62 results about "Hypotype" patented technology

The invention belongs to the technical field of biology, and particularly relates to a group of paired monoclonal antibodies for resisting H9N2 subtype avian influenza viruses and a surface enhanced Raman spectroscopy rapid detection test strip established based on the antibodies. The paired monoclonal antibody comprises a labeled antibody 1E9 and a capture antibody 3C10 which are prepared by taking hemagglutinin protein of the H9N2 subtype avian influenza virus as antigens and can be specifically combined with the H9N2 subtype avian influenza virus. According to the invention, an SERS (Surface Enhanced Raman Scattering) probe Au-coated Pt-4ATP is used as a marker and is coupled with a labeled antibody 1E9 to prepare a labeled probe, and the labeled probe is paired with a capture antibody 3C10 to establish an SERS immunochromatography test strip. The test strip has a colorimetric and Raman dual interpretation mode, can be used for qualitative and quantitative detection, has the advantages of strong specificity, high sensitivity, good repeatability and stability and the like, is simple and rapid in clinical detection operation, and provides reliable technical support for on-site rapid screening of subtype viruses.

The invention discloses a multi-subtype influenza A virus nucleic acid detection kit and a detection method, and relates to the technical field of medical detection.The kit comprises a group of reverse transcription RT-RPA amplification primer pairs used for amplifying influenza A virus M gene target sequences, the reverse transcription RT-RPA amplification primer pairs are designed for specific areas of subtypes H1N1, H2N2, H3N2, H5N1 and H7N9, and the reverse transcription RT-RPA amplification primer pairs are designed for specific areas of subtypes H1N1, H2N2, H3N2, H5N1 and H7N9; the crRNA library comprises a plurality of crRNA molecules which are respectively complementary with different conserved regions in the M gene target sequence and is used for guiding Cas12a protein to carry out specific recognition; a Cas12a protein reagent; the reporter molecule can be subjected to non-specific cleavage by the Cas12a protein; the enzyme preparation, the buffer solution and the nucleotide substrate are required by RT-RPA reaction. The invention aims to realize synchronous, rapid, high-sensitivity and high-specificity detection of various subtype influenza A viruses.

The invention discloses RT-qPCR-HRM (real-time quantitative polymerase chain reaction-high-resolution melting) detection primers and a detection method for identifying five different subtype avian influenza viruses, and belongs to the technical field of biology. The invention discloses an RT-qPCR-HRM detection method for identifying five different subtypes of avian influenza viruses, which comprises the following steps: designing a specific primer based on a highly conserved region of an AIV M gene, and simultaneously carrying out genetic typing on five subtypes of AIV strains H3, H5, H6, H7 and H9 in combination with an HRM technology; by comparing melting curve characteristics of M gene segments of different subtypes of AIV, an AIV detection method with good sensitivity and specificity is established. According to the method, the five AIVs of H3, H5, H6, H7 and H9 can be accurately typed, the defect of missing detection of a traditional AIV detection method is overcome, and the method has a wide application prospect.

The invention relates to construction and application of H7 subtype and H5 and H7 tetravalent avian influenza DNA vaccines. The invention belongs to the field of molecular biology, and aims to provide a DNA (deoxyribonucleic acid) vaccine for providing efficient immune protection for H7 subtype avian influenza virus. Specifically, the invention discloses an H7 subtype avian influenza virus hemagglutinin protein, which has an amino acid sequence as shown in SEQ ID NO: 5 and / or SEQ ID NO: 6. The invention also discloses polynucleotide for coding the protein, and the polynucleotide has a sequence as shown in SEQ ID NO: 1 and / or SEQ ID NO: 2. The polynucleotide can be used for preparing a vaccine aiming at the current epidemic H7 subtype avian influenza virus. The H5 + H7 tetravalent DNA vaccine is obtained by combining the vaccine with a vaccine aiming at the H5 subtype, and the H5 + H7 tetravalent DNA vaccine can be used for prevention and control of current H5 subtype and H7 subtype avian influenza.

