874 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.

The present disclosure provides systems and methods for separating and characterizing oligonucleotides. Fixed dose combinations of small interfering RNAs can be subjected to denaturing ion pairing reverse phase liquid chromatography using optimal conditions to separate single RNA strands for purity analysis.

The application discloses a kind of carrier, kit and application for long-acting gene knockdown of animal parasitic nematode, belong to the field of animal parasitic disease prevention and control.The lentivirus vector in the application integrates specific coding sequence to the genome of the infected nematode, stably and continuously expresses short hairpin RNA (shRNA) in the nematode, efficiently produces primary single-stranded small RNA (siRNA), these siRNAs target homologous target gene mRNA to cause its degradation, realize stable and continuous gene silencing effect.The application breaks through the bottleneck of traditional animal parasitic nematode RNA interference (RNAi) technology with low efficiency and instability, significantly improves the timeliness of conventional RNAi, can be used to establish long-acting RNAi technology system of animal parasitic nematode, has application value in the research of host in vivo process such as nematode infection, parasitism and pathogenicity and animal parasitic nematode disease prevention and control.

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 disclosure provides methods for processing nucleic acid populations containing different forms (e.g., RNA and DNA, single-stranded or double-stranded) and / or extents of modification (e.g., cytosine methylation, association with proteins). These methods accommodate multiple forms and / or modifications of nucleic acid in a sample, such that sequence information can be obtained for multiple forms. The methods also preserve the identity of multiple forms or modified states through processing and analysis, such that analysis of sequence can be combined with epigenetic analysis.

Provided are a tetrahedral framework nucleic acid and a preparation method therefor. Escherichia coli is used as a host to produce an M13 bacteriophage so as to obtain single-stranded DNA (ssDNA) in the M13 bacteriophage, ssDNA required for assembling the tetrahedral framework nucleic acid is obtained by cleavage with restriction endonuclease II, and then the tetrahedral framework nucleic acid is obtained by self-assembly of the ssDNA. The production costs of TDN are reduced while achieving large-scale industrial production of the TDN, and the present invention has good practicability.

Embodiments are directed to N3-kethoxal reagents and derivatives thereof, and related methods that allow fast and reversible labeling of single-stranded nucleic acids in live cells. By way of example, one aspect is directed to a process for reversible labeling of single-stranded guanine bases in live cells, which results in an effective in vivo method for transcriptome-wide RNA secondary structure mapping and RNA G-quadruplex prediction.

The invention provides a quantitative detection system combining a CRISPR-Cas system with a MetaSPR optical sensor, a detection method and application, and relates to the technical field of biosensing and optical detection. The system comprises a MetaSPR optical sensor, the surface of a gold substrate of the MetaSPR optical sensor is modified with single-stranded DNA H1, the 5'end of H1 is modified with sulfydryl, and H1 is fixed to the gold substrate of the MetaSPR optical sensor through an Au-S bond; h1 is combined with single-chain DNA H2 with gold balls through complementary base pairing to form a double-chain structure, the 5'end of H2 is also modified with sulfydryl, and the gold balls are fixed on the surface of a gold substrate; the CRISPR-Cas reaction system comprises a molecular solution to be detected, Cas protein, a buffer solution, guide RNA (Ribonucleic Acid), nuclease-free water and target DNA (Deoxyribose Nucleic Acid); the CRISPR-Cas reaction system is used for recognizing a target molecule, and when the target molecule is recognized, H1 is cut.

The invention provides a method for eliminating ribosomal RNA in a mouse total RNA sample, which comprises the following steps: carrying out reverse transcription on the total RNA in the mouse sample into cDNA, and amplifying the cDNA by adopting a primer sequence group to obtain a DNA fragment covering all sequences of the mouse ribosomal RNA; carrying out amplification by taking the DNA fragment as a template and adopting a single primer in the primer sequence group to obtain a single-stranded DNA probe; hybridizing the total RNA of the mouse sample by adopting a single-stranded DNA probe, and performing RNase H digestion to obtain a digestion product; sequentially carrying out DNase I digestion and RNA purification on the digestion product to obtain a target product; wherein the primer sequence group comprises upstream primers from the first to the nineteenth and downstream primers from the first to the nineteenth, and the primer sequence group has the characteristics of low cost, stable performance and high reduction efficiency.

