586 results about "Protein precipitation" patented technology

The invention provides methods for concentrating a macromolecule from a solution comprising the macromolecule and an organic polymer by first subjecting the solution to ultrafiltration to produce a first retentate solution, then adjusting the conductivity of the first retentate solution such that any protein precipitation induced by the organic polymer is essentially prevented to produce a second retentate solution, and then subjecting the second retentate solution to ultrafiltration. In a preferred embodiment, the conductivity is adjusted by diafiltration against water, suitable diluent or buffer. Preferably, the invention pertains to the concentration of solutions of native or recombinant proteins. The invention further pertains preferably to methods for the concentration of cell culture supernatant comprising a product protein and organic polymers of the Pluronic family of block co-polymers, and more preferably comprising Pluronic F-68 block co-polymer.

The invention relates to a cervical exfoliated cell preservative liquid, the preservative liquid comprises the following components with the contents (by weight): 20 percent to 50 percent of alcohols; 15 percent to 50 percent of anti-aggregation reagent; 5 percent to 10 percent of buffer solution; 1 percent to 20 percent of ion strength maintaining reagent; 0.01 percent to 0.5 percent of anti-microbial reagent; 0.1 to 5 percent of mucus dissolving reagent; and 0 to 0.5 percent of cleaning agent. Compared with the prior art, the preservative liquid can not only lead cells to maintain the shape in an in vitro liquid suspension environment, minimize the protein precipitation, dissolve larger protein substances, such as blood and mucus, and reduce the cell aggregation, but can also selectively eliminate or reduce red cells, effectively kill microbes, prevent the activity of reverse transcriptase and retain the integrity of nucleic acids and proteins for facilitating the later analysis; in addition, the preservative liquid can greatly reduce the costs of consumptive materials for the TCT detection, improve the sensitivity and the specificity of the cervical cancer screening and accelerate the promotion and the popularization of the TCT technology in a medical system.

A method for extracting proteins from heterogeneous fluids by precipitation using microfluidics. The method uses an automated protocol for precipitation of proteins onto surfaces, rinsing the precipitates to remove impurities, and resolubilization in buffer for further analysis. The method is compatible with proteins representing a range of different physicochemical properties, as well as with complex mixtures such as fetal bovine serum and cell lysate. In all cases, the quantitative performance (measured using a fluorescent assay for % recovery) was comparable to that of conventional techniques, which are manual and require more time.

A composition, method and device for the preparation of biological samples for subsequent LC-MS analysis using a combined and concurrent protein precipitation and solid phase extraction (SPE) process is described. Through an integrated combination of protein precipitation, filtration, and SPE using a novel zirconia-coated chromatographic media, interfering compounds, such as proteins and phosphate-containing compounds, are eliminated from the biological samples, affording a higher degree of analyte response during LC-MS analysis.

A novel ventricular catheter designed to reduce CSF shunt obstruction is disclosed comprising a tip using a membrane without any opening and capable of filtering the CSF. When the CSF flows through the membrane, neither tissue (choroid plexus, blood cells, tumor cells, suctioned ependymal tissue) nor proteins can break through the membrane, making this ventricular catheter capable of preventing obstruction from tissue invasion but also preventing clogging from protein precipitation, coagulation or flocculation along the downstream shunt system.

The present invention relates to a method of measuring a vitamin D metabolite in a sample, the method comprising the steps of (a) treating said sample with a vitamin D metabolite releasing reagent under conditions appropriate to release a vitamin D metabolite from vitamin D-binding protein and not to cause protein precipitation, (b) subjecting the treated sample obtained in step (a) to a chromatographic separation, and (c) measuring a vitamin D metabolite during or after said chromatographic separation. The present invention also relates to methods for determining the vitamin D status of a subject, for use in the diagnosis of disease, and to agents and kits for use in performing the methods of the invention.

The present invention provides a hemostatic bone graft product and method. Hemostatic bone grafts may include demineralized bone matrix in combination with additives. In one embodiment, the graft comprises demineralized bone and polyethylene glycol. Methods for producing the hemostatic bone graft may include mixing demineralized bone with additives to facilitate protein precipitation, surface tension reduction in blood, and / or a cytolytic effect on cells at a bleeding site.

