30 results about "Nucleic acid secondary structure" patented technology

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 andselective detection of the target molecules.

The invention discloses a polyaryl-substituted imidazole fluorescence probe. The structural formula of the polyaryl-substituted imidazole fluorescence probe is shown in the formula (I). The invention further discloses a preparation method of the polyaryl-substituted imidazole fluorescence probe and application of the polyaryl-substituted imidazole fluorescence probe in the specific detection of a G-quadruplex. The fluorescence probe is simple to prepare, stable in structure and can be applied to the specific detection of a wild c-MYC G-quadruplex nucleic acid secondary structure, the raw materials are easily available, the wild c-MYC G-quadruplex nucleic acid secondary structure in a solution can be rapidly detected by virtue of a fluorescence spectrometer, and the fluorescence probe has no fluorescent responsiveness to mutational c-MYC G-quadruplexes or other DNA secondary structures. The method for the specific detection of the wild c-MYC G-quadruplex nucleic acid secondary structure has the beneficial effects that the operation is simple and convenient, the sensitivity and the specificity are strong, and disadvantages of other detection methods that the cost is high, the equipment requirement is high, the technical operation is relatively complex, and the like can be overcome.

The invention provides a bifunctional probe. The concrete structural formula of the probe is shown in the specification. In the formula, R1 is F or an N-methylpiperazinyl group, R2 is F or an N-methylpiperazinyl group, and R1 and R2 cannot simultaneously be F; and R3 is a methoxy group, a diethylamino group, a dimethylamino group, an N-methylpiperazinyl group, F or H. The probe has the advantages of simple preparation steps, easily available raw materials and stable structure, can be used for the specific detection of the orthographic parallel conformation G-quadruplex nucleic acid secondary structure, can rapidly detect the orthographic parallel conformation G-quadruplex nucleic acid secondary structure in a nucleic acid sample through an ultraviolet spectrophotometer, a fluorospectrophotometer or an enzyme linked immunosorbent assay instrument, and even naked eye observation under sunlight or an ultraviolet lamp, and overcomes the disadvantages of difficult distinguishing of many different conformations of G-quadruplex nucleic acid, high price, high device requirements and complex technical operation of other detection methods.

The invention provides a preparation method of a quinoxaline fluorescent probe and its application in detecting G-quadruplexes. At least one of ethylamino, R2 adopts F, methyl, and R3 adopts at least one of F, methyl, N-methylpiperazinyl and triazolyl. Compared with the prior art, the present invention has the following advantages: (1) The probe is easy to prepare, easy to obtain, stable in structure and convenient for storage. (2) The probe provided by the present invention can specifically detect the G-quadruplex structure, realize the distinction between the G-quadruplex structure and other secondary structures, and use a simple fluorescence spectrometer, even without any instrument, to observe with the naked eye The secondary structure of the nucleic acid sample can be identified, which is fast, easy to operate, low in cost, and can realize on-site detection. (3) The probe has no obvious influence on the secondary structure of the nucleic acid to be detected, and can accurately detect the original structure of the nucleic acid.

The invention discloses a bifunctional probe, its preparation method and its application in detecting the G-quadruplex structure. This type of probe is easy to prepare, easy to obtain, and has a stable structure. It can be used to specifically detect the secondary structure of G-quadruplex nucleic acid. It can be quickly detected by ultraviolet-visible absorption spectroscopy, fluorescence spectrophotometer, or directly by naked eye observation. The secondary structure of a DNA sample in solution is detected. This type of probe has the advantages of simple operation, good selectivity, quickness, and visible to the naked eye for the detection of the secondary structure of G-quadruplex nucleic acid, and overcomes the disadvantages of other detection methods such as expensive, high equipment requirements, and relatively complicated technical operations. .

The invention discloses a method for realizing over expression of the thermostable laccase gene through location transformation. Thermostable laccase produced from thermus thermophilus bacteria has great application potential in the industrial processes of pulp bleaching, textile decoloring, biomass hydrolysate detoxifying and the like, but the thermostable laccase gene has low expression level and can not become an enzyme source. In the invention, a carrier in a pHsh series is firstly applied to carrying out cloning, in-situ mutagenesis and induced expression on the laccase gene. By carryingout case analysis and multiple explorative site-directed mutagenesis on a special sequence of the thermostable laccase gene, the invention has the effects of reducing rare codons in the gene, lowering the GC base content and weakening formation of a nucleic acid secondary structure and the like, thereby enhancing the expression level of the gene in escherichia coli by 317 times compared with a natural gene.

The invention relates to a method for implementing targeted cleavage on arbitrary nucleic acid; a structural identification endonuclease is constructed and expressed for establishing the method. The method comprises the concrete steps: selecting a cleavage position of a target nucleic acid, and designing a nucleic acid probe complementary with target nucleic acid; adding into a reaction system, making the probe hybridized with a substrate, and forming a secondary structure which can be identified by the structural identification endonuclease; and adding the enzyme, and carrying out a cleavage reaction. The nucleic acid structure which can be identified includes a nucleic acid intrusive structure and the like; an endonuclease identification functional domain is composed of a peptide fragment which can identify a nucleic acid secondary-structure enzyme and can be selected from E.coliMuts and the like; the cleavage functional domain is selected from a cleavage function of an IIS type endonuclease; a connection fragment between the identification functional domain and the cleavage functional domain of the endonuclease is mainly composed of serine and glycine; and the method breaks through the limit of a sequence of a nucleic acid substrate, so that the method can realize effective targeted cleavage of nucleic acids with different sequences.

The invention relates to a method for detecting nucleic acid structure based on surface-enhanced Raman spectroscopy, comprising the following steps: (1) preparing iodide ion-modified and cleaned silver nanoparticle sol; (2) preparing iodide ion-modified silver nanoparticle centrifuge tube Add the DNA sample to be detected, add a buffer solution with a pH value of 3.0-5.0, and then add aluminum ions or titanium ion aggregation agents to perform surface-enhanced Raman spectroscopy detection. It effectively detects the secondary structure of nucleic acid, has the advantages of simplicity and speed of SERS, and has high reproducibility and reliability. This method overcomes the difficulty of detecting the secondary structure of nucleic acid in the traditional SERS detection, and has the advantages of simple, fast, high sensitivity and good reproducibility, and obtains a signal with a very high signal-to-noise ratio, realizing the detection of various High sensitivity detection of nucleic acid secondary structure.

The invention discloses a fluorescent probe, as well as preparation method of the fluorescent probe, and applications of the fluorescent probe in detecting conformation of G-quadruplex nucleic acid. The specific structural formula is as shown in specification, wherein R1 in the formula is F or N-methylpiperazine, and R2 is N-methylpiperazine. The probe is simple to prepare and easily available, and stable in structure, and can be used for specifically detecting the secondary structure of the orthographically parallel conformed G-quadruplex nucleic acid, and the secondary structure of a DNA sample in a solution can be rapidly detected through a fluorospectro photometer. A method for detecting the secondary structure of the orthographically parallel conformed G-quadruplex nucleic acid through the probe has the advantages of being simple and convenient to operate, and good in selectivity, and the defects that other detection methods are difficult for various conformations of the G-quadruplex nucleic acid to distinguish, expensive in price, high in equipment requirement, relatively complicated in technical operations, and the like can be overcome.