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 polypeptide-nucleic acid tetrahedron compound as well as a preparation method and application thereof. The compound comprises a nucleic acid tetrahedron and polypeptide, wherein the polypeptide is nonapeptide-1 with an amino acid sequence as shown in SEQ ID NO: 13; the nucleic acid tetrahedron is formed by self-assembly of four single-stranded DNAs with the same length. According to the compound, the transdermal function of nucleic acid tetrahedron capable of inhibiting melanogenesis and the melanocyte targeting function of nonapeptide-1 are combined, so that the TDN-NA-1 compound has the melanocyte targeting property while having the autonomous transdermal ability, and the blackness inhibiting effects of the nucleic acid tetrahedron and the nonapeptide-1 are combined, so that the effect of inhibiting melanogenesis is achieved. Therefore, the whitening composition has a stronger capability of inhibiting melanin generation, so that the purpose of precise whitening is achieved, and the whitening composition has a wide application prospect in the field of cosmetics.

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 invention discloses a double-CRISPR (clustered regularly interspaced short palindromic repeats) coupled isothermal amplification efficient detection technology, and a double-CRISPR coupled isothermal amplification reagent provided by the invention comprises a pair of efficient Cas12a variant-guide RNA (Ribonucleic Acid) complexes, an isothermal amplification system, bovine serum albumin, a fluorescence resonance energy transfer single-stranded DNA (Deoxyribose Nucleic Acid) probe, a reaction buffer solution and target nucleic acid to be detected, the double CRISPR coupling isothermal amplification detection technology disclosed by the invention has the remarkable advantages of high reaction speed, high signal-to-noise ratio, high sensitivity and strong specificity, can efficiently detect low-copy or low-quality target nucleic acid, and can be combined with a 3D printing chip to realize reagent freeze-drying and simultaneous detection of multiple types of target nucleic acid; the method shows a great application prospect, and particularly has a great potential in detection of bacteria deployed on site.

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 present disclosure relates to methods of using single-stranded RNA ligase for synthesis of oligonucleotides, including oligonucleotides containing a conjugate moiety. In some embodiments, the present disclosure further provides recombinant single-stranded RNA ligases, polynucleotides encoding the recombinant single-stranded RNA ligases, and compositions of the single-stranded RNA ligases.

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 provides a lipid nanoparticle for the targeted combined delivery of a CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-Cas9) system and a single-stranded DNA (deoxyribonucleic acid) repair template of the liver, and the lipid nanoparticle is prepared from an ionizable lipid ALC-0315, a PC (polycarbonate) lipid DOPC (dioctyl-phthalate), cholesterol and DMG-PEG (dimethyl glycol-polyethylene glycol) (2000) according to a molar ratio of 50: 10: 38.5: 1.5. The lipid nanoparticles can simultaneously package Cas9 mRNA (messenger ribonucleic acid), sgRNA (small guide ribonucleic acid) and a single-stranded DNA (deoxyribonucleic acid) repair template required by homologous directional repair (HDR) gene editing according to a certain proportion to prepare All-in-one LNP. According to the All-in-one LNP, the three nucleic acids are successfully delivered in a liver-targeted combined manner, HDR editing is successfully performed on the liver of a young rat, and an accurate and efficient tool is provided for in-vivo editing.

Disclosed herein are systems for LNP-mediated delivery of circular single-stranded DNA (cssDNA). The systems can be used to facilitate integration of the cssDNA into a cellular genome for a variety of purposes, including treatment of human diseases.

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.

Provided are compositions, systems and methods for removal of double stranded RNA from a mixture utilizing affinity agents having high binding affinity and selectivity for double stranded RNA over single stranded RNA.

The present application relates to the technical field of molecular biology detection, in particular to an absolute antibody Taq DNA polymerase activity determination method based on real-time fluorescence quantitative detection, comprising the following steps: firstly, establishing a standard curve of DNA content and fluorescence value by reacting different concentrations of double-stranded lambda DNA with fluorescent dyes; then, performing an extension reaction in a specific reaction system using M13 single-stranded DNA as a template, recording fluorescence values in real time, calculating net fluorescence values and establishing a linear relationship between the net fluorescence values and reaction time; converting the amount of newly generated double-stranded DNA at different time points by using the standard curve, further calculating the consumption amount of dNTPs, and finally obtaining the absolute activity of the antibody Taq DNA polymerase according to the definition of the activity of the antibody Taq DNA polymerase. The whole process combines fluorescence detection and a standard curve to realize accurate determination of enzyme activity.

