177 results about "Streptomycin" patented technology

The invention relates to a norhalal-enoxacin conjugate as well as a preparation method and application thereof. The norhalal-enoxacin conjugate comprises a norhalal-enoxacin coupling compound, or a stereoisomer, a prodrug, a crystal form, a pharmaceutically acceptable salt, a pharmaceutically acceptable ester or a pharmaceutically acceptable solvate selected from the compound. Compared with enoxacin, kanamycin, streptomycin, lincomycin and azithromycin, the norharmann-enoxacin conjugate disclosed by the invention has a smaller MIC (Minimum Inhibitory Concentration) value, which shows that the norharmann-enoxacin conjugate has a better anti-staphylococcus aureus effect.

The invention discloses a culture medium and application thereof, and a method for in-vitro separation culture and adipogenic differentiation of precursor adipocytes in goat muscle, and relates to the technical field of cell culture, the culture medium comprises the following components: 8-12 [mu] g / mL of insulin, 8-12% by volume of fetal calf serum, 95-105 U / mL of penicillin, 95-105 [mu] g / mL of streptomycin and the like. On the basis of the prior art, a proper amount of liquiritin and pilocarpine are mainly added into a culture medium, and synergistic cooperation of the liquiritin and pilocarpine is found, so that the adipogenic differentiation capacity of cells such as mesenchymal stem cells and precursor adipocytes is remarkably improved, and the application range is wide. On the basis, the invention also provides a complete set of perfect in-vitro isolated culture and adipogenic differentiation method of the goat intramuscular precursor adipocytes, and a method and a way are provided for a series of researches developed through the goat primary intramuscular precursor adipocytes in the future.

The invention discloses a human small cell lung cancer brain metastasis organoid culture medium and a culture method. According to the culture medium, an advanced DMEM / F12 culture medium is used as a basic culture medium, and the following components are added: 2 to 5 [mu] M of GlutaMax, 8 to 10 [mu] M of HEPES, 1 * to 2 * of B27, 500 [mu] M of SB202190, 5 to 10 [mu] M of Y-27632, 0.5 [mu] M of A83-01, 0.5 to 2 [mu] M of N-Acetyl-L-cysteine, 5 mM of Nicotinamide, 25 to 100 ng / ml of recombinant human FGF7, 100 to 500 ng / ml of recombinant human FGF10, 100 to 200 ng / ml of Human Noggin, 50 to 500 ng / ml of Human R-Spondin-1, 50 to 100 ng / ml of According to the culture method, TryPLE Express is used for dissociation, the time is short, the activity of dissociated single cells is high, and the success rate of organoid culture can be increased to the maximum extent. Meanwhile, by combining with a culture medium with an optimized formula proportion, formation and growth of brain metastatic organs of the human small cell lung cancer can be promoted, and the construction success rate is increased.

The invention discloses a zebra fish spermatogonial stem cell separation and transplantation method, and belongs to the technical field of fish germline stem cell separation. The method comprises the following steps: washing complete sexual glands of zebra fish testis by adopting penicillin / streptomycin double-antibody-containing PBS (Phosphate Buffer Solution), physically shearing, digesting and dissociating, and filtering by a screen, so as to obtain zebra fish testis cell suspension; performing density gradient centrifugation to obtain zebra fish spermatogonial stem cells; dyeing, marking, centrifuging, washing, re-suspending, and carrying out micro-injection transplantation to enter the back of the abdominal cavity of the acceptor zebrafish juvenile fish. According to different physical properties of different cells, spermatogonial stem cells are separated, purified and transplanted from zebra fish testis cell suspension by adopting a density gradient centrifugation method, and migration and proliferation processes of donor germ cells can be observed in receptor fish after fluorescence labeling. And a new technical path is provided for fish germplasm resource preservation, endangered fish protection, economic cultured fish yield increase and new variety cultivation.

