668 results about "Streptavidin" patented technology

The invention provides a nucleic acid aptamer for specific recognition of morphine and application of the nucleic acid aptamer, and belongs to the technical field of biosensing and detection. The nucleotide sequence of the nucleic acid aptamer is as shown in SEQ ID NO: 1. The screening method is based on a Capture-SELEX technology and comprises the key steps that streptavidin magnetic beads are used for fixing an ssDNA library, estradiol, deabietic acid and totarol are introduced to serve as reverse screening substances so as to remove non-specific sequences, and finally the high-specificity aptamer is obtained through high-throughput sequencing and affinity determination. The dissociation constant of the aptamer and morphine is 127.31 nM, and the aptamer shows high affinity and high specificity. The invention further relates to application of the aptamer in preparation of a sensor and a kit for detecting morphine, and a new technical means is provided for rapid detection of morphine.

The invention discloses a magnetic particle chemiluminescence protein detection method, which comprises the following steps: (1) combining surface modified magnetic particles with a chicken anti-mouse IgY antibody to prepare an R1 compound; (2) combining the chicken anti-mouse IgY antibody coated with the magnetic beads with a target mouse anti-human IgG antibody to prepare an R2 compound; (3) combining the Protein A subjected to streptavidin treatment with the alkaline phosphatase subjected to biotinylation to form a biotin-avidin compound, and preparing an R3 compound; and (4) combining the R3 compound with a target mouse anti-human IgG antibody to prepare an R4 compound. According to the present invention, the immunocompetence of the coating antibody and the detection antibody is prevented from being damaged during the coupling process, the coating antibody and the detection antibody directly participate in the immunoreaction, and the biotin-avidin system is introduced, such that the detection sensitivity is substantially improved, and the kit is suitable for the in vitro detection of the low-abundance disease markers such as the early diagnosis of the Alzheimer's disease or the cytokine storm.

The invention relates to the technical field of in-vitro diagnostic reagent chemiluminescence detection, in particular to a Christmas liquefied carbohydrate chain antigen chemiluminescence detection kit and a preparation method thereof. The chemiluminescence detection kit comprises the following components: a KL-6 calibrator, an amino magnetic bead coupled KL-6 monoclonal antibody, an alkaline phosphatase labeled KL-6 monoclonal antibody, an AMPPD rapid chemiluminescence substrate solution and a cleaning solution, and the chemiluminescence detection kit prepared from the components is simple in detection process, easy to operate, high in automation degree and high in detection sensitivity. The kit is high in sensitivity, good in specificity and good in stability, a result can be automatically obtained within 12.5 min, the requirement for clinical auxiliary diagnosis of interstitial lung diseases can be met, and the problem that in the prior art, a chemiluminescence detection kit prepared by adopting an acridinium ester magnetic particle chemiluminescence immunoassay method or a biotin-streptavidin detection system is poor in specificity and high in sensitivity is solved. The technical problems of low marking efficiency, high manufacturing cost and poor detection result reliability in the prior art are solved.

The invention relates to a method for improving chemiluminescence immunoassay sensitivity of magnetic particles, a detection kit and application thereof, firstly, magnetic beads are coupled with an antibody, then magnetic beads are sealed to obtain a magnetic bead coated antibody, sealing comprises pre-sealing and second-step sealing, glycine and ethanolamine are added in the pre-sealing process, and in the second-step sealing process, glycine and ethanolamine are added in the second-step sealing process. Casein hydrolysate and dodecyl dimethyl amine ethyl lactone are added; then coupling the antibody with alkaline phosphatase or streptavidin to obtain an alkaline phosphatase labeled antibody or a streptavidin labeled antibody; the magnetic bead coated antibody, the alkaline phosphatase labeled antibody or the streptavidin labeled antibody is used for sample detection. The method is high in sensitivity and wide in detection range, is adaptive to a common immunoassay instrument, does not need expensive equipment, and is also simple to operate; in addition, the AMH concentration with extremely low concentration can be accurately detected.

