510 results about "Single strand" patented technology

The invention relates to a metallized microbubble and a preparation method thereof, a construction method of a multifunctional composite probe, and a rapid bacterium capturing and sterilizing method, and belongs to the technical field of functional material preparation. The method aims at solving the technical problems that in the prior art, a metal coating on the surface of the hollow glass microbubble is not uniform, combination is not firm, and stability is poor. According to the technical scheme, the method is characterized by comprising the following steps: mixing surface-activated hollow glass microbubbles with a polyethyleneimine solution for reaction, and washing and drying to obtain polyethyleneimine-coated hollow glass microbubbles; then reacting with a single-stranded DNA buffer solution to obtain an intermediate product loaded with DNA; then introducing a silver nitrate solution to load silver ions on the surface of the compound; and finally, reducing through a sodium borohydride solution to prepare the metallized microbubbles. The metalized microbubbles prepared by the method can be used for constructing a multifunctional composite probe to realize efficient capture and synergistic antibiosis of targets such as bacteria.

This invention provides a process for sequencing single-stranded DNA by employing a nanopore and modified nucleotides.

The invention relates to a nucleic acid aptamer for specifically recognizing tilmicosin as well as screening and application of the nucleic acid aptamer, and belongs to the technical field of food safety detection and biosensing. Aiming at the defects of the existing method for detecting tilmicosin residues in food, the invention provides a high-affinity and high-specificity nucleic acid aptamer obtained by screening based on a graphene oxide index enrichment ligand systematic evolution technology. The aptamer is obtained by multiple rounds of screening from a random single-stranded DNA library through a GO-SELEX technology, and a core sequence Apt-2-1 with the length of 33 nt is finally obtained through sequence analysis and structure optimization. The aptamer shows excellent binding capacity to tilmicosin, the dissociation constant reaches 9.82 nM, and the aptamer has good specificity. The nucleic acid aptamer provided by the invention can be used for constructing a rapid and sensitive tilmicosin residue detection method, and has important application value in monitoring of livestock and poultry products and food safety.

This invention discloses a primer and probe set, a kit, and their applications for detecting Staphylococcus aureus L based on real-time fluorescence MIRA technology. The primer and probe set consists of single-stranded DNA sequences 1-3. Based on the aforementioned primer and probe set, this invention establishes and optimizes a real-time fluorescence MIRA detection method for Staphylococcus aureus L. Furthermore, the optimized real-time fluorescence MIRA method is innovatively combined with a simplified nucleic acid extraction method and a portable fluorescence detection device, significantly reducing extraction and time costs while enabling rapid on-site detection of the virus, making it particularly suitable for grassroots units and remote areas. In addition, the real-time fluorescence MIRA detection method for Staphylococcus aureus L established in this invention has advantages such as high specificity, high sensitivity, and simple operation. Moreover, the detection process does not require opening the lid, effectively avoiding aerosol contamination, providing an effective technical means for the differential diagnosis and rapid detection of Staphylococcus aureus L.

The invention relates to a nano groove array and a manufacturing method and application thereof, and the manufacturing method of the nano groove array comprises the following steps: taking single-stranded DNA (ssDNA) as a DNA brick, and carrying out self-assembly by adopting a complementary pairing principle of the ssDNA to obtain the nano groove array with a base and a side wall; wherein the width and the height of the nano groove array are fixed, the number of grooves is determined, and the nano groove array extends along a single direction; in the nano groove array, the width of the side wall and the width of the groove are equivalent to the diameter of two double-helix DNA (dsDNA). Compared with the prior art, the number of the grooves of the nano groove array is controllable, the width of the grooves is 4 nm, the period of the groove array is 8 nm, and the self-assembly defect can be greatly reduced.

The invention discloses a composition, a detection method and a kit for SpaceAS variable splicing space in-situ detection of nucleic acid. The composition comprises a pi-type probe, a U-type probe, an O-type probe, an S-type probe and a signal probe, and the O-type probe adopts an in-vitro cyclization strategy, so that the problem of low hybridization efficiency caused by dependence on enzymatic cyclization reaction in a traditional hybridization method is effectively solved; meanwhile, an efficient probe hybridization system, a high-sensitivity signal amplification mechanism and a multi-round iterative imaging process are combined, so that the detection sensitivity and specificity are remarkably improved. The detection method has the advantages of high efficiency, high sensitivity, high specificity, good repeatability, strong expandability and the like through the synergistic effect of five-step single-stranded DNA probe hybridization reaction and one-step DNA amplification reaction, and can be widely applied to space in-situ detection and analysis of variable splicing events.