The application discloses a recombinant nanobody against swine influenza virus of H1N1 subtype, and a preparation method and application thereof, and belongs to the field of biological medicines. A VHH sequence of the nanobody against swine influenza virus of H1N1 subtype is screened from a nanobody bacterial library of an immunized llama, the VHH sequence is directionally cloned into a pPIC9K vector to construct a recombinant eukaryotic expression plasmid, and the recombinant eukaryotic expression plasmid is transformed into a Pichia pastoris expression system to screen an expression engineering strain, and the recombinant nanobody is obtained after induction culture of the expression engineering strain. It is proved by in-vitro and in-vivo experiments that the recombinant nanobody developed in the application can neutralize CA / 04 and has a remarkable therapeutic effect. Therefore, the neutralizing nanobody provided in the application has considerable potential in treating CA / 04. The findings will provide experimental data for developing nanobody preparations against swine influenza virus of H1 subtype and provide a new strategy for preventing and controlling swine influenza.

The invention relates to the technical field of molecular biology. The invention provides a primer probe combination for detecting an H10 subtype avian influenza virus, the primer probe combination comprises a primer pair and a probe for detecting the H10 subtype avian influenza virus, and the primer pair for detecting the H10 subtype avian influenza virus comprises an H10-F sequence as shown in SEQ ID NO.1 and an H10-R sequence as shown in SEQ ID NO.2; and the probe for detecting the H10 subtype avian influenza virus is an H10-P sequence as shown in SEQ ID NO.3. The invention further discloses a kit for detecting the H10 subtype avian influenza virus. The primer probe combination disclosed by the invention can be used for detecting and distinguishing epidemic H10 viruses of European subpedigree and North American pedigree, does not generate cross reaction with other common viruses, and is high in detection sensitivity, and the minimum detectable quantity is 5 copies.

The application discloses a chicken Newcastle disease, avian influenza and chicken infectious rhinitis triple inactivated vaccine and preparation and application thereof, and relates to the technical field of bioengineering. The application discloses a preparation method and application of a chicken Newcastle disease, avian influenza and chicken infectious rhinitis (A, B and C three serotypes) subunit protein triple inactivated vaccine. The preparation method comprises the following steps: constructing and expressing a serum B paracolon avian bacillus subunit protein expression strain; and preparing the chicken Newcastle disease, H9 subtype avian influenza and chicken infectious rhinitis (A, B and C three serotypes) subunit protein triple inactivated vaccine at a certain ratio. The triple inactivated vaccine has good safety, can be used for the prevention of chicken Newcastle disease, H9 subtype avian influenza and A, B and C three serotypes paracolon avian bacillus diseases in a laying hen group, and does not cause the decrease of the laying rate after immunization. Meanwhile, the paracolon avian bacillus subunit protein can improve the antibody level of the Newcastle disease and the H9 avian influenza, and the protection of the vaccine on the A, B and C three serotypes paracolon avian bacillus can reach 100%.

The application discloses a kind of avian influenza and avian infectious bronchitis two-union recombinant subunit vaccine and its preparation method and application.The recombinant protein is by replacing the head domain of AIV HA protein with the RBD domain of IBV S protein, while adding GCN4, Trimer-tag trimer tag in sequence, the recombinant protein obtained, the recombinant protein is expressed in vitro using insect cells and prepared into subunit vaccine.The vaccine prepared by the application can produce high-level neutralizing antibodies against homologous and heterologous H9N2 subtype avian influenza virus after immunizing chicken population, while significantly reducing the virus discharge level and the histopathological changes caused, and can also induce high-level specific antibodies and neutralizing antibodies against QX subtype avian infectious bronchitis virus, effectively inhibit discharge, viral load, and reduce tissue lesions.The application does not depend on chicken embryo, and has low production cost and short cycle, and can simultaneously prevent avian influenza and avian infectious bronchitis.