The invention discloses a high-sensitivity cardiac troponin-T electrochemiluminescence detection kit. The kit comprises a magnetic microsphere reagent coated by a high-sensitivity cardiac troponin-T capture antibody and a high-sensitivity cardiac troponin-T detection antibody reagent labeled by an electrically neutral ruthenium compound, the structural general formula of the electrically neutral ruthenium compound is # imgabs0 # n = 0-9; the magnetic microsphere reagent coated with the high-sensitivity cardiac troponin-T capture antibody comprises a magnetic microsphere coated with the high-sensitivity cardiac troponin-T capture antibody and a diluent; the electrically neutral ruthenium compound labeled high-sensitivity cardiac troponin-T detection antibody reagent comprises an electrically neutral ruthenium compound labeled high-sensitivity cardiac troponin-T detection antibody and a diluent; the diluent is prepared from piperazine-1, 4-diethyl sulfonic acid or 3-(N-morpholinyl)-2-hydroxy propanesulfonic acid. When the high-sensitivity cardiac troponin-T electrochemiluminescence detection kit is used for detection, a reaction system does not contain streptavidin coated magnetic beads or biotinylated antibodies, so that interference of biotin in a sample is avoided.

The invention provides an immunodetection method of a multi-index immune checkpoint detection kit, which belongs to the technical field of immunodetection and comprises three main stages of sample preparation, immune reaction and data analysis. The method comprises the following steps: firstly, carrying out centrifugal separation to obtain a plasma sample, and preparing a fluorescent microsphere coupled capture antibody and biotin labeled detection antibody compound; then carrying out immune reaction, forming a sandwich type immune complex through specific binding, and adding streptavidin marked by phycoerythrin for signal amplification. Detecting a fluorescence signal by adopting a flow cytometer to obtain an original data matrix; a contribution feature vector, a utility feature vector and an expression feature matrix are extracted through a feature decomposition algorithm, and a deep learning model of a total-score-total structure is established for data analysis. Finally, a detection report containing a quantitative result, an importance score and reliability evaluation is generated, and the technical problem that in the prior art, the analysis accuracy of a multi-index immune checkpoint detection result is insufficient is solved.

The invention belongs to the field of immunological detection, and provides a double-antibody sandwich ELISA kit for detecting the content of human beta-NGF. The enzyme-linked immunosorbent assay kit constructed by the invention is based on a double-antibody sandwich method, and is combined with a biotin-streptavidin signal amplification system and an enzyme developing amplification system, so that the detection sensitivity and specificity are greatly improved, and low-content samples can be accurately and quickly detected. The kit shows excellent stability and specificity and can be used for quantitatively detecting the content of beta-NGF in samples such as human serum, cell supernatant or tissue homogenate, so that an objective detection basis is provided for diagnosis, curative effect evaluation and pathogenesis research of related diseases.

The invention discloses a method for screening a non-natural nucleic acid aptamer of targeted thrombin based on streptavidin magnetic beads and application, and belongs to the technical field of biology. According to the method, an initial screening library is efficiently constructed through a primer extension technology, and a chemical modification SELEX technical process is simplified; a streptavidin magnetic bead separation technology is introduced, so that the screening specificity and efficiency are improved, the screening period is remarkably shortened, and the cost is reduced; by selecting non-natural nucleic acid modification sites and adopting a strategy of combining reverse screening and forward screening, high specificity and affinity of the aptamer are ensured, and limitation of an existing screening method is overcome; the screened non-natural nucleic acid aptamer shows high affinity and excellent stability, the aptamer with a specific structure and function is successfully obtained by optimizing the proportion of nucleoside triphosphate monomers and extension reaction conditions, and a wide application prospect is provided for the fields of drug development, biosensor preparation and the like. A new path is opened up for research and application of the nucleic acid aptamer.