The disclosure provides, for example, a DNA molecule comprising a first strand of DNA, wherein the first strand is circular and single stranded over at least 90% of its length, and a second strand of DNA covalently linked to the first strand as described herein. The DNA molecule may comprise an effector sequence encoding a therapeutic effector. In some embodiments, the DNA molecule shows improved conversion to double-stranded DNA relative to a DNA molecule that lacks the second strand.

The invention discloses an application of a composition of a polypeptide and a PARP inhibitor in preparation of a medicine for treating breast cancer, the sequence of the polypeptide is as shown in SEQ ID NO: 1, and the PARP inhibitor is Olaparil or taprazopalil. The polypeptide can down-regulate the expression of the DNA damage repair gene FANCD2 protein and block the cross-linking damage repair between DNA chains. The PARP inhibitor blocks DNA single-stranded fracture damage repair by inhibiting the catalytic activity of PARP, and is mainly used for breast cancer treatment of BRCA mutation. DNA damage caused by the polypeptide and the PARP inhibitor in two different modes jointly destroys a cell replication fork protection mechanism, so that a DNA replication fork of a breast cancer cell is prone to stagnation and collapse, and cell death is caused. The invention shows synergistic cancer suppression activity in both BRCA wild type and BRCA mutant breast cancer subtypes, and is expected to provide a new treatment strategy for clinical treatment of breast cancer.

The invention designs a preparation method of a magnetic molecular imprinting-aptamer sandwich fluorescence sensor for detecting kanamycin. And the magnetic molecular imprinting composite material Fe3O4 (at) UiO-66 (at) MIP with a specific adsorption target object KANA is prepared. When a detection target object KANA exists, the Fe3O4-coated UiO-66-coated MIP can rapidly and specifically capture the KANA in a short time. Then, a DNA single-stranded aptamer marked with FAM is added, after the aptamer and KANA captured on the surface of the Fe3O4 at-UiO-66 at-MIP are subjected to specific recognition and magnetic separation again, an aptamer probe can enter sediment along with the magnetic composite material Fe3O4 at-UiO-66 at-MIP, the fluorescence intensity of supernate is reduced, and quantitative analysis is conducted according to the fluorescence difference value delta F. When the KANA does not exist, the aptamer cannot enter the precipitate, so that the fluorescence signal intensity is not changed. Double recognition is formed through specific binding of an MIP imprinting cavity and the aptamer, matrix interference is reduced by means of fluorescence characteristics and magnetic separation capacity, the method has the advantages of being high in adsorption capacity, specific in recognition, high in sensitivity, wide in detection range, good in selectivity and the like, and rapid and accurate detection of KANA in a complex sample can be achieved.

The invention discloses a method for enhancing mechanical force of CAR-T cells on target cells to overcome mechanical immune checkpoints of SFs and application, and relates to the technical field of crossing of immunotherapy and biomechanics, in particular to CAR-T cells targeting fibroblast activated protein. The invention discloses a CAR-T (chimeric antigen receptor T-T) cell and SFs (small-form-factor s) DNA (deoxyribonucleic acid) nano connector for connecting the CAR-T cell with the SFs, the formation of a CAR cluster and mechanical force transmission are promoted by shortening the membrane spacing of an immune synaptic interface to 16-28nm, the DNA nano connector is formed by self-assembling complementary tetrahedral DNA structures, and the TDS comprises a single-stranded DNA vertex S4 with the length of 24-58 nucleotides. According to the method for enhancing the mechanical force of the CAR-T cells on the target cells to overcome the mechanical immune checkpoints of the SFs and the application, the escape and killing problems of the soft target cells are solved, the soft target cells are efficiently removed, and the killing rate of the CAR-T cells treated by DNJ-17 on the SFs is remarkably increased.

