406 results about "Biotin" patented technology

The invention discloses a fermentation medium for regulating and controlling a clostridium aerovorans target product and a fermentation method of the clostridium aerovorans target product. The medium comprises a basic component and a regulating component, the basic components comprise ammonium chloride, potassium chloride, magnesium sulfate heptahydrate, sodium chloride, monopotassium phosphate, yeast powder, calcium chloride dihydrate, sodium selenite, nickel chloride hexahydrate, biotin, folic acid, pyridoxine hydrochloride, thiamine, riboflavin, nicotinic acid, D-calcium pantothenate, cobalamin, para aminobenzoic acid and lipoic acid; the adjusting component comprises sodium tungstate, ferrous sulfate and sodium molybdate, sodium tungstate and ferrous sulfate have a forward adjusting effect on increasing the yield of acetic acid, ethanol and butanol in the target product, and sodium molybdate has a reverse adjusting effect on the target product. By optimizing the proportion of trace elements in the culture medium, the clostridium metabolism efficiency is improved, synthesis of a target product is regulated and controlled, and the method is particularly suitable for industrial production of acetic acid, ethanol, butanol and the like.

The invention relates to the technical field of exosomes, in particular to an exosome compound preparation with a hair growing effect and a preparation method of the exosome compound preparation. Comprising 12 to 22 parts of ginsenoside Rb1, 15 to 12 parts of biotin tripeptide-15, 8 to 15 parts of diammonium glycyrrhizinate, 50 to 70 parts of fish collagen peptide, 10 to 20 parts of soybean peptide, 0.5 to 4.5 parts of SHH protein, 0.5 to 2.5 parts of SMO inhibitor, 0.5 to 1.5 parts of HhSP protein, 5 to 10 parts of N-acetyl tyrosine, 0.1 to 2 parts of hyaluronic acid, 0.1 to 1 part of melatonin, 0.1 to 1 part of quercetin, 0.1 to 1 part of kaempferol, 0.1 to 1 part of tanshinone, 0.1 to 1 part of biotin and 0.1 to 1 part of vitamin A. The compound preparation is combined with exosomes from various sources, so that the hair papilla cell function is synergistically enhanced, and the damaged hair follicle structure is repaired.

The invention relates to an extracellular vesicle surface protein detection paper-based kit and application thereof, and belongs to the technical field of biology. The technical problems that an existing sEVs detection technology is insufficient in specificity, depends on professional instruments and cannot meet the instant detection requirement are solved. According to the method, sEVs are synergistically captured through double aptamers, the target specificity is improved, signals are amplified in a cascaded mode through hyper-branched rolling circle amplification (HRCA) and a CRISPR / Cas12a system, and visual detection is achieved by detecting FAM-biotin probe separation before and after cutting through a transverse flow test strip. According to the method, interference of free protein is effectively avoided through double-target recognition, and the detection limit is as low as 406 parts / mL; cRISPR and a paper-based technology are combined to realize high sensitivity and instant detection; the system is simple and convenient to operate, does not need professional instruments, is suitable for tumor diagnosis and treatment monitoring of clinical samples, and provides a portable solution for precise medical treatment.

The invention discloses a hair follicle targeting nano-liposome anti-hair loss and hair growth compound preparation. The compound preparation is prepared from the following raw materials in parts by mass: 70 to 85 parts of bionic liposome carrier and 15 to 30 parts of active ingredients, the bionic liposome carrier is prepared from 50 to 60 parts of egg yolk lecithin, 15 to 20 parts of pH sensitive phospholipid DOPE, 10 to 15 parts of cholesterol and 5 to 10 parts of mesenchymal stem cell exosome membrane protein; the active ingredients comprise 5 to 10 parts of minoxidil, 3 to 5 parts of caffeine, 0.5 to 1 part of miR-218-5p, 1 to 2 parts of biotin and 2 to 3 parts of quercetin; the average particle size of the nano-liposome formed by the bionic liposome carrier is 120-180nm, and the polydispersity index (PDI) is less than or equal to 0.15. The invention relates to the technical field of biological medicines, in particular to a hair follicle-targeted nano-liposome anti-hair loss and hair growth compound preparation, which has the following advantages due to the adoption of the technical scheme: accurate targeted delivery is realized, and the treatment safety and accuracy are improved; intelligent response release is achieved, and the local microenvironment of hair follicles is optimized; the multi-target synergistic effect breaks through the limitation of single treatment.

