112 results about "Nucleic Acid Strand" patented technology

The invention relates to retrieving or modifying target nucleic acids, such as host cell chromosomal DNA, by homologous recombination with vectors that have been cut to provide recombinogenic nucleic acid strands in situ. The methods described herein can be used to modify a target nucleic acid in vitro or in any prokaryotic or eukaryotic cell using homologous recombination.

The present disclosure in some aspects relates to methods, compositions, and kits for rolling circle amplification (RCA) comprising extending a nucleic acid priming sequence hybridized to a circular nucleic acid template using a polymerase to generate an extended priming sequence, wherein the circular nucleic acid template is crosslinked to a second nucleic acid strand; de-crosslinking the circular nucleic acid template from the second nucleic acid strand; and extending the extended priming sequence to generate a rolling circle amplification product (RCP).

The invention discloses an EV membrane protein single molecule detection method based on droplet microfluidics and application thereof. The method comprises the following steps: firstly, constructing an Ab-oligo compound which is formed by sequentially connecting an antibody, Linker, Linker connection DNA, RNA capable of being specifically cut by RNA enzyme and template DNA for starting signal amplification; then capturing the extracellular vesicles in the plasma by using the CD9 / CD63 / CD81 functionalized magnetic beads; the method comprises the following steps: adding an Ab-oligo compound and a sealing buffer solution into extracellular vesicles, incubating, removing the uncombined Ab-oligo compound, adding RNA enzyme for incubating and enzyme digestion, collecting template DNA for starting signal amplification, and performing microdroplet digital PCR analysis to realize single molecule analysis of EV membrane protein. According to the invention, the one-to-one correspondence relationship between the antibody and oligonucleotide is established through Linker for the first time, single protein information is converted into single nucleic acid chain information, and EV membrane protein single molecule detection is realized. The method is simple to operate, can qualitatively and quantitatively detect the single EV membrane protein, and is beneficial to further research on the relationship between the EV membrane protein and diseases.

A method of reducing the level of a transcription product in a cell comprising contacting with the cell a composition comprising a double-stranded nucleic acid complex comprising a first nucleic acid strand annealed to a second nucleic acid strand, wherein: (i) the first nucleic acid strand hybridizes to the transcription product and comprises (a) a region consisting of at least 4 consecutive nucleotides that are recognized by RNase H when the strand is hybridized to the transcription product, (b) one or more nucleotide analogs located on 5′ terminal side of the region, (c) one or more nucleotide analogs located on 3′ terminal side of the region and (d) a total number of nucleotides and nucleotide analogs ranging from 8 to 35 nucleotides and (ii) the second nucleic acid strand comprises (a) nucleotides and optionally nucleotide analogs and (b) at least 4 consecutive RNA nucleotides.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

The invention is directed to methods for massively parallel template-free enzymatic synthesis of a plurality of different polynucleotides of predetermined sequences. In one aspect, methods of the invention employ large scale arrays of reaction sites each associated with at least one working electrode for controlling deprotection and deblocking steps at predetermined user selected sites. In another aspect, the invention provides template-free enzymatic synthesis with proofreading, wherein completed polynucleotides at predetermined reaction sites are sequenced using a sequencing by synthesis technique, particularly employing electrochemically labile blocking groups.

The invention is directed to methods for massively parallel template-free enzymatic synthesis of a plurality of different polynucleotides of predetermined sequences. In one aspect, methods of the invention employ large scale arrays of reaction sites each associated with at least one working electrode for controlling deprotection and deblocking steps at predetermined user selected sites. In another aspect, the invention provides template-free enzymatic synthesis with proofreading, wherein completed polynucleotides at predetermined reaction sites are sequenced using a sequencing by synthesis technique, particularly employing electrochemically labile blocking groups.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

Provided herein include methods, systems, and compositions for designing a sensor nucleic acid strand of a conditionally activatable small interfering RNA (siRNA) complex as well as the siRNA complexes generated using the method herein described and the component strands. The siRNA complex can be conditionally activated upon a complementary binding to an input nucleic acid strand (e.g. a mRNA of a biomarker gene specific to a target cell) through a sequence in a sensor nucleic acid strand of the nucleic acid complex. The activated nucleic acid complex can release a potent RNAi duplex formed by a core nucleic acid strand and a passenger nucleic acid strand, which can specifically inhibit a target RNA.