The application discloses a specific nucleic acid aptamer for a heterogeneous core ribonucleoprotein hnRNPA2B1 and application, and belongs to the technical field of nucleic acid aptamer. The hnRNPA2B1 aptamer is a small single-stranded DNA screened from a designed oligonucleotide library through an in-vitro exponential enrichment ligand system evolution (SELEX), is composed of 80 nucleotides, and has high affinity to the target. The hnRNPA2B1 aptamer can be applied in a detection method or a detection product of the hnRNPA2B1 protein, and a targeted regulation drug or a biological preparation, and can be specifically made into a molecular probe, used as a detection reagent, used as a targeted preparation and the like for diagnosis and treatment of diseases related to the hnRNPA2B1 protein. The hnRNPA2B1 aptamer has strong affinity and specificity, has the advantages of low production cost, stability, convenient synthesis and easy modification compared with an antibody, and is a potential substitute for the antibody in disease diagnosis and treatment.

The invention relates to the technical field of virus detection, and discloses a method and a kit for detecting Chinese sacbrood virus. The method comprises: firstly, carrying out isothermal amplification on a CSBV specific target sequence in a sample nucleic acid by using an RPA technology, the RPA technology adopting a specific primer pair, the sequences of which are SEQ ID NO: 4 and SEQ ID NO: 5; then, an amplification product is mixed with a CRISPR / Cas12b detection system, and the system comprises Cas12b protein, specific sgRNA with the sequence shown as SEQ ID NO: 2 and a single-chain DNA reporter probe marked by fluorescence; when a CSBV target exists, the activated Cas12b protein trans-cleavage reporter probe generates a detectable fluorescence signal, so that rapid and high-sensitivity detection of the CSBV is realized. The invention further provides a detection kit suitable for the method. The detection kit comprises the primer pair, sgRNA and Cas12b protein. When the CSBV is detected based on the method and the kit, complex instruments are not needed, the operation is simple and convenient, the detection time is shorter than 1 hour, the sensitivity and the specificity are high, and the method and the kit are suitable for onsite rapid detection in a bee field.

The present application relates to a kind of hAAG photoelectrochemical detection method based on sulfur vacancy engineering, belong to analytical detection technical field.The present application will prepare hairpin structure DNA to single-stranded DNA, sequentially join different concentrations of human alkyladenine DNA glycosylase (hAAG), endonuclease IV, exonuclease I and its reaction buffer;Dopamine solution is added to reaction, and the enzymatic reaction system of hAAG is obtained;CdZnS modified electrode is immersed in enzymatic reaction product solution and reacts, so that dopamine and zinc atom on the surface of CdZnS are combined by ortho-hydroxy coordination, and sulfur vacancy is induced to generate;Photoelectrochemical test is carried out to CdZnS modified electrode, the photocurrent signal is detected, the linear relationship between photocurrent signal and hAAG concentration is established, and the quantitative detection of hAAG is realized.The present application not only provides efficient strategy for hAAG detection, but also provides new ideas for performance optimization of sulfide-based photoelectrochemical device.

The present disclosure provides compositions comprising nucleic acid double-stranded splint adaptors, including kits, and methods that employ the double-stranded splint adaptors. The double-stranded splint adaptors (200) can be used in a one-pot, multi-enzyme reaction to introduce one or more new adaptor sequences into a library molecule. The double-stranded splint adaptor (200) comprises a first splint strand (long splint strand (300)) and a second splint strand (short splint strand (400)), where the first and second splint strands are hybridized together to form the double-stranded splint adaptor (200) having a double-stranded region and two flanking single-stranded regions. The second splint strand (400) carries the new adaptor sequence(s) to be introduced, such as for example a universal binding sequence, an index sequence and / or a random sequence.

