55 results about "Nucleic Acid Strand" patented technology

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 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.

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.

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.

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.

A sequencing scaffold for attachment of target nucleic acid strands includes at least one nucleic acid backbone with a plurality of attachment regions at predetermined positions. Each attachment region includes at least one attachment site. The attachment sites are configured to hybridise the target nucleic acid strands. The nucleic acid backbone has a three-dimensional lattice structure. The attachment regions are arranged on the lattice structure of the nucleic acid backbone in three dimensions.

A composition includes a plurality of biocompatible metal nanospheres. the biocompatible nanospheres each having an outer surface with elemental carbon connected thereto. The composition also includes a plurality of single nucleic acids strands, wherein at least a portion of the respective individual single nucleic acid stands are in coordinated connection with the nanospheres, and a carrier medium.

This invention belongs to the field of CRISPR / Cas12a system regulation technology, and discloses a method for post-activation inhibition of the CRISPR / Cas12a system without modification or additional stimulation. The core of this method is to provide a post-activation inhibition approach to address safety concerns such as runaway editing, off-target effects, and unexpected cytotoxicity caused by the long-term maintenance of high activity after CRISPR / Cas12a system activation. The core innovation of this method lies in the design of an RNA inhibitor (iRNA). This inhibitor requires no chemical modification and does not rely on external stimuli such as light, small molecule induction, or temperature changes to function, possessing advantages such as simple structure and ease of use. Its mechanism of action utilizes the conformational dynamic sensitivity of Cas12a itself, leveraging the thermodynamic advantages and kinetics of nucleic acid strand displacement reactions to induce conformational rearrangement of the activated Cas12a RNP complex, refolding it into an inactive state, thereby achieving highly efficient inhibition of the CRISPR / Cas12a system.

The invention relates to the technical field of biological medicine, particularly discloses a novel coupling method of double-target nucleic acid molecules and application thereof, and provides a strategy method for connecting two nucleic acid chains through cyclization reaction between tetrazine and alkene or alkyne. According to the present invention, a cyclization reaction is performed between a nucleic acid chain of a tetrazine group (Strand 1) and a nucleic acid chain of an alkene or alkyne group (Strand 2), a connection unit of dihydropyridazine or pyridazine is generated between the two nucleic acid chains, and four connection modes are selected: between 5'of Strand 1 and 3 'of Strand 2, between 5' of Strand 1 and 5 'of Strand 2, and between 3' of Strand 1 and 5 'of Strand 2. Furthermore, two nucleic acid chains connected with dihydropyridazine or pyridazine are respectively combined with complementary nucleic acid chains according to complementary base pairing to prepare a double-target oligonucleotide drug.

A double-stranded nucleic acid complex is provided having first and second nucleic acid strands. The first nucleic acid strand includes an artificial nucleic acid and is capable of hybridizing to at least part of a target gene or a transcription product thereof and can induce exon skipping, exon inclusion and / or steric blocking to the target gene or transcription product thereof. The second nucleic acid strand includes a base sequence complementary to at least part of the first nucleic acid strand and includes at least one blocking region which is resistant to a nuclease which is present in a body fluid, and at least one cleavage region which undergoes degradation by a nuclease which is present intracellularly. The cleavage region includes two or more consecutive sugar-unmodified nucleosides.

The invention discloses a multifunctional nanoprobe for lung cancer drug resistance diagnosis and treatment and a preparation method and application thereof, and relates to the technical field of DNA nanoprobes, the multifunctional nanoprobe comprises a Y-shaped structure formed by self-assembly of three nucleic acid chains S1, S2 and S3 and PTX, the Y-shaped structure and PTX are self-assembled to form a spherical structure, and the particle size of the spherical structure is 80-120nm; the S1 nucleic acid chain is loaded with an anti-ABCB1 sequence, is modified with a Cy5 fluorophore and is subjected to fluoro modification treatment; the S2 nucleic acid chain is loaded with an S6 sequence of a targeted A549 cell membrane surface specific structure; and the S3 nucleic acid chain is loaded with an anti-beta III-tubulin sequence. By integrating multiple functions of targeting recognition, gene silencing and chemotherapy drug delivery, diagnosis and treatment integration of the paclitaxel drug-resistant lung cancer is realized.