The invention relates to the technical field of biological products, and discloses a mesenchymal stem cell hair growth liquid and a preparation method thereof, and the mesenchymal stem cell hair growth liquid comprises the following components: hair follicle mesenchymal stem cells; a hair follicle mesenchymal stem cell exosome; growth factors: a vascular endothelial growth factor (VEGF), a fibroblast growth factor (FGFs), a keratinocyte growth factor (KGF-7) and interleukin-10 (IL-10); vitamins: vitamin E, vitamin B5, vitamin B2, vitamin B6, vitamin C and biotin; the plant extracts comprise a cacumen biotae extract, a polygonum multiflorum extract, a ginseng extract, a peppermint extract, a purslane extract and a rhodiola rosea extract; other active ingredients: tripeptide and digoxin; the auxiliary material is a hyaluronic acid-collagen peptide graft copolymer; and the balance of a phosphate buffer solution.

The invention relates to the technical field of bacterium enrichment nutrient solutions, in particular to a bacterium enrichment nutrient solution for fermentation and a preparation method of the bacterium enrichment nutrient solution. The culture medium is prepared from the following raw materials in parts by weight: maltodextrin, crystalline glucose, low-pigment yeast extract powder, refined soy peptone, dipotassium phosphate, monopotassium phosphate, magnesium sulfate heptahydrate, sodium chloride, phytic acid, L-ascorbic acid, manganese sulfate monohydrate, biotin, thiamine hydrochloride and choline chloride. Through a double-carbon-source structure, maltodextrin and crystalline glucose cooperate, metabolic oscillation is avoided, and the energy utilization rate is increased; the low-pigment yeast extract powder and the refined soy peptone are complementary, so that the rapid growth requirement of thalli is met; phytic acid is chelated with metal ions to prevent precipitation, L-ascorbic acid is used for resisting oxidation, and biotin and thiamine activate a coenzyme pathway to realize accurate regulation and control of a metabolic network.

The invention belongs to the technical field of biology, and particularly relates to a kit for detecting breast cancer and a detection method. The kit comprises an elisa plate coated with a capture antibody L4-CAP, a biotin-labeled detection antibody L4-SIG, a protein standard substance, HRP, a sample diluent, a washing solution, a developing solution and a stop solution. The heavy chain amino acid sequence of the capture antibody L4-CAP is as shown in SEQ ID NO.1, and the light chain amino acid sequence of the capture antibody L4-CAP is as shown in SEQ ID NO.2; the heavy chain amino acid sequence of the detection antibody L4-SIG is shown as SEQ ID NO.3, and the light chain amino acid sequence of the detection antibody L4-SIG is shown as SEQ ID NO.4. The kit for detecting the breast cancer is high in specificity, can specifically detect the content of the URCL4 protein in serum, serves as an auxiliary diagnosis means for breast cancer with high expression of URCL4 protein, and has a good application prospect.

The invention discloses a biotin ligase mutant and application thereof, and belongs to the technical field of gene engineering. According to the invention, a series of biotin ligase mutants are prepared by docking biotin ligase and substrate molecules thereof and carrying out multiple mutations on screened 10 amino acids with binding force acting sites. On the basis, a biotin ligase mutant is connected to escherichia coli through a homologous recombination technology, a series of escherichia coli recombinant bacteria with high biotin yield are obtained, and the biotin yield reaches 0.873 mg / L to the maximum after 24-hour fermentation.