Disclosed is a process for the co-manufacture of ingredients having food and beverage applications, using potatoes as starting material. The process comprises six steps. The first step is a cutting and dipping of washed raw potatoes in an anti-oxidant solution. The second step is an extraction of undiluted juice free of starch and fibers from a purée made from the anti-oxidant-dipped raw potatoes. The third step is a concentration and enzymatic treatment of the juice. The fourth step is a heating of the juice to specific temperatures to cause precipitation of proteins and separation of precipitated protein therefrom. The fifth step is a thermal browning of the clear juice. The sixth step is an adjustment of the final pH of the juices of the fourth and fifth steps and a blending of these juices in ratios appropriate for intended use. These six steps yield products which may be used as the main flavor principle in malt-free beer, as a coffee substitute and as a flavor enhancer in savory mixes. They also yield dietary fibers, a concentrated edible protein and non-gelatinized granular starch, thereby increasing revenues derived from potato processing while minimizing liquid waste stream.

The invention discloses a method and kit for simultaneously measuring 35 kinds of psychotropic drugs by liquid chromatography-mass spectrometry. By optimizing chromatographic conditions and mass spectrometry conditions, the 35 kinds of psychotropic drugs can be simultaneously treated, the pretreatment step of the psychotropic drugs is simple, and protein precipitation is conducted simply through methanol. Compared with the prior art, the kit and the corresponding detection method have the advantages that the cost is greatly reduced, the analysis time is greatly shortened, the sensitivity is improved, the flux is increased, and the needs for clinical detection are met.

The embodiment of the invention provides a method for detecting 25(hydroxyl)vitamin D by using a high-pass liquid chromatography-tandem mass spectrometry. The method comprises the following steps of: adding an acetonitrile solution containing an internal standard substance of the 25(hydroxyl)vitamin D into a human serum sample to carry out protein precipitation; sufficiently and uniformly mixing the solution, and then, adding an n-hexane extracting solvent; sufficiently and uniformly mixing the solution, then centrifuging the solution, movably taking a supernatant and drying the supernatant, and adding a complex solution to obtain a sample to be detected; detecting the sample to be detected by using a high-pass liquid chromatography-tandem quadrupole mass spectrometer; and quantifying according to the relative retention time of 25(hydroxyl)vitamin D2 and / or 25(hydroxyl)vitamin D3 and the detected abundance ratio of quantitative ion pairs by using an internal standard curve method. According to the embodiment of the invention, the method has the advantages of simplicity in pretreatment, strong specificity and matrix interference resistance, short detection time, high pass, high detection precision and low cost.

The invention relates to a method for extracting heparin sodium by utilizing pork lungs, which has the following steps of: grinding fresh pork lungs into pork lung paste; adding deionized water, lysis agent and preservative; reacting to obtain pork lung serous fluid; adding deionized water and sodium chloride; reacting to obtain pork lung alkaline hydrolysis liquid; slowly heating the pork lung alkaline hydrolysis liquid and adding heparin sodium protamex; after heat preservation and reaction, slowly heating and continuously carrying out heat preservation to obtain pork lung enzymolysis liquid; replenishing sodium chloride after cooling the pork lung enzymolysis liquid; reacting to obtain pork lung salt hydrolysis liquid; heating and carrying out heat preservation on the pork lung salt hydrolysis liquid; adding composite protein precipitation agent; stirring; collecting clear liquid after static placing; concentrating the clear liquid and then adding ethanol; precipitating overnight to obtain precipitate; and dehydrating and drying to obtain a crude product of the heparin sodium. According to the invention, the production cost of the heparin sodium can be reduced, the product quality and the yield can be improved, the large-scale production can be easily realized, meanwhile, the usage amount of chemical reagents is reduced, the emission of waste is reduced, and no waste gas orwaste water is discharged. The economic benefit and the social benefit are obvious.

A composition, method and device for the preparation of biological samples for subsequent instrumental analyses, such as GC, GC-MS, LC and LC-MS analysis, using a solid phase extraction (SPE) process is described. Through SPE process alone or an integrated combination of protein precipitation, filtration, and SPE using a hydrophobic zirconia-coated chromatographic media, interfering compounds, such as proteins, glycerides and phosphate-containing compounds, are eliminated from the biological, food, environmental and biotechnology samples, affording an enhanced analyte response during the instrumental analysis.