The invention discloses a composite insecticide targeting aedes aegypti PGRP gene and application thereof, the insecticide is a preparation taking double-stranded RNA of a key PGRP gene as an effective component, and the double-stranded RNA comprises a gene aiming at PGRP-LB subtype and coding dsPGRP-LB and a gene aiming at PGRP-SC2 subtype and coding dsPGRP-SC2; wherein the nucleotide sequence of a front primer of the gene for coding the dsPGRP-LB is as shown in SEQ ID NO. 1; the nucleotide sequence of a rear primer for coding the gene dsPGRP-LB is as shown in SEQ ID NO. 2; the nucleotide sequence of a front primer for coding the gene dsPGRP-SC2 is as shown in SEQ ID NO. 3; and the nucleotide sequence of a rear primer of the gene for coding the dsPGRP-SC2 is as shown in SEQ ID NO. 4. According to the invention, the target specificity is strong, non-target biological interference is avoided, the insecticidal efficiency is obviously improved, the synergistic increasing agent has good suitability, mistaken killing of beneficial organisms in an ecological system is avoided, and accurate mosquito control is realized.

This invention provides a microfluidic chip for the multiplex differentiation and diagnosis of different avian influenza virus subtypes and its application. Specifically, it is a microfluidic chip based on TaqMan probes that can simultaneously and rapidly differentiate and diagnose 25 avian influenza subtypes, enabling high-throughput simultaneous detection of multiple gene targets. This invention utilizes high-throughput microfluidic chip technology to simplify the differential diagnosis procedure for avian influenza virus subtypes, resulting in more accurate and time-saving results. It is more suitable for rapid clinical diagnosis of avian influenza, providing technical support for rapid clinical detection, diagnosis, and prevention of avian influenza, and is of great significance for epidemic prevention and control and safeguarding public health security.

The invention relates to a multi-antigen component PEI lipid delivery system and an anti-avian influenza virus multivalent vaccine comprising the same, belongs to the technical field of biological medicines, and provides a delivery system consisting of PEI, squalene, cholesterol and mPEG. The preparation method comprises the following steps of: constructing mRNA (messenger ribonucleic acid) molecules and a composite vaccine antigen system consisting of prokaryotic expression purified H7N9 avian influenza NP antigen, loading the composite vaccine antigen system into a delivery system to obtain the nanoparticles with a virus-like structure, and displaying the HA protein antigen and the NP antigen in the structure of the nanoparticles in a particle form by the nanoparticles, so that the nanoparticles can be used for preparing the H7N9 avian influenza NP / H7N9 avian influenza NP / H7N9 avian influenza NP / H7N9 avian influenza virus. And the mRNA molecule for coding the NA antigen, which is combined with the mRNA molecule, can be delivered into a cell in a manner of fusing lipid and a cell membrane, so that the mRNA molecule can be effectively expressed to induce a body to generate specific antibody reactions aiming at HA, NA and NP, and the body can also generate specific CTL reactions aiming at HA, NA and NP of different influenza virus strain subtypes.

The invention discloses an RT-RAA-CRISPR / Cas13a visual detection kit for on-site rapid detection of a swine influenza virus and an application of the RT-RAA-CRISPR / Cas13a visual detection kit. The kit comprises a set of universal molecular detection composition for broad-spectrum detection of different subtype swine influenza viruses, the composition comprises a specific primer pair used for RT-RAA system amplification, a specific crRNA used for CRISPR / Cas13a system targeted recognition, and an RNA report probe used for carrying out amplification and visual output on a target recognition signal. Based on the sequence conservative property of each subtype M gene of the swine influenza virus, the kit can realize the broad-spectrum visual detection of the swine influenza virus on site. The method has the advantages of short detection time, simple operation, strong specificity and high sensitivity, and is expected to provide a new visual detection means for on-site rapid screening of swine influenza viruses.