The invention provides an anti-hair-loss and hair-growing product containing plant extract components and a preparation method thereof, and relates to the field of wash supplies, the anti-hair-loss and hair-growing product is prepared from the following raw materials by weight: 50-80 parts of water, 5-10 parts of propylene glycol, 1-5 parts of 1, 3-propylene glycol, 1-5 parts of 1, 3-propylene glycol, and 1-5 parts of 1, 3-propylene glycol. The composition is prepared from the following components in parts by weight: 0.1 to 1 part of 1, 2-pentanediol, 0.1 to 1 part of pyrrolidinyl diaminopyrimidine oxide, 0.1 to 0.5 part of diaminopyrimidine oxide, 0.01 to 0.02 part of caffeine, 0.01 to 0.1 part of adenosine, 0.05 to 0.2 part of vitamin B6, 0.01 to 0.5 part of biotin tripeptide-1, 0.1 to 1 part of dipotassium glycyrrhizinate, 0.02 to 0.05 part of ethylenediamine tetraacetic acid, 0.1 to 1 part of D panthenol, 0.2 to 1 part of p-hydroxyacetophenone, 0.01 to 1 part of 1, 2-pentanediol, 0.1 to 1 part of 1, 2-pentanediol, 0.1 to 1 part of 2, 2-pentanediol, 0.1 to 1 part of 2, 2-pentanediol, 0.1 to 1 part of 2, 2- The composition comprises the following components in parts by weight: 1-2 parts of 1, 2-hexanediol, 0.1-0.5 part of citric acid, 1-2 parts of 1, 3-butanediol, 0.01-1 part of NMN and 3-5 parts of a plant extract. According to the present invention, the extraction method of the plant extract in the raw materials is specifically adjusted so as to significantly reduce the content of the pigment and the odor substance in the extract, such that the obtained hair growing liquid has characteristics of good hair growing effect, light color and light drug taste, can be easily accepted by consumers, and is suitable for large-scale promotion and application.

Various benefits to intestinal health are made by delivery of an active agent to the colon of an animal, including a human. Active ingredients include of riboflavin, vitamin A, vitamin C, vitamin D, vitamin E, vitamin K, folic acid, β-carotene, vitamin B1, niacin, vitamin B5, vitamin B6, biotin, vitamin B12, omega-3 fatty acids and combinations thereof. Benefits include increased concentration of at least one short-chain fatty acid its salt thereof in the intestine, increased microbiome diversity in the intestine, increased beneficial bacteria in the intestine, increased the butyrate synthesis pathway in the intestine, improved barrier function of the intestine, reduced redox potential of the gut, reduced amount of gas produced in the intestine; and stimulation of intestinal immune responses.

The invention belongs to the technical field of biological detection, and provides a multiple cell factor detection kit in tumor immunity and a preparation method and application thereof, and the detection kit comprises a capture antibody, a detection antibody, a mixed protein standard substance, a diluent and a washing buffer solution. The capture antibody is prepared by coupling a biotinylated antibody with a fluorescent microsphere coated with biotin to obtain a capture antibody coupled with a fluorescent encoding microsphere, and the detection antibody is prepared by coupling derivatized phycoerythrin PE-SMCC with a specific thioether bond of a sulfhydrylated antibody to obtain a fluorescent labeled antibody; the mixed protein standard substance adopts a freeze-drying protection system containing BSA, trehalose and the like. The single hole of the kit can synchronously detect various cell factors, the sample dosage is only 25 microliters, the kit is suitable for immune monitoring of iron overload and other chronic inflammation models, compared with a traditional ELISA method, the efficiency is improved by 10 times, the cost is reduced, and the kit has the remarkable advantages of being high in throughput, wide in linear range and high in stability.

The invention provides a magnetic bead for IgG antibody biotin labeling and purification and an application method, and the magnetic bead is prepared by the following steps: 1) preparing rProtein A and rTurbo ID into a protein solution; (2) mixing the protein solution with the carboxyl magnetic beads to react, so that the protein is coupled to the carboxyl magnetic beads to obtain rProtein A and rTurbo ID protein coated magnetic beads; according to the magnetic bead disclosed by the invention, biotin labeling of an antibody can be realized by applying Turbo ID enzyme, only ATP and common biotin molecules need to be used, and the cost is very low; and the biotin labeling reaction is carried out on the magnetic beads, so that the purification and biotin labeling operation is simplified, and the operation is simple and convenient.