The invention belongs to the technical field of cell biology, and particularly discloses a culture medium and a culture method of fish primary liver cells. The culture medium of the fish primary liver cells comprises the following components: 90% of an M199 culture medium, 10% of fetal calf serum, 100 U / mL of penicillin, 0.1 mg / mL of streptomycin, 5 ng / mL of EGF, 10 [mu] U / ml of insulin and 10 mM of dexamethasone. Based on the culture medium, an efficient and stable fish liver cell culture method is developed by combining a standardized anesthesia and disinfection process, a precise dissection and liver sampling method, an optimized tissue digestion and cell separation scheme, an efficient cell purification and adherent culture system, a stable passage technology and the like; a standardized hepatocyte line establishment operation process is defined, and the problems that species binding exists in an existing fish liver cell culture method, and a standardized culture process suitable for multiple fish fingerlings is difficult to form are solved.

The invention belongs to the technical field of biology, and particularly relates to bifidobacterium longum subsp.infantis FMBL B250020GXY for metabolizing breast milk oligosaccharide and application of the bifidobacterium longum subsp.infantis FMBL B250020GXY, the bifidobacterium longum subsp.infantis FMBL B250020GXY is preserved in China Center for Type Culture Collection on September 1, 2025, and the preservation number is CCTCC M 20251931; three kinds of breast milk oligosaccharides, namely 2 '-fucosyllactose (2'-FL), lactose-N-neotetraose (LNnT) and lactose-N-tetraose (LNT), can be metabolized; plant source carbohydrates such as fructo-oligosaccharide and synanthrin can be metabolized; the compound has a relatively strong capability of removing DPPH and ABTS free radicals; a good inhibition effect is achieved on common pathogenic bacteria; good tolerance to acid and cholate is achieved; the strain is sensitive to gentamicin, streptomycin, tetracycline, chloramphenicol and vancomycin; the compound can be used for preparing antioxidant products, medicines for inhibiting pathogenic bacteria, infant foods and fermented foods, and has a wide application prospect.

The invention relates to the technical field of preparation of carbon dioxide adsorbents, and discloses a carbon dioxide solid adsorbent and a preparation method and application thereof, the carbon dioxide solid adsorbent comprises 10-15 parts of aminated montmorillonite, 5-8 parts of modified chitosan, 20-25 parts of desulfurized gypsum, 3-5 parts of a composite water-retaining agent, 1-2 parts of a functional buffer agent and 0.5-1 part of an ammonia adsorption accelerant. According to the invention, the aminated montmorillonite is adopted to replace traditional streptomycin, so that the raw material cost is reduced, and the risk of antibiotic residue is thoroughly eliminated; chitosan is modified through graphene quantum dots, the excellent oxidation resistance of the graphene quantum dots is utilized, an antioxidant does not need to be additionally added, the environment burden is reduced while the preparation process is simplified, and the degradation rate of the adsorbent in the natural environment is increased. All the components in the adsorbent have a synergistic effect, the aminated montmorillonite provides abundant adsorption active sites, the modified chitosan enhances the mechanical strength and stability of the adsorbent, the composite water-retaining agent and the buffer agent guarantee the stability of an adsorption environment, and the ammonia adsorption accelerant accelerates CO2 adsorption kinetics.

The invention discloses a method for separating and transplanting spermatogonial stem cells of Chinese sturgeons, and belongs to the technical field of separation of germline stem cells of fishes. The separation method comprises the following steps: washing Chinese sturgeon testis tissues with an L-15 culture medium containing penicillin / streptomycin double antibodies, and carrying out physical shearing, digestive enzyme enzymolysis and screen filtration to obtain a Chinese sturgeon testis cell suspension; performing percoll density gradient centrifugation to obtain high-purity spermatogonial stem cells of the Chinese sturgeons; and dyeing, washing, resuspending and carrying out micro-injection transplantation to enter the gonad primordium reproductive ridge part of the juvenile acceptor fish. According to the physical characteristics of the spermatogonial stem cells of the Chinese sturgeons, the spermatogonial stem cells with high purity are obtained by adopting percoll density gradient centrifugation, and the purpose of abdomen borrowing reproduction is achieved by adopting a microinjection mode, so that the preservation of germ cells of endangered fishes and the reconstruction of artificial populations are realized; and a new technical approach is provided for protecting genetic resources of the Chinese sturgeons and breaking through artificial propagation bottlenecks.