Provided is a method and a kit for synthesizing and retrieving a polynucleotide enzymatically, including an initiator containing having a free 3′-hydroxyl group; a polymerase for incorporating nucleotide monomers to the initiator to form a nucleic acid strand from the free 3′-hydroxyl group, wherein the nucleic acid strand includes a guiding nucleotide to be recognized by an endonuclease; and the endonuclease cleaving the nucleic acid strand to release a predetermine polynucleotide and newly form a free 3′-hydroxyl group at 3′ end of the remaining nucleic acid strand which serve as a reusable initiator. Also provided is a kit for synthesizing and retrieving a polynucleotide using the method.

Provided are a method for purifying a nucleic acid library, and a kit, the method comprising the steps of: providing a nucleic acid library comprising single-stranded template nucleic acids; obtaining a library of complementary nucleic acids by binding complementary nucleic acid units to each base of the strand of the template nucleic acids; introducing at least one modified nucleic acid unit during the binding process of the nucleic acid units; and selectively selecting a nucleic acid having a desired length from the library of complementary nucleic acids using the modified nucleic acid unit. According to the present invention, the nucleic acid library may be purified regardless of the complexity, sequence or length of the nucleic acid library, and nucleic acids having different lengths may be simultaneously purified. The purification may be carried out through direct experiment or using a next-generation sequencing instrument.

The present disclosure discloses a universal aptamer-based colloidal gold lateral flow test strip for detecting small-molecule substances and belongs to the fields of analytical chemistry, medicine, environment, food safety detection, nano-biosensing and the like. An AuNPs@poly-DNA probe is used for rapidly and sensitively capturing an aptamer, streptavidin sprayed in a test zone and streptavidin-biotin-DNAc sprayed in a control zone do not need to be changed, and another substance can be detected only by changing a nucleic acid chain part of the AuNPs@poly-DNA probe. A universal colloidal gold lateral flow test strip, which is rapid, sensitive and low in cost, has been developed. The test strip method for detecting small-molecule substances is simple, convenient and rapid, and can be used for detection at any time. Only a test solution is needed to be added into a sample port and the test strip is completely developed after 5 min, thus an experiment result can be observed and the detection efficiency can be greatly improved. Qualitative analysis can be conducted by naked eyes, and quantitative analysis can be conducted by a colloidal gold test strip quantitative analyzer.

The invention relates to the technical field of biological medicines, particularly discloses synthesis and application of a double-target nucleic acid molecule, and provides a strategy method for connecting two nucleic acid chains through a click chemical reaction. A connection unit of triazole is generated between the two nucleic acid chains through a click chemical reaction between a nucleic acid chain (Strand 1) of an azide group and a nucleic acid chain (Strand 2) of an alkyne group, and four connection modes are selected between 5'of the Strand 1 and 3 'of the Strand 2, between 5' of the Strand 1 and 5 'of the Strand 2, between 3' of the Strand 1 and 3 'of the Strand 2, and between 3' of the Strand 1 and 5 'of the Strand 2. Furthermore, two nucleic acid chains connected with triazole are respectively combined with complementary nucleic acid chains according to complementary base pairing, so as to prepare a double-target oligonucleotide drug.

The invention relates to high throughput nucleic acid sequencing with a single molecule sensor array. Embodiments of single molecule array sequencing (SMAS) devices and systems are disclosed herein. Each sensor in a sensor array of the SMAS device is capable of detecting a label attached to a nucleotide incorporated into a single nucleic acid strand that binds to a respective binding site. Each sensor may detect a single label (e.g., fluorescent, magnetic, organometallic, charged molecules, etc.) attached to the incorporated nucleotides. Also disclosed are methods of highly tunable nucleic acid (e.g., DNA) sequencing based on synthetic sequencing (SBS) of various examples of colonized amplified DNA immobilized on such SMAS devices using the SMAS devices and systems. Also disclosed are error correction methods that mitigate errors generated in sequencing individual nucleic acid strands (e.g., detecting or not detecting error markers).