The present invention relates to a bone trauma repair bone paste and a preparation method thereof, belonging to the technical field of biomedical material manufacturing. The bone paste of the present invention is prepared by mixing nano calcium phosphate biphasic ceramics, biomimetic mineralized collagen fibers, biodegradable polymers, modified hyaluronic acid, β-cyclodextrin-coated recombinant human bone morphogenetic protein-7, angiogenesis promoters and immunomodulatory additives in a certain proportion; the nano calcium phosphate biphasic ceramics are hydroxyapatite and β-tricalcium phosphate biphasic ceramics; the biomimetic mineralized collagen fibers are prepared by mineralizing freeze-dried fibers of type I collagen admixed with hydroxypropyl chitosan; the modified hyaluronic acid is hyaluronic acid-thiol and hyaluronic acid-hydrazide; the angiogenesis promoter is a polylactic acid sustained-release microsphere loaded with tanshinone and hydroxy polyethylene glycol biotin; the immunomodulatory additive is disodium glycyrrhizinate, lentinan and astragalus polysaccharide. The bone paste can effectively improve the bone induction ability, promote angiogenesis and reduce the risk of immunogenicity.

Various benefits to intestinal health are made by delivery of an active agent to the colon of an animal, including a human. Active ingredients include of riboflavin, vitamin A, vitamin C, vitamin D, vitamin E, vitamin K, folic acid, β-carotene, vitamin B1, niacin, vitamin B5, vitamin B6, biotin, vitamin B12, omega-3 fatty acids and combinations thereof. Benefits include increased concentration of at least one short-chain fatty acid its salt thereof in the intestine, increased microbiome diversity in the intestine, increased beneficial bacteria in the intestine, increased the butyrate synthesis pathway in the intestine, improved barrier function of the intestine, reduced redox potential of the gut, reduced amount of gas produced in the intestine; and stimulation of intestinal immune responses.

The invention relates to the field of biomedicine, and discloses a method for screening KRAS mutant interacting proteins, an HEK293T cell line for continuously expressing an HA-Turbo ID-KRAS variant is established by utilizing lentivirus transduction, the stability of transgene expression is ensured through puromycin screening, and variation caused by transient transfection is reduced as much as possible. After a Turbo ID mediated proximity marker is activated by biotin treatment, KRAS proximity binding proteins are covalently biotinylated, captured by NeutrAvidin bead purification, and analyzed by quantitative mass spectrometry. According to the invention, two potential KRAS mutation treatment target proteins of LZTR1 and LAMTOR1 can simultaneously inhibit activation and efficacy exertion of three different mutants of G12C, G12D and G12V of the G12 mutant, compared with drugs on the market that a single target of G12C directly targets the KRAS mutant, a brand new KRAS mutation targeting intervention strategy is provided, the clinical curative effect can be further improved, and the occurrence rate of secondary drug resistance can be effectively reduced.

The invention belongs to the technical field of biological detection, and provides a multiple cell factor detection kit in macrophage polarization and a preparation method and application thereof, and the detection kit comprises a capture antibody, a detection antibody, a mixed protein standard substance, a diluent and a washing buffer solution. The capture system is used for preparing a capture antibody coupled with a fluorescence coding microsphere by coupling a biotinylated antibody with a fluorescence microsphere coated with biotin, and the detection system is used for preparing a fluorescence labeled antibody by coupling derivatized phycoerythrin PE-SMCC with a specific thioether bond of a sulfhydrylated antibody. The mixed protein standard substance adopts a freeze-drying protection system containing BSA, trehalose and the like. The single hole of the kit can synchronously detect multiple cell factors, the sample dosage is only 25 microliters, the kit is suitable for in-vitro tests of mouse mononuclear macrophage leukemia cell lines RAW264.7, compared with a traditional ELISA method, the efficiency is improved by 10 times, the cost is reduced, and the kit has the remarkable advantages of being high in throughput, wide in linear range and high in stability.

