5 results about "Sodium phosphate buffer" patented technology

The application discloses a preparation method of structural stable porous starch, which comprises the following steps: adding a hydrophilic colloid into deionized water to prepare a solution, then adding starch, mixing uniformly to obtain a compound suspension, heating the compound suspension at a crystal starting melting temperature, then performing vacuum freeze drying, grinding and sieving to obtain melting coated starch, adding the melting coated starch into a citric acid-sodium phosphate buffer solution, mixing uniformly to obtain a starch-buffer solution suspension, adding an enzyme to perform oscillation reaction, adjusting the reaction solution to alkaline to terminate the reaction after the reaction is completed, then adjusting the reaction solution to neutral, finally performing centrifugation, washing, vacuum freeze drying, grinding and sieving to obtain the structural stable porous starch. The method has the advantages of simple process and low manufacturing cost, and the prepared porous starch has excellent adsorption, structural stability and thermal stability, and solves the problems of complex manufacturing process, long preparation time, poor structural stability of the prepared porous starch and limited pore forming effect in the prior art.

The application discloses a triglyceride and cholesterol mixed quality control liquid and a preparation method and application thereof, relates to the technical field of in vitro diagnostic reagents, and solves the problem of poor compatibility of components of the triglyceride and cholesterol mixed quality control liquid. The triglyceride and cholesterol mixed quality control liquid comprises a mother liquor and a diluent, the mother liquor comprises the following components in percentage by mass: glyceryl trioleate 7-10%, Triton X-100 85-90% and cholesterol 3-5%; and the diluent comprises the following components in percentage by mass: isopropyl alcohol 50-51%, sodium phosphate buffer 39-40%, sodium cholate 9.50-9.75% and sodium benzoate 0.25-0.50%. The mixed quality control liquid is high in stability and accuracy, can detect triglyceride and cholesterol at the same time, and the detection results do not interfere with each other.

The invention belongs to the field of collagen extraction, and particularly relates to a preparation method of a high-stability I-type collagen solution for injection and an obtained product. The method is realized by the following steps: firstly, pretreating a type I collagen freeze-dried product; and sequentially adding a sodium hyaluronate mixed solution and a chitosan mixed solution 3, fully and uniformly mixing, and adding a disodium hydrogen phosphate buffer solution to obtain the I-type collagen solution for injection. The preparation method disclosed by the invention is simple and easy to operate, the prepared animal-derived I-type collagen solution for injection is relatively good in uniformity and stability, and the selected components are safe and relatively excellent in effectiveness. The type I collagen and the chitosan have good effects of promoting cell proliferation, migration and repair, and related repair products are sold on the market; the type I collagen and the sodium hyaluronate have a good moisturizing effect; the trehalose component has good moisturizing and anti-oxidation effects, and particularly, the trehalose has excellent characteristics of keeping cell viability and biomacromolecule activity; the mannitol component has a good effect of improving the osmotic pressure molar concentration of the solution, the osmotic pressure of the solution can be basically kept consistent with the osmotic pressure of body fluid in the solution, and side effects such as edema are not prone to occurring.

This invention relates to a method for degrading PET fibers using a mechanical enzymatic method and recycling the degradation products, comprising: (1) extracting crude enzyme solution using screened PET-degrading strains. When the bacteria are in the late logarithmic growth phase, the supernatant of the culture medium is collected by centrifugation, and then placed in a freeze dryer to remove water from the crude enzyme solution, thereby obtaining the desired enzyme powder. (2) accurately weighing a certain amount of PET and placing it in a homogenizer, adding a certain amount of enzyme powder and sodium phosphate buffer with added green surfactant, performing preliminary mechanical treatment using a homogenizer, and then incubating the treated mixture at a constant temperature. (3) reacting the degradation products in the solid reaction mixture with sodium carbonate solution, filtering through cotton, and then acidifying with hydrochloric acid to precipitate substances such as terephthalic acid. Finally, centrifuging is used to remove the acidic supernatant to separate the degradation products such as terephthalic acid. This process avoids the use of large amounts of solvent, reduces costs and environmental impact, realizes the direct enzymatic hydrolysis of highly crystalline PET fibers, and simultaneously achieves high-purity recovery of degradation products, which can be recycled for the production of new PET products.

The present invention relates to a method for synthesizing α-Fe2O3 / Fe3O4 nanoparticles having Bst3 polymerase immobilized on their surface, the method being characterized in that it comprises the following steps: 1) synthesis of α-Fe2O3 / Fe3O4 nanoparticles; a) dissolving chitosan in an acid solution to obtain a chitosan solution; b) adding a glutaraldehyde solution to the chitosan solution; c) stirring to form a chitosan hydrogel; d) mineralizing magnetic nanoparticles in the chitosan hydrogel; e) resuspending the chitosan hydrogel in distilled water in an FeCl3 solution at least once to form a CS-Fe complex; f) wetting the CS-Fe complex with a NaOH solution to obtain a black magnetite / chitosan compound; g) degrade the magnetite / chitosan compound in acetic acid and an H2O2 solution to obtain magnetic chitosan nanoparticles;h) Recover the α-Fe2O3 / Fe3O4 nanoparticles by centrifugation; i) Functionalize the α-Fe2O3 / FeO4 nanoparticles; 2) Immobilization of the Bst3 polymerase; a) Take a sample of 0.5 to 1.5 g of functionalized magnetic nanoparticles; b) Mix the functionalized magnetic nanoparticles with glutaraldehyde to a final concentration of 2 to 5%; c) Wash the functionalized magnetic nanoparticles with sodium phosphate buffer and resuspend them in the same buffer; d) Immobilize the Bst3 polymerase by mixing 7,000 to 15,000 units of enzyme with the nanoparticles suspended in sodium phosphate buffer; e) Mix the nanoparticles suspended in sodium phosphate buffer with the enzyme by stirring for 18 to 30 hours; f) separate the nanoparticles suspended in sodium phosphate buffer mixed with the enzyme using a magnet and resuspend them in a sodium phosphate buffer containing 20 to 30% sterile glycerol.;