The invention relates to the field of single-molecule gene sequencing, in particular to a composite nucleotide probe based on a nucleic acid nanostructure and application of the composite nucleotide probe. The structure of the composite fluorescent nucleotide probe provided by the invention is a multi-level structure, the multi-level structure respectively comprises a nano nucleic acid molecule, streptavidin and a biotin-nucleoside polyphosphate compound from inside to outside, and the nano nucleic acid molecule, the streptavidin and the biotin-nucleoside polyphosphate compound are connected through biotin. The nucleic acid chain, biotin modification and fluorescent dye molecule modification assembled into the nucleic acid nanostructure can be ordered and synthesized by commercial synthesis companies, the price is low, and synthesis is rapid and convenient; the three-dimensional branched connecting molecules can fully disperse the dendritic macromolecules with large volumes in a three-dimensional space. The planar branched connecting molecule is used for connecting the nucleoside polyphosphate and the polyethylene glycol dispersing element, so that the distance between the nucleoside polyphosphate and the polyethylene glycol is relatively short, the polyethylene glycol can conveniently separate and protect the nucleoside polyphosphate, and the diffusion effect of the nucleoside polyphosphate in an aqueous solution is improved.

The object of the present invention is to provide a nucleic acid agent that can be efficiently delivered to the nervous system, particularly the central nervous system to which the BBB mechanism prevents drug delivery, and can produce an antisense effect on a target transcriptional product at the delivered site, and a composition comprising the same. Provided is a double-stranded nucleic acid complex formed by annealing a first nucleic acid strand capable of hybridizing to part of a target transcriptional product, and has an antisense effect on the target transcriptional product, to a second nucleic acid strand comprising a base sequence complementary to the first nucleic acid strand, and is bound to tocopherol or an analog thereof, cholesterol or an analog thereof, or a substituted or unsubstituted C1-30 alkyl group, a substituted or unsubstituted C2-30 alkenyl group, or a substituted or unsubstituted C1-30 alkoxy group.

This invention provides a multivalent protein-targeting degradation system based on a programmable nucleic acid template, its preparation method, and its applications, belonging to the fields of biomedicine and molecular engineering. The system includes monovalent nucleic acid degradation units and a nucleic acid template. The monovalent degradation unit is formed by hybridization of two nucleic acid chains coupled with a target protein ligand and an E3 ubiquitin ligase ligand. The nucleic acid template has n loading sites, which assemble into multivalent nucleic acid degraders through complementary base pairing. This invention achieves precise control over the spacing and configuration of monovalent units by regulating the template spacer sequence length and topology, resulting in a spatially ordered multivalent synergistic degradation effect and significantly improving the degradation efficiency of target proteins. This system is highly modular and programmable, providing a new technological platform for the development of targeted protein degradation drugs.

The application discloses a multifunctional nanodiagnosis and treatment probe and a preparation method and application thereof, and belongs to the technical field of nanobiomedicine and tumor molecular diagnosis and treatment. The multifunctional nanodiagnosis and treatment probe is prepared by the following steps: coating mesoporous silica on the surface of a core-shell structure upconversion nanoparticle, then adsorbing platinum particles and methylene blue into the mesoporous silica, then modifying polydopamine to the surface of the mesoporous silica coated core-shell structure upconversion nanoparticle on which the platinum particles and the methylene blue are adsorbed, and finally linking nucleic acid PH1 chains and EH2 dendrites to the surface of the upconversion nanoparticle and dispersing and preparing by using a PBS buffer. The multifunctional nanodiagnosis and treatment probe prepared by the application can not only realize specific recognition, quantitative detection and in-situ imaging of a target microRNA, but also can form a synergistic tumor treatment mode of "photodynamic therapy-optical thermal therapy-oxygen enhancement", and has a wide application prospect in early tumor screening, curative effect evaluation and individualized treatment.