The invention discloses a large yellow croaker hepcidin antibacterial peptide and a preparation method thereof, relating to fish gene engineering in the biotechnology field, and providing a large yellow croaker hepcidin antibacterial peptide and a preparation method thereof. The preparation method of the large yellow croaker hepcidin antibacterial peptide comprises the following steps: cloning a large yellow croaker hepcidin antibacterial peptide gene; constructing a recombinant vector; converting a host cell; selecting positive clone for prokaryotic expression; separating and purifying an expression product; and obtaining the large yellow croaker hepcidin antibacterial peptide. During separation and purification, the yield of protein is improved, thus solving the problem of protein precipitation when the hepcidin antibacterial peptide expresses renaturation. The solution has simple preparation and low cost. The prepared large yellow croaker hepcidin antibacterial peptide has high broad-spectrum antimicrobial activity, can be used for scientific researches, can serve as feed additive for preventing and curing diseases of sea farming fishes and has wide application prospect.

The double enzyme hydrolysis process for preparing soybean peptide without bitter includes material pre-treatment, enzymolysis, terminating reaction, purifying product and mathematic simulation of the hydrolysis process. Soybean separating protein material is first pretreated at high temperature to destroy the structure of soybean protein and shorten enzymolysis time, then hydrolyzed with two kinds of proteinase of different characteristics to reach proper hydrolysis degree before high temperature treatment to terminating enzyme reaction. Through further pH regulation to precipitate residual protein, centrifugal separation and desalting the supernatant, the soybean peptide product is obtained. The soybean peptide product is ivory powder and has amino acid composition the same as that of soybean protein, balanced amino acid proportion and rich nutrients.

A soluble canola protein isolate is prepared from canola protein micellar mass by solubilizing the protein micellar mass in a calcium salt solution, preferably a calcium chloride solution, followed by dilution of the resulting canola protein solution. Following removal of the precipitate phytic acid, the aqueous canola protein solution is concentrated, optionally diafiltered, and acidified to a pH of about 2.5 to 4.0 to produce an acidified clear canola protein solution, which may be concentrated, subjected to a colour removal step and dried. The canola protein isolate so formed is soluble, transparent and heat stable in an acid aqueous environment and also is soluble at natural pH, without precipitation of protein.

The invention provides a preparation method of allergen-free oat beta-glucan. The preparation method comprises the following steps: (1) microwave drying; (2) carbon dioxide supercritical extraction; (3) amylase hydrolysis; (4) glucoamylase hydrolysis; (5) alkali extraction; (6) isoelectric point protein precipitation; (7) centrifugal separation to collect the supernate; (8) protease hydrolysis; (9) flocculant precipitation; (10) centrifugal separation to collect the supernate; (11) membrane separation; (12) vacuum condensation; (13) alcohol precipitation; (14) centrifugal separation to collect the precipitate; (15) vacuum drying. The oat beta-glucan extracted from oat bran does not contain any allergen, has the advantage of high purity, and has a specific molecular weight.

The invention belongs to the technical field of medicine detection, and particularly relates to a method for detecting 43 types of medicines in blood by liquid chromatogram tandem mass spectrum. Aiming at the problem of lack of a method capable of simultaneously detecting seven types of common poisons, eleven types of antihypertensive drugs, eleven types of hypoglycemic agents and fourteen types of psychiatric drugs in the prior art, the invention provides the method. The method comprises the following steps of (a) performing protein precipitation on a to-be-detected sample with acetonitrile;and (b) detecting a selected drug by a multi-reaction monitoring (MRM) mode of high performance liquid chromatography-tandem mass spectrometry, and mass spectrum screening analysis is performed in a segmented way according to compound retention time and by two or three pairs of parent ions / daughter ions. By the method, the screening analysis of 43 types of drugs such as common antihypertensive drugs, common hypoglycemic agents, psychiatric drugs and poisons can be rapidly and accurately completed within 25 minutes in one time, the detection efficiency is high, and the method is good in sensitivity and is suitable for promotion and application.

The invention discloses a gingko protein source beverage manufacturing method and a beverage manufactured by the method. Firstly, pure gingko kernel homogenate is obtained; secondly, suspension is obtained after starch in the homogenate is settled, and the suspension is settled by a starch settling method to obtain gingko protein; and thirdly, the obtained protein is baked, homogenized, enzymatically hydrolyzed, blended and sterilized to obtain the gingko protein source beverage.

