150 results about "Protein precipitation" patented technology

The invention provides a method for separating extracellular vesicles from a milk source, which comprises the step of adding a dispersing agent before adding a precipitator into the milk source to precipitate casein so as to reduce the wrapping of protein precipitation on the extracellular vesicles and improve the yield of the extracellular vesicles, thereby obtaining a milk source extract rich in the extracellular vesicles.

The invention discloses a separation and purification method for improving protein purity and emulsifying property of fusarium venetii based on a cell wall simplification engineering strategy, and belongs to the technical field of food processing and protein separation and purification. The method for separating and purifying the Fusarium venanii protein comprises the following steps: dispersing Fusarium venanii fermented hyphae in water, and adjusting the pH value to 10-12 to obtain a Fusarium venanii solution; performing high-pressure homogenization, collecting supernate, adjusting the pH value to 4.4-4.5, performing centrifugation, and taking protein precipitate; redissolving the protein precipitate in water, adding chitinase for reaction, carrying out acid precipitation again after the reaction is finished, centrifuging, and taking the protein precipitate; and redissolving the protein precipitate in water, adjusting the pH value, dialyzing and drying to obtain the fusarium venanii protein. The fusarium protein obtained by the method is high in purity, has the characteristics of higher solubility, high interfacial activity, emulsifying property and the like, and is beneficial to food industrial application of the fusarium protein.

The invention belongs to the technical field of active peptides, and particularly relates to an active peptide capable of improving memory, a brain peptide enzymolysis extract and a preparation method and application of the brain peptide enzymolysis extract. The amino acid sequence of the active peptide is shown as SEQ ID NO.1 Ala-Ala-Val-Pro, and the active peptide can improve sleep and improve memory; on the other hand, the invention provides a preparation method of the brain peptide enzymolysis extract. The preparation process comprises the steps of raw material pretreatment and grinding, microwave treatment and centrifugal separation, protein precipitation and enzymolysis, microwave-assisted enzymolysis and purification and nanofiltration membrane filtration. Pepsase is added in the microwave treatment, and the temperature is not more than 50 DEG C in the enzymolysis process, so that the small molecule peptide keeps relatively high activity; furthermore, carbon dioxide gas is introduced in the microwave treatment for aeration, and the aeration pressure and the pH value are optimized, so that the activity and the yield of the brain peptide enzymolysis extract are further improved.

The present disclosure provides methods for isolating nucleic acids from a sample, comprising: (a) contacting a sample, a lysate of the sample, a supernatant of the lysate, or a portion of the sample, the lysate or the supernatant with one or more first agents (e.g., protein precipitating agents) and one or more second agents (e.g., inhibitor removing agents) to generate a mixture, (b) separating the mixture of step (a) into a solid phase and a liquid phase, wherein the one or more second agents are primarily in the solid phase, and (c) isolating nucleic acids from the liquid phase of step (b). Compositions and kits useful in such methods are also disclosed. Further disclosed are methods, compositions and kits for preparing a lysate using a lytic reagent comprising one or more relatively mild chaotropic agents and one or more phosphates from a sample, especially a complex sample, such as a soil or stool sample.

The present invention relates to a kit for detecting porcine epidemic diarrhea and a preparation method thereof, belonging to the technical field of virus detection, and specifically comprising the following steps: after extracting the antigen, treating it with a virus purification agent containing polyethylene glycol, nuclease and concanavalin, and then obtaining a virus antigen suspension with a composite dissociation solution. The suspension is coated on a microporous reaction plate to form a solid-phase antigen. Subsequently, the porcine epidemic diarrhea virus solid-phase antigen, enzyme marker, sample diluent, Tris buffer, color developer and stop solution are aseptically stored to prepare a kit for detecting porcine epidemic diarrhea. The present invention provides a novel kit and a preparation method thereof, which can not only effectively purify porcine epidemic diarrhea virus, but also significantly reduce the risk of protein precipitation, while overcoming nucleic acid interference and improving purification efficiency.