The invention relates to multiple preparation processes for targeted treatment of a class of non-enveloped virus nucleic acid or early-stage difficult-to-diagnose epidemic situation control. The key point is that different epidemic situations caused by enveloped or non-enveloped viruses are summarized and recognized from thousands of viruses and epidemic situations which are erupted all the time; the light is adopted to activate the methylene blue riboflavin, so that a plurality of enveloped viruses and a plurality of non-enveloped viruses can be respectively inactivated; the light-activated methylene blue riboflavin can be embedded into a virus nucleic acid chain to prevent replication so as to achieve targeted therapy, and the light-activated methylene blue riboflavin compound preparation is firstly used for treatment when virus types are difficult to diagnose in the early stage of an epidemic situation. In order to control epidemic situation propagation as soon as possible, after it is confirmed that enveloped virus infection or non-enveloped virus infection exists, light-activated methylene blue and a light-activated riboflavin preparation are adopted for targeted therapy. The light-activated methylene blue is adopted for treating three or five positive cases of hepatitis B once every two days by 120 milligrams every time, and all the cases are effectively turned to negative. The preparation process comprises the step of preparing the photoactivated methylene blue riboflavin and the capsule of the photoactivated methylene blue riboflavin.

A method and device for performing DNA sequencing and extracting structural information from unknown nucleic acid strands. The device includes a microwell structure, where identical DNA strands are immobilized within the microwell structure on a surface of a micro-bead, an active electrode or a porous polymer. The device further includes a CMOS-integrated semiconductor integrated circuit, where the CMOS-integrated semiconductor integrated circuit includes metal layers on a silicon substrate, where the metal layers form an active electrode biosensor. In addition, a sensing electrode is formed by creating openings in a passivation layer of the CMOS-integrated semiconductor integrated circuit to hold a single bead, on which the DNA strands are immobilized.

A label for analysing a biological sample includes a first label part including a first nucleic acid strand, and a second label part including a second nucleic acid strand. The first nucleic acid strand and the second nucleic acid strand are configured to form a duplex. The label further includes at least one first labelling moiety and at least one second labelling moiety, and the label further includes at least one blocking nucleic acid strand.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

The application discloses a kind of photoactivation manganese ion bridging type deoxyribozyme probe preparation and its application in Cistanche inhibiting acetylcholinesterase activity.The probe is pSD@MnO2 Composite structure, which is composed of manganese dioxide nanosheet and functional nucleic acid assembly adsorbed on its surface, the assembly includes S chain labeled with fluorescence / quenching group and containing deoxyribozyme cleavage site, and pD chain partially hybridized with S chain and containing photocleavage site.Its preparation includes nucleic acid probe assembly, MnO2 Nanosheet complexing and purification steps.When applied, AChE catalytic product decomposes MnO2, releases Mn 2+ And nucleic acid chain; after centrifugation, pD chain is cut by ultraviolet light activation trigger, and released DNAzyme is cut under the assistance of Mn 2+ It produces amplified fluorescence signal; by comparing signal change before and after adding inhibitor, inhibition activity can be quantitatively evaluated.The application combines photocontrol activation with enzyme cascade amplification, realizes high sensitivity and operation synchronism of detection process, and is especially suitable for high-throughput rapid screening of AChE inhibitor in Cistanche and other natural products.

Multivalent binding compositions including a particle-nucleotide conjugate having a plurality of copies of a nucleotide attached to the particle are described. The multivalent binding compositions allow one to localize detectable signals to active regions of biochemical interaction, e.g., sites of protein-protein interaction, protein-nucleic acid interaction, nucleic acid hybridization, or enzymatic reaction, and can be used to identify sites of base incorporation in elongating nucleic acid chains during polymerase reactions and to provide improved base discrimination for sequencing and array based applications.