The invention relates to a nano-drug delivery system targeting neutrophil and a preparation method and application thereof. The nano-drug delivery system is prepared by the following method: S1, preparing a liposome 1 wrapping a drug 1; s2, preparing a liposome 2 wrapping a medicine 2; and S3, mixing and incubating the liposome 1 wrapping the medicine 1 and the liposome 2 wrapping the medicine 2, and connecting the corresponding ligand and receptor in the liposome 1 and the liposome 2 to obtain the liposome. The ligand and the receptor are respectively biotin and streptavidin. The nano-drug delivery system is obtained by successfully connecting two drug liposomes with different functions through a ligand and a receptor system, so that the chemotaxis of neutrophil to an infected part can be enhanced, the antibacterial property of NETs can be improved, and the nano-drug delivery system has a very good anti-infection effect.

The invention discloses a preparation method of Fe3O4 magnetic nanoparticles rich in carboxyl groups on the surface, which comprises the following steps: modifying Fe3O4 nanoparticles by using polyethylene glycol and silicon dioxide to enhance the dispersity and biocompatibility of the magnetic nanoparticles, modifying the surfaces of PEG-Fe3O4 coated SiO2 nanoparticles by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface, and modifying the magnetic nanoparticles rich in carboxyl groups on the surface by using a silane coupling agent containing silane groups and unsaturated double bonds to obtain the magnetic nanoparticles rich in carboxyl groups on the surface. Then octavinyl-POSS and double bonds on the surfaces of the nano particles are subjected to click modification to form an octahedral cage, 4-mercaptobenzoic acid and double bonds are further subjected to click modification, the surfaces of the nano particles are rich in carboxyl, and a polymer brush rich in carboxyl is constructed. Compared with a conventional streptavidin coupling method, a high-density polymer chain provides a large number of carboxyl active binding sites, so that the streptavidin coupling amount is increased, the antibody coupling rate is increased, and a solution is provided for applications such as high-sensitivity biological detection, efficient targeted drug delivery and stable immunoassay.

The invention relates to a second antibody for resisting mouse IgG and rabbit IgG as well as a preparation method and application of the second antibody. The second antibody of the anti-mouse IgG and the rabbit IgG sequentially comprises an anti-mouse IgG nano antibody, a biotin fixed-point binding peptide fragment and an anti-rabbit IgG nano antibody from an amino terminal to a carboxyl terminal. According to the design of the second antibody of the anti-mouse IgG and rabbit IgG with a brand-new structure and the preparation method, high-efficiency expression is realized, the second antibody of the anti-mouse IgG and rabbit IgG capable of realizing fixed-point biotinylation is obtained, the second antibody can be further subjected to various modification reformation based on a biotin-streptavidin bridge, the preparation method of the second antibody of the polymerase labeled anti-mouse IgG and rabbit IgG is further developed, and the application of the second antibody of the polymerase labeled anti-mouse IgG and rabbit IgG is expanded. According to the method, the polymerase-labeled mouse-rabbit universal secondary antibody with similar affinity to mouse IgG and rabbit IgG is obtained, the preparation period of the secondary antibody can be shortened, the preparation process of the secondary antibody is simplified, the stability between batches is improved, and meanwhile, the dependence on experimental animals is reduced.

The invention discloses a chemiluminescence heparin binding protein kit and a determination method thereof. The kit comprises reagent components of a reagent R1, a reagent R2 and a reagent R3, as well as a matched calibrator, a matched quality control product, a matched pre-excitation liquid, a matched excitation liquid and a matched cleaning liquid, wherein the reagent R1 contains magnetic particles coated with streptavidin, and the reagent R2 and the reagent R3 are respectively monoclonal antibodies which are labeled by acridinium ester and biotin and are used for recognizing different epitopes of human HBP. The kit shows better sensitivity, wider detection range and high specificity, and can effectively reduce potential endogenous and exogenous interference in clinical samples of potential interference people.

