144 results about "Nucleic acid structure" patented technology

This invention relates to compounds, compositions, and methods useful for modulating gene expression using chemically modified double stranded nucleic acid molecules. In particular, the instant invention features double stranded nucleic acid molecules including small nucleic acid molecules, such as short interfering nucleic acid (siNA), short interfering RNA (siRNA), double-stranded RNA (dsRNA), micro-RNA (miRNA), and short hairpin RNA (shRNA) molecules and methods used to modulate the expression of genes via RNA interference (RNAi). The invention features various modifications to double stranded nucleic acid structures, including chemically modified overhangs and optimized stabilization motifs of guide (antisense) strand and passenger (sense) strands of double stranded nucleic acid molecules that allow for potent RNA interference in therapeutically relevant applications.

A method for detecting an analyte in a sample, comprising (a) contacting the sample with at least one set of at least first, second and third proximity probes, which probes each include an analyte-binding domain and a nucleic acid domain and can simultaneously bind to the analyte, the nucleic acid domain of the third proximity probe being a splint which is capable of hybridizing at least to the nucleic acid domains of the first and second proximity probes, wherein when all of the at least three proximity probes bind to the analyte, the nucleic acid domains of the first and second proximity probes are conjugatable by means of an interaction mediated by the hybridized splint of the third proximity probe; (b) conjugating the nucleic acids, of the first and second proximity probes; and (c) detecting the conjugation. Also provided is a kit for use in such a method.

The present disclosure relates to a fusion nano liposome-fluorescence labeled nucleic acid in which a bead having a surface binding with a branch-shaped nucleic acid structure labeled with a fluorophore or a branch-shaped nucleic acid structure having a hairpin loop end is included in an inside of a liposome, and a diagnosis application thereof. The fusion nano liposome-fluorescence labeled nucleic acid, or fusion nano liposome-fluorescence labeled hairpin loop structured nucleic acid may sense an external or internal signal, and high-sensitive diagnosis is possible even when mRNA and miRNA which is present at a low concentration in cells being targeted. Further, various target materials expressed inside and outside of a cell membrane may be targeted, and thus even a type of cancer which is hard to diagnose such as triple negative breast cancer also be flexibly diagnosed. Further, using various fluorophores, multiple cancer may be diagnosed at the same time.

The present invention is directed to a hairpin nucleic acid structure and its use. In a preferred embodiment, the hairpin nucleic acid structure can be used in a method of amplification of a template nucleic acid sequence that substantially reduces polymerase-induced errors.

The invention provides compositions and methods for making closed nucleic acid structures in which one or both strands are continuous. The closed nucleic acid structures can be used as sequencing templates among other applications.

The invention provides a protein synthesis efficiency enhancing RNA element and particularly discloses a nucleic acid structure formed by coding sequences of optional promoters, yeast-derived IRES enhancers (such as ScGPR1, ScFLO8, ScNCE102, ScMSN1, KlFLO8, KlNCE102 and KlMSN1) and heterologous proteins. By application of the nucleic acid structure to a yeast in-vitro protein synthesis system, thesynthesized luciferase activity RLU (relative light unit) is extremely high.

Methods and compositions for rendering nucleic acids directly responsive to an external signal utilizing modulators that themselves respond to the external signal and are associated with the nucleic acid. In response to the external signal, the modulator alters physical properties of the specific nucleic acid molecule(s) with which it is associated, thereby altering the structural and functional properties thereof. The modulator may, for example, transfer applied energy to a nucleic acid, or to a portion of the nucleic acid, thereby changing the nucleic acid structure.

The invention discloses a detection method of target molecules, which is based on manometer gold and a nucleic acid structure and comprises the sequential steps: (1), hybridizing specific DNA (Deoxyribonucleic Acid) with cDNA (Complementary Deoxyribonucleic Acid) in fluorescence labeling to form a double-stranded capture probe, wherein the specific DNA can be in specificity combination with the target molecules; (2), adding a solution to be detected for reaction; (3), adding a manometer gold solution for reaction and recording a fluorescence spectrum of the reaction solution. The detection method of the invention has commonality and wide range of application so that detection objects can be any target molecule. The invention can be utilized to conveniently realize the rapid, sensitive and selective detection of the target molecules.

The invention discloses a target molecule detection method based on nano-Au and nucleic acid structure. The detection method sequentially comprises the following steps: (1) specific DNA which can specifically react with target molecules is sufficiently hybridized with the cDNA of the DNA to form a double-chain capture probe, wherein the target molecules are proteins or ions; (2) target molecule solution is added for full reaction; (3) nano-Au solution with the mol number of 0.01-1 time of that of the specific DNA is added, and the solution is red after reaction; (4) high salting solution with the final concentration of 1-100 mM is added, and the color change of the solution is observed. The detection method has commonality, wide application range, good specificity and high sensitivity, can quickly detect any proteins or any ions with low cost, and does not need DNA mark or dear instruments.

The present invention relates to an RNAi-inducing nucleic acid molecule having a new structure and the use thereof, and more particularly to a novel nucleic acid molecule having a structure comprising a first strand, which is 24-121 nt in length and comprises a region complementary to a target nucleic acid, and a second strand which is 13-21 nt in length and has a region that binds complementarily to the region of the first strand, which is complementary to the target nucleic acid, so that the nucleic acid molecule inhibits the expression of a target gene with increased efficiency, and to a method of inhibiting the expression of a target gene using the nucleic acid molecule. The nucleic acid molecule structure of the present invention increases the efficiency with which the nucleic acid molecule inhibits the target gene. Alternatively, the nucleic acid molecule of the present invention can either increase the ability of the siRNA to bind to the target gene or cause synergistic cleavage, by introduction of antisense DNA, antisense RNA, ribozyme or DNAzyme, thereby increasing the efficiency with which the nucleic acid molecule inhibits the target gene. In addition, when the nucleic acid molecule according to the present invention is used, the efficiency with which the target gene is inhibited can be maintained for an extended period of time. Accordingly, the RNAi-inducing nucleic acid molecule of the present invention can be effectively used for the treatment of cancer or viral infection in place of conventional siRNA molecules.

