17results about How to "Low background" patented technology

The invention provides a folate receptor targeting small molecule compound, a preparation method, a composition and application. Specifically provided is a compound represented by formula I or a pharmaceutically acceptable salt thereof. The compound or the pharmaceutically acceptable salt thereof provided by the invention can be used as a small-molecule targeting fluorescence contrast agent for assisting surgical treatment, has the advantages of novel structure, good solubility, small steric hindrance and strong targeting property, can obviously improve the view field of tumor surgery, and is beneficial to efficiently and accurately implementing excision of pathological tissues such as tumor tissues, boundary tissues and the like. # imgabs0 #

The invention provides a composition containing folic acid compounds and a near-infrared fluorescence capture system. The near-infrared fluorescence capture system comprises an imaging module, and the imaging module comprises a compound shown in the formula I or pharmaceutically acceptable salt of the compound. The compound shown in the formula I or the pharmaceutically acceptable salt of the compound can be used as a near-infrared fluorescence imaging agent, and is good in targeting property and clinical application prospect. # imgabs0 #

This invention relates to the field of biomedical detection technology, and discloses a bitetrahedral framework nucleic acid TDN cascade amplification system and its application, including TDN-1 and TDN-2. TDN-1 has a hairpin H1 containing a fluorescent reporter group attached to its surface, and TDN-2 has a hairpin H2 attached to its surface. The sequences of H1 and H2 are designed to undergo an alternating hybridization chain reaction triggered by target mRNA. This scheme relies on the synergistic effect of TDN structural anchoring and precise hairpin probe sequence design to overcome the technical defects of traditional free HCR hairpins in living cells, such as poor stability, low reaction efficiency, and non-specific triggering, achieving more efficient and specific intracellular signal amplification. Furthermore, it enables highly specific and sensitive in-situ imaging and dynamic tracking of low-abundance mRNAs such as c-Myc in single living cells, effectively solving the problems of insufficient detection sensitivity and false positives caused by the inability of traditional detection methods to effectively enrich targets and the low efficiency and high background of traditional HCR and other signal amplification technologies in intracellular applications.

The invention relates to a fluorescence and colorimetric dual-mode biosensing method for detecting caffeine and application thereof, the method causes CRISPR / Cas13a to regulate and control Fe-MOFs to fall off from a signal probe based on to-be-detected liquids with different concentration gradients, the fallen Fe-MOFs collapses under the action of sodium pyrophosphate to release 2-aminoterephthalic acid and ferric ions, and the 2-aminoterephthalic acid and ferric ions are subjected to fluorescence and colorimetric dual-mode biosensing method is used for detecting caffeine. 2-aminoterephthalic acid is converted into a fluorescence signal, meanwhile, Prussian blue generated by reaction of ferric ions and potassium ferrocyanide is converted into a colorimetric signal, and a fluorescence and colorimetric dual-mode biosensing method is constructed; according to the sensor, interference factors can be effectively eliminated by outputting two detection signals and performing cross validation; the advantages of high sensitivity and wide linear range of a fluorescence method and the advantages of simple operation and visual result of a colorimetric method are combined, so that a target object can be accurately recognized, the lower detection limit can be reduced, and the accuracy of a quantitative result can be ensured; according to the sensing method, visual observation can be achieved, precise instruments are not needed, and good application value is achieved.

The invention relates to the technical field of immunodetection, in particular to an anti-human phosphorylated Tau181 rabbit monoclonal antibody, an anti-human phosphorylated Tau217 rabbit monoclonal antibody, a preparation method and combined detection application, provides two anti-human phosphorylated Tau rabbit monoclonal antibodies, and provides preparation, application and a combined application method of the two antibodies. The antibody has good accuracy and sensitivity in detection of a phosphorylated Tau marker, can be applied to sandwich ELISA, indirect ELISA, immunochromatography, chemiluminescence or flow detection fields and the like, and is beneficial to discovery and screening of patients suffering from early Alzheimer's disease; the invention provides an antibody pair formed by applying the two antibodies to immunodetection and jointly applying the two antibodies to immunodetection, the advantages of high accuracy, high sensitivity and low background are shown in detection, the G122 (p-Tau217)-G69 (p-Tau181) antibody pair can detect two indexes of Tau181 and Tau217 at a time, and compared with a common two-step detection method, the G122 (p-Tau217)-G69 (p-Tau181) antibody pair is quicker and more convenient, and the accuracy is guaranteed.

