6 results about "Infranatant" patented technology

The invention discloses a method for separating plasmid DNA through floating impurities in combination with an alkali lysis method, which comprises the following steps of: S1, lysing bacteria through the alkali lysis method, and releasing the plasmid DNA; s2, adding sodium bicarbonate into a product obtained in the step S1, and floating impurities; and S3, taking a lower-layer clear solution, and purifying to obtain plasmid DNA. According to the method disclosed by the invention, sodium bicarbonate is added into a product after alkali cracking to generate a large amount of gas, impurities such as cell debris and denatured protein generated by cracking can float on the surface of liquid within 3-10 minutes, and solid-liquid separation is simply and conveniently carried out, so that plasmid DNA is separated out, and expanded production is facilitated; the method does not need to use a centrifugal machine, is convenient for process amplification, can directly carry out subsequent steps without using a deep filter, reduces the production cost, shortens the test time, and achieves the purposes of reducing the cost and improving the efficiency.

The application discloses a preparation method of metal organic framework densely wrapped hollow glass microspheres, which comprises the following steps: 1) adding the hollow glass microspheres into a piranha solution, stirring, removing the lower layer of debris after standing, washing with ultrapure water, drying to obtain product A; 2) adding polyethyleneimine solution into the product A, mixing and reacting, standing and separating, washing the upper layer of floating matter with ultrapure water, vacuum drying to obtain product B; 3) adding N, N-dimethylformamide into 2-amino terephthalic acid, benzoic acid and ZrCl4, ultrasonic dissolving, adding the product B, stirring and reacting, standing and separating, taking the upper layer of floating matter, washing with N, N-dimethylformamide and ethanol, vacuum drying, and the metal organic framework densely wrapped hollow microspheres prepared by the method can be used as a general type of capture probe, and can be used in the capture detection and analysis of target extracellular vesicles, phosphoproteome, phosphopeptide, nucleic acid and cells, and has a wide application prospect in liquid biopsy.

This invention relates to the field of solid-liquid separation technology, specifically to a solid-liquid separation device and method for peptide purification. The device includes a support frame, with an equidistant telescopic component on one side of the support frame. A filter assembly for filtering a crude peptide solution is located on another side of the equidistant telescopic component. The equidistant telescopic component is used to separate or combine the filter assembly. The filter assembly consists of multiple vertically distributed, detachable chambers. Each chamber comprises an upper chamber, a lower chamber, and two stacked middle chambers located between them. These chambers are used for stepwise filtration of the crude peptide solution from top to bottom. This solid-liquid separation device and method for peptide purification, through the equidistant telescopic component and the filter assembly, allows for the separation or combination of the upper filter chamber, lower filter chamber, and two middle filter chambers. During maintenance, rapid and synchronous separation of each chamber is possible, making disassembly and assembly of the chambers quick and convenient, thereby improving maintenance efficiency.

The application discloses a kind of cryogenic biological sample bank equipment and access method, including frame platform, storage mechanism, transfer mechanism, freezing tank, clamping mechanism, tray access mechanism and pick-up mechanism;Frame platform includes outer frame and middle layer platform;Middle layer platform divides outer frame into upper space and lower space;Storage mechanism is arranged in lower space, and built-in basket frame is arranged;Middle layer platform is provided with first through hole and second through hole;The lower end of transfer mechanism is located in lower space;Freezing tank is installed in second through hole;Clamping mechanism, tray access mechanism and pick-up mechanism are all arranged in upper space;Tray access mechanism is located below clamping mechanism;Pick-up mechanism is located above freezing tank.The application can complete the function of automatic access of cryopreservation box by the cooperation of the above device, thereby effectively reducing the interference of human factors, improving the safety, reliability and convenience of access, and effectively improving the protection effect of biological sample.

This invention belongs to the field of organic matter detection technology and relates to a method for detecting six p-phenylenediamine compounds in milk. The method includes: mixing saturated saline solution, glutathione solution, extraction solvent, milk, and internal standard; sequentially subjecting the mixture to vortexing, sonication, and centrifugation; collecting the upper organic phase; adding the extraction solvent again to the lower aqueous phase; repeating the extraction and combining the organic phases; concentrating the mixture under nitrogen and redissolving it in acetonitrile; filtering to obtain the sample; and finally, using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS / MS) for detection, calculating the content based on peak area and a standard curve. This invention employs liquid-liquid extraction pretreatment combined with isotope internal standard method and optimized chromatographic and mass spectrometric conditions. It is simple, efficient, low-cost, has good repeatability, high sensitivity, and a recovery rate that meets detection requirements. It can simultaneously achieve qualitative and quantitative detection of six p-phenylenediamine compounds in milk.