Methods and compositions are provided for the detection of specific nucleic acid sequences purified from cellular or tissue sources. More particularly, the present invention includes methods and compositions for the detection of nucleic acid sequences using a protection molecule that forms a protected nucleic acid sequence (PNAS) such as a triplex or duplex nucleic acid structure that includes the target nucleic acid sequence. An assay using the methods of the present invention may include one, two or three levels of specificity to minimize false positive signals. An assay using the methods or compositions of the present invention can be performed on large amounts of purified DNA in a single test, with high levels of sensitivity, thus eliminating the need for DNA amplification procedures.

Compositions of nucleic acid hybridization probes for detecting a nucleic acid target sequence and methods for their production are described. In one preferred embodiment, the nucleic acid hybridization probe includes a hybridization domain, an adaptor, a linker, and a signaling domain. The hybridization domain includes a nucleic acid sequence having complementarity to the nucleic acid target sequence. The adaptor is a nucleic acid sequence. The linker includes a moiety having at least one abasic site, such that the moiety blocks extension by an elongating polymerase on a nucleic acid template containing the moiety. The signaling domain comprises a nucleic acid having at least one label or a nucleic acid having at least one nucleic acid domain for binding at least one additional nucleic acid.

The present invention relates to compositions and methods for the use of enzymes composed of nucleic acid and/or protein enzymes to generate and amplify a signal indicative of the presence of a target. More particularly, the invention relates to compositions comprising nucleic acid structures that serve as partial or complete enzyme substrates and methods for using these structures to facilitate detection of targets.

The invention discloses a copper ion detection method based on click chemistry and a detection kit. The bivalent copper ion is reduced to the cuprous ion under the effect of a reducing agent, so that the click chemistry reaction is activated; two sections of nucleotide sequences are connected with each other; a catalytic nucleic acid structure with catalytic activity can be further assembled after the magnetic bead separation; a substrate nucleic acid can be cut, so that fluorescence groups and quenching groups at the two ends of the substrate nucleic acid can be separated; and the copper ion concentration can be identified through fluorescence detection. The copper ion detection method has higher sensitivity; a detection limit to copper ions is 2pM; the detection has excellent specificity; the other conventional interfering ions have no influence on the detection; and the detection process is simple in operation, low in cost and suitable for quick detection for the copper ion concentration in practical samples.

A method for purifying a desired substance by separating from each other a substance (I) from a substance (II), one of which is the desired substance, both of which have affinity for the same ligand structure, and wherein substance (I) is smaller than substance (II). The method comprising the steps of: (i) providing substances I and II in a liquid; (ii) contacting the liquid with an adsorbent which selectively adsorbs substance I; (iii) recovering the desired substance; The adsorbent has (a) an interior part which carries a ligand structure that is capable of binding to substances I and II, and is accessible to substance I, and (b) an outer surface layer that does not adsorb substance II, and is more easily penetrated by substance I than by substance II.

The invention discloses a fluorescence detection kit based on an aptamer. The fluorescence detection kit comprises exonuclease III, a reaction buffer solution, DNA1, DNA2 and stem-loop structure nucleic acid H1. The aptamer is used for specific recognition of a molecular recognition element, a 3' double-chain nucleic acid structure with a flush end is obtained, and circular signal amplification isperformed after exonuclease III is added, so that a large amount of double-chain DNA become single-chain DNA; after fluorescent dye is added, the content of to-be-detected molecules is detected by distinguishing fluorescence intensity change. The linear range for malathion detection is 10 pM to 100 nM, and the limit of detection is 5 pM; meanwhile, the detection system has good specificity and the detection results cannot be interfered by other common analogues. No separation and purification processes are required in the detection process, the kit can be used for detection after simple mixing, has the advantages of being simple to operate, low in cost, rapid in response and the like and can be used for rapid and high-sensitivity detection of pesticide residues in food, water sources, soil and other samples.

The invention discloses a nucleic acid structure of which the interchain exchange is achieved by a support DNA (deoxyribonucleic acid). The nucleic acid structure is a two-dimensional or three-dimensional nucleic acid structure with controllable size and shape, which is formed by achieving interchain exchange by the support DNA. The nucleic acid structure comprises a set of parallel double helices connected by interchain exchange and a single-chain DNA segment, wherein the double helices are formed by carrying out folding and interchain exchange by the support DNA, carrying out specific matching with a plurality of short-chain DNAs and carrying out annealing reaction; and the single-chain DNA is the part of the support DNA which does not form the double helices. The invention provides the multiple nucleic acid structures and synthesis methods thereof. The nucleic acid structure is a variant technique based on DNA paper folding. The invention aims to form the nucleic acid structure with controllable size, shape, complexity and modification by achieving interchain exchange by using the support DNA. The nucleic acid structure is completed by the support DNA/short-chain DNA self-assembly process, and has the advantages of higher yield and simple design; and the predicated two-dimensional and three-dimensional structures can be simultaneously synthesized.