The present invention discloses a hs-TnI detection method based on quantum dot microspheres, which directly reacts a sample with a first solution containing antibody 1 and a second solution containing antibody 2 to generate a sandwich structure complex of antibody 1-antigen-antibody 2, and the antigen and antibody react in a reaction cup, incubate at a constant temperature, and the reaction time is longer, and the reaction is more sufficient, which is conducive to the improvement of detection sensitivity. At the same time, during chromatography, with the high affinity of streptavidin and biotin, the complex obtained by the reaction can be better captured on the T line, so that the reaction can be made more sensitive, and the detection time is also faster relative to the existing reagent strips. Further, combined with the advantages of high sensitivity and wide linear range of quantum dot microspheres, detection repeatability (CV) is better, CV is increased from the traditional 15wt% to within 8wt%, and the detection sensitivity is as high as 2pg / ml, while the linear range is 2-30000pg / ml, and full coverage is achieved for low-concentration and high-concentration samples.

The invention discloses a light-activated chemiluminescence immunodetection method for rapidly quantifying C-reactive protein (CRP), and belongs to the technical field of marker detection. Comprising a luminous microsphere-CRP coated antibody complex, a biotin-CRP labeled antibody complex and a streptavidin coated photosensitive microsphere. The light-sensitive microspheres and the light-emitting microspheres are ingeniously combined, and key factors such as coupling efficiency of antibodies on the surfaces of the light-emitting microspheres, reagent dosage, incubation temperature and time and the like are elaborately optimized, so that an optimized light-activated chemiluminescence detection system is constructed. The system not only simplifies the experimental process, but also ensures the reliability and consistency of the detection result by enhancing the stability and specificity of signal transduction. By screening and optimizing conditions of the system, the invention successfully develops a novel CRP (C-reactive protein) light-activated chemiluminescence immunoassay kit, and the detection limit is 6.20 ng.mL <-1 >.

The invention relates to a line elimination method immunochromatography test paper, which is formed by bonding a sample pad, a combination pad, a nitrocellulose membrane and a water absorption pad on a bottom plate in a mutual overlapping manner in sequence, and the nitrocellulose membrane is provided with a C line for contrast and a T line for detection, a colloidal gold compound marked by streptavidin and a colloidal gold compound marked by rabbit IgG (immunoglobulin G) are sprayed on the combination pad; a T line on the nitrocellulose membrane is coated with an FITC labeled antibody, and a C line on the nitrocellulose membrane is coated with anti-IgG. The line elimination method immunochromatography test paper can eliminate lines when the cutting proportion of the probe reaches 50%, so that the detection sensitivity is greatly improved, and the line elimination method immunochromatography test paper can be applied to target gene detection products in a CRISPR (clustered regularly interspaced short palindromic repeats) mode, including genotyping of pathogenic microorganisms, SNP (Single Nucleotide Polymorphism), insertion and deletion, structural variation, methylation modification site detection or drug resistance gene identification.

The invention relates to a kit for detecting granzyme B as well as a preparation method and application of the kit. The kit for detecting granzyme B comprises a magnetic microsphere working solution, a detection antibody and streptavidin labeled phycoerythrin. The invention also provides a preparation method of the kit for detecting granzyme B. The preparation method comprises the following steps: coupling a granzyme B antibody by using a magnetic fluorescence coding microsphere to obtain a granzyme B antibody-coupled magnetic fluorescence coding microsphere; labeling the granzyme B detection antibody with biotin to obtain a detection antibody; the preparation method comprises the following steps: mixing granzyme B antibody coupled magnetic fluorescence coded microspheres, a PBS buffer solution, a stabilizer, a preservative, a surfactant and a blocking agent to obtain a magnetic microsphere working solution, and assembling the magnetic microsphere working solution with a detection antibody and streptavidin labeled phycoerythrin to obtain the kit. The invention also provides a kit for detecting serum granzyme B. The invention solves the problem of poor detection reliability caused by false positive results and cross reaction in the existing serum granzyme B detection method.