The invention belongs to the technical field of food processing methods, and particularly relates to a preparation method of squid skin chelated calcium peptide powder. Squid skin is used as a raw material, small-molecular-weight squid skin peptide powder is obtained through enzymolysis, ultrafiltration and membrane separation, then the small-molecular-weight squid skin peptide powder, calcium chloride and ethyl alcohol are subjected to a chelation reaction and protein precipitation, centrifugation is conducted, precipitates are collected, and the squid skin chelated calcium peptide powder is obtained. According to the preparation method, the utilization rate of the squid skin leftovers is increased, and active substances contained in the squid skin leftovers are fully developed and utilized. Moreover, according to the embodiment, the operation is simple, and the prepared squid skin chelated calcium peptide powder has relatively strong oxidation resistance and relatively high calcium chelation rate, and the highest calcium chelation rate can reach 63.18%; and the calcium absorption rate and the calcium content are relatively high and can reach 77.14% and 65.82 mg / g respectively.

The invention discloses a method for detecting arenecycline in plasma by an HPLC-MS / MS (High Performance Liquid Chromatography-Mass Spectrometry / Mass Spectrometry) method. According to the method, a protein precipitation method is adopted for pretreatment; an Agela Venusil MP C18 (2) chromatographic column is adopted as the chromatographic condition, and an aqueous solution of 1% FA and methanol of 1% FA are used as mobile phases for gradient elution; an electrospray ionization source (ESI) tandem mass spectrum is adopted as a mass spectrum condition, and verapamil is used as an internal standard for quantitative detection. The method is easy and convenient to operate, high in analysis speed, high in sensitivity and suitable in linear range, and meets the requirement for large-batch sample analysis in clinical research.

The invention discloses a purification method of bovine serum albumin. The purification method comprises the following steps: S1, pre-treating bovine plasma to remove impurities and fibrin; s2, adsorption with tourmaline or sepiolite; s3, protein precipitation through heat shock; and S4, carrying out heparin-agarose chromatography. The bovine serum albumin sample is purified by combining tourmaline or sepiolite with heparin-agarose chromatography, nuclease in the bovine serum albumin sample can be removed, and the product purity is improved; and one-step heat shock is combined with heparin-agarose chromatography, so that the energy consumption is reduced, reagents such as ethanol influencing the protein activity are prevented from being used, the recovery yield is high, and large-scale production is facilitated.

The invention discloses a method for determining the concentration of letemovir in plasma by using liquid chromatography-tandem mass spectrometry, which comprises the following steps: S1, preparing a calibrator working solution and a quality control working solution of letemovir, respectively adding the calibrator working solution and the quality control working solution into a plasma matrix to obtain a plasma calibrator and a plasma quality control, preparing an internal standard working solution taking the lenvatinib-d5 as an internal standard substance; s2, respectively adding a plasma calibration material and a plasma quality control material into the internal standard working solution obtained in the step S1, carrying out protein precipitation treatment, collecting supernate, carrying out liquid chromatography-tandem mass spectrometry analysis on the supernate, and drawing a liquid chromatography-tandem mass spectrometry standard curve; and S3, obtaining the concentration of letemovir in the plasma of a sample to be detected according to the liquid chromatography-tandem mass spectrometry in the step S2. According to the method, the sample pretreatment step is simplified, the operation difficulty and time consumption are reduced, a rapid, accurate and high-sensitivity analysis result is ensured, and the method is suitable for the requirements of rapid clinical and research fields.

The invention discloses a liquid chromatography-tandem mass spectrometry detection method for catecholamine and metabolites thereof, which comprises the following steps: step 1, sequentially adding a sample to be detected, an internal standard solution, a derivatization buffer solution and a derivatization solution into holes in the third / ninth column of a 96-well plate, oscillating at room temperature, replenishing water, and continuing oscillating; step 2, adding an activating solution and magnetic beads into the first / seventh column of the 96-well plate; adding equilibrium liquid into the second / eighth column; a first leacheate is added into the fourth column and the tenth column; adding a second leacheate in the fifth / eleventh column; adding the eluent into the 6 / 12th column; then placing the sample on a 32-channel sample pretreatment system for magnetic solid-phase extraction; and step 3, liquid chromatography-tandem mass spectrometry detection. According to the method, the sample is firstly derivatized and then is subjected to magnetic solid-phase extraction, so that only less sample size is needed, the sensitivity is higher, and the economical efficiency is better; according to the method for directly derivatizing the sample, the sample does not need to be derivatized after being subjected to protein precipitation and supernatant removal, and the steps are simpler, more convenient and more automatic.

The invention relates to the technical field of biological detection, in particular to a composition for protein precipitation, a protein precipitation agent containing the composition, a protein precipitation combined product, a detection kit and a preparation method and a detection method of a blood analysis sample. The composition for protein precipitation comprises zinc sulfate and ammonium acetate in a dosage ratio of (5-17) mg: (0.5-1) mmol. Compared with the prior art, the composition has the following beneficial effects that the zinc sulfate and the ammonium acetate are matched according to a specific proportion, so that the specific composition is formed, and hemoglobin in a blood sample can be effectively removed by taking the composition as a protein precipitation component.