The invention discloses a preparation method of a space chip, the space chip and application of the space chip, the preparation method comprises the following steps: hybridizing: connecting a single-stranded nucleic acid molecule to the surface of a solid-phase substrate, the single-stranded nucleic acid molecule comprises a first fixed sequence, a space bar code sequence, a sequencing primer binding sequence and a second fixed sequence, the surface of the solid-phase substrate of the chip substrate is connected with a first probe, and the first probe comprises a first fixed sequence complementary sequence and a second fixed sequence complementary sequence; carrying out ring closing to enable the single-stranded nucleic acid molecules to form annular nucleic acid molecules; carrying out rolling circle amplification; sequencing to obtain sequence information of the space bar code sequence; synthesizing single-stranded nucleic acid molecules by taking the rolling circle amplification product as a template to obtain a single-stranded nucleic acid molecule library; fixing and clustering: fixing the single-stranded nucleic acid molecule library on the surface of a solid-phase substrate to form a single-stranded nucleic acid molecule cluster. According to the invention, the chip with the nucleic acid probe carrying spatial position coordinate information can be prepared.

This invention provides a method and kit for enhancing the yield and quality of gene synthesis products, comprising the following steps: providing a total primer mixture, which includes multiple oligonucleotide single strands encoding a target gene sequence / encoding an operational sequence and sterile water; using the primer mixture as a template, performing the first... PCR The reaction yielded the primary spliced ​​product; a second reaction was then performed using start and end primers. PCR The reaction yielded the crude gene synthesis product; nested primers were then used for a third reaction. PCR The reaction yields a nested structure. PCR Products; nested PCR The product was subjected to agarose gel electrophoresis, and the target band was excised and recovered. This application improves upon traditional gene synthesis methods by adding operation sequences to both ends of the synthesized gene sequence and utilizing highly specific nested primers for nested gene synthesis. PCR It can synthesize more than 2000bp in one go. DNA Double-stranded sequences significantly improve the yield and quality of gene synthesis products.

The application belongs to the field of chemical biology, and relates to a Fusobacterium nucleatum single-stranded DNA aptamer and a screening method and kit. The nucleotide sequence of the aptamer is as follows: 5'-TGACTGACGACGACTCCGCX1GX2X3X4GX5AGX6X7X8X9X 10 CGTX 11 X 12 X 13 X 14 X 15 X 16 X 17 X 18 X 19 X 20 X 21 X 22 X 23 GX 24 X 25 X26X 27 X 28 AX 29 X 30 GX 31 X 32 X 33 X 34 X 35 X 36 AGACTGCTCGAGCTG-3'. The aptamer obtained by the application has the characteristics of simple operation, high sensitivity, low manufacturing cost and strong specificity, and has a broad application prospect in the detection of Fusobacterium nucleatum.

Disclosed is a method for editing mitochondrial DNA (mtDNA) within a cell, which include introducing into the cell (a) a DNA cleaving enzyme targeted to the mtDNA sequence to be deleted; (b) a first DNA binding component targeted to a sequence adjacent to the 5′ end of a mtDNA sequence to be deleted; and (c) a second DNA binding component targeted to a sequence adjacent to the 3′ end of the mtDNA sequence to be deleted, where the DNA cleaving enzyme generates a double stranded break (DSB) within the mtDNA sequence to be deleted or generates a single strand nick on the light strand of the mtDNA sequence to be deleted, and wherein the mtDNA sequence between the target sequence for the first DNA binding component and the target sequence for the second DNA binding component is deleted.

The invention discloses a method for distinguishing clematis palustris from other clematis plants and application of the method. The method for distinguishing the clematis from the other clematis plants comprises the following steps: detecting whether the genotype of 201st deoxyribonucleotide in a sequence 1 of a plant to be detected is an AA genotype or a CC genotype by adopting a primer pair consisting of a single-stranded DNA (Deoxyribonucleic Acid) shown in a sequence 2 and a single-stranded DNA shown in a sequence 3; the to-be-detected plant is clematis hispida; if the genotype of the plant to be detected is AA genotype, the plant to be detected is other clematis plants. Experiments prove that the method provided by the invention can be used for effectively distinguishing the clematis palustris from other 14 clematis plants, and an important tool is provided for quickly and accurately identifying the clematis palustris in the seedling stage.