The invention provides a transferrin modified targeted lipid nano bubble as well as a preparation method and application thereof, and relates to the technical field of synthesis of ultrasonic medical imaging contrast agents. The transferrin modified targeted lipid nano bubble provided by the invention has a bubble-like structure; the shell of the transferrin modified targeted lipid nano bubble is made of single-layer phospholipid; the surface of a shell of the transferrin modified targeted lipid nano bubble is coupled with biotinylated TF through streptavidin; and perfluoropropane gas is wrapped in the transferrin modified targeted lipid nano bubble. The transferrin modified targeting lipid nano bubble provided by the invention has good stability and strong targeting property, and can target ferroptosis cells.

The invention belongs to the technical field of in-vitro diagnosis and rapid detection, and relates to an interleukin 6 and procalcitonin joint detection kit, a preparation method and a detection method, the interleukin 6 and procalcitonin joint detection kit comprises a Ra1 reagent, a Ra2 reagent, an Rb1 reagent, an Rb2 reagent and a substrate solution; the Ra1 reagent is an interleukin 6 antibody magnetic bead labeling solution, and is prepared from a biotin labeled interleukin 6 first antibody solution and a streptavidin magnetic bead solution; the Ra2 reagent is a procalcitonin antibody magnetic bead labeling solution, and is prepared from a biotin labeled procalcitonin first antibody solution and a streptavidin magnetic bead solution; the Rb1 reagent is prepared from an alkaline phosphatase labeled interleukin 6 second antibody solution; the Rb2 reagent is prepared from a second procalcitonin antibody solution labeled by horse radish peroxidase; the substrate solution comprises a first substrate solution and a second substrate solution. The detection sensitivity can be improved, the detection time is shortened, the detection efficiency is improved, and the operation is simple.

The present invention belongs to the technical field of immunochromatography. Provided are a streptavidin multimer, and a preparation method therefor and the use thereof. The prepared streptavidin multimer has a strong affinity for a biotin / fluorescein nucleic acid probe. A nucleic acid test strip prepared with the prepared streptavidin multimer can realize rapid and high-sensitivity detection of a sample to be detected. Results can be obtained in 5 minutes, the false positive rate can be reduced, and the cost of the nucleic acid probe is reduced, which is convenient for non-professional technicians to easily and accurately judge the results.

The present disclosure relates to a method for increasing the sensitivity of latex immunoturbidimetry reagents. A biotin-streptavidin amplification system, a biotin-labeled antibody and streptavidin cross-linked latex microsphere are used, and the kit is characterized by comprising a first reagent and a second reagent, the first reagent comprises a buffer solution, a stabilizer, a polymerization accelerator, a preservative, a blocking agent and the biotin-labeled antibody, and the second reagent comprises a buffer solution, a stabilizer, a polymerization accelerator, a preservative, a blocking agent and a streptavidin cross-linked latex microsphere. The second reagent comprises a buffer solution, a stabilizer, latex microspheres labeled by streptavidin and a preservative. According to the present invention, the antibody is placed in the first reagent, such that the contact time of the antibody and the antigen is increased, the recognition efficiency is improved so as to improve the reaction sensitivity, and after the second reagent is added, the biotin-labeled antibody and the streptavidin latex microspheres are rapidly combined to form the agglutination so as to produce different reaction gradients, such that the sensitivity and the repeatability are significantly improved.

The invention provides an anti-streptavidin antibody which is high in specificity, high in sensitivity, less in cross reaction and small in batch difference. The antibody not only can realize similar application of a streptavidin-biotin system, but also can be used in combination with the streptavidin-biotin system for related applications such as cell sorting, immunochromatography and the like.