The invention belongs to the technical field of detection, and particularly relates to a nucleic acid detection method based on triple amplification and application of the nucleic acid detection method in ginseng identification. Mixing the liquid to be detected with the hairpin DNA, and assembling to form DNA enzyme; a hairpin substrate is added, enzyme digestion reaction is completed, and a trigger chain is generated; adding a circular DNA probe, carrying out rolling circle amplification, and collecting generated long single-stranded DNA; a G quadruplex structure in the long single-stranded DNA is utilized to catalyze a chromogenic reaction, and the concentration of miRNA in the to-be-detected liquid is analyzed through the RGB value of the color. According to the method disclosed by the invention, the low detection limit of the 651 fM is realized. The analysis of ginseng samples and related products verifies the effectiveness of the triple amplification platform, and a portable and reliable solution is provided for food safety supervision and quality control.

The present invention relates to hybrid full LNA oligonucleotides. The present report relates to hybridizing single stranded (ss-) oligonucleotides consisting entirely of locked nucleic acid (LNA) monomers. This document shows hybridization experiments of pairs of fully complementary ss-oligonucleotides that fail to form double strands within a given time interval. The present report provides a method of identifying such incompatible oligonucleotide pairs. In another aspect, the present report provides pairs of complementary ss-oligonucleotides capable of rapidly forming double strands. The present report also provides methods of identifying and selecting compatible oligonucleotide pairs. In another aspect, the present report provides the use of a compatible oligonucleotide pair as a binding partner in binding assays, such as receptor-based assays.

The invention relates to the technical field of biology, and provides a primer group and a kit for simultaneously detecting a dengue virus and a Zika virus and application of the primer group, and the primer group is formed and comprises a primer pair 1 aiming at the dengue virus, a primer pair 2 aiming at the Zika virus and a universal LAMP (Loop-Mediated Isothermal Amplification) primer pair. When in use, target virus single-stranded RNA is used as a bridge molecule, under the catalysis of Splint R ligase, adjacent DNA probes with specific sequences are guided and connected, and a double-ring (dumbbell-shaped) structure product containing a general cyclization primer sequence is directly formed. The two key technical breakthroughs of forming a universal double-ring primer through target RNA mediated probe connection and outputting a high-specificity signal dependent on RNase H2 are realized; a dengue virus and Zika virus isothermal nucleic acid amplification detection platform which is simple and convenient to operate, rapid in reaction, high in sensitivity, strong in specificity (capable of effectively avoiding interference of primer dimers and non-specific dyes) and suitable for multiple detection is constructed, and compared with conventional fluorescent quantitative PCR, the dengue virus and Zika virus isothermal nucleic acid amplification detection platform has remarkable advantages.

The invention relates to an intramolecular strand displacement reaction-based microRNA detection method and kit, and the kit is characterized in that the kit comprises four single-stranded sequences forming a DNA tetrahedron, a probe S and DNA polymerase; a probe T structure is designed at the top end of the DNA tetrahedron, and the probe T is used for capture of the probe S and intramolecular strand displacement reaction triggered by microRNA to be detected. The DNA tetrahedral structure is utilized to enhance the probe fixing efficiency and stability, and the detection sensitivity is improved; signal amplification is realized through intramolecular strand displacement reaction, and the detection limit is as low as 5 * 10 <-17 > mol / L; good selectivity is achieved, and single-base mismatch sequences can be distinguished; the kit has good performance in serum samples and has practical application potential.

The application discloses a set of general primers for amplifying the whole genome of the mitochondrion of Trionychidae, and belongs to the technical field of molecular biology; the specific steps comprise the following steps: extracting the total DNA of the genome of Trionychidae, designing the general amplification primers of the whole sequence of the mitochondrial genome, and performing PCR amplification and sequencing on the mitochondrial genome DNA. The amplification primers for the whole genome sequence of the mitochondrion of Trionychidae are composed of 11 pairs of single-stranded oligonucleotides. The general amplification primers of the application can be used to quickly and efficiently amplify the whole sequence of the mitochondrial genome of various Trionychidae, and provide a favorable technical means for the identification of unknown germplasm of Trionychidae, the protection of species resources, and the research on the system evolution.

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.