The invention belongs to the technical field of nano-antibodies, and particularly relates to a nano-antibody for resisting H1N1 influenza virus NA protein as well as a preparation method and application of the nano-antibody. The method comprises the following steps: by taking A / Puerto Rick / 8 / 34 (H1N1) influenza virus as a research object, purifying and inactivating the influenza virus through sucrose density gradient centrifugation, immunizing alpaca by taking the influenza virus as an immunogen, and screening by utilizing a phage display technology to obtain a high-affinity spectral anti-avian influenza virus NA protein nano antibody. Animal experiments show that the nano antibody has a good prevention effect when acting on A / Puerto Radio / 8 / 34 (H1N1) influenza virus infected C57 mice. Through preparation of the anti-influenza virus NA protein nano antibody, not only is a material provided for development of an H1N1 influenza virus diagnostic reagent, but also a thought is provided for identification of H1N1 subtype influenza virus epitope and vaccine design.

The invention relates to the field of genetic engineering and biological medicine, in particular to an influenza A virus mutant strain and application thereof in preparation of vaccines, and the influenza A virus mutant strain is obtained by mutation of acetylation modification sites on hemagglutinin protein of influenza A H1N1 subtype viruses. The influenza A virus mutant strain can reduce the pathogenicity of the virus to mice without reducing the antigenicity of the virus, so that the pathogenicity of the virus to the mice through intrapulmonary inoculation is remarkably reduced, meanwhile, pathological changes of virus infection are not generated, but complete challenge protection can be provided for the mice, and therefore, the influenza A virus mutant strain can be used for preparing vaccines.

The invention provides a method for detecting H3, H9 and H10 subtype avian influenza viruses through multiple real-time RT-PCR (Reverse Transcription-Polymerase Chain Reaction), and belongs to the technical field of molecular medicines. The primer group, the probe group, the kit and the like are provided, so that one-stop synchronous detection and accurate typing of avian influenza virus subtypes H3, H9 and H10 can be realized, and the detection efficiency is remarkably improved. The method has excellent specificity, can effectively avoid misjudgment, has extremely high detection sensitivity, can find virus traces in the early stage of infection, and strives for precious time for epidemic situation early warning. The method is convenient to operate, stable and reliable in result and easy to popularize and use, provides powerful technical support for daily monitoring and epidemiological investigation of the low-pathogenicity avian influenza in livestock and poultry farms, and has important practical application value for guaranteeing safe production of the breeding industry and preventing public health risks.

The present invention relates, in particular, to an immunogenic composition for use in the treatment or prevention of infection by influenza virus. The immunogenic composition comprises (a) a first nucleic acid encoding the hemagglutinin (HA) antigen of a strain of a first subtype of influenza A virus, (b) a second nucleic acid encoding the HA antigen of a strain of a second subtype of influenza A virus, (c) a third nucleic acid encoding the HA antigen of a first strain of influenza B virus, and (d) a fourth nucleic acid, optionally included, encoding the HA antigen of a second strain of influenza B virus, wherein the immune response is induced against the aforementioned strains of the first and second subtypes of influenza A virus, the aforementioned first strain and optionally included second strain of influenza B virus, and the HA antigen of at least one further HA antigen subtype of influenza A virus (different from any of the HA antigen subtypes of influenza A virus encoded by the nucleic acids present in the composition). [No selection diagram available]

The application belongs to the field of biology, and discloses a method for high-throughput screening of viral CTL epitopes based on immunopeptidomics, which comprises the following steps: transfecting mammalian cells with eukaryotic expression plasmids having MHC I molecules in series with the alpha chain and the beta2m chain to establish a mammalian cell line expressing animal MHC I molecules; using a virus to infect the mammalian cell line expressing MHC I molecules to prepare MHC I-peptide complexes; and obtaining antigen peptides existing in the MHC I-peptide complexes. The method takes chicken MHC I allele BF2*1901 molecules as the research object, takes H9N2 subtype avian influenza virus as the model virus, comprehensively characterizes chicken MHC I restricted H9N2 antigen peptide groups, and identifies immunodominant CTL epitope immunity, and is suitable for CTL epitope screening of different chicken MHC I molecules and different subtypes of avian influenza viruses, provides a fast, efficient and economical technical means for studying the specific binding of chicken MHC I molecules and antigen peptides, provides a favorable reference for T cell epitope screening of major animal pathogens, and provides a scientific basis for poultry disease-resistant breeding, development of new vaccines and immune evaluation strategies. Meanwhile, the application also discloses restricted epitope peptides, nucleic acid molecules and applications.