The invention relates to the technical field of bacterial detection, in particular to a nucleic acid colorimetric / photo-thermal dual-mode instant detection kit and system based on CRISPR / Cas12a and Au (at) PtNPs. One purpose of the invention is to provide a nucleic acid colorimetric / photo-thermal dual-mode instant detection kit based on CRISPR / Cas12a and Au (at) PtNPs. The nucleic acid colorimetric / photo-thermal dual-mode instant detection kit based on CRISPR / Cas12a and Au (at) PtNPs comprises the following components: Au (at) PtNPs coupled with Biotin-ssDNA-SH, a specific primer targeting a GBS conserved gene, a CRISPR / Cas12a cleavage reaction mixed solution and a reaction mixed solution. According to the technical scheme, the high robustness and reliability of the detection result in bedside, community clinics and other basic-level application scenes are jointly ensured through the simplified pretreatment process and the internal cross validation mechanism of the colorimetric / photo-thermal dual-mode signals, and a solid foundation is laid for wide popularization of the technology.

The invention discloses a method for detecting the content of biotin in a composite vitamin tablet. The method for detecting the content of biotin in the composite vitamin tablets comprises the following steps: crushing the composite vitamin tablets to obtain composite vitamin tablet powder; mixing a sulfuric acid solution with the composite vitamin tablet powder, and carrying out hydrolysis reaction to prepare a test product hydrolysate; adjusting the pH value of the hydrolysate of the test sample to 7.1-8.1, and preparing a solution of the test sample; and detecting the content of biotin in the test solution by adopting high performance liquid chromatography. In the provided detection method, a complex formed by combining biotin with other components in the vitamin complex tablet is hydrolyzed in a sulfuric acid solution, then the content of biotin is detected by adopting high performance liquid chromatography, and the provided method is good in specificity and linearity, relatively high in repeatability and accuracy and suitable for measuring the content of biotin in the vitamin complex tablet.

The application discloses a covalent polypeptide inhibitor targeting protein kinase A, a conjugate, a kit, a pharmaceutical composition and application. The general formula of the covalent polypeptide inhibitor is Z1-Seq-Z2; wherein Seq is an amino acid sequence; the C-terminal of Seq comprises a pseudo-substrate recognition motif recognized by protein kinase A, a non-natural amino acid with a covalent reaction group, and can be covalently crosslinked with a Cys200 residue on a catalytic subunit of protein kinase A; Z1 is selected from hydrogen, an acyl group, a fluorescent group, biotin, an isotopic tag or a biological ortho-reaction group; and Z2 is selected from a hydroxyl group, an amino group, a cell-penetrating peptide or a stabilization modification group. The covalent polypeptide inhibitor can strongly and irreversibly inhibit PKA activity, and can be used as an active probe to specifically label active PKA in a complex biological sample, and is used for biological research and drug development.

The invention relates to the technical field of water pollution and water body odor substance detection, in particular to a primer group, a kit and a method for detecting cyanobacteria generating 2-methylisoborneol in a water body based on a recombinase-mediated isothermal nucleic acid amplification (RAA) technology. The primer group is designed based on a mic gene conserved region of the 2-methylisoborneol-producing cyanobacteria, and comprises a forward primer, a reverse primer and a specific probe; the 5'end of the reverse primer is modified with a fluorescent marker, the 5 'end of the probe is modified with biotin, the 3' end of the probe is modified with a phosphorylation group, and nuclease cleavage sites are contained in the probe. The primer group disclosed by the invention can effectively amplify the mic gene of the 2-methylisoborneol, has relatively high specificity and sensitivity, has no cross reaction with cyanobacteria which does not generate the 2-methylisoborneol, and can be combined with lateral flow immunochromatography to be used for on-site rapid detection of the 2-methylisoborneol; the method is of great significance in early warning of excessive content of 2-methylisoborneol in the water body.