This invention belongs to the field of membrane separation and functional membrane materials technology, and discloses a chiral graphene oxide-based separation membrane, its preparation method, and its application. The membrane is composed of graphene oxide and / or reduced graphene oxide sheets and a single-stranded DNA-single-walled carbon nanotube complex. The single-stranded DNA helically winds around the outer surface of the single-walled carbon nanotubes to form a one-dimensional chiral nanochannel and intercalates between the sheets, forming a three-dimensional chiral channel network connected in the membrane thickness direction. The preparation method includes: heating and decohexing salmon sperm double-stranded DNA in a urea-containing buffer to obtain single-stranded DNA; dispersing single-walled carbon nanotubes and then complexing them with the single-stranded DNA; further mixing with a graphene oxide or reduced graphene oxide dispersion; and vacuum filtration to form the membrane. This membrane exhibits a high separation factor for chiral enantiomers such as L / D-phenylalanine, with an excess value of up to 99.95% for L-phenylalanine enantiomers after multi-stage separation, making it suitable for the efficient separation of chiral drugs and amino acids.

The present invention relates to a single-stranded DNA aptamer that binds to glutathione to inhibit oxidation of the glutathione or stabilize the glutathione, characterized in that the single-stranded DNA aptamer has one or more stem-loop structures; a method for oxidation prevention and stabilization of glutathione using the aptamer; and application to various fields such as pharmaceuticals, cosmetics, and food, using the aptamer. The aptamer of the present invention can be applied to various fields, such as pharmaceuticals, cosmetics, and food, which require oxidation prevention and stabilization of glutathione.

This invention discloses a method to avoid the influence of cations on carbon nanotube fluorescent sensors, and a gel-based dopamine sensor based on Al-(AT)15-SWCNTs complex and its application. The method to avoid the influence of cations on carbon nanotube fluorescent sensors first involves preparing a single-stranded DNA sequence (AT). 15 Modified single-walled carbon nanotube solution ((AT) 15 -SWCNTs); then (AT) 15 The SWCNTs solution and agarose gel were mixed at a 1:1 volume ratio and allowed to settle at (AT). 15 -SWCNTs solidify to obtain a gel-based dopamine sensor; the gel-based dopamine sensor is placed in an Al(NO₃)₃ solution for at least one hour, and then washed by immersing it in an HCl solution with pH ≤ 3.7 to remove residual free Al from the gel. 3+ The ions ultimately yield Al−(AT). 15 A gel-based dopamine sensor for ssDNA-SWCNT complexes. Trivalent aluminum ions pre-occupy the interaction sites of phosphate groups to prevent further interactions between other cations and phosphate groups. Agarose gel-based ssDNA-SWCNTs avoid cation-induced aggregation.

The application provides a double-stranded walking type DNA nanomachine and a preparation method and application thereof, and relates to the technical field of fluorescent analysis and detection.The double-stranded walking type DNA nanomachine for ctDNA fluorescent detection comprises a gold nanoparticle carrier, an anchor probe, a FAM fluorescent reporter probe, a double-stranded walking arm, a Cas12a protein and a crRNA to form a ribonucleoprotein complex.The walking arm of a conventional CRISPR / Cas12a nanomachine is a DNA single-stranded structure, which is easily cut in trans by activated Cas12a, thereby reducing the stability and sensitivity of the nanomachine.The application introduces a double-stranded DNA structure into the walking arm design to replace the conventional DNA single-stranded walking arm, constructs a double-stranded walking type three-dimensional DNA CRISPR / Cas12a nanomachine, effectively resists the reverse cutting of Cas12a on the walking arm, maintains the structural integrity and functional stability of the nanomachine, and greatly improves the detection sensitivity and specificity of lung cancer ctDNA, thereby having a good clinical application prospect.

The present disclosure provides compositions comprising nucleic acid double-stranded splint adaptors, including kits, and methods that employ the double-stranded splint adaptors. The double-stranded splint adaptors (200) can be used in a one-pot, multi-enzyme reaction to introduce one or more new adaptor sequences into a library molecule. The double-stranded splint adaptor (200) comprises a first splint strand (long splint strand (300)) and a second splint strand (short splint strand (400)), where the first and second splint strands are hybridized together to form the double-stranded splint adaptor (200) having a double-stranded region and two flanking single-stranded regions. The second splint strand (400) carries the new adaptor sequence(s) to be introduced, such as for example a universal binding sequence and / or an index sequence.