The invention belongs to the technical field of food microorganism detection, and provides a lateral flow chromatography kit for high-sensitivity quantitative detection of salmonella enteritidis, which comprises a salmonella enteritidis RPA primer group and a lateral flow chromatography test strip, raman label streptavidin, a Digoxin antibody and a streptavidin antibody are coated on the lateral flow chromatography test strip. The reporter probe is combined on the release pad of the flow measurement chromatography test strip, has two characteristics of colorimetry and SERS (Surface Enhanced Raman Scattering), can finish simultaneous qualitative and quantitative detection of pathogenic bacteria, and improves the detection sensitivity; and the Digoxin antibody and the streptavidin antibody are respectively combined on the detection line and the quality control line. The kit does not need to use large experimental equipment in the whole detection process, is high in detection accuracy and good in specificity, and is very suitable for real-time detection under the condition of relatively low development level.

The invention discloses a method for detecting 17 beta-estradiol by using a colorimetric-fluorescent dual-mode biosensor, and belongs to the technical field of chemical analysis and detection. According to the method, a colorimetric-fluorescent dual-mode biosensor for detecting 17 beta-estradiol is established based on oxidase-like activity and fluorescence quenching characteristics of manganese dioxide nanosheets and catalytic characteristics of alkaline phosphatase by taking a nucleic acid aptamer as a recognition molecule. The synthesis cost of the nucleic acid aptamer is low, the method has universality, and other target objects can be detected by changing the nucleic acid aptamer; mBs-DNA-ALP is prepared by using a biotin-streptavidin reaction and a DNA hybridization reaction, and a structure conversion process from double-stranded DNA to an aptamer / target compound is realized by using targeted induction, so that a detection signal is amplified; according to the method for detecting 17 beta-estradiol through colorimetric-fluorescence signals, dual-mode output is achieved, results are verified and supplemented mutually, and the specificity and accuracy of the method are improved.

The invention discloses detection test paper and a detection kit for detecting telomerase activity and application, the detection test paper comprises a nitrocellulose membrane, the surface of the nitrocellulose membrane is provided with a test area, and a first detection line and a second detection line are printed in the test area; wherein the first detection line and the second detection line are respectively formed by printing a first capture probe sequence and a second capture probe sequence of streptavidin-biotinylation, the first capture probe is used for capturing a DNA neck ring structure extending after telomerase reaction, and the second capture probe is used for capturing a DNA sequence with a fluorophore replaced after telomerase reaction. Meanwhile, the invention discloses a detection kit, which contains a colloidal gold nucleic acid probe solution, can realize rapid dual visual detection of telomerase activity through colloidal gold color development and fluorescence detection, and has the advantages of sensitive and rapid response to telomerase extension products and high sensitivity. The problem of false positive rate in telomerase activity detection can be greatly reduced.

The invention provides a preparation method of streptavidin magnetic beads, and relates to the technical field of preparation of polymer composites.The preparation method comprises the steps that S1, PS / SiO2 composite microspheres are prepared; s2, carboxyl magnetic beads are prepared on the basis of the PS / SiO2 composite microspheres prepared in the step S1; s3, activating the carboxyl magnetic beads; s4, carrying out covalent coupling on the carboxyl magnetic beads and streptavidin; step S5, stripping of the physically combined streptavidin; and S6, sealing and storing the streptavidin magnetic beads. The streptavidin magnetic beads prepared through the method are controllable in particle size, superparamagnetic, good in stability and high in activity, compared with a traditional method, a cross-linking agent does not need to be additionally added, the process is effectively simplified, the cost is reduced, the streptavidin magnetic beads have excellent performance in the using process of a chemiluminescence platform, and the process is easy to amplify and beneficial to control.

The invention belongs to the field of biological materials, and particularly relates to a multifunctional DNA nanometer material, a preparation method and application of the multifunctional DNA nanometer material in treatment of traumatic brain injury secondary encephaledema. The multifunctional DNA nano material comprises a plurality of deoxyribozyme (DNAzyme) targeting C1q mRNA (messenger Ribonucleic Acid) and a repeating unit which is integrally connected with G-quadruplex / Hemin in series, wherein the G-quadruplex / Hemin is labeled by streptavidin SA and biotin and is used for scavenging free radicals. The DNAzyme for silencing the C1q gene of the mouse is designed on the basis of a bioinformatics method, and the C1q gene overexpressed in an inflammation model can be knocked down to an approximate normal level. The RCA technology mediated self-assembled nano material SA-B / H has excellent enzyme mimetic activity, can effectively remove free radicals such as H2O2 and O2 <.->, and has the potential of in-vivo oxidation resistance. In-vitro experiments prove that SA-B / H can effectively relieve high-level oxidative stress of cells caused by H2O2 stimulation.

