12 results about "Dna complex" patented technology

The application provides a skin interstitial fluid miRNA multicolor visualization semi-quantitative detection method, which comprises the following steps: incubating a skin interstitial fluid sample with magnetic nano probes of surface immobilized hairpin probes H1, opening H1 and triggering a subsequent hybridization chain reaction of hairpin probes H2 and H3 in the presence of target miRNA, and constructing a biotin-rich DNA complex on the surface of the magnetic beads; performing enzyme labeling by using an alkaline phosphatase-streptavidin coupling compound, and catalyzing ascorbic acid phosphate to generate ascorbic acid potassium iodate, so that the color of the solution changes, and high-sensitivity detection of the target miRNA is realized. The multicolor visualization detection method can produce near-full-spectrum color changes by combining the gold nano double-cone local surface plasmon resonance property change, and is beneficial to improving the portability of the sensor and the accuracy of the visual analysis.

The application discloses a doxorubicin scavenger for protecting ovarian fertility and a preparation method thereof, comprising a DNA complex wrapped by a red blood cell membrane, wherein the red blood cell membrane is surface-modified by an anti-Mullerian duct antibody alphaAMH; the doxorubicin scavenger is specifically combined with AMH which is highly expressed in ovarian tissues through alphaAMH, is enriched in the ovarian part in a targeted manner, adsorbs doxorubicin through a DNA fragment in the DNA complex, reduces toxic damage of doxorubicin to ovarian cells, and further protects ovarian fertility. The doxorubicin scavenger can adsorb injected doxorubicin Dox, reduce side effects of doxorubicin Dox on ovarian granulosa cells, and further protect ovarian function and fertility.

The application discloses a kind of plant whole genome RNA-chromatin interaction detection methods, the method includes the interaction state of fixed RNA and chromatin, preparation double link, obtain nuclear, chromatin DNA fragment, RNA / linker / DNA chimera, RNA-DNA double-stranded complex in turn;Tn5 transposase fragmentization cuts double-stranded complex;PCR amplification forms DNA library.The application applies Tn5 transposase to the original RADICL-seq method, successfully to RNA-DNA complex is cut and library, greatly simplifies the process, experimental procedure is reduced by at least half, experimental period is shortened from 4-5 days to 3 days, the fragment size of DNA library produced is between 250bp-400bp, increase the length of final effective RNA / DNA fragment pair, thereby greatly improve the efficiency when aligning to plant genome in subsequent bioinformatics analysis, provide effective means for plant whole genome RNA-chromatin interaction detection.

The application discloses a construction of a constant-temperature enzyme-free system for detecting ctDNA and application thereof. The constant-temperature enzyme-free system is composed of a hairpin sequence H1, a hairpin sequence H2, a Reporter-F and a Reporter-Q. The hairpin sequence H1 and the hairpin sequence H2 are hybridized to each other to form a stable double-stranded DNA complex (H1-H2) under the initiation of target ctDNA. The Reporter-F is complementary to a sequence D part of the hairpin sequence H1, and the number of paired bases is greater than that of paired bases of the Reporter-Q. The detection limit of the constant-temperature enzyme-free system for the ctDNA can reach 7 pM, and the constant-temperature enzyme-free system has high signal gain, low background, good selectivity and specificity and good serum stability, thereby providing effective technical support for early screening of breast cancer.

本发明属于DNA水凝胶技术领域，具体涉及一种智能响应性Cas12a / CrRNA‑DNA复合水凝胶及其制备方法和在ATP检测中的应用。本发明通过功能化DNA链构建交联网络，将Acrydite‑DNA（1）链和DNA（2）链、Acrydite‑DNA（3）链以及ATP适配体链构成以DNA为交联单元的聚丙烯酰胺聚合物。将Cas12a / CrRNA复合物稳定锚定于水凝胶体系，依托ATP适配体介导的凝胶构象转变激活Cas12a酶切活性，实现ATP的靶向识别与信号放大检测，为ATP及其他小分子生物标志物的即时检测（POCT）提供新型高效的技术方案。

The application discloses a rigid response fluorescence polarization biosensor for detecting AFB1 and application. The rigid response fluorescence polarization biosensor comprises a target recognition unit, the target recognition unit comprises an aptamer-complementary chain double-stranded complex which specifically recognizes AFB1; a signal amplification unit, the signal amplification unit comprises a rolling circle amplification reaction system; a signal conversion unit, the signal conversion unit comprises a CRISPR / Cas12a detection system; and a signal output unit, the signal output unit comprises a conformational restriction depolarization reporter, and the conformational restriction depolarization reporter is a single-stranded DNA / double-stranded DNA complex structure. The application realizes quantitative detection of AFB1 by using FP value change, has the advantages of low detection limit, strong specificity, strong anti-matrix interference capacity, simple operation and the like, and can be widely applied to rapid and high-sensitivity detection of AFB1 in complex samples such as grains, foods and feed.