The present application provides a kit and method for detecting RNA at room temperature. The kit for detecting RNA at room temperature comprises: a target RNA recognition and amplification component and a double signal amplification component, and the further amplification and reporting of the signal are completed by coupling the two components, and the high-sensitivity detection of RNA is realized. The method for detecting RNA at room temperature of the present application does not need a complex reverse transcription process, can reduce the complexity of the reaction and the cost of the instrument, and has high detection efficiency.

The application provides a method for separating and purifying cell surface proteins and application thereof. The method comprises the following steps: culturing cells to be separated, adding an azide solution to the cells for incubation, then adding a Tris-HCl buffer to terminate the reaction, so as to label the cell surface proteins with azides; then adding a TNTE buffer and a protease inhibitor to lyse the cells, centrifuging to obtain cell lysates labeled with azides; incubating the cell lysates labeled with azides with phosphine-biotin-streptavidin magnetic beads, so as to enrich the cell surface proteins labeled with azides, and obtain magnetic beads containing the cell surface proteins. The method can effectively separate the cell surface proteins, has low background, high efficiency and good repeatability, and can be applied to quantitative analysis of cell surface proteomes.

The application discloses an RNA-protein complex, an expression vector, a kit and application thereof. The RNA-protein complex comprises: a chimeric RNA having a molecular structure represented as N1-N2 or N2-N1; wherein N1 is a target RNA sequence, and N2 is an RNA aptamer configured to activate a fluorophore molecule to emit spectral fluorescence; and a recombinant fusion protein having a molecular structure represented as P1-P2 or P2-P1; wherein P1 is a target protein, and P2 is a fluorescent protein, and the target protein recognizes and binds to the target RNA sequence.

The invention relates to the technical field of lead ion detection, in particular to a lead ion detection colorimetric sensor and application thereof.The lead ion detection colorimetric sensor comprises hemin, a substrate chain S, an enzyme chain Dz and a DNA chain DS with three palindromic structures; in the absence of Pb < 2 + >, the substrate chain S and the enzyme chain Dz are hybridized to form a stable S-Dz double chain; when Pb is introduced, an enzyme chain Dz can be activated, and lead ions are specifically recognized and used as cofactors. Through an annealing process, the DNA chain DS is subjected to intramolecular hybridization and self-folding so as to be self-assembled into a definitely-defined and monodisperse DNA nanosphere; the substrate chain S and the enzyme chain Dz can be hybridized to form a stable S-Dz double chain; a plurality of S-Dz are concentrated on a limited nanosphere surface (DS-S-Dz), the catalysis direction is optimized, side reactions are reduced, and a signal DNAzyme can be quickly formed, so that a color signal is remarkably amplified, and lead ion detection with higher sensitivity, lower background and higher stability is realized.

The invention provides a detection method based on weighted Fourier integral method, which adopts double triangular window, double cosine window and double Kaiser window multi-group windowing mode to shift left and right and select small value for beam diagram of weighted Fourier integral method. Since beam diagrams of three weighting modes have differences in sidelobe level, the invention can reduce the sidelobe level of beam diagram by selecting small value for blending, reduce the background level of target estimation result, improve the detection performance of weak target, accurately estimate the position of weak target, and overcome the problem that weak target is difficult to detect under high background caused by high sidelobe level of beam diagram when single window function is weighted; the invention obtains narrower main lobe of beam by using the method of shifting left and right of beam diagram, overcomes the problem that main lobe of beam diagram is wide under single window function, and improves the display effect of target in azimuth estimation result.

The invention discloses a fluorescent probe based on a nucleic acid amplification technology, a construction method of the fluorescent probe and application of the fluorescent probe to in-situ visualization of glycoRNA on cells. Comprising three DNA chains: a DNA sequence AK complementary with glycoRNA; a chain H1 complementary to the AK moiety; and the chain H2 achieves a signal amplification effect. The AK opens the hairpin structure of the H1, then the exposed part of the H1 continues to open the hairpin structure of the H2, and finally the long-chain nano-cluster compound with the H1, the H2 and the AK in cross complementation is formed. The hybridization chain reaction can help people amplify and increase the signal intensity of glycoRNA, so that the detection sensitivity is improved, a nucleic acid amplification technology in which enzyme participates is not needed, the preparation is simple and convenient, and the detection cost can be reduced. By combining a nucleic acid amplification technology and a fluorescent aptamer means, direct in-situ visualization of glycoRNA on a living cell level can be realized, steric hindrance caused by antibodies and the like is avoided, and the content and spatial distribution of glycoRNA are analyzed.