The invention relates to a phenylacetylglutamine / phenylacetylglycine induced vascular smooth muscle cell senescence model and an establishment method and application thereof, and belongs to the technical field of cell models.The method comprises the following steps that vascular smooth muscle cell suspension is placed in a porous plate, 10% of FBS and 1% of mycillin are added into a culture medium, 24 h after cells adhere to the wall, the vascular smooth muscle cell senescence model is obtained, and the vascular smooth muscle cell senescence model is obtained. The method comprises the following steps of: adding a proper amount of phenylacetyl glutamine or phenylacetyl glycine dimethyl sulfoxide solution into a porous plate, changing a serum-free culture medium, continuously culturing for 24 hours, adding a proper amount of phenylacetyl glutamine or phenylacetyl glycine dimethyl sulfoxide solution into the porous plate, changing the culture medium added with phenylacetyl glutamine or phenylacetyl glycine once every 24 hours, and collecting cells after 72 hours. According to the invention, phenylacetylglutamine / phenylacetylglycine is used for inducing and establishing the vascular smooth muscle cell senescence model for the first time, the method is easy to operate and low in cost, and a foundation is laid for researching the relationship between cardiovascular diseases and senescence.

The invention discloses an anti-streptomycin monoclonal antibody and application thereof, and relates to the technical field of streptomycin detection. According to the invention, a hybridoma cell strain capable of stably secreting an anti-streptomycin monoclonal antibody is screened, and the preservation number of the hybridoma cell strain is CGMCC (China General Microbiological Culture Collection Center And screening to obtain the specific and sensitive streptomycin monoclonal antibody. Immunodetection experiments prove that the streptomycin monoclonal antibody provided by the invention has high specificity to streptomycin, high detection sensitivity to streptomycin and wide linear detection range. Therefore, the anti-streptomycin monoclonal antibody provided by the invention can be used for developing streptomycin detection kits, test strips and other products, and a detection tool and means are provided for rapid detection of streptomycin and other antibiotic residues in animal products, aquatic products and agriculture.

The present invention belongs to the technical field of semen cryopreservation, and more specifically, relates to sheep semen freezing solution and semen preservation method. The sheep semen freezing solution components of the present invention include Tris, citric acid, fructose, lactose, trehalose, penicillin, streptomycin, soy lecithin, nobiletin, glycerol and water. By using a specific content of nobiletin as an effective antioxidant component of a sheep sperm cryopreservative, it plays an antioxidant role when the sperm is frozen, making the sperm more stable during the cryopreservation process. After adding nobiletin, the vitality and motility of sheep sperm after freezing and thawing can be significantly improved. It effectively reduces the oxidative stress damage of sperm during the freezing process and improves the antioxidant capacity of sperm.

This invention discloses a method for directed evolution of antibiotic-resistant Escherichia coli strains based on cytidine deaminase, belonging to the field of microbial directed evolution and genetic engineering technology. This method uses E. coli as the host, introducing a recombinant plasmid expressing an optimized double-stranded cytidine deaminase mutant. Utilizing the low toxicity and high mutagenicity of this mutant, continuous passage evolution is carried out under gradient concentrations of aminoglycoside antibiotics (kanamycin and streptomycin). Combined with whole-genome sequencing, molecular docking, and reverse genetics verification, the A145T missense mutation in the wcaE gene is identified as the core functional site. This invention overcomes the shortcomings of traditional spontaneous and chemical mutagenesis, which suffer from low efficiency and significant strain damage. The mutation type is controllable, the evolutionary cycle is short, and the obtained engineered strains can tolerate up to 300 mg / L kanamycin while exhibiting streptomycin cross-resistance, and the genetic stability of the tolerance trait is strong. This method is simple, highly reproducible, and suitable for industrial breeding of stress-resistant E. coli, and can be widely applied in antibiotic fermentation, industrial microbial culture, and other scenarios.