The invention discloses a synchronous analysis method for trace nicotine in blood-brain samples of an animal and main metabolites thereof. The synchronous analysis method is characterized by comprising the following steps of: utilizing a microdialysis system to synchronously collect blood dialysate and brain tissue dialysate samples of an animal in lined pipes of different chromatographic sampling bottles, respectively adding NIC-d3 and COT-d3 to be mixed with internal labeled solution, and after mixing uniformly, directly analyzing and detecting the content of the nicotine and cotinine in a microdialysis sample by using UPLC-MS / MS. The synchronous analysis method disclosed by the invention has the advantages that the pretreatment steps of protein precipitation and purification for the samples are not needed, the synchronous and accurate analysis of nicotine and metabolites in an animal body is realized; and compared with the prior art, the synchronous analysis method has the characteristics of simple operation, high sensitivity and reliable result and the like, and a new method for researching the metabolism of the nicotine in the animal body is provided.

In the method for efficiently extracting endocrine disruptors in a sample of the present invention, the sample to be tested is preliminarily treated by filtering, grinding, homogenizing, ultrasonication, protein precipitation, protein hydrolysis or degreasing to make a sample solution of an aqueous matrix; adjust the pH value of the sample solution, Or add inorganic salts or organic salts to increase the ionic strength of the sample solution to reduce the distribution coefficient of endocrine disruptors in the water phase; use the membrane disc solid phase extraction device to make the sample solution flow continuously or "flow-stop-flow" intermittent Through the activated nylon nanofiber membrane, the endocrine disruptors in the sample are retained by the nylon nanofiber to achieve extraction. The invention synergizes the advantages of solid-phase membrane extraction and nano-adsorption media, and can realize efficient extraction of internally distributed interfering substances in various actual samples with only a few milligrams of nylon nanofiber membrane and hundreds of microliters of elution solvent , The extraction and enrichment process of separation, adsorption, concentration and elution can be completed within a few minutes to ten minutes.

The invention relates to a method for detection of 25-hydroxyvitamin D in serum. The method comprises sample pretreatment: adding an acetonitrile solution containing a 25-hydroxyvitamin D internal standard substance into a serum sample, carrying out protein precipitation, carrying out centrifugation, taking the supernatant and diluting the supernatant through acetonitrile to obtain a sample to be detected, wherein a volume ratio of the serum sample to the acetonitrile solution is 1: 1-4 and a volume ratio of the supernatant to acetonitrile is 1: 1-4, and enrichment, separation and detection: carrying out enrichment, separation and detection on the sample to be detected through a two-dimensional liquid chromatography-tandem quadrupole mass spectrometer. The method is simple, greatly shortens the detection time, improves the detection flux of the sample and has a high detection precision, a low cost, specificity and strong matrix interference resistance.

The invention discloses a zymolytic oat milk product and a preparation method of ultra-high pressure sterilization. The raw material of the zymolytic oat milk product comprises the following components: fresh milk, oat powder, a stabilizer and water, wherein the percentage is mass percent relative to the raw material; and the preparation method comprises the following steps: (1) mixing an enzymic preparation with water evenly, mixing with oat powder, and filtering to obtain oat slurry after enzymolysis; (2) mixing the stabilizer with the fresh milk evenly, and mixing with the oat slurry obtained from the step (1) evenly; (3) adding water to the product obtained from the step (2) to a constant volume after colloid mill treatment, so as to obtain a precursor; (4) carrying out high-pressure homogenization on the precursor prepared from the step (3); (5) carrying out enzyme deactivation treatment on the precursor which is homogenized in the step (4); and (6) carrying out ultra-high pressure sterilization on the precursor which is sterilized in the step (5), so as to prepare the zymolytic oat milk product. According to the preparation method disclosed by the invention, the problem of protein participation is solved; the nutritional ingredients in oat and fresh milk are reserved; and the final product is cool and smooth in taste, natural, and milky white in color and luster, and has good stability.

