Naxcor, Inc.

David Albagli

Michael L Wood

Peter C Cheng

Reuel VanAtta

Reuel B Van Atta

Bingfang Huan

Douglas Y Thien

Reuel Van Atta

Methods and compositions are provided for detecting nucleic acid sequences. Probes comprising a crosslinking agent are combined with a sample which may comprise a target sequence which is complementary to the probe. Hybridization is allowed to occur between complementary sequences. The crosslinking agent is activated. Covalent bonds are formed between the probe and the target sequence if they are hybridized to one another. The crosslinked nucleic acids can then be detected to indicate the presence of the target sequence. Also provided are kits comprising reagents.

Nucleic acid sequence detection employing probes comprising non-nucleosidic coumarin derivatives as polynucleotide-crosslinking agents

Improved methods for in situ hybridization assays of cellular and subcellular systems and tissue sections, and immobilization-based assay techniques such as Northern blotting, Southern blotting, dot blots, and the like, and assay techniques wherein the probes are bound to substrates are disclosed. The subject invention employs crosslinker-containing hybridization probes capable of forming covalent bonds between the probe and the target nucleic acid. Upon activation, the crosslinker will, if the probe has hybridized with its essentially complementary target, form covalent bonds with the complementary strand to covalently crosslink the probe to the target. Subsequently, stringent wash conditions may be employed to reduce background signals due to non-specific absorption or probes or targets, while retaining all crosslinked probe/target hybrids. Also disclosed are diagnostic kits for use in clinical and diagnostic laboratories.

Assays using crosslinkable immobilized nucleic acids

Methods and compositions are provided for detecting nucleic acid sequences. In particular, pairs of probes are employed, where the pair defines a substantially contiguous sequence on a target nucleic acid. Each of the pairs has a side chain which forms a stem of the two side chains which non-covalently binds and is capable of forming a cross-link upon activation, when the probes and sample nucleic acid are base paired. Cross-linking of the stems when unbound to complementary DNA is inhibited. Each of the nucleic acids is initially present as single stranded nucleic acid to allow for base pairing, so that the probes bind to homologous target nucleic acid. The assay mixture is activated to provide cross-linking, the double stranded nucleic acid melted, and the process of base pairing, activation and melting repeated, a sufficient number of cycles, to provide a detectable amount of cross-linked probes. To inhibit background cross-linking, the side chains may provide for duplex formation, where a portion of the side chain binds to a different portion of the side chain or the portion of the probe homologous to the target. Also provided are kits comprising reagents, as well as automatic devices, for carrying out the subject method.

Nucleic acid sequence detection employing amplification probes

Nucleic acid probes that are susceptible to chemical or enzymatic degradation are described herein. In addition, assays and methods using such probes in the detection of target nucleic acid sequences are disclosed. The target-specific hybridization region or target-complementary region of the degradable probes can be separated via a degradation process from the detectable region. The remaining portion of the degradable probes can be easily detected. The use of the degradable probes described herein improves the signal-to-noise ratio by reducing background specific or non-specific signal generation in assays and methods of nucleic acid detection.

Degradable nucleic acid probes and nucleic acid detection methods

Novel aryl derivatives comprising an aryl olefin moiety linked to a non-nucleosidic backbone moiety are disclosed. The resulting molecules are typically used as photoactivated crosslinking groups when incorporated into oligonucleotides to crosslink nucleic acid strands.

Polynucleotide crosslinking agents

Double-stranded conformational polymorphism analysis is performed by combining a probe comprising a cross-linking agent and optionally a label with a sample having a target sequence, which may be complementary or have one or a few mismatches with respect to the probe sequence. After sufficient time for hybridization under mild or lesser stringency conditions, hybridized pairs are irradiated to induce cross-link formation by the cross-linking agent. The sample is then analyzed by denaturing gel electrophoresis where the rate of migration depends upon the degree of complementarity between the probe and the target. For corroboration, in a second experiment, the probe may be combined with the sample under high stringency conditions, where it is found that the formation of cross-linked probe/target is substantially lower for pairs having mismatches than for fully matched pairs. After cross-linking, the sample may be separated by gel electrophoresis, and the amount of cross-linked nucleic acid determined.

Double-stranded conformational polymorphism analysis

Automatic device for nucleic acid sequence detection employing

Novel coumarin derivatives comprising a coumarin moiety linked to a non-nucleosidic backbone moiety are disclosed. The resulting molecules are typically used as photoactivate cross-linking groups when incorporated into polynucleotides as replacements for one or more of the complementary nucleoside bases present in probes used in procedures involving nucleic acid hybridization reactions.

Non-nucleosidic coumarin derivatives as polynucleotide-crosslinking

Methods and compositions are provided for detecting nucleic acid sequences. In particular, pairs of probes are employed, where the pair defines a substantially contiguous sequence on a target nucleic acid. Each of the pairs has a side chain which forms a stem of the two side chains which non-covalently binds and is capable of forming a cross-link upon activation, when the probes and sample nucleic acid are base paired. Each of the nucleic acids is initially present as single stranded nucleic acid to allow for base pairing, so that the probes bind to homologous target nucleic acid. The assay mixture is activated to provide cross-linking, the double stranded nucleic acid melted, and the process of base pairing, activation and melting repeated, a sufficient number of cycles, to provide a detectable amount of cross-linked probes. Also provided are kits comprising reagents, as well as automatic devices, for carrying out the subject method.

Oligonucleotides containing base-free linking groups with

Methods and compositions are provided for detecting nucleic acid sequences. In particular, pairs of probes are employed, where the pair defines a substantially contiguous sequence on a target nucleic acid. Each of the pairs has a side chain which forms a stem of the two side chains which non-covalently bind to is capable of forming a cross-link upon activation, when the probes and sample nucleic acid are base paired. Each of the nucleic acids is initially present as single stranded to allow for base pairing, so that the probes bind to homologous target nucleic acid. The assay mixture is activated to provide cross-linking, the double stranded nucleic acid melted, and the process of base pairing, activation and melting repeated, a sufficient number of cycles, to provide a detectable amount of cross-linked probes. Kits are provided with the appropriate reagents for carrying out the subject method.

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Millbrae, CA, United States of America

David Albagli