The invention relates to the technical field of protein detection, and particularly provides a double-antibody sandwich ELISA kit for detecting H5 subtype avian influenza virus M1 protein. The inactivated H5 subtype avian influenza virus subjected to sucrose density gradient centrifugal concentration and purification is used as an immunogen to immunize a BALB / c mouse, the H5 subtype avian influenza virus M1 protein is used for screening to obtain a detection antibody, and the detection antibody is prepared after an SPF chicken is immunized. On the basis, a double-antibody sandwich ELISA kit for detecting the H5 subtype avian influenza virus M1 protein is researched and developed. The technology can be used for quantitative detection of H5 subtype avian influenza M1 protein and quality control of avian influenza subunit products, and ensures stable product quality; and the method can also be used for detecting the expression characteristics of the recombinant avian influenza baculovirus seed protein.

The invention discloses a two-component biosensor and application thereof. The two-component biosensor comprises a first biosensor and a second biosensor, the first biosensor is a fusion protein of a head antibody targeting influenza virus HA protein and a small subunit of nano luciferase, and the second biosensor is a fusion protein of a head antibody targeting influenza virus HA protein and a small subunit of nano luciferase. The second biosensor is a fusion protein of a stem antibody targeting influenza virus HA protein and a large subunit of nano luciferase; or the first biosensor is the fusion protein of the head antibody of the targeted influenza virus HA protein and the large subunit of the nano luciferase, and the second biosensor is the fusion protein of the stem antibody of the targeted influenza virus HA protein and the small subunit of the nano luciferase. Based on the two-component bioengineering sensor, rapid detection of influenza viruses, especially detection of H5 / H7 subtype influenza viruses, can be realized.

The invention belongs to the technical field of genetic engineering of animal molecular breeding, and particularly relates to application of a scavenger receptor SCARA3 in resisting H9N2 subtype avian influenza virus (AIV) infection. The invention discovers that the expression quantity of the SCARA3 gene in the DF-1 cell infected by the H9N2 AIV is obviously reduced. The silent SCARA3 can significantly inhibit the replication of the H9N2 avian influenza virus in host cells, which indicates that the SCARA3 gene is a susceptible gene of the H9N2 AIV, and the gene knockdown / knockout can significantly improve the resistance of chicken to the H9N2 AIV. The SCARA3 gene provided by the invention can be used as a target spot for resisting replication of the H9N2 subtype avian influenza virus, can be used as a disease-resistant molecular marker, is used for carrying out assistant breeding on new varieties resisting infection of the H9N2 subtype avian influenza virus, and has important application value in genetic assistant disease-resistant breeding.

The invention belongs to the technical field of quadruple vaccine research and development, and particularly relates to a preparation method of a chicken new flow glandular synovial quadruple vaccine, which comprises the following steps: step one, strain selection: selecting a Newcastle disease LaSota strain, an avian influenza H9 subtype NJ02 strain, a chicken glandular FADV-4 strain and a chicken synovial sac HN01 strain; the selected Newcastle disease strain, the selected avian influenza strain, the selected chicken gland strain and the selected chicken synovial sac strain are inoculated in different culture solutions for culture amplification, the culture environment is controlled to be about 37 DEG C (the temperature before and after the culture is not larger than 0.5 DEG C), and the strain culture time is controlled to be 2-4 days. By selecting the Newcastle disease LaSota strain, the avian influenza H9 subtype NJ02 strain, the chicken gland FADV-4 strain and the chicken synovial sac HN01 strain, the subsequent quadruple vaccine prevention effect can be guaranteed, sufficient quadruple vaccine raw materials can be provided through strain culture, and the production efficiency is guaranteed.