This invention discloses a method, apparatus, and application for the simultaneous detection of aroA1, aroA2, and aroA3. A sample tube is simultaneously irradiated with an 808nm external coaxial reflective LED light source. The photosensitizer CsYF4@Yb2O3, phototriggered, provides photoelectrons and heat to the LAMP process. The target gene serves as a template to initiate the amplification reaction, yielding a large amount of double-stranded DNA product. Signal probes are obtained by modifying CsYF4@Yb2O3 with nucleic acid strands. The detection area of ​​the photothermal detection paper captures the amplification product and signal probes in a sandwich configuration, providing a photothermal temperature change signal positively correlated with the amplification product content. The aroA1, aroA2, and aroA3 in the sample are quantified based on this temperature change signal. This invention utilizes the photoactive properties of the photosensitizer CsYF4@Yb2O3 to generate photoelectrons and photothermal effects, enabling rapid temperature control and direct molecular-level contact with the amplification system before photothermal detection, significantly improving photothermal efficiency.

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. The label further includes at least one blocking nucleic acid strand that is at least partially complementary to one of the first nucleic acid strand and the second nucleic acid strand.

The invention relates to the technical field of tumor detection, in particular to a CRISPR-Cas12a system for one-step detection of a tumor marker APE1 based on an autocatalytic strand displacement reaction. According to the system, the trans-cleavage activity of Cas12a and the dynamic characteristic of a nucleic acid strand displacement reaction are coupled to form a self-sustaining positive feedback cycle. A template probe is constructed by designing a blocking chain containing an AP site and an activation chain, and crRNA invasion, Cas12a activation and feedback cutting of the blocking chain are realized under the triggering of APE1, so that a binding domain is continuously regenerated, multiple rounds of chain replacement and Cas12a reactivation are driven, and a self-circulation amplification detection platform is established. According to the technical scheme, the technical problem that in the prior art, a novel detection system which does not need exogenous amplification, does not depend on additional enzymes, has self-driven and positive feedback amplification capabilities and is used for accurate, rapid and on-site detection of APE1 is lacked can be solved, and the method has ideal application prospects.

A marker for analyzing a biological sample is provided. The marker comprises a first tagging moiety comprising a first nucleic acid strand (106) and a second tagging moiety comprising a second nucleic acid strand (110). The first nucleic acid strand (106) and the second nucleic acid strand (110) are configured to form a duplex. The marker further comprises at least one first tagged moiety (108) and at least one second tagged moiety (112), and the marker further comprises at least one blocking nucleic acid strand (126, 128). In other aspects, markers (100, 500, 600) comprising a marker and corresponding methods are provided.

The present invention discloses a system and a method for detecting different developmental stages of fungi life cycle in postharvest crops. More particularly, the system comprises a measuring transducer, such as a CMOS photodetector and immobilized fungal nucleic acid strands. RNA from the tested postharvest produce sample is loaded onto the system of the present invention, and specific fungal mRNA transcripts anneal to the immobilized strands. A reporter strand conjugated to a signal-generating component further binds the mRNA transcripts, and when a detectable reaction is produced post binding, the transducer captures said reaction and converts it to measurable values, indicating the quantity, presence and the developmental stage of the fungus.

Staple nucleic acids capable of forming guanine quadruplex structure on a target nucleic acid even when four guanine repeat sequences are not present on the target nucleic acid. The oligonucleotide (second generation-type Staple nucleic acid) can supply guanine repeat sequences so that a guanine quadruplex structure can be formed on a target nucleic acid by a total of four guanine repeat sequences, consisting of guanine repeat sequences on the target nucleic acid and guanine repeat sequences on the oligonucleotide.