This invention discloses a detection method for ultrasensitive fluorescence counting immunoassay using bioorthogonal reaction-immobilized bacteria, comprising the following steps: (1) transforming recombinant plasmids into *E. coli*, and inducing transcription into the T promoter using IPTG to induce *E. coli* to express green fluorescent protein; (2) dissociating Cu-MOF nanoparticles with ascorbic acid, allowing the azide groups of *E. coli* modified with azidoform to bind to the alkyne groups on alkyne-modified bovine serum albumin, thus immobilizing *E. coli* on a well plate; (3) amplifying the signal through the self-replication of luminescent *E. coli*, converting the concentration of the biomarker into fluorescent bright spots of fluorescent *E. coli*, thereby achieving quantitative detection. This invention has strong detection specificity, good stability and accuracy, and a detection limit lower than the clinical gold standard ELISA, allowing for visual detection of biomarker concentrations.

The present disclosure relates to a knee joint lesion detection method and device, an electronic device and a storage medium, and relates to the technical field of knee joint lesion detection. The method comprises: performing similarity information calculation on a T1 first image and a T2 second image in an acquired knee image, and obtaining a corresponding third image based on the similarity information; synthesizing the T1 first image, the T2 second image and the third image to obtain a to-be-processed image; and performing knee joint lesion detection on the to-be-processed image based on a preset target detection model. The present disclosure can realize knee joint lesion detection.

The invention discloses a plasmid vector for visually detecting cadmium ions based on biosynthetic biliverdin as well as a biosensor and a quantitative detection method of the plasmid vector. The sequence of the plasmid vector pET21a-cadR-C448SCY-ho1 is as shown in SEQ ID NO. 1. According to the whole-cell biosensor prepared by the invention, far-red fluorescence of a biosensor cell culture solution can be used as an output signal, and blue-green of a biosensor cell precipitate can also be used as an output signal to quantitatively detect the cadmium ion concentration in a real environment, which is reflected on a structural element of the biosensor, and is also reflected on the basis of a detection result. The invention further provides a novel method for quantifying the color change of the cell precipitate.

The invention relates to the field of medical detection, provides a preparation method of a novel BCR / ABL fusion gene fluorescence in-situ hybridization probe, solves the problems that an existing common fluorescence in-situ hybridization probe is complex in preparation process and is limited by BAC cloning, and overcomes the problems that an existing probe is non-uniform in cell permeation, high in background and weak in signal intensity and is combined with non-specific fragments. The preparation method of the fluorescent probe provided by the invention is suitable for practical application, the fluorescent probe which is uniform in size, high in cell transmittance, uniform in penetration, high in targeting specificity, low in background, clear and obvious in signal, simple and efficient in production mode and capable of being synthesized at one time to meet permanent application requirements is prepared, and through process exploration, the fluorescent probe has a good application prospect. The dye, the dye concentration, the primer and the high-fidelity polymerase which are most suitable for the fluorescence labeling process of the BCR / ABL fusion gene fluorescence in-situ hybridization probe are screened out.

The invention provides a precipitation type single-component TMB (Tetramethylbenzidine) substrate solution and application thereof. The precipitation type single-component TMB substrate solution adopts a citric acid-sodium citrate buffer system, the pH value of the buffer system is 4.5-5.0, and the buffer system contains TMB and heparin. Compared with a BCIP / NBT substrate commonly used in immunoblotting at present, the precipitation type single-component TMB substrate solution is more sensitive, lower in background, faster in color development and high and stable in precipitation efficiency under the same condition, blue purple precipitates can be formed on materials such as an NC membrane and polystyrene, and imprint of the precipitation type single-component TMB substrate solution is more suitable for visual inspection and comparison. The substrate solution is good in stability, long in shelf life, ready-to-use and convenient and fast to use.

The application discloses a kind of network construction methods for extracting space-time features of dynamic gesture RGB video frame, belong to computer vision and deep learning field.Aiming at the problems that existing network weakly resists blur, hand small target extraction effect is poor, gesture frame offset and time sequence redundancy influence training precision, the application constructs single mode space-time feature extraction network based on ShuffleNetV2-GRU.Spatial branch adds learnable gaussian blur branch, adopts SPDConv optimization down sampling, Stage4 layer is replaced by lightweight DCNv2 to extract hand irregular features, and multi-scale feature fusion is completed by WAFF-ASFF.The time sequence branch accesses TAM module between spatial network and GRU to correct frame offset, and relies on adjacent frame weighting module to strengthen key time sequence information.Preprocessing distinguishes trajectory, gesture posture and makes differential enhancement, and combines hand ROI to optimize input data.The application has excellent extraction precision, model lightweight, inference is fast, and is suitable for embedded device deployment.