The present invention relates to a composition, a kit and a detection method for detecting hydrogen peroxide on the basis of self-biotinylation according to the peroxidation activity of a guanine quadruplex, and, more specifically, to a composition, a kit and a detection method for detecting hydrogen peroxide, the composition comprising: i) a guanine quadruplex-hemin complex (G-quadruplex-hemin complex); ii) biotinyl tyramide; and iii) a probe capable of binding to the guanine quadruplex.

The invention belongs to the technical field of biological detection and analysis, and particularly relates to a high-fidelity biotinylation probe as well as a preparation method and application thereof in polysulfide detection. Specifically, the invention develops a novel biotinylation probe HPB, and the probe is formed by coupling HPE-IAM and biotin. Experimental results show that HPB is superior to IAB and other traditional reagents in the aspects of maintaining and efficiently labeling polysulfide, and a high-specificity solution is provided for Pr-SnH analysis at the proteomics level. By optimizing a marking scheme and introducing a precipitation-redissolution step, the detection accuracy of the polysulfide modified protein is further improved, so that a reliable tool is provided for protein polysulfide modification detection research under a complex cell background, and the method has a good practical application value.

The application discloses a fucose glycoprotein detection kit, a preparation method thereof and a fucose glycoprotein color developing method. First, a liquid sample is dropped on the surface of the kit, and the sample and test paper are infiltrated through a sample inlet. Under the action of transverse flow force, the sample flows to an observation window along a hydrophilic test paper. The glycoprotein containing alpha 1,2-fucose in the sample is combined with agglutinin 1, and the rest of the sample continues to flow to the next layer of test paper. Then, the glycoprotein containing alpha 1,3-fucose is combined with agglutinin 2, and the rest of the sample flows to the third layer and is combined with agglutinin 3 containing alpha 1,6-fucose glycoprotein. All the combined fucose glycoproteins are combined with agglutinin biotin through their antibodies, and horseradish peroxidase is used for labeling color development, so that quantitative detection of the fucose glycoprotein in the sample is realized. The method has important significance for studying the changes of different connection fucose glycoproteins in cells and body fluids in diseases.

This invention discloses a Zn-based framework material, Bi-Cur@Zn-MOF, its preparation method, and its applications in antibacterial and antioxidant properties, belonging to the field of functional materials and biomedical technology. The method specifically involves: dissolving zinc salt in water to obtain a zinc salt solution; dissolving curcumin and biotin together in water to obtain a mixed solution, and adjusting the pH of the mixed solution; mixing and stirring the zinc salt solution and the mixed solution evenly to obtain a precursor solution; subjecting the precursor solution to a hydrothermal reaction; after the reaction, performing solid-liquid separation and collecting the solid; washing and vacuum drying the solid to obtain the Zn-based framework material, Bi-Cur@Zn-MOF. The preparation method of this invention is green and simple, requiring no toxic reagents, and is suitable for large-scale preparation. The Bi-Cur@Zn-MOF prepared by this invention possesses both antibacterial and antioxidant functions, exhibits structural stability and good biocompatibility, and can be used to prepare medical dressings, food packaging materials, skin care products, wound repair, and antioxidant and antibacterial coatings, etc.

The invention relates to the technical field of reagent preservation, in particular to biotinylated tyrosine phosphatase antigen preservation liquid as well as a preparation method and application thereof. The pH value of the biotinylated tyrosine phosphatase antigen preserving fluid is 7.0-7.5, and the biotinylated tyrosine phosphatase antigen preserving fluid is prepared from the following raw material components: a buffering agent, soluble metal salt, an organic dispersing agent, poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) 8400, a metal ion complexing agent, bovine serum albumin, a protein protective agent and a preservative. By optimizing the components of the biotinylated tyrosine phosphatase antigen preserving fluid, when the prepared antigen preserving fluid is used for preserving a biotin-labeled tyrosine phosphatase antigen, the storage life is greatly prolonged under the condition of 2-8 DEG C. The biotinylated tyrosine phosphatase antigen preserving fluid prepared by the method is convenient to use, stable to store, economical and practical, and simple to prepare.

