two or more of the reporter signal/analyte conjugates in a set have one or more common properties that allow the reporter signal/analyte conjugates having the common property to be distinguished and/or separated form other molecules lacking the common property. Reporter signals can also be in conjunction with analytes (such as in mixtures of reporter signals and analytes), where no significant physical association between the reporter signals and analytes occurs; or alone, where no analyte is present.
摘要:
Disclosed are compositions and a method for of amplifying nucleic acid sequences useful for detecting the presence of molecules of interest. The method is useful for detecting specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of a DNA ligation operation, an amplification operation, and a detection operation. The DNA ligation operation circularizes a specially designed nucleic acid probe molecule. This operation is dependent on hybridization of the probe to a target sequence and forms circular probe molecules in proportion to the amount of target sequence present in a sample. The amplification operation is rolling circle replication of the circularized probe. A single round of amplification using rolling circle replication results in a large amplification of the circularized probe sequences. Following rolling circle replication, the amplified probe sequences are detected and quantified using any of the conventional detection systems for nucleic acids such as detection of fluorescent labels, enzyme-linked detection systems, antibody-mediated label detection, and detection of radioactive labels. Because, the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that the ligation step can be manipulated to obtain allelic discrimination, the DNA replication step is isothermal, and signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme. In multiplex assays, the primer oligonucleotide used for the DNA polymerase reaction can be the same for all probes. Also described are modes of the method in which additional amplification is obtained using a cascade of strand displacement reactions.
摘要:
Disclosed is a method for the comprehensive analysis of nucleic acid samples and a detector composition for use in the method. The method, referred to as Fixed Address Analysis of Sequence Tags (FAAST), involves generation of a set of nucleic acid fragments having a variety of sticky end sequences; indexing of the fragments into sets based on the sequence of sticky ends; associating a detector sequence with the fragments; sequence-based capture of the indexed fragments on a detector array; and detection of the fragment labels. Generation of the multiple sticky end sequences is accomplished by incubating the nucleic acid sample with one or more nucleic acid cleaving reagents. The indexed fragments are captured by hybridization and coupling, preferably by ligation, to a probe. The method allows a complex sample of nucleic acid to be quickly and easily cataloged in a reproducible and sequence-specific manner. One form of the method allows determination of associations, in a nucleic acid molecule, of different combinations of known or potential sequences. Another form of the method assesses modification of sequences in nucleic acid molecules by basing cleavage of the molecules on the presence or absence of modification.
摘要:
Disclosed are compositions and a method for amplification of and multiplex detection of molecules of interest involving rolling circle replication. The method is useful for simultaneously detecting multiple specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of an association operation, an amplification operation, and a detection operation. The association operation involves association of one or more specially designed probe molecules, either wholly or partly nucleic acid, to target molecules of interest. This operation associates the probe molecules to a target molecules present in a sample. The amplification operation is rolling circle replication of circular nucleic acid molecules, termed amplification target circles, that are either a part of, or hybridized to, the probe molecules. A single round of amplification using rolling circle replication results in a large amplification of the amplification target circles. Following rolling circle replication, the amplified sequences are detected using combinatorial multicolor coding probes that allow separate, simultaneous, and quantitative detection of multiple different amplified target circles representing multiple different target molecules. Since the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that a large number of distinct target molecules can be detected simultaneously, and that differences in the amounts of the various target molecules in a sample can be accurately quantified. It is also advantageous that the DNA replication step is isothermal, and that signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme.
摘要:
Disclosed is a method for the comprehensive analysis of nucleic acid samples and a detector composition for use in the method. The method involves amplifying nucleic acid fragments of interest using a primer that can form a hairpin structure; sequence-based coupling of the amplified fragments to detector probes; and detection of the coupled fragments. The amplified fragments are coupled by hybridization and coupling, preferably by ligation, to detector probes. A hairpin structure formed at the end of the amplified fragments facilitates coupling of the fragments to the probes. The method allows detection of the fragments where detection provides some sequence information for the fragments. The method allows a complex sample of nucleic acid to be quickly and easily cataloged in a reproducible and sequence-specific manner. The method can also be used to detect amplified fragments having a known sequence.
摘要:
Disclosed are compositions and a method for amplification of and multiplex detection of molecules of interest involving rolling circle replication. The method is useful for simultaneously detecting multiple specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of an association operation, an amplification operation, and a detection operation. The association operation involves association of one or more specially designed probe molecules, either wholly or partly nucleic acid, to target molecules of interest. This operation associates the probe molecules to a target molecules present in a sample. The amplification operation is rolling circle replication of circular nucleic acid molecules, termed amplification target circles, that are either a part of, or hybridized to, the probe molecules. A single round of amplification using rolling circle replication results in a large amplification of the amplification target circles. Following rolling circle replication, the amplified sequences are detected using combinatorial multicolor coding probes that allow separate, simultaneous, and quantitative detection of multiple different amplified target circles representing multiple different target molecules. Since the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that a large number of distinct target molecules can be detected simultaneously, and that differences in the amounts of the various target molecules in a sample can be accurately quantified. It is also advantageous that the DNA replication step is isothermal, and that signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme.