20results about How to "Low cross-reactivity" patented technology

The invention provides an infectious bronchitis virus antigen epitope fusion peptide, and the prepared antigen epitope fusion peptide can be used for preparing an antibody and can also be used as a coating antigen for preparing an indirect ELISA detection product. The amino acid sequence of the provided epitope fusion peptide is SEQ ID NO: 4. After antigen epitope analysis is performed on S1 protein of an infectious bronchitis virus strain through bioinformatics software, a plurality of antigen epitopes are fused to obtain the antigen epitope fusion peptide. Specificity tests show that the prepared antigen epitope fusion peptide is a coating antigen, does not have cross reaction with positive serum of other common pathogens, and only has good reaction with positive serum of GI-19 type IBV, that is, the antigen epitope fusion peptide has good serotype specificity as a detection antigen, and has small cross reaction with non-GI-19 type IBV antibody.

The invention discloses a food allergen visual detection chip preparation method, which comprises: using a nitrocellulose membrane as a carrier, coating an allergen component protein antibody dissolved in a PBS buffer solution system on the nitrocellulose membrane by using a chip spotting instrument, and drying to form a detection reagent strip; preparing a liquid reagent required by a reaction system, and subpackaging to form a liquid detection reagent; and assembling the detection reagent strip and the liquid detection reagent component into a complete kit. The invention has the following technical effects: high sensitivity and specificity: multiple allergens can be detected at the same time, and cross reaction is reduced; compared with a traditional method, the method has the advantages that the detection time is remarkably shortened, and the working efficiency is improved. Through a visual result, non-professionals can easily understand a detection result, and the attention of the public to food safety is promoted.

The invention belongs to the technical field of biology, and particularly relates to a hybridoma cell strain BAP1C12, an anti-benzo [a] pyrene monoclonal antibody generated by the hybridoma cell strain BAP1C12 and application. The hybridoma cell strain BAP1C12 provided by the invention can be used for preparing a high-sensitivity anti-benzo [a] pyrene monoclonal antibody, and the titer measured by an enzyme-linked immunosorbent assay (ELISA) method can reach 2 * 10 < 5 >. The anti-benzo [a] pyrene monoclonal antibody provided by the invention is high in sensitivity and good in specificity, and the 50% inhibition concentration IC50 of the anti-benzo [a] pyrene monoclonal antibody to benzo [a] pyrene is 0.45 ng / mL. The anti-benzo [a] pyrene monoclonal antibody provided by the invention is high in sensitivity and good in specificity, the cross reactions of the anti-benzo [a] pyrene monoclonal antibody to the structural analogues of fluoranthene, benzo [b] fluoranthene, indeno [1, 2, 3-cd] pyrene, benzo [a] anthracene, benzo [k] fluoranthene, anthracene, phenanthrene, acenaphthene, fluorene and naphthalene are less than 3.5%, and the anti-benzo [a] pyrene monoclonal antibody can be applied to benzo [a] pyrene content determination.

The invention relates to the technical field of sigma NS protein, and particularly discloses a preparation method of a sigma NS polyclonal antibody, which comprises the following steps: construction of pET-28a-S3 plasmid, expression and purification of His tag recombinant protein, and preparation and identification of the polyclonal antibody. The present invention provides an efficient method for extracting and purifying [sigma] NS protein from nelson bay positive reovirus (NBV). A pET-28a-S3 recombinant plasmid is constructed and is efficiently expressed and purified in escherichia coli, so that high-purity sigma NS recombinant protein with a His tag is obtained and is used as an ideal antigen for preparing a polyclonal antibody. According to the method, the problems of low antigen purity, poor antibody specificity and the like in the traditional antibody preparation process are effectively solved. Meanwhile, the identification result shows that the antibody has high specific binding capacity to sigma NS protein and low cross reaction with other related proteins, the quality and usability of the antibody are ensured, and the antibody has wide application prospects.

The present application provides a novel means for treating ornithine transcarbamylase deficiency. More specifically, the present application provides a modified adeno-associated virus vector which expresses ornithine transcarbamylase so that an attack from a neutralizing antibody in blood is reduced and a gene is efficiently introduced into a liver of a living body (for example, human). The present application provides, for example, a modified adeno-associated virus vector which expresses ornithine transcarbamylase, which contains a modified VP1 protein that contains, for example, an amino acid sequence obtained by substituting at least one of the amino acids at positions 472, 587 and 706 in the amino acid sequence of the VP1 protein with another amino acid, and which does not cross-react with a neutralizing antibody against AAV2.

The invention discloses an enzyme-free fluorescence immunoadsorption method based on DNA three-way junction auxiliary signal amplification, and belongs to the technical field of molecular biological detection. According to the invention, gold nanoparticles are taken as a carrier, an AuNPs-DNA-antibody detection probe is synthesized, an antibody is used for capturing a target object, DNA is used for amplifying a signal, the amplified signal is formed by utilizing a DNA three-way junction structure, and the signal is output through combination of generation of a G-quadruplex and a fluorescent dye. The detection on the staphylococcus aureus enterotoxin B is realized. According to the invention, high-flux, high-specificity and high-sensitivity detection of SEB can be realized. The detection limit is 7.21 ng / L, and the linear range is 0.01-10 ng / mL. The cross reaction rate to staphylococcus aureus enterotoxin A is 34.78%, and the cross reaction rates to bovine serum albumin, hemoglobin, aflatoxin B1, chloramphenicol, oxytetracycline and the like are all lower than 10%.

The invention belongs to the technical field of molecular biology, and particularly discloses a theophylline aptamer and a virtual screening method and application thereof. The theophylline aptamer is selected from one or more of MUT9, MUT16, MUT67, MUT78 or MUT89. The invention further discloses a preparation method of the theophylline aptamer. The invention discloses a theophylline aptamer as well as a virtual screening method and application thereof, the theophylline aptamer is high in affinity and specificity, the virtual screening method remarkably improves the accuracy and efficiency of virtual screening, the theophylline aptamer can be quickly obtained at low cost, and a powerful calculation tool is provided for rational design and application of the aptamer.

The invention relates to a hybridoma cell strain capable of secreting a climbazole monoclonal antibody and application of the hybridoma cell strain, and belongs to the technical field of immunodetection. The climbazole monoclonal antibody cell strain CLM-5D8 is obtained by synthesizing a climbazole hapten, preparing a climbazole complete antigen and a climbazole coating antigen and carrying out cell fusion and screening, the number of the climbazole monoclonal antibody cell strain CLM-5D8 is CGMCC NO.45924, and the climbazole monoclonal antibody cell strain CLM-5D8 is preserved in the China General Microbiological Culture Collection Center. The hybridoma cell strain secretes the climbazole monoclonal antibody, the climbazole monoclonal antibody has good detection sensitivity and detection specificity to climbazole, the IC50 value to climbazole is 2.03 ng / mL, the cross reaction rates to climbazole structural analogues and functional analogues are both smaller than 1%, a solid foundation is established for a climbazole immunological detection method, and the application prospect is broad. The method can be applied to quantitative detection of climbazole.

This invention discloses chloramphenicol hapten, antigen, antibody, colloidal gold detection device, and their preparation methods and applications. The chloramphenicol hapten prepared by this invention using a total synthesis method retains all potential recognition sites of chloramphenicol to the maximum extent, and in particular, for the first time retains the most critical dichloro structure of chloramphenicol. After introducing a spacer arm, its electron cloud distribution is almost identical to the overall electron cloud distribution of chloramphenicol, improving the immunogenicity of the chloramphenicol antigen. The chloramphenicol antigen and monoclonal antibody prepared by this invention have high specificity for ELISA detection, with an IC50 value of [missing information]. 50 The value was 8.21 pg / mL, the linear detection range was 1.71–39.45 pg / mL, the cross-reactivity to common structural analogs was less than 0.01%, and the sensitivity to chloramphenicol in the sample was 0.1 µg / kg.

The application relates to a monoclonal antibody of alpha, beta and gamma amatoxin and a preparation method and application thereof. The monoclonal antibody of alpha amatoxin is prepared from an alpha amatoxin artificial antigen, the monoclonal antibody of beta amatoxin is prepared from a beta amatoxin artificial antigen, and the monoclonal antibody of gamma amatoxin is prepared from a gamma amatoxin artificial antigen; the alpha amatoxin artificial antigen is a conjugate of alpha amatoxin and keyhole limpet hemocyanin, the beta amatoxin artificial antigen is a conjugate of beta amatoxin and bovine serum albumin, and the gamma amatoxin artificial antigen is a conjugate of gamma amatoxin and human serum albumin. The three antibodies have a small cross-reaction rate, can simultaneously detect and distinguish alpha-AMA, beta-AMA and gamma-AMA in a sample, and have high accuracy.

The invention relates to the field of cytobiology, and particularly discloses a method and a system for screening cell components based on flow cytometry, the method comprises the following steps: digesting a target tissue into a cell solution, preparing a buffer solution of an impurity-removed cell solution, and preparing the impurity-removed cell solution into a single-cell suspension by using the buffer solution; analyzing the property specificity of the target cell component and a non-target cell component corresponding to the single-cell suspension, determining a fluorescent marker of the target cell component, mixing the fluorescent marker and the single-cell suspension, constructing a cell scatter diagram of the marked cell suspension, and determining gating parameters of the cell scatter diagram; calculating the cell proportion and the average cell fluorescence intensity of the to-be-screened cell population, determining sorting parameters of the labeled cell suspension, and performing cell sorting on the to-be-screened cell population by using a preset flow cytometer to obtain a target cell population. The cell component screening efficiency can be improved.

The present invention discloses a multicolor fluorescence analysis method for pollutants in food based on artificial ribozymes, which belongs to the field of molecular biological detection. The present invention uses gold nanoparticles as carriers to synthesize AuNPs-DNA-antibody detection probes, antibodies are used to capture targets, and primer DNA is used to amplify signals. Under optimal conditions, the method of the present invention achieves the detection of CAP, 17β-E 2 and AFM 1 The detection ranges were 0.333ng / mL-3.333μg / mL, 3.333ng / mL-3.333μg / mL, 3.333fg / mL-3.333ng / mL, and the limits of quantification were 0.333ng / mL, 3.333ng / mL, and 3.333fg / mL, respectively. The detection accuracy, sensitivity, and stability of the present invention are high. Compared with the prior art, the method established by the present invention does not require the addition of additional nuclease during the detection process, thereby reducing the reaction cost.

This invention discloses a recombinant protein of Coxsackievirus B3 type 3C protease, a polyclonal antibody, and their preparation method and applications. Based on the CVB3 genome sequence, full-length primers were designed, and the 3C fragment was obtained by PCR amplification. The pET28a-3C recombinant expression vector was constructed, transformed into competent bacteria, and induced to express by IPTG. The CVB3 3C protease recombinant protein was then purified. Using this recombinant protein as an immunogen, it was emulsified with Freund's adjuvant and used to immunize animals. After multiple immunizations, serum was collected to obtain the CVB3 3C protein polyclonal antibody. The prepared polyclonal antibody exhibits high specificity, specifically recognizing the 3C protein band at 28 kDa. It can be widely applied in detection methods such as Western blot, immunofluorescence, and immunoprecipitation for the expression analysis, intracellular localization study, and screening of interacting proteins of the 3C protein during CVB3 infection.

The invention discloses a protein affinity purification method based on non-natural amino acid, which is applied to the field of protein affinity purification, and comprises the following steps: selecting proper non-natural amino acid and sites, optimizing codons, constructing a gene vector and transforming cells, optimizing cell culture conditions, and formulating a proper inducible expression strategy. The expression process is monitored in real time, the specific affinity ligand is prepared, the combination, washing and elution conditions are optimized, and the target protein is captured. The non-natural amino acid is introduced into the target protein at a fixed point through genetic engineering, for example, the non-natural amino acid with an azido group is introduced, integration of the specific non-natural amino acid in cells has high specificity, and compared with a traditional natural amino acid tag, the possibility of non-specific labeling is greatly reduced, and the application prospect is wide. Therefore, co-purification of impurities in the purification process is reduced.

The embodiment of the present invention discloses a canine distemper virus protein N‑F‑H truncated tandem antigen and its application, which belongs to the field of pet disease detection. The amino acid sequence of the truncated tandem antigen is shown in SEQ ID No. 7; the nucleotide sequence of the truncated tandem antigen is shown in SEQ ID No. 8. According to the existing and predicted three-dimensional structure of the protein, the present invention compares and analyzes the structures of the three antigenic proteins N, F and H of the canine distemper virus, thereby selecting fragments with better stability, and expressing them in series using a eukaryotic insect cell expression system. The canine distemper virus tandem antigen protein has higher sensitivity, better specificity and stronger stability. The Elisa antibody detection kit and antibody fluorescence detection test strip of the canine distemper virus protein N‑F‑H truncated tandem antigen provided by the present invention are used to detect the antibody level of canine distemper virus in canine serum, and have the characteristics of high specificity and good sensitivity.

The application discloses a method for improving the sensitivity of RPA-CRISPR-Cas12a detection and application thereof in one-tube detection of chikungunya virus, and relates to the technical field of biology.The full-length crRNA is reformed to form a truncated crRNA (Truncate crRNA), the non-key region is accurately shortened, the space-time regulation of Cas protein activity is realized, and the truncated crRNA plays a key role in CRISPR molecular detection (such as an RPA-CRISPR-Cas12a system). The method can significantly improve the specificity of RPA-CRISPR-Cas12a detection, effectively avoid cross-reaction, inhibit non-specific early activation, significantly reduce background signals, and provide an optimization strategy for developing a molecular diagnostic technology with higher sensitivity.

The present application relates to the technical field of nanobody, in particular to anti-FcRH5 nanobody and its application. The present application provides a kind of anti-FcRH5 nanobody with high affinity and specificity, which is based on the single domain heavy chain variable region structure of camelid origin, with the advantages of small molecular weight, high stability, strong tissue penetration, easy to be engineered and the like. The nanobody specifically recognizes and binds to the target point highly expressed and stably expressed on the surface of multiple myeloma cells through its complementarity determining region. The nanobody of the present application can be used as a core recognition element to construct a variety of therapeutic or diagnostic tools such as chimeric antigen receptor T cells, bispecific antibodies, antibody drug conjugates or immunodetection probes. The technical scheme can solve the technical problem that there is a lack of high-quality, functionally clear anti-FcRH5 antibody in the prior art. The nanobody of the present application has significant clinical transformation and industrialization advantages, and promotes the treatment of multiple myeloma to multiple target points.

The application belongs to the technical field of biological medicine, and provides a mouse anti-human PRCC monoclonal paired antibody, a hybridoma cell strain and application thereof. The application provides hybridoma cell strains 5F9C2 (CCTCC NO: C2025312) and 15F7B5 (CCTCC NO: C2025341) which respectively secrete antibodies with unique heavy chain / light chain variable regions; the antibodies can be used for immunohistochemical and immunoblotting detection of PRCC alone, and can also be paired to establish a sandwich method system through an enzyme-linked immunosorbent assay. The antibodies provided by the application are high in specificity and sensitivity, and can be used for accurate qualitative and quantitative analysis of PRCC.

The invention discloses a maltol hapten, an antigen, an antibody as well as a preparation method and application thereof, and relates to the maltol hapten, the antigen, the antibody as well as the preparation method thereof and the application of detecting residues of maltol compounds in food. According to the invention, a maltol hapten, a maltol coating antigen and an immunizing antigen are prepared, a maltol monoclonal antibody is prepared, an enzyme-linked immunosorbent assay method for directly detecting maltol compounds in food is constructed, the IC50 of ethyl maltol reaches 5.01 ng / mL, the linear range is 1.47 ng / mL to 16.96 ng / mL, and the IC50 of methyl maltol reaches 4.15 ng / mL; compared with the prior art, the method has the advantages that the detection sensitivity is high, the specificity is high, the detection flux is high and the like, and an immunodetection method is established for rapid and accurate detection of ethyl maltol and methyl maltol.

This invention discloses a semi-quantitative RT-LAMP method and kit for viral nucleic acid detection based on dispensed lyophilized microspheres and a multi-channel microfluidic chip. The method includes: designing two independent LAMP primer sets (P1 and P2) for each of the SARS-CoV-2 Omicron strain N gene, Zika virus NS5 gene, H1N1 influenza virus M1 gene, and H3N2 influenza virus NP gene; preparing two independent types of lyophilized microspheres by independently mixing RT-LAMP premix containing Bst DNA polymerase and other components with LAMP primer mixture and a lyophilization protectant; and using an N-channel microfluidic chip to perform serial dilutions and parallel RT-LAMP amplification of the same sample, determining the concentration of viral nucleic acid in the sample by the positive / negative inflection points of each channel. This invention is simple to operate, requires no equipment such as a real-time PCR instrument, and is suitable for rapid virus detection in various scenarios.