The invention discloses a DNA tetrahedron gating logic nanometer machine and a preparation method and application thereof, and belongs to the technical field of biomedicine. According to the invention, a DNA tetrahedron gating logic nanometer machine DTDN is constructed, and the DNA tetrahedron gating logic nanometer machine DTDN is composed of two DNA tetrahedron nanometer structures functionalized by AS1411 aptamers. Each tetrahedron is loaded with a functional DNA hairpin structure, and the structure is composed of a stem-loop structure and an extended single-stranded tail containing an AP site. The framework gating strategy of DTDN enables efficient delivery of functional DNA hairpins, and also prevents signal leakage by blocking cohesive end sequences of HCR reactions. The cascade activated logic loop has high specificity and anti-interference capability, and can accurately activate a downstream regulation and control path. Therefore, the DTDN realizes synchronization of imaging and regulation, and a programmable, safe and accurate nucleic acid nano platform is provided for cancer diagnosis and accurate treatment based on a cGAS-STING signal channel.

The invention provides a chain-specific library preparation method and a high-throughput sequencing method for rapidly detecting multiple types of RNAs (Ribonucleic Acid). The method comprises the following steps: artificially adding poly A tails at 3'tail ends of multiple RNAs by utilizing poly A polymerase; meanwhile, a polydeoxythymine ribonucleotide primer with deoxyuracil is used for synthesizing single-stranded cDNA under the action of reverse transcriptase, obtained single-stranded cDNA molecules are subjected to a series of reactions and finally subjected to PCR amplification to obtain strand specific libraries of multiple types of RNA, and samples of the libraries can be subjected to computer sequencing.

The invention discloses an activity detection method of formamide pyrimidine-DNA (deoxyribonucleic acid) glycosylase, which comprises the following steps: providing a double-chain probe which comprises two complementary single-chain probes containing 8-oxoG (8-oxoG) modification sites; uniformly mixing the Fpg enzyme, the double-stranded probe, a buffer solution and water to form a mixed system; carrying out PCR (Polymerase Chain Reaction) on the mixed system, and cutting the double-stranded probe containing the 8-oxoG modification site by using Fpg enzyme to obtain a longer and shorter fragment sample; performing electrophoresis on the fragment sample by using non-denaturing polyacrylamide gel; the non-denaturing polyacrylamide gel obtained after electrophoresis is completed is subjected to vibration dyeing, and a dyeing result is photographed so as to detect the activity of the Fpg enzyme. Compared with the prior art, the method is relatively simple and easy to operate, the reagent cost is relatively low, and the experimental result is sensitive and easy to observe; no radioactive and cancerogenic substance pollution exists, and the method is environment-friendly.

This invention relates to the field of medical detection technology and discloses a fluorescent sensor for high-sensitivity detection of circRNA and its detection method based on machine learning. The sensor includes a splitting probe M, a splitting probe N, a circular template T, a probe CrRNA, and a reporter gene. The 5' end of probe M is modified with a phosphate group, and the 5' end of probe M and the 3' end of probe N each have 15 nucleotides complementary to the target. The single-stranded DNA of splitting probe M and the single-stranded DNA of splitting probe N are ligated into the single-stranded DNA of probe MN in the presence of the target. The 5' end of the circular template T is modified with a phosphate group, and probe T, from its 5' end to its 3' end, consists of the N probe complementary region, the functional region, and the M probe complementary region, respectively. The CrRNA probe, from its 5' end to its 3' end, consists of the protein-binding region and the functional complementary region, respectively. The 5' end of the reporter gene is modified with a fluorescent group, and the 3' end is modified with a quenching group, which quenches the fluorescence signal of the 5' end fluorescent group.

The present application discloses partially single-stranded deoxyribonucleic acid (ssDNA) molecules comprising at least one nucleic acid sequence of interest flanked by a at least one stem loop structure, methods of making, and methods of use for delivery and expression of a transgene in host cells.

The present invention relates to a method for preparing a long double-stranded nucleic acid. The present invention relates to a method for synthesizing a long double-stranded nucleic acid from a short single-stranded nucleic acid. The method is characterized by the presence of an intermediate, and the intermediate refers to a long double-stranded nucleic acid with a nick. In addition, the present invention further relates to use of the method in the synthesis of a long double-stranded nucleic acid.