The invention discloses a culture medium for preparing a human-derived Merkel cell model and a construction method, and relates to the technical field of biologication.The key points of the technical scheme are that the culture medium comprises a culture medium E, and the culture medium E is formed by adding PRCi into an OMM culture medium; the OMM is prepared by adding GlutaMax (GlutaMax), B-27 (B-27) Minus, N2 (N2) suppliers, Penicilin-Streptomycin and 2-Mercaptoethanol into an Advanced DMEM (Dulbecco's Modified Eagle Medium) / F12 (Fullcap 12) culture medium and a Neurobasic culture medium, and the OMM is prepared by adding GlutaMax, B-27 Minus, N2 (N2) suppliers, Penicilin-Streptomycin and 2-Mercaptoethanol into a medium; and the PRCi comprises EED226, PRT4165 and GSK126 (glutamine synthase 126). According to the invention, a small molecule compound combination PRCi (EED226 + PRT4165 + GSK126) is added into a culture medium, so that the amount of MC in the organoid can be remarkably increased, and a human-derived system is established for researching the MC.

The invention belongs to the technical field of microbial pharmacy, and discloses a polyketone macrolide compound generated by genetically engineered streptomyces as well as a preparation method and application thereof. The polyketone macrolide compound disclosed by the invention is a cinnamyl streptomycin derivative, has cell proliferation inhibition activity better than that of a natural product Cinnamomycin A-D, can exert anti-tumor activity by inhibiting activity of human exonucleotide pyrophosphatase / phosphodiesterase 1 (ENPP1) and activating an inherent immune pathway, can be prepared into a medicine or a medicinal composition, and can be used for preparing medicines or medicinal compositions. The compound is used for treating tumors and related diseases.

The invention relates to a Zhongshengmycin production strain and application of the Zhongshengmycin production strain, the strain is streptomyces sp. ZS-2, the Zhongshengmycin production strain has good Zhongshengmycin production activity, and a fermentation product has higher bacteriostatic activity and a wider bacteriostatic range.

The invention relates to an isolated culture method of functional Chinese softshell turtle ovarian granular cells. The isolated culture method comprises the following steps: S1, collecting ovarian tissues: collecting Chinese softshell turtle ovarian tissues; s2, separating and collecting a granular cell layer; s3, digesting and collecting granular cells; s4, primary culture of granulosa cells: transferring the collected cells into a cell culture bottle containing 4 ml of a complete culture medium for primary culture, wherein the complete culture medium comprises the following main components: a DMEM culture medium, 15% of fetal calf serum, 1% of penicillin streptomycin and 1% of an insulin-transferrin-selenium additive; and S5, subculturing the granular cells. The isolated culture method and the culture medium system provided by the invention are simpler and more time-saving and labor-saving; according to the method, the aromatase CYP19A1 can be expressed normally, the characteristics of the granular cells are kept, the aromatase CYP19A1 can be expressed normally, it is indicated that the in-vitro cultured cells can keep the functionality of the cells, and the in-vitro proliferation capacity of the granular cells is improved to a great extent.

The application discloses a preparation method of a nanogel preparation for preventing and treating tobacco diseases, and specifically comprises the following steps: (1) preparing bacillus licheniformis bacterial liquid; (2) preparing nanometer selenium precipitate; (3) preparing purified nanometer selenium particles; (4) preparing streptomycin-nanometer selenium solid; (5) preparing nanometer titanium dioxide photo-semiconductor sol; and (6) mixing low-melting agarose powder, the streptomycin-nanometer selenium solid and the nanometer titanium dioxide photo-semiconductor sol, centrifuging, washing, and drying to obtain the nanogel preparation. The nanogel preparation has significant bacteriostatic efficacy, can effectively prevent and treat tobacco diseases (especially tobacco bacterial wilt and tobacco wild fire disease), has a promoting effect on tobacco growth, is simple to make, has strong adhesion, and does not pollute the soil environment.