The present disclosure discloses a composition for hair growth comprising Larix europea wood extract, Camellia sinesis leaf extract, Pisum sativum sprout extract, Curcuma longa (Turmeric) callus conditioned media, Hamamelis virginiana (Witch Hazel), Rosmarinus officinalis Leaf Oil, Glycerin, Glycine, Zinc Chloride, Sodium Metabisulfite, Gluconolactone, Sodium Benzoate, Calcium Gluconate, Tetrasodium ethylenediaminetetraacetic acid (EDTA), Saccharide Isomerate, Hyaluronic Acid, Hydrolyzed Hyaluronic Acid, Propanediol, Biotinoyl Tripeptide- 1, Alpha Glucosyl Hesperidin, Caffeine, Hydrolyzed Pea Protein, Polyalkylene Glycol Mono Butyl Ether, Acrylates / C 10-30 Alkyl Acrylate Crosspolymer, Panthenol, Niacinamide, Arginine, PEG-40 Hydrogenated Castor Oil, Ethylhexylglycerin, Phenoxyethanol, and water is added to the composition until the desired volume is achieved. A method for preparing the composition for hair growth is also provided.

A full continuous-flow preparation method of (+)-biotin, including: subjecting a cyclic anhydride and a chiral biphenyl propylene glycol to asymmetric ring-opening reaction to produce a first intermediate, which undergoes selective reduction with a borohydride and cyclization with an inorganic mineral acid to produce (3aS, 6aR)-lactone; subjecting the (3aS, 6aR)-lactone and a sulfenylating reagent to sulfenylation to produce (3aS, 6aR)-thiolactone, which undergoes Fukuyama coupling with a zinc reagent in the presence of a palladium catalyst and elimination reaction in the presence of an inorganic mineral acid to produce an alkenyl valerate compound; subjecting the alkenyl valerate compound to reduction in the presence of a Pd / C catalyst to produce a valerate ester, which undergoes hydrolysis to produce a valeric acid salt; and subjecting the valeric acid salt to debenzylation in the presence of an inorganic mineral acid to produce the target product (+)-biotin.

This invention provides an induction culture medium and method for using marigold anthers as explants. The induction culture medium is based on MS solid medium containing agar, with specific amounts of sucrose, tryptophan, phenylalanine, arginine, casein amino acids, anhydrous asparagine, 6-benzylpurine, naphthaleneacetic acid, silver nitrate, pyridoxine hydrochloride, thiamine hydrochloride, nicotinic acid, D-biotin, folic acid, ascorbic acid, and coconut juice added. This invention also provides a method for induction culture using this induction culture medium. This invention can greatly improve the callus induction rate of marigolds, significantly increasing the number of regenerated seedlings, and provides technical guidance for the cultivation of haploid marigolds using anthers.

The application provides a method for detecting the labeling efficiency of protein biotin, characterized in that: after denaturation of the protein, the protein is incubated with blocked magnetic beads, and the labeling efficiency of the biotin protein is calculated through the concentration change of the biotin protein before and after incubation with the magnetic beads. The scheme has good stability and high accuracy.

The application discloses a kind of cell membrane chromatographic column based on biotin ligase directional covalent fixation and its preparation method and application, belong to chromatography science and technology field. By bonding 2-imino biotin to silica gel, then using biotin ligase specific recognition with Avi-Tag cell membrane fragments, and stable covalent bonding occurs with 2-imino biotin silica gel, so that cell membrane is fixed on the surface of silica gel to obtain Avi-Tag bridged cell membrane chromatographic stationary phase, finally using wet column packing, obtain cell membrane chromatographic column based on biotin ligase directional covalent fixation. The cell membrane chromatographic column can prolong the service life of cell membrane chromatographic column, improve the stability of cell membrane chromatographic column during use, and the short peptide tag (Avi-Tag) used can improve the non-specific adsorption and poor specificity of the cell membrane chromatographic column prepared based on protein tag technology to a certain extent, providing technical support for the wide application of cell membrane chromatographic column.