The application discloses a CRISPR / Cas14a1 system based on double closure modification and application thereof in pancreatic cancer mutant gene detection, comprising BLK-DNA, BLK-RNA, sgRNA, an activator, Cas14a1 protein, FAM and BHQ modified ssDNA probe, NEBuffer 2.1 and ultrapure water; the activator, BLK-DNA, sgRNA and BLK-RNA are subjected to a warming annealing program, so as to form an sgRNA-BLK RNA complex and an activator-BLK DNA complex, four-strand strand displacement reactions are carried out by means of toehold, so that the BLK DNA and the BLK RNA are combined, the activator is combined with the sgRNA, and the trans-cleavage activity of the Cas14a1 protein is activated. The system has very high distinguishing ability and specificity.

The application belongs to the technical field of plant transgenics, and particularly relates to a nano-magnetic-bead-mediated pollen tube channel transgenic method of Pennisetum. The method comprises the following steps: magnetic bead and plasmid DNA complexing, magnetic bead-DNA complex and pollen culture solution complexing, magnetic transfection, and pollination. Compared with a traditional transformation mode, the nano-magnetic-bead-mediated transformation method does not need to pass through tissue culture, the transformation condition is more moderate, the time is shorter, and the method is a high-efficiency and rapid transformation mode, which has great guiding significance for the genetic breeding work of the Pennisetum. A large amount of seeds can be obtained through artificial pollination, and more materials are provided for the screening of subsequent transgenic plants. The method is simple in operation, saves resources, and has a synergistic effect between the operation steps, and excellent effects are achieved.

The invention provides a DNA composite nanostructure separation method based on density gradient ultracentrifugation and application of the DNA composite nanostructure separation method. The separation method comprises the following steps: (1) sequentially adding a density gradient liquid I and a density gradient liquid II into a super-separation tube in an equal volume manner, and forming a density gradient liquid with a continuous nonlinear gradient through a vertical rotation instrument; the density gradient liquid I is 5-25% of glycerol, and the density gradient liquid II is 45-55% of glycerol; (2) loading the mixed sample before purification to the top end of the density gradient liquid; (3) performing density gradient ultracentrifugation; and (4) after centrifugation, collecting centrifugal samples through a segmented pipetting method, taking each collected sample to carry out agarose gel electrophoresis verification, and taking the sample with single lane band and corresponding correct molecular weight as the separated sample containing the target DNA composite nanostructure. The method disclosed by the invention is mild in condition, simple to operate and high in universality, and has an important application prospect.

The embodiment of the invention provides a gene editing cell off-target detection method and an off-target prediction model construction method, and relates to the technical field of gene editing. The method comprises the following steps: 1) obtaining a gene editing cell containing a protein-single-stranded DNA compound; (2) separating out single-stranded DNA from the gene editing cells; 3, sequencing analysis is carried out on the single-stranded DNA, and off-target information is determined, specifically, the step 1 comprises the substeps that exonuclease is adopted to carry out gene editing on cells to be detected, and / or a pathway inhibitor is adopted to carry out culture treatment on the cells subjected to gene editing, and the off-target detection sensitivity is remarkably improved through the treatment strategy of the embodiment of the invention.

The invention provides a T-DNA complex as well as a preparation method and application thereof, and belongs to the technical field of genetic engineering. The invention provides a preparation method of a T-DNA (T-deoxyribonucleic acid) complex, which comprises the following steps: binding a single-chain T-DNA containing a target gene with RecA protein and VirD2 protein in sequence to obtain VirD2-RecA-ssT-DNA. The preparation method is simple in step and convenient to operate. The invention further provides a transgenic method of the T-DNA complex based on the scheme, the T-DNA complex VirD2-RecA-ssT-DNA is transferred into a plant receptor under the action of the cell permeable membrane peptide, a transgenic plant is obtained through screening, and the average transformation efficiency is about 6.1%. According to the transgenic method disclosed by the invention, a technical system for transforming the T-DNA complex into the gramineous plant is established, and a technical support is provided for functional genomics research of the gramineous plant.

The invention discloses a deoxyribozyme probe for specifically distinguishing inosine and adenosine and application, and belongs to the technical field of deoxyribozyme probes. A substrate chain containing an unmodified RNA site or a substrate chain with an RNA modification site is connected with a DNA library to construct a chain DNA complex, in-vitro screening is carried out, chain deoxyribozyme capable of specifically recognizing an inosine site is obtained through screening, and the catalytic activity of the chain deoxyribozyme is the highest in a publically reported specific recognition RNA modified deoxyribozyme probe. The probe obtained by the invention can specifically detect and recognize sites containing inosine, and has the potential of being applied to the aspect of biosensing.