The invention discloses an amplification culture solution of TILs cells and a culture method thereof. The amplification culture solution comprises a complete culture medium, and an anti-BTLA antibody with the final concentration of 0.1-10 [mu] g / mL, penicillin with the final concentration of 50-500 [mu] g / mL, streptomycin with the final concentration of 50-500 [mu] g / mL, gentamicin with the final concentration of 10-100 [mu] g / mL and amphotericin with the final concentration of 1-50 [mu] g / mL are added into the complete culture medium. The anti-BTLA antibody component in the culture solution can relieve inhibition of BTLA on T cells by blocking combination of BTLA and a ligand HVEM of BTLA, so that the anti-tumor capability of TILs is enhanced; meanwhile, after the BTLA is combined with the ligand HVEM, T cell activation and proliferation can be inhibited, and rapid proliferation of TILs is promoted; the irradiation PBMC added in the TILs cell culture process can provide an activation signal for the TILs and drive rapid proliferation of the TILs cells.

The invention provides a THP-1 mononuclear cell culture medium and a culture method thereof. The THP-1 mononuclear cell culture medium comprises the following components: a complete culture medium, 8v / v%-12v / v% of fetal calf serum, 20mM-30mM of HEPES, 0.8 mM-1.2 mM of sodium pyruvate and 0.8 v / v%-1.2 v / v% of antibiotics. Wherein the HEPES is 2-4M HEPES mother liquor prepared by using a complete culture medium, the sodium pyruvate is 2-4M sodium pyruvate mother liquor prepared by using a complete culture medium, the complete culture medium is an RPMI 1640 culture medium, and the antibiotic is mycillin. The invention provides a series of optimized processes of a THP-1 cell culture method, passage, culture medium and the like, so that the THP-1 cell culture method is improved, the resuscitation state of the cryopreserved THP-1 cells is improved, and the phenomena of cell death and the like are reduced; besides, the THP-1 cell culture medium provided by the invention is optimized in formula and scientific in proportioning, the sensitivity degree of THP-1 cells to serum quality is reduced, and the good growth state of the THP-1 cells is further improved.

The invention relates to an establishment method and application of a micropterus salmoides muscle cell line, and belongs to the technical field of cell culture. The invention provides a culture solution which takes an M199 culture medium as a basic culture medium and further comprises sodium pyruvate, hydroxyethyl piperazine ethanesulfonic acid, beta-mercaptoethanol, penicillin, streptomycin and fetal calf serum. The culture solution provides optimal conditions for micropterus salmoides muscle cell culture, the culture cost is also reduced, the micropterus salmoides muscle cell line is established by adopting the culture solution, the method is simple and easy to operate and high in repeatability, the established cell line is good in stability, continuous passage and ultralow-temperature cryopreservation can be realized, the cell division speed is high, the passage time is short, the adherence rate is high, and the method is suitable for large-scale popularization and application. In the method, the micropterus salmoides muscle primary cell culture time is short, the number of obtained cells is large, the activity is good, and passage can be carried out in only 8 days.

The present invention belongs to the technical field of sensorineural hearing. Provided is the use of SPTBN1 as a target in the treatment of GJB2-related sensorineural hearing loss. The use comprises: the construction of a stably transfected cell line, wherein: HEK293T cells are cultured using a DMEM culture medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin in a humidified incubator at 37ºC with 95% air and 5% CO2, and when the cells reach 80%-90% confluence, cell passage is performed; IP-MS analysis, wherein: protein complexes are purified using Protein A / G immunoprecipitation magnetic beads, a portion of the extracted proteins is used as input, and then 2 μg of anti-Cx26 antibody is added to the remaining protein extract, same are gently pipetted and mixed, and incubated on a rotating shaker at 4℃ overnight; immunofluorescence observation of the co-localization of Cx26 and SPTBN1, wherein: a stably transfected cell line expressing WT-Cx26 and Mut-Cx26 is constructed; and co-immunoprecipitation (Co-IP) validation, wherein: a stably transfected cell line expressing WT-Cx26 is constructed. The present invention overcomes the limitations of therapeutic methods, such as the relatively low targeting specificity and short therapeutic time windows associated with full-length protein supplementation via gene therapy, thereby providing new insight into GJB2-related hearing loss, and a new target and a new treatment for same.