A method for detecting hematopoietic stem cells comprises the steps that a CD133 nucleic acid aptamer functionalized ITO electrode is used as a substrate, e-Y-Click labeling of hematopoietic stem cell surface protein is achieved through in-situ electrochemical activation of PTAD-N3, N3 groups combined on the surface and DBCO modified nucleic acid chains T are subjected to SPAAC reaction, and the hematopoietic stem cells are obtained. The method comprises the following steps of: triggering a self-replication cycle reaction of DNA (Deoxyribose Nucleic Acid), enriching electrochemical signal substances on the surfaces of the hematopoietic stem cells, qualitatively judging the hematopoietic stem cells by detecting electrochemical signals, and correspondingly judging the quantity of the hematopoietic stem cells contained in a sample to be detected according to the established relationship between the intensity of the electrochemical signals and the quantity of the hematopoietic stem cells, so as to realize quantitative detection.

Provided herein include conditionally activatable small interfering RNA (siRNA) complexes, components, compositions, and related methods and systems. The siRNA complex can be conditionally activated upon a complementary binding to an input nucleic acid strand through a sequence in a sensor nucleic acid strand of the nucleic acid complex. The activated nucleic acid complex can release a potent RNAi duplex formed by a core nucleic acid strand and a passenger nucleic acid strand, which can specifically inhibit a target RNA.

A sequencing scaffold for attaching a target nucleic acid strand (204) comprises at least one nucleic acid scaffold (100, 102, 104, 200a, 200b), the at least one nucleic acid scaffold (100, 102, 104, 200a, 200b) having a plurality of attachment regions (118, 119) at predetermined locations, each attachment region comprising at least one attachment site (122, 124, 124a, 124b), the attachment sites (122, 124, 124a, 124b) being configured to hybridize directly or indirectly to the target nucleic acid strand (204), and the nucleic acid scaffold (100, 102, 104, 200a, 200b) having a three-dimensional lattice structure, and attachment sites (122, 124, 124a, 124b) are arranged in three dimensions on the lattice structure of the nucleic acid backbone (100, 102, 104, 200a, 200b). In further aspects, methods of sequencing are provided.

The present disclosure relates to an extrahepatic delivery drug and the use thereof. An oligonucleotide comprises a group as shown in general formula (I) located at any position of a nucleic acid chain of the oligonucleotide. A compound and the oligonucleotide of the present disclosure can achieve effective delivery of the oligonucleotide to tissue other than the liver, thus providing more tools for regulating gene expression, and expanding the uses thereof in RNAi drug research and development.

The application discloses a pyridaben lateral flow analysis method and test paper based on triple helix bivalent aptamer and nano enzyme, and belongs to the fields of analytical chemistry, medicine, environment, food safety detection and nano biosensing. By constructing a triple helix bivalent aptamer, the binding rate of the aptamer and the target is greatly improved, and the response time is shortened to 1 / 6 of that of a conventional aptamer. With the excellent peroxidase-like activity of the Au@Pt nano enzyme, the sensitivity of the Apt-LFA test for detecting pyridaben is improved by 5 times. The streptavidin and streptavidin-biotin-DNAc sprayed in the detection zone and the control zone do not need to be changed, and only the nucleic acid chain part on the probe Au@Pt NPs@poly-DNA needs to be changed to detect another substance. A new lateral chromatography method for rapid, sensitive and low-cost detection is developed, and the nano enzyme triple helix aptamer test paper has great application potential.

This invention provides a method for testing a sample for the presence of one or more targets, including multiplexed catalytic reporter deposition (CARD). [Solution] The method comprising: (1) contacting a sample to be tested with one or more target-specific binding partners, each target-specific binding partner being linked to a nucleic acid chain, with differently specific target-specific binding partners being linked to different nucleic acid chains; (2) contacting the sample with (a) an enzyme linked to a nucleic acid chain, and (b) an intermediate portion including a first domain that specifically binds to the nucleic acid chain linked to the target-specific binding partner and a second domain that specifically binds to the nucleic acid chain linked to the enzyme; (3) contacting the sample from step (2) with a substrate conjugate consisting of a detectably labeled substrate; (4) inactivating the bound enzyme; and (5) detecting a signal from the bound detectably labeled substrate.