The application provides a preparation method of a phosphorescent biosensor for specifically detecting messenger RNA. In the application, a phosphorescent biosensor is constructed by using phosphorescence resonance energy transfer (PRET) between polydopamine (PDA) and persistent luminescence nanoparticles (PL). The biosensor comprises a PDA particle carrier and three nucleic acid chains, one of which is a hairpin chain (H) that is complementary to target TK1 mRNA, one is a DNA chain (PL-DNA) that is combined with the persistent luminescence nanoparticles through an amide bond, and the other is a substrate chain (S-15A) that is complementary to the PL-DNA. In the absence of the target, the phosphorescence of the PL is absorbed by the PDA, resulting in a weak signal; after the target is added, the target opens the H, and the exposed flexible end displaces the PL-DNA from the S-15A, so that the PL is away from the PDA, the PRET is closed, the phosphorescence signal is restored, and the phosphorescence signal is enhanced with the increase of the concentration of the target, and the linear relationship is 0-200 nM. The detection limit of the application is 1.74 nM.

In a first aspect, a marker (102, 402, 600) for analyzing a biological sample is provided. The marker (102, 402, 600) comprises: a first marker portion (300) comprising at least one first nucleic acid strand (104, 302); a second marker moiety comprising a second nucleic acid strand (108); and a third marker moiety comprising a third nucleic acid strand (110). The first nucleic acid strand (104, 302), the second nucleic acid strand (108), and the third nucleic acid strand (110) are configured to form a triplex with each other. The first marker portion (300) further comprises at least one marker portion (106, 304, 306). In other aspects, a corresponding marker (100, 400, 500) and method for analyzing a biological sample is provided.

A composition for detecting hematopoietic stem cells includes hematopoietic stem cell-binding peptide-functionalized magnetic beads, crRNA, maleimide-modified activating nucleic acid chains, and methylene blue-modified signaling nucleic acid chains. Using a CRISPR / Cas signal amplification reaction, the activating nucleic acid chains of the CRISPR / Cas system are labeled onto the surface of hematopoietic stem cells via a mild reduction reaction. Through complementary binding of the labeled chains with crRNA, the trans-cleavage activity of Cas12a protein is activated, randomly cleaving the long DNA signal chain and releasing terminally modified methylene blue (MB). MB molecules are incubated with a graphite electrode co-functionalized with CB[7], AuNPs, and PDDA. The MB molecules are captured by the hydrophobic cavity of CB[7], forming a stable host-guest complex that generates an electrochemical signal. The detection of hematopoietic stem cells can be achieved by measuring the methylene blue electrochemical signal enriched on the surface of the functionalized graphite electrode.

The invention relates to isolated antisense molecule capable of inhibiting the expression of the LMNA gene in a mammalian cell, wherein said antisense molecule comprises an anti-sense nucleic acid strand which is substantially complementary to a target region of a transcript encoded by the LMNA gene, wherein said antisense nucleic acid strand is at least complementary to SNP rs538089, rs505058 or rs4641 in said target region.

A label for analyzing a biological sample includes a first label part comprising a first nucleic acid strand, and a second label part comprising 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 at least one blocking nucleic acid strand. The at least one blocking nucleic acid strand is at least partially complementary to one of the first nucleic acid strand and the second nucleic acid strand.

A nucleic acid strand cleaving method that is characterized by comprising a nucleic acid preparation step in which a nucleic acid to be cleaved that has a structure indicated in formula (1) is prepared, and a cleaving step in which the nucleic acid to be cleaved is cleaved at X in formula (1) by reacting the nucleic acid to be cleaved with a cleaving agent, and a nucleic acid that has a structure indicated in formula (2) is generated, wherein the cleaving agent is metal nanoparticles that include atoms selected from the group consisting of silver, mercury, and cadmium.　[Formula 1] (B indicates a base, and X indicates sulfur or selenium. NucA comprises at least one nucleotide, is part of the nucleic acid to be cleaved, and indicates a section on the 5'-end side, relative to X. NucB comprises at least one nucleotide, is part of the nucleic acid to be cleaved, and indicates the 3'-end side, relative to X.)