The present invention discloses a protective agent for endogenous iron death inhibitory protein in sheep sperm, a protective method and an application thereof. The protective agent for endogenous iron death inhibitory protein in sheep sperm comprises the following components: Tris, citric acid, glucose, chloroquine, glycerol, a mixture of penicillin-streptomycin, egg yolk liquid and ultrapure water, and the above substances are dissolved in the ultrapure water. The present invention also provides a method for protecting endogenous iron death inhibitory protein in sheep sperm, comprising the following steps: preparing an endogenous iron death inhibitory protein protective agent for sheep sperm; semen collection; diluting semen with an endogenous iron death inhibitory protein protective agent for sheep sperm; and freezing semen. The present invention also provides an application of an endogenous iron death inhibitory protein protective agent for sheep sperm. The present invention can protect the iron death inhibitory protein during the freezing recovery process, ensure the expression level of the iron death inhibitory protein, ensure the sperm motility and the integrity of the biofilm structure, and greatly improve the resistance of sheep sperm to freezing damage.

The present invention discloses a culture medium and its application, as well as a method for in vitro isolation and culture of yak skeletal muscle satellite cells, which relates to the technical field of cell culture. The culture medium is composed of the following raw materials: fetal bovine serum with a mass fraction of 9-13%, penicillin at 95-105 U / mL, streptomycin at 95-105 μg / mL, bamboo leaf flavonoids at 5-12 μmol / L, apigenin at 20-30 μmol / L, and the balance is DMEM. The present invention mainly adds appropriate amounts of bamboo leaf flavonoids and apigenin to the culture medium. The two cooperate synergistically, significantly improving the proliferation ability of bovine skeletal muscle satellite cells, and further applying it to the in vitro isolation and culture of yak skeletal muscle satellite cells, establishing a complete and unique sterile isolation, purification, and culture system for yak skeletal muscle satellite cells, providing methods and approaches for a series of future research carried out through yak skeletal muscle satellite cells.

The invention belongs to the field of biological medicine, and relates to a curcumin-loaded bone marrow mesenchymal stem cell source exosome which is obtained by the following steps: step 1, culturing BMSCs (bone marrow mesenchymal stem cells): simultaneously adding 10% of fetal calf serum and 1% of myclostreptomycin into an MEM culture medium, culturing at 37 DEG C under 5% CO2, and counting and subculturing when the cell density reaches 90%; 2, dissolving Cur in a DMSO solution, preparing a mother solution with the culture medium, and filtering and diluting to 30-50 [mu] g / mL; adding into BMSCs (bone marrow mesenchymal stem cells) with the cell density of 85-100%, and culturing for 12-36 hours; collecting supernate, and carrying out gradient centrifugation to obtain the mesenchymal stem cell source exosome loaded with curcumin. The invention provides a novel administration route which depends on the self function of the mesenchymal stem cell source exosome and the self function of the curcumin at the same time.

The invention belongs to the technical field of nerve cell culture, and particularly relates to application of a culture medium in co-culture of SVGP12 and HMEC-1. The culture medium is based on a mixture of DMEM and MCDB 131 according to a ratio of 1: 1, HEPES, Glutamax, N2, G-5, B-27, hEGF, penicillin-streptomycin and fetal calf serum are added, and the components are prepared according to a specific final concentration. When being applied to a Transwell co-culture model, the culture medium can meet the nutritional requirements of two cells at the same time, maintain the normal growth and form of the cells, and promote the transmission of functional signal molecules. Experiments show that the culture medium can significantly up-regulate expression of ABCG2, CYP2D6, CYP1B1 and CYP2E1 in HMEC-1 (P is less than 0.05), provides a reliable in-vitro model for researching an interaction mechanism of two cells, and assists drug screening and disease simulation.

The invention relates to the technical field related to medicines, in particular to a method for preventing and controlling orbiculaeas on the basis of an artemisia apiacea extract, which comprises the following specific steps: step 1, purchasing the artemisia apiacea extract from Shanghai Yuan Leaf Biotechnology Co., Ltd; step 2, separating blood egg whipstock in the economic crustacean animals to obtain an amoeboid-shaped trophozoite and microspores of the economic crustacean animals; 3, the amoeboid-shaped trophozoite is inoculated into a culture medium containing specific components to be cultured, the culture medium comprises 0.1% of mycillin, 5% of healthy portunus trituberculatus serum, 10% of fetal calf serum and 85% of NephropsSaline buffer solution, and the microspores are cultured with sterile filtered seawater. According to the method for preventing and controlling the oryza sativa based on the artemisia apiacea extracts, in-vitro experiments verify that the artemisia apiacea extracts with different concentrations (10-1000mg / L) can remarkably promote apoptosis of oryza sativa somatic cells, destroy microstructures of the oryza sativa somatic cells and inhibit physiological activity, and a new way is provided for developing novel green anti-parasitic drugs.

The application belongs to the technical field of microorganism detection, and particularly relates to a bifidobacterium viable count detection culture medium, a detection method and application. The application provides a culture medium for detecting bifidobacterium, wherein the culture medium comprises MRS culture medium and an antibiotic solution; the antibiotic solution comprises streptomycin, kanamycin and sodium propionate. The culture medium can ensure normal growth of bifidobacterium, has strong inhibition on lactobacillus, can effectively realize accurate detection of bifidobacterium, and avoids interference of lactobacillus.

The application provides a preparation method of a ratio fluorescent aptamer sensor for detecting streptomycin in milk, and belongs to the field of food safety detection. The application comprises screening of streptomycin (STR) specific aptamer and construction of a ratio fluorescent sensor. The STR aptamer (Apt) is obtained by using a magnetic graphene oxide screening technology for the first time, the binding site is analyzed according to the secondary structure and molecular docking analysis, and the Apt52 with the best affinity to the target is obtained by truncation. The carbon quantum dots (CQDs) modified by the Apt52 are used as a reference signal, the AgNCs-SMP@ZIF-8 is used as a response signal to construct a fluorescent sensing method for judging whether the streptomycin is contained in the sample to be detected. The specific binding of the aptamer to the target causes the AgNCs-SMP@ZIF-8 to expose and quickly adsorb a large amount of Cu 2+ The fluorescence signal of the AgNCs-SMP@ZIF-8 is quenched, and the fluorescence signal of the CQDs always remains stable, and the streptomycin residue is detected by the fluorescence signal ratio change of the AgNCs-SMP@ZIF-8 and the CQDs. The detection limit of the sensor for the STR is 0.978 nM, and the sensor has satisfactory specificity and sensitivity.

The invention relates to a culture method and a culture medium for reducing the number of differential transcripts of epithelial organoid and in-vivo tissues, and solves the technical problems of low growth rate and low formation rate of the organoid in the prior art. The basic components of the culture medium comprise a DMEM / F12 basal culture medium, a penicillin-streptomycin solution, a Glutamax additive, a recombinant spinal protein, a recombinant head protein, Y-27632, an epidermal growth factor, an N-2-hydroxyethyl piperazine-N-2-ethanesulfonic acid buffer solution, nicotinamide, A83-01 and CHIR99021, and the additional components of the culture medium comprise a Wnt-3A additive, an ITS-X additive and hydrocortisone. The invention also provides a culture method of the epithelial organoid. The method can be used for culturing epithelial organs.

The application discloses a kind of monoclonal antibody of streptomycin resistance and application thereof, it is related to streptomycin detection technical field.The application filters out the hybridoma cell strain that can stably secrete anti-streptomycin monoclonal antibody, and its preservation number is CGMCC NO.46126.Specific, sensitive streptomycin monoclonal antibody is obtained by screening.The experiment proves that the streptomycin monoclonal antibody provided in the application has high specificity to streptomycin, and has high detection sensitivity to streptomycin, and wide linear detection range.Therefore, the anti-streptomycin monoclonal antibody provided in the application can be used for developing streptomycin detection kit, test strip and other products, and the application provides detection tools and means for rapid detection of streptomycin and other antibiotic residues in livestock products, aquatic products and agriculture.