The invention belongs to the technical field of medicinal chemistry, and particularly relates to application of PHA-767491 or pharmaceutically acceptable salt thereof as an H3N2 subtype swine influenza virus replication inhibitor. In-vitro cell experiments show that the GPCR small molecule compound PHA-767491 has a remarkable inhibition effect on the H3N2 subtype swine influenza virus, the median inhibitory concentration (IC50) of the GPCR small molecule compound is 6.07 M, and the median cytotoxic concentration (CC50) of the GPCR small molecule compound is greater than 200M. The inhibition rate exceeds 97% when the drug is administered when the H3N2 subtype swine influenza virus is infected and after the H3N2 subtype swine influenza virus is infected. The results show that the PHA-767491 can be used as a new drug for the H3N2 subtype swine influenza virus replication inhibitor, and the PHA-767491 is high in inhibition activity, high in safety to normal cells, easy to popularize and wide in application prospect.

The invention discloses a multiplex fluorescence quantitative detection method for simultaneously detecting four influenza A virus subtypes, a primer composition used by the multiplex fluorescence quantitative detection method and application of the primer composition. The invention belongs to the technical field of biological detection, and particularly relates to a multiplex fluorescent quantitative detection method for simultaneously detecting four influenza A virus subtypes, a primer composition used by the multiplex fluorescent quantitative detection method and application of the primer composition. The primer composition for detecting the four influenza A virus subtypes is composed of a primer probe group A, a primer probe group B, a primer probe group C and a primer probe group D, and the specific nucleotide sequences are sequence 1-sequence 12. The primer probe composition has the advantages of being high in specificity, sensitivity, repeatability and reproducibility, easy to operate and the like, the detection speed can be increased, the detection cost can be saved, and high application value is provided for influenza A virus screening and clinical disease diagnosis.

The application belongs to the technical field of biological detection, and particularly relates to a combination of monoclonal antibodies against hemagglutinin protein of avian influenza virus H9 subtype and application thereof. The combination comprises monoclonal antibodies 5E2 and 1F3, the CDR sequences of the heavy chain and light chain variable regions of which are clear, and are shown as SEQ ID NO. 1-12 respectively, ensuring high affinity and specific recognition of H9-HA protein. The antibody combination is suitable for constructing a colloidal gold immunochromatographic detection test strip, wherein 5E2 is used as a capture antibody for membrane drawing, and 1F3 is used as a labeled antibody for gold labeling. The technical scheme effectively solves the problem of cross-reaction with other HA subtypes (such as H5 and H7) caused by poor antibody specificity of the existing detection means. The sensitivity of the test strip to H9-HA recombinant protein can reach 1 ng / mL, and there is no cross-reaction, so the test strip is suitable for on-site rapid screening and large-scale monitoring of avian influenza virus H9 subtype.

The present application relates to construction and application of H7 subtype and H5 and H7 tetravalent avian influenza DNA vaccine. The present application belongs to the field of molecular biology, and aims to provide a DNA vaccine for providing efficient immunoprotection against H7 subtype avian influenza virus. Specifically, the present application discloses a hemagglutinin protein of H7 subtype avian influenza virus, which has an amino acid sequence as shown in SEQ ID NO: 5 and / or SEQ ID NO: 6. The present application also discloses a polynucleotide encoding the protein, which has a sequence as shown in SEQ ID NO: 1 and / or SEQ ID NO: 2. The polynucleotide can be used for preparing a vaccine against currently prevalent H7 subtype avian influenza virus. The present application also combines the vaccine with a vaccine against H5 subtype to obtain an H5+H7 tetravalent DNA vaccine, which can be used for prevention and control of current H5 subtype and H7 subtype avian influenza.

