160 results about "Nonspecific binding" patented technology

The invention belongs to the technical field of biological detection, and particularly relates to a monoclonal antibody combination for detecting measles virus nucleoprotein and application of the monoclonal antibody combination. The combination is composed of monoclonal antibodies 5E2 and 5G9 and can efficiently and specifically recognize measles virus nucleoprotein, amino acid sequences of complementary determining regions (CDR) of heavy chain and light chain variable regions of the combination are clear and are shown as SEQ ID NO.1-12 respectively, high specificity and high affinity of the antibodies are guaranteed, the antibody combination can effectively capture and detect target antigens, and the antibody combination can be used for detecting measles virus nucleoprotein. The risk of non-specific binding and cross reaction is obviously reduced. The combination shows excellent sensitivity and specificity in detection platforms such as colloidal gold immunochromatography, and provides a stable and reliable biological recognition tool for rapid and accurate detection of measles viruses.

The invention provides a kit and a method for detecting common fusion genes of lymphoid leukemia based on a multiple digital PCR (Polymerase Chain Reaction) method. By constructing a synergistic effect mechanism of the primer and the fluorescent probe and optimizing matching of the primer, the probe and a fluorescent marker, non-specific binding among amplification products is effectively avoided. A composite reaction aid with a specific formula, namely a PCR enhancer, is innovatively introduced, so that the amplification efficiency and specificity of a multiple detection system are remarkably improved. According to the kit provided by the invention, the integrated detection capability on seven fluorescent channels, namely Atto 425, VIC, FAM, ROX, CY5, CY5.5 and CY7, is realized in a single-hole design. By innovatively constructing an ROX + CY5 and Atto425 + VIC dual-channel joint detection system, when the ROX and CY5 channels or Atto425 and VIC channels in the same detection hole simultaneously present positive signals, two additional detection targets can be specifically interpreted. The innovative detection strategy based on channel combination enables the kit to realize precise detection of 18 fusion genes only through two detection holes in a breakthrough manner.

The invention relates to the technical field of fluorescent probes, and provides a low-concentration ratio type high-concentration enhanced fluorescent probe as well as a preparation method and application thereof in order to solve the problems that a traditional fluorescent probe depends on a high-concentration use condition and is often faced with fast probe consumption, increased biotoxicity, non-specific target binding and the like in a biological sample. The preparation method of the fluorescent probe comprises the following steps: step 1, preparing phenothiazine dialdehyde; and 2, mixing phenothiazine dialdehyde, malononitrile, ethanol, acetonitrile, DMF and piperidine, and carrying out a reflux reaction to obtain the low-concentration ratio-type high-concentration enhanced fluorescent probe. The probe provided by the invention realizes quantitative detection of HClO through synchronous change of two emission channels, and the detection sensitivity and reliability are remarkably improved; when the concentration is high, an enhanced single-channel fluorescence amplification effect is shown, and strong signal identification and macroscopic visual imaging in specific application are facilitated, so that the dual requirements of trace monitoring and high-throughput screening are met.

The invention discloses an anti-soluble transferrin receptor monoclonal antibody as well as a preparation method and application thereof, and belongs to the technical field of antibody detection. According to the antibody, an L101-F760 amino acid sequence of human TfR protein is used as an immunogen, specific screening of B cells, reverse RNA (Ribonucleic Acid) into cDNA (Complementary Deoxyribose Nucleic Acid) through RT-PCR (Reverse Transcription-Polymerase Chain Reaction), then homologous recombination is performed to construct heavy and light chain vectors, and finally multiple rounds of screening are performed to obtain the purified sTfR monoclonal antibody, so that the sTfR protein can be specifically recognized, and the antibody has the advantages of high specificity and high sensitivity and can be widely applied to the field of immunotherapy. The natural sTfR protein in human serum can be recognized. The kit is applied to the detection and screening fields of immunohistochemistry, immunofluorescence chemistry, western blot, co-immunoprecipitation, indirect ELISA, flow cytometry and the like, especially has low background and no interference of non-specific binding impure protein during immunohistochemistry detection, can obtain more accurate detection and evaluation results, avoids interference of false positive and false negative, and has high detection accuracy. The method has great application value in the aspects of basic scientific research and clinical pathology detection.

The invention belongs to the field of molecular sieve material characterization, and particularly relates to a method for analyzing aluminum atom pairs in a ZSM-5 molecular sieve based on super-resolution fluorescence microscopic imaging, which comprises the following steps: activating a ZSM-5 molecular sieve sample; contacting the obtained sample with probe molecules; washing the ZSM-5 molecular sieve sample, and removing unbound or nonspecifically bound probe molecules; imaging the marked sample by using a super-resolution fluorescence microscope to obtain an image sequence containing a single fluorescent molecule emission event; processing the image sequence, determining a space coordinate of each fluorescence event, and reconstructing a super-resolution fluorescence image exceeding an optical diffraction limit; and based on the space coordinates of the fluorescent dots in the super-resolution fluorescence image, carrying out statistics to obtain the position, surface density or distribution information of the aluminum atom pairs in the ZSM-5 molecular sieve. According to the method disclosed by the invention, nanoscale spatial resolution, direct imaging and quantitative analysis of Al-pair in ZSM-5 (Zeolite Socony Mobil-5) can be realized.

The invention belongs to the technical field of biomedicine, and discloses an antinuclear antibody IgG indirect immunofluorescence detection method and system, and the detection standardization degree and the result reproducibility are significantly improved through the full-automatic system design in combination with precise mechanical transmission and an automatic sample adding device. Through an optimized FITC labeling system and a refined washing procedure, non-specific binding is remarkably reduced, and meanwhile, the binding efficiency of the antinuclear antibody and the secondary antibody is improved, so that the detection sensitivity is improved. Through the design of the automatic sample adding and sheet sealing device, the sample treatment efficiency is greatly improved, and simultaneous detection of large-scale samples can be realized. Through combination of a high-resolution imaging system and an intelligent image analysis algorithm, morphological characteristics and distribution rules of fluorescence signals are automatically extracted, and the accuracy and objectivity of a detection result are greatly improved.

The invention belongs to the technical field of protein calibration, and particularly relates to an enhanced protein-free confining liquid for protein detection, which comprises the following components: trihydroxymethyl aminomethane, sodium chloride, Tween-20, polyvinyl alcohol, trehalose, EDTA (Ethylene Diamine Tetraacetic Acid) and a polyoxyethylene-polyoxypropylene block copolymer, and sodium chloride and trehalose are matched to provide ions and small molecular compounds to form a stable closed environment. Wherein the trehalose assists in filling and covering small pores of PVDF, the sodium chloride provides ion balance, the EDTA-Na is used for precipitating metal ions, and the Tween-20 assists in repairing the PVDF film. According to the invention, the polyvinyl alcohol and the polyoxyethylene-polyoxypropylene block copolymer are mixed for use, so that non-specific sites on the membrane are blocked while impurity proteins are prevented from being introduced, the sealing effect is achieved, and the problem of false positive or non-specific binding easily caused by the traditional sealing liquid is effectively solved.

The invention provides a nucleic acid probe, a primer group, a kit, a detection method and application, and relates to the technical field of biology. The nucleotide sequence of the nucleic acid probe is as shown in SEQ ID NO. 1; wherein the 3'end of the nucleic acid probe is modified with MGB, and locked nucleic acid is modified at a base position corresponding to the difference between the swine fever wild strain and the swine fever vaccine strain in the nucleotide sequence. According to the nucleic acid probe, a specific sequence is utilized to precisely target a swine fever wild strain, and locked nucleic acid modification is introduced at a differential site, so that the recognition capability on single-base mismatch is remarkably enhanced, non-specific binding to a vaccine strain is thoroughly blocked, and false positive interference is eliminated; and 3 '-terminal MGB modification is matched to improve the binding stability and sensitivity, so that the efficient and accurate identification of the swine fever wild strain under the immune background is ensured.

The invention belongs to the technical field of biological detection, and particularly relates to a monoclonal antibody combination for detecting porcine epidemic diarrhea virus NP protein and application of the monoclonal antibody combination. The combination is composed of monoclonal antibodies 1E11 and 5C8 and can efficiently and specifically recognize porcine epidemic diarrhea virus NP protein, amino acid sequences of complementary determining regions of heavy chain and light chain variable regions of the combination are clear and are shown as SEQ ID NO.1-12 respectively, high specificity and high affinity of the antibodies are guaranteed, the antibody combination can effectively capture and detect target antigens, and the antibody combination can be used for detecting the porcine epidemic diarrhea virus NP protein. The risk of non-specific binding and cross reaction is reduced. The combination shows excellent sensitivity and specificity in detection platforms such as colloidal gold immunochromatography and the like, and provides a stable and reliable biological recognition tool for rapid and accurate detection of the porcine epidemic diarrhea virus.

The invention belongs to the technical field of biochemical detection, and particularly relates to a micro-fluidic chip PSMA prostate cancer circulating tumor cell immunoenrichment detection kit and a preparation method thereof. According to the kit, an EpCAM antibody, a Vimentin antibody and a double-site PSMA capture combination are fixed in a chip channel through a streptavidin-biotin system, double enrichment of epithelial and mesenchymal CTCs is achieved, PSMA targets are recognized through combination of an aptamer and the antibody, and the detection specificity and sensitivity are improved. Competitive oligopeptides are further introduced to block non-specific binding sites on the surfaces of leukocytes and reduce false positive. By combining a multiple fluorescent chromosome system and a double-antibody nucleic acid probe signal amplification strategy, accurate recognition and quantification of CTC and PSMA positive cells are realized. The scheme is suitable for early screening, curative effect evaluation and relapse monitoring of prostate cancer, and has a good clinical application prospect.

The invention provides a tsutsugamushi disease pathogen detection primer, a probe and a kit, the sequences of the primer and the probe in an asymmetric primer ERA detection system are designed and screened according to the target sequence of a tsutsugamushi disease pathogen gene, and the proportion of upstream and downstream primers and an amplification reaction system are optimized; the nucleic acid sequence of the tsutsugamushi disease pathogen can be specifically recognized, and non-specific binding with other irrelevant nucleic acid is reduced, so that the detection specificity is improved; meanwhile, efficient amplification of the tsutsugamushi disease pathogen nucleic acid is achieved, accurate detection can be achieved even under the condition that the virus nucleic acid content is extremely low, and therefore the detection sensitivity and the amplification efficiency are improved.

The invention belongs to the technical field of immunohistochemical detection, and discloses a modified composite sealing buffer solution as well as a preparation method and detection application thereof. The modified composite blocking buffer solution comprises a basic buffer system, a composite blocking agent, a nonionic detergent, an endogenous interferent blocking agent and an antibody stabilizer, wherein the basic buffer system provides a stable pH environment and ionic strength; the composite sealing agent firstly occupies a shielding site, and the background is lowered; the nonionic detergent destroys hydrophobic interaction, effectively elute and loosen adsorbed molecules, and promote dissolution of components with relatively strong hydrophobicity; the endogenous interferent blocker can be combined with a receptor firstly, so that non-specific combination of an antibody and the receptor is blocked, and the problem of specific background is solved; the antibody stabilizer can protect the activity of the detection reagent and maintain the stability, and the obtained modified composite sealing buffer solution and the kit thereof have the advantages of multiple cooperative sealing mechanisms, prospective blocking of endogenous interference, improvement of the stability, compatibility and high efficiency of the antibody and the like.

The present invention relates to a polymer conjugate comprising a ULA polymer a) and one or more polypeptides b), wherein the polypeptides are conjugated to the ULA polymer, and the conjugate is coated on the surface of a device for culturing cells. The peptides can interact with receptors on the surface of the cells, while the polymer prevents non-specific binding of the cells to the surface of the device.

The invention provides a super-sensitive molecule system for biological signal amplification, a detection method and application, and belongs to the technical field of biological sensing. The super-sensitive molecular system for biological signal amplification is composed of a hairpin probe H and gold nanoparticles (TS (at) CP (at) loading a trajectory chain TS and a capture chain CP (CP), a traditional DNA walking machine walking chain is split into the hairpin probe H and the capture chain CP which are spatially isolated, and a target-dependent activation mechanism is constructed: when no target exists, the hairpin probe H realizes self-protection through a self-folding stem-loop structure; non-specific binding with the capture chain CP / trajectory chain TS is blocked; after the target is beaten on the clamping probe H, the exposed sequence of the clamping probe H is hybridized with the capture chain CP to form a complete walking chain, and a signal amplification reaction driven by cutting incision enzyme is triggered, so that the problem of false positive caused by co-localization of the walking chain and a track chain interface is fundamentally solved.

The invention relates to the technical field of biological medicine detection, and particularly discloses an electrochemical luminescence kit for rapidly detecting tumor markers, which comprises a capture molecule, an electrochemical luminescence ECL labeled molecule, a biotin labeled detection antibody, a streptavidin fixed plate and a liquid reagent, according to the present invention, the capture molecule, the ECL labeling molecule, the biotin labeling detection antibody and the streptavidin fixation platform interact to form the novel multi-protein complex, such that each target antigen can initiate multiple signal conversion during the reaction process; theoretically, the tetramolecular structure can obviously improve the signal transmission efficiency, so that the low-abundance tumor marker can be quickly and accurately detected, and the high-specificity recognition of the target tumor marker is realized by capturing molecules and detecting antibodies. The high affinity between biotin and streptavidin is utilized, so that non-specific binding is greatly reduced, background signals are reduced, and the accuracy and reliability of detection are improved.

The invention discloses a detection method of inflammatory marker protein. According to the method, the micro-fluidic chip with a sample loading area, a buffer treatment area, a sample channel and a detection area is prepared on filter paper through wax printing; chitosan is preset in the sample loading area and is used for treating a sample, and bromothymol blue is fixed in the detection area and is used as a pH indicator. During detection, a sample is driven by a phosphate buffer solution with the pH value of 6.0 to flow to a detection area through capillary action, the C-reactive protein and the indicator are subjected to non-specific binding, so that the color of the detection area is changed from yellow to green, the length of a green developing signal is in direct proportion to the concentration of the CRP, and quantitative detection can be realized by measuring the length. The method does not need an antibody, is low in cost, is simple and convenient to operate, can complete detection within 15 minutes, has the detection limit of 1.56 ng / ml and the linear range of 5-25 ng / ml, and is suitable for rapid screening and field detection of basic medical institutions.

The invention belongs to the technical field of electrochemical analysis and detection, and particularly relates to an electrochemical immunosensor for detecting adiponectin as well as a preparation method and application of the electrochemical immunosensor. The preparation method comprises the following steps: (1) connecting a screen-printed electrode SPCE to an electrochemical workstation by using a 0.01 M PBS (Phosphate Buffer Solution) with the pH value of 7.4, performing-0.2 V-1. 2V cyclic voltammetry scanning, and activating for 10 circles under 50mV / S; and (2) by taking 0.01-1M H2SO4 as a base solution, connecting the screen-printed electrode SPCE to an electrochemical workstation, carrying out electro-polymerization on poly-o-phenylenediamine in a 50-100mM o-phenylenediamine and NH2-UiO-66 solution to form a poly-o-phenylenediamine and NH2-UiO-66 composite modified electrode, washing with deionized water, and drying at room temperature. (3) soaking the modified electrode in a glutaraldehyde solution for 10-70 minutes, cleaning with deionized water, drying at room temperature, adding 10-100 [mu] L of ADPN antibody solution and 100-600 [mu] g / mL of ADPN antibody solution, and incubating; and (4) washing with ionized water, drying at room temperature, preventing non-specific binding sites at 37 DEG C for 0.5-1.5 hours by using 3-10 microliters of 0.8-1.2 wt% casein solution, and washing the screen-printed electrode again to obtain the electrochemical immunosensor.