Methods, assays, systems, and kits for determining the presence, severity, and / or predisposition of heart failure (HF) in an individual are disclosed. The methods utilize a solid substrate, wherein streptavidin-coated particles are pre-incubated with biotinylated antibody to form the solid phase reagent. Because the solid phase reagent is now presented with the biotinylated antibody in a pre-complexed form, there are fewer opportunities for biotin from the sample to interfere in the assay. The methods, systems, assays, and kits of the present disclosure allow the NT-proBNP assay to demonstrate no biotin interference up to a concentration of 3510 ng / mL biotin.

The application provides a preparation method of a functionalized phage probe and application of the functionalized phage probe in detection of escherichia coli. The functionalized phage is a recombinant phage (M13KO7@SaBP) in which streptavidin binding peptide (SaBP) is fused and expressed at the N terminal of the main capsid protein P8 protein of M13K07 phage. In the application, the gene encoding SaBP (MDVEAWLGAR) is inserted into the N terminal of the P8 protein gene of M13K07 phage by site-directed mutagenesis to prepare M13K07@SaBP. The stable signal amplification is realized by using the abundant P8 protein (about 2700) of M13 phage and the super strong binding force of biotin-streptavidin, the interference of food sample matrix is reduced by combining the magnetic separation technology, and a detection method of escherichia coli with high sensitivity and small sample matrix interference is constructed.

The invention relates to a multi-target gene detection method based on a liquid phase chip, which comprises the following steps: S1, target genes: selecting O-type serum antigens to synthesize key genes; s2, probe design: synthesizing key genes aiming at seven serotype antigens, and designing a specific primer pair; s3, Luminex microsphere coding and coupling: using MagPlex microspheres with different fluorescence codes, and fixing a probe on the surface of the microspheres through a carboxyl-amino coupling method; s4, carrying out multiplex PCR amplification and hybridization detection; s5, a data analysis algorithm is adopted, and a threshold value is set, wherein a negative control MFI mean value + 3 * standard deviation is a Cuff value; and positive judgment: the MFI value of the microsphere corresponding to a certain serotype is greater than or equal to Cuff, and the signal-to-noise ratio (S / N) is greater than or equal to 5. By adopting the technical scheme, the method is based on a Luminex liquid phase chip technology, target gene sequences are amplified through multiple PCR (Polymerase Chain Reaction), and high-flux specific detection on seven serotypes of Escherichia coli is realized by combining microsphere coding probe hybridization and a biotin-streptavidin signal amplification system.

The invention belongs to the technical field of biology, and particularly discloses a pH response type probiotic-liposome hybrid system, a preparation method and application thereof, and the pH response type probiotic-liposome hybrid system comprises engineered escherichia coli Nissle 1917, pinocembrin-loaded biotinylated liposome and an enteric polymer; wherein the engineered escherichia coli Nissle 1917 is in non-covalent binding with the biotinylated liposome loaded with the pinocembrin through surface display streptavidin, so that EcNPIN is formed, and the EcNPIN is coated with an enteric polymer, so that the pH response type probiotic-liposome hybrid system is formed. The pH response type probiotic-liposome hybrid system EcNPIN-L provided by the invention can resist the acidic environment of the stomach, completes pH response release and colonization in the intestinal tract, solves the problems of lack of intestinal tract localization of drugs and low probiotic treatment efficiency, improves the local intestinal tract concentration of pinocembrin, and promotes intestinal tract colonization of probiotics.