A process and system for recovering protein and lipid from food animal byproducts, and the products thereof, involves homogenizing animal byproducts with water to form a homogenate, solubilizing the homogenate by adjusting the pH of the homogenate to form a first pH adjusted composition, separating the first pH adjusted composition forming a light fraction containing lipids (oil), a medium fraction containing protein in solution, and a heavy fraction containing fat-free impurities, separation by first centrifugation, adjusting the pH of the medium fraction to about the isoelectric point of the proteins thereby precipitating the medium fraction forming a second pH adjusted composition, and separating the second pH adjusted composition forming a light fraction containing water and a heavy fraction containing precipitated proteins. The water may then be recycled and used in the homogenization of further byproducts.

The invention relates to a detection method for simultaneously determining the metabolic products of seven CYP450 enzyme probe substrate in human liver microsomes, and belongs to the technical field of biological detection. The detection method comprises the following steps: performing incubation on specificity probe substrates of CYP450 enzyme and the human liver microsomes for different periods of reaction time to generate corresponding metabolic products, using Zaltoprofen as an interior label, adopting a high performance liquid chromatography-tandem mass spectrometry after protein precipitation pretreatment, and thus simultaneously detecting the concentrations of the metabolic products of seven probe substrates. The method disclosed by the invention is high in specificity, high in sensitivity and simple and convenient in operation, and has already successfully been applied to the research of baicalin on CYP450 enzyme inhibiting action of the human liver microsomes.

A process is provided for isolating a protein component of animal muscle tissue by mixing a particulate form of the tissue with an acidic aqueous liquid having a pH below about 3.5 to produce a protein rich solution substantially free of myofibrils and sarcomere tissue structure. The protein rich aqueous solution can be treated to effect protein precipitation, followed by protein recovery.

A system and method for generating a protein concentrate includes generating an initial alkalized slurry by combining flour, water and a base and generating a solubilized rich protein stream therefrom. The method and system includes generating a de-oiled solubilized rich protein stream by separating the solubilized protein rich stream and generating a protein precipitate including an acid curd by mixing the de-oiled solubilized rich protein stream with an acid and separating the acid curd from the protein precipitate. The system and method further includes washing the first protein curd using a wash station to generate a second protein curd, generating a neutral hydrolyzed protein slurry by mixing the second protein curd with a base and water and generating a homogenized protein slurry from the protein slurry. The method and system includes generating a cooled protein slurry by pasteurizing the homogenized protein slurry and extracting the protein concentrate therefrom.

The extracting process of chitin and biological protein powder from raised fly includes: fly maggot or fly pupa material selection; soaking in NaOH solution of 2-3 % concentration at 90-100 deg.c for10-15 hr; filtering to obain chitin as filtrated matter and filtrate protein liquid; soaking filtrate protein liquid in HCl solution of 2-3 % concentration to separate protein through deposition and subsequent filtering; water washing and stoving the chitin as filtrated matter and filtered protein separately to a water content lower than 10% to obtain the chitin and biological protein powder products. The chitin is used as fertilizer to raise the resistance of crop and prolong the fresh preserving period. The protein powder containing rice protein and amino acids is excellent feed for milk cow and laying egg.

The invention discloses a process for extracting pachyman from poria coccus wolf. The process comprises the following steps: (1) selecting a poria coccus wolf raw material, and conducting ultrafine grinding to obtain poria coccus wolf coarse powder; (2) adding water into the poria coccus wolf coarse powder for soaking, and placing the soaked poria coccus wolf coarse powder in 40000 Hz ultrasonic waves to be treated for 20-25 min; (3) conducting water bathing and then conducting centrifugal separation; (4) conducting enzymolysis separation by adopting a compound enzyme to obtain a filtrate; (5) conducting protein precipitation and filtration, and centrifugally collecting a supernate; (6) concentrating a pachyman extract to be 10 to 20% of the original volume to obtain a pachyman concentrate, and conducting spray drying to obtain coarse pachyman; (7) conducting ultrafiltration, then conducting column chromatography to obtain purified pachyman, and conducting freeze drying so as to obtain the pachyman. According to the process, an ultrasonic-assisted extraction method is utilized, the process steps are simple, the pachyman leaching rate can be obviously increased, the extracted pachyman is low in possibility of stereostructure damage and high in biological activity, and the advantages that the leaching time is shortened, the extraction conditions are mild, and the reaction product is free of toxic or side effect are achieved.