The invention relates to the technical field of molecular biology, and discloses an LAMP (loop-mediated isothermal amplification) primer group and a kit for detecting three items (Uu, CT and NG) of venereal diseases. The LAMP primer group disclosed by the invention comprises a first primer group for targeting a ureaplasma urealyticum UreB gene, a second primer group for targeting a chlamydia trachomatis gyrA gene and a third primer group for targeting a gonococcus glnA gene. The LAMP primer group provided by the invention has good thermal stability, is suitable for an LAMP amplification detection system at a high temperature of 70 DEG C, reduces non-specific binding, and has good detection sensitivity and specificity. The LAMP primer group and the kit provided by the invention provide an innovative solution for accurate diagnosis of sexually transmitted diseases.

The invention relates to the technical field of biological detection, and discloses a sample diluent and application thereof and a kit, pure water is taken as a solvent, and the sample diluent at least comprises 15-80 g / L of soluble sodium salt, 0.05-0.5 g / L of soluble potassium salt, 8-15 g / L of amino acid, 0.2-1 g / L of goat serum albumin, 0.2-1 g / L of surfactant, 0.5-2 g / L of trehalose and 0.5-2 mL / L of Proclin-300 according to concentration, the sample diluent provided by the invention can weaken non-specific binding of impurities in a blood sample and a target analyte, so that the accuracy of a final detection result is improved.

A high-throughput screening system and method for small molecule-protein interactions includes first immobilizing selected small molecules on a solid matrix. Immobilization is preferably performed via photoaffinity labeling, where a linker is used to bind the small molecule to the matrix. cDNA libraries are constructed based on various human tissues. Tissue mRNA is transcribed into cDNA and transferred to a phage genome to construct a phage display library, which is then mixed with small molecules conjugated to microspheres and incubated. The incubated mixture is washed to remove unbound phages, including non-specific and weakly bound phages. Bound phages are amplified and used for the next round of biopanning. The biopanning cycle is repeated, and then PCR is performed on each plaque obtained from the final round of biopanning. The PCR products from each small molecule experiment are barcoded, merged, and then subjected to next-generation sequencing.

The invention belongs to the technical field of biomedical detection, and particularly relates to a standardized lung tissue microthrombus digital quantitative analysis method. Comprising the following steps: S1, embedding a left lung lobe of a complete mouse by using paraffin to obtain a wax block, slicing the wax block, and selecting a slice which can completely display each tissue structure of the lung at a lung door for dyeing and analysis; s2, paraffin sections are immersed, rinsed and subjected to antigen repair; blocking endogenous peroxidase of the paraffin section, and closing a non-specific binding site of the paraffin section to obtain a paraffin section tissue; s3, preparing a primary antibody working solution to carry out antigen-primary antibody reaction; preparing an HRP secondary antibody working solution and carrying out primary antibody-secondary antibody reaction; s4, carrying out DAB color development by using a DAB color development solution, re-dyeing the cell nucleus by using hematoxylin, and carrying out immersion, dip dyeing and dehydration treatment to obtain a transparent sealing sheet; s5, using a full-automatic slide scanner to obtain a lung tissue panoramic digital scanning picture; and S6, performing batch analysis on the mouse lung tissue microthrombus by using an HALO pathological image analysis platform.