The invention discloses a primer probe composition for detecting AIV, NDV virulent strains and IBV, a kit and application, and belongs to the technical field of fluorescence detection. The sequence of the primer probe combination is shown as SEQ ID NO.1-SEQ ID NO.9, the primer probe combination comprises a primer pair and a probe for detecting the avian influenza virus, the Newcastle disease virus virulent strain and the avian infectious bronchitis virus, and the primer probe combination can be used for detecting and distinguishing all subtypes of the avian influenza virus and the Newcastle disease virus virulent strain and different genotypes of the avian infectious bronchitis viruses. The kit is high in specificity and sensitivity, does not have cross reaction with other common viruses, and is high in detection sensitivity, and the minimum detectable quantity of the three viruses is 0.8 copy, so that the specific, sensitive and rapid detection of AIV, NDV and IBV can be realized, and the defects of the conventional detection technology are overcome. The method has important practical significance on timely blocking epidemic situation propagation, reducing breeding loss, guaranteeing public health safety and the like.

This invention belongs to the field of biodetection technology, specifically relating to a monoclonal antibody combination that specifically recognizes the hemagglutinin protein of the H6 subtype of avian influenza virus and its applications. The antibody combination consists of monoclonal antibodies 2D12 and 4G3, targeting different epitopes of the H6 hemagglutinin protein, and possesses clearly defined heavy and light chain variable region complementarity-determining region sequences, as shown in SEQ ID NO. 1-12, respectively. The antibody combination exhibits high specificity and affinity, effectively avoiding cross-reactivity with other influenza subtypes such as H1, H5, H7, and H9, as well as common avian pathogens. The colloidal gold test strip constructed based on this antibody combination is highly sensitive and easy to operate, suitable for in vitro detection and epidemiological screening of the H6 subtype of avian influenza virus. It solves the false positive problem caused by cross-reactivity in existing technologies, providing a reliable technical means for the monitoring and quarantine of the H6 subtype of virus.

The invention belongs to the technical field of biological detection, and particularly relates to a monoclonal antibody for resisting avian influenza virus H7 subtype hemagglutinin protein and application. The amino acid sequence of a heavy chain variable region CDR of the monoclonal antibody 1F4 is shown as SEQ ID NO.1-3, the amino acid sequence of a light chain variable region CDR of the monoclonal antibody 1F4 is shown as SEQ ID NO.4-6, and the heavy chain variable region, the light chain variable region and coding nucleotide sequences of the monoclonal antibody 1F4 are clear. The monoclonal antibody has high specificity and good affinity, can effectively distinguish the H7 subtype from other influenza virus subtypes, and has no cross reaction. The invention also provides application of the colloidal gold test strip in preparation of a recognition tool, the constructed colloidal gold test strip takes 1F4 as a capturing and labeling antibody, is simple and convenient to operate, visual in result and suitable for on-site rapid screening and large-scale monitoring, and provides technical support for prevention and control of H7 subtype avian influenza.

The invention discloses an avian influenza and avian infectious bronchitis bigeminy recombinant subunit vaccine as well as a preparation method and application thereof. The recombinant protein is obtained by replacing a head structural domain of an AIV HA protein with an RBD structural domain of an IBV S protein and adding GCN4 and Trimer-tag trimer tags into a sequence, and the recombinant protein is expressed in vitro by using insect cells and is prepared into a subunit vaccine. After chicken flocks are immunized by the prepared vaccine, high-level neutralizing antibodies aiming at homologous and heterologous H9N2 subtype avian influenza viruses can be generated, meanwhile, the detoxification level of the viruses and caused tissue pathological changes are remarkably reduced, and high-level specific antibodies and neutralizing antibodies aiming at QX subtype avian infectious bronchitis viruses can also be induced; toxin expelling and virus load are effectively inhibited, and tissue lesion is relieved. The method does not depend on chick embryos, is low in production cost and short in period, and can prevent avian influenza and avian infectious bronchitis at the same time.