4results about How to "Single component" patented technology

The invention relates to a device and a method for eluting, purifying and recovering oversized DNA (deoxyribonucleic acid) based on pulsed field gel electrophoresis, which are used for efficiently recovering complete DNA molecules from hundred kb level to Mb level. The device comprises an electrophoresis protection chamber with a polygonal container structure and a sample recovery chamber, the side edge of the protection chamber is provided with a semi-permeable membrane for current to pass through, and the recovery chamber is detachably placed in the center and comprises the semi-permeable membrane; the detachable and replaceable magnesium sheet is arranged in the protection chamber and is used for ionizing magnesium ions to promote DNA (Deoxyribose Nucleic Acid) compression; the method comprises the following steps: preparing a biological sample into an agarose gel block, cracking and cleaning the agarose gel block, placing the agarose gel block in a device, and adding a recovery protection solution containing PEG; under the condition of pulsed field gel electrophoresis, DNA migrates out of a gel block and is combined with magnesium ions to be compressed into spheres, and the spheres are collected in a recovery chamber after charges are neutralized. Compared with the prior art, the method provided by the invention overcomes the defects of low product purity and tedious steps of a traditional recovery method, realizes high-purity and high-efficiency integrated recovery, and is suitable for genomics research and biotechnology application.

The application discloses a glycerol / polyethylene glycol-based aspartic acid monoester amphoteric-nonionic surfactant and a preparation method thereof, and belongs to the technical field of special surfactants. The application takes maleic anhydride, a low-melting-point polyol with excellent mutual solubility and a primary aliphatic amine as raw materials, and prepares the target product through three steps of selective monoesterification, Michael addition and neutralization of acid-base equivalent, and can select a reaction atmosphere according to the material characteristics of the polyol. The application avoids the use of high-boiling-point solvents throughout the whole process, can realize directional monoester synthesis, and effectively solves the technical pain points of traditional aspartic acid ester products, such as disordered components, purification difficulty and limited industrial production. The product has the dual advantages of mild and low irritation of amphoteric surfactants and acid and alkali resistance and salt resistance of nonionic surfactants, and has the advantages of green and simple overall preparation process, adjustable performance and suitable scale industrial production, and has a wide application prospect in the fields of daily chemicals, medicines and industrial emulsification.

The invention discloses a chlorhexidine gluconate solution and a preparation method thereof. The method comprises the following steps: dispersing chlorhexidine free alkali in purified water, introducing carbon dioxide, pressurizing and carbonizing, and constructing a homogeneous or quasi-homogeneous reaction system; adding gluconic acid-delta-lactone under the condition that the system pressure is not lower than 0.30 MPa, maintaining the pressure, carrying out constant-pressure stirring reaction, and inhibiting carbonic acid decomposition by utilizing back pressure so as to match lactone hydrolysis kinetics; and after the reaction is finished, carrying out gradient pressure relief, vacuum degassing and filtering. According to the present invention, the gas-liquid-solid three-phase coupling and the variable pressure-pressure maintaining delayed release process are adopted, such that the low-temperature total synthesis of chlorhexidine is achieved, the generation of parachloroaniline impurities and the discoloration of the product caused by the high temperature are effectively avoided, and the technical problems of incomplete reaction and easy muddy reaction at the low temperature are solved. The process has the advantages of no residue, high product purity and good safety.

This invention discloses a glycerol / polyethylene glycol-based aspartic acid monoester amphoteric-nonionic surfactant and its preparation method, belonging to the field of specialty surfactant technology. Using maleic anhydride, low-melting-point polyols with excellent melt miscibility, and fatty primary amines as raw materials, the invention prepares the target product through a three-step reaction involving selective monoesterification, Michael addition, and acid-base equivalent neutralization. The reaction atmosphere can be selected based on the characteristics of the polyol materials. This invention avoids the use of high-boiling-point solvents throughout the process, enabling directional monoester synthesis and effectively solving the technical pain points of traditional aspartic acid ester products, such as disordered composition, difficult purification, and limited industrial production. This product combines the advantages of mild and low-irritation amphoteric surfactants with the acid, alkali, and salt resistance of nonionic surfactants. The overall preparation process is green and simple, with adjustable performance, suitable for large-scale industrial production, and has broad application prospects in the fields of daily chemicals, pharmaceuticals, and industrial emulsification.