The invention provides a kit for separating ADAMTS-13 protein in blood by using nickel magnetic beads. The kit is used for separating ADAMTS-13 protein in plasma or serum, and the method comprises the following steps: activating nickel magnetic beads in the kit, separating the magnetic beads by adhering to the wall, and sucking supernate; the nickel magnetic beads are specifically bound with ADAMTS-13 protein in plasma or serum in a binding buffer solution, the magnetic beads are subjected to adherent separation, and supernate is sucked; adding an elution buffer solution to clean the nickel magnetic beads, and removing non-specific binding proteins and impurities; 1% trifluoroacetic acid is added, the captured ADAMTS-13 protein on the nickel magnetic beads is dissolved, the magnetic beads are subjected to adherent separation, and supernate is sucked to obtain the separated ADAMTS-13 protein; the supernate can be directly used for MALDI-TOF-MS (Matrix-Assisted Laser Desorption / Ionization Time-Of-Flight Mass Spectrometry) mass spectrometry The kit for separating ADAMTS-13 protein in blood by nickel magnetic beads has the advantages of high sensitivity, strong specificity, wide application range, high flux, automation, low cost, rapidness, simplicity, convenience, flexibility in operation and small sample dosage, and can be used as a relatively important reference index clinically.

The invention belongs to the technical field of chemiluminescence detection, and particularly relates to a kit for detecting a bovine leukemia virus IgG antibody as well as a detection method and application of the kit. A sample treatment solution in the kit is prepared from Protein A, disodium hydrogen phosphate dodecahydrate, monopotassium phosphate, potassium chloride, sodium chloride, casein, mercaptoethanol, Tween-20 and Proclin; and the mark of the magnetic bead is sealed by combining PEG4000 and ethanolamine. Compared with traditional single protein sealing, the sealing mode provided by the invention has the advantages that interference of foreign protein is removed, non-specific binding in a sample is reduced, the background is reduced, and the stability, sensitivity and specificity of detection are improved; compared with a traditional large-proportion diluted sample, the sample treatment liquid has the advantages that excessive IgG in the sample is removed, dilution treatment of an equipment dilution module is not needed in the detection process, manual pre-dilution treatment is also not needed, and the detection efficiency is improved.

Processes and compositions are described for preparing new, colloidally stable, coated nanomagnetic particles useful for both in-vitro and in-vivo biomedical applications, including cell targeting and capturing cells, microorganisms, and cellular organelles or entities such as exosomes. These nanomagnetic particles can also be used as imaging contrast agents due to their small size and high magnetic moment. The nanomagnetic particles include a series of sequentially added, stabilizing surface coatings rendered onto nano-sized magnetic crystal clusters (e.g., magnetite particles) to impart colloidal stability in complex biological samples with minimal leaching of the coating materials, high binding capacity, and low non-specific binding. Another benefit of this invention is the ability to utilize both external and internal magnetic field-generating separation devices to effect separation of the magnetic nanoparticles.

The invention relates to a method for preparing a nano metal iron oxide material from iron ion binding protein with specific binding capacity, and belongs to the technical field of genetic engineering. In order to overcome the technical problems of non-specific binding of metallothionein and iron ions and relatively low production efficiency in a traditional nano # imgabs0 # biological preparation method, the invention provides an iron ion binding protein with specific binding capacity, and a specific binding iron ion polypeptide sequence is connected on the basis of metallothionein, so that the iron ion binding protein with specific binding capacity is obtained. The specific binding amount of iron ions is increased, and the specific binding iron ion protein is used as a template to prepare the # imgabs 1 # nano material. According to the method for preparing the nano-metal iron oxide material through specific binding of the iron ion protein, reaction conditions are mild, # imgabs2 # is prepared and synthesized in an oriented mode through high selectivity of the specific binding iron ion protein, the preparation process is easy to control, and the particle size range of the prepared # imgabs3 # is 20-1000 nm.

The invention relates to a preparation method of a specific inflammatory factor nucleic acid aptamer. The preparation method comprises the following steps: providing a high-purity active protein sample of inflammatory factors such as TNF-alpha, IL-16, C5a, MMP-8 or IL-3; designing an RNA library containing a random sequence, and covering a diversified secondary structure; the method comprises the following steps: eliminating a non-specific binding sequence by using a control protein (such as GM-CSF instead of IL-3) or a low-concentration target protein sample which is similar to a target protein in structure but irrelevant to a function through ultracentrifugation, magnetic bead sorting or ion-exchange chromatography technologies; incubating the library subjected to negative screening and high-purity target protein, and optimizing the binding specificity and affinity of the aptamer through multiple rounds of iterative screening by combining with a magnetic bead separation technology; high-throughput sequencing is adopted to analyze an enriched sequence, surface plasmon resonance (SPR) is utilized to determine affinity, interference of a conservative structural domain is eliminated through negative screening, functional sequences are accurately enriched in combination with positive screening, and the targeting of the aptamer to inflammatory factors is remarkably improved.

The invention belongs to the technical field of biotechnology and protein determination, and particularly relates to confining liquid as well as a preparation method and application thereof. Modified bovine serum albumin and recombinant casein polypeptide are used as core components of the confining liquid, hydroxypropyl-beta-cyclodextrin, polyglycerol fatty acid ester and other auxiliary components are added, and the confining liquid is prepared through a specific technology. The modified bovine serum albumin and the recombinant casein polypeptide have a synergistic effect, so that active sites of the detection carrier can be efficiently sealed; the stabilizing agent and other components are supplemented, so that the stability and compatibility of the confining liquid are improved. The confining liquid is simple and convenient in preparation process, controllable in cost, suitable for various detection carriers such as elisa plates and nitrocellulose membranes, capable of reducing non-specific binding and improving detection sensitivity, and suitable for various biological detection scenes such as enzyme-linked immunosorbent assay.

The disclosure relates to the extraction and detection of pathogens using carbohydrate-functionalized biosensors. Immobilized carbohydrate moieties on the biosensor provide a means for non-specific binding of a plurality of target analytes. When a sample containing the target analyte is applied or otherwise transported to the biosensor detection surface, non-specific binding interactions between the carbohydrate moiety and the analyte immobilize / retain the analyte at the detection surface. The carbohydrate moiety is a stable binding pair member that allows on-sensor rinsing of a sample to enhance detection of an analyte in the sample. Specific analyte identification can be achieved with an analyte probe having a detection moiety and a binding pair member specific to the target analyte of interest.

The present invention relates to the technical field of rapid detection of malachite green, and specifically relates to a fluorescence sensor for detecting malachite green compounds, a preparation method thereof, and an application thereof. The fluorescence sensor includes: thioflavin T for generating a fluorescence signal; a nucleic acid aptamer for specifically binding to a malachite green compound; wherein, thioflavin T and the nucleic acid aptamer non-specifically bind to form a G-quadruplex-thioflavin T conjugate, which is the fluorescence sensor. The fluorescence sensor does not require modification with nanomaterials. When it is used for detecting malachite green compounds, the detection of malachite green compounds can be achieved without any separation steps. It has the characteristics of simplicity, rapidity, and high sensitivity, and the detection limit is 5.4 ng / L.

The present invention relates to an antibody fragment consisting of only the constant region of an antibody, and more particularly to an antibody fragment having no variable region of an antibody and consisting of only a heavy chain constant region (C H ) and a light chain constant region (C L ). For example, the present invention relates to an antibody fragment consisting of a heavy chain constant region and a light chain constant region (IgCw-gamma1epsilon2-4 / kappa), in which a gamma constant region (Cgamma1) and an epsilon constant region (Cepsilon2-4) are fused; a nucleic acid encoding the antibody fragment; a kit comprising the antibody fragment; and a use of the antibody fragment. In order to evaluate the efficacy of an antibody in the development of a new antibody drug or the like, a control, i.e., a reference antibody, is required, and the existing reference antibody cannot be completely free from non-specific binding, i.e., off-target effects due to reactions with other antigens, and the purification yield is also low. On the other hand, when the recombinant protein IgCw-gamma1epsilon2-4 / kappa consisting of only the constant region of an antibody according to the present invention is used, the problems of the existing reference antibody can be overcome, and the recombinant protein can also be used as an Fc epsilon receptor inhibitor that inhibits an allergic reaction. Therefore, the IgCw-gamma1epsilon 2‑4 / kappa according to the present invention can be used in various ways in the field of biomedical science.