The utility model relates to the field of protein purification, and discloses a protein precipitation supernate drainage device, a precipitation tank is mounted in a mounting cylinder, the upper half part of the precipitation tank is of a cylindrical structure, the inner diameter of the lower end of the precipitation tank is gradually reduced to form a conical part, a pipeline is welded at the bottom end of the conical part, and the lower end of the pipeline is provided with a liquid outlet. A valve is installed below the pipeline, a cover plate is rotationally installed above the centrifugal machine, the cover plate penetrates through the upper portion and the lower portion of the cover plate and is slidably connected with a liquid suction pipe in a sleeving mode, and a liquid suction hose is connected to the end, away from the sedimentation tank, of the liquid suction pipe and connected with a liquid inlet of an external peristaltic pump. The settling tank is fixed in the mounting cylinder, and the settling tank is combined with the centrifugal machine, so that the settling tank can be centrifuged after isoelectric point settling, secondary transfer of protein precipitate after settling is not needed, the loss is reduced, and the convenience is improved.

The invention relates to the field of detection, in particular to a method for simultaneously detecting multiple fat-soluble vitamins, which comprises the following steps: (S.1) carrying out protein precipitation and liquid-liquid extraction on a sample to be detected to obtain an extract containing fat-soluble vitamins; (S.2) carrying out derivatization reaction on the extract by using a PTAD derivatization reagent; and (S.3) analyzing the derivatized product by adopting a liquid chromatography-tandem mass spectrometry method, wherein the detected target fat-soluble vitamins comprise vitamin A, vitamin E, 25-hydroxy vitamin D2, 25-hydroxy vitamin D3, vitamin K1, vitamin K2 and vitamin K2. According to the application, PTAD is creatively adopted as a unified derivatization reagent, simultaneous and efficient derivatization of seven fat-soluble vitamins is successfully realized, the detection sensitivity of low-content targets, especially vitamin D, K2 and the like, is greatly improved, and the core problems of weak signal response and difficulty in accurate quantification are solved.

The invention discloses a purification method of cord blood mesenchymal stem cell source exosome, and relates to the technical field of bioengineering. The method comprises the following steps: firstly, carrying out pH regulation pretreatment on cell culture supernate through a technical path of combining gradient centrifugation and membrane filtration, and sequentially removing cell debris and large-particle impurities by adopting multi-stage differential centrifugation; then carrying out selective protein precipitation by utilizing polyethylene glycol with specific molecular weight, and realizing fine separation of the exosome by combining sucrose-meglumine diatrizoate density gradient centrifugation; and finally, terminal purification is completed under low-temperature and low-pressure conditions through a polyethersulfone membrane filtration system with an optimized pore size. According to the method, centrifugal parameters, reagent concentration and filtering conditions are precisely regulated and controlled, so that the particle size of the obtained exosome is intensively distributed in the range of 30-150nm, the protein purity reaches 95% or above, the recovery rate exceeds 85%, and the separation efficiency and quality of the exosome are remarkably improved.

This invention provides a method for the simultaneous and rapid detection of four oxidative stress-related biomarkers and its application. The detection method includes: (S1) pretreatment of samples using a protein precipitation extract to simultaneously extract four target compounds: 8-hydroxydeoxyguanosine, 8-isoprostaglandin F2β, 8-isoprostaglandin F2α, and acetyllysine, and preparing a test solution; the protein precipitation extract is a methanol-acetonitrile-perchloric acid mixed solution containing formic acid, wherein the volume ratio of methanol, acetonitrile, and perchloric acid is (8-10):(8-10):(0.5-1), and the volume concentration of formic acid is 0.1-0.5%; (S2) detection of the test solution and standard solution using liquid chromatography-tandem mass spectrometry, and matrix calibration using an internal standard method; plotting a standard curve with the peak area ratio of the target compound to the internal standard as the ordinate and the concentration as the abscissa; and calculating the concentration of the target compound in the test solution based on the standard curve.

The application relates to a component detection method of a cosmetic liquid and a permeability detection method of the cosmetic liquid, and the component detection method comprises the following steps: adding a protein precipitant to purify the cosmetic liquid; performing liquid chromatography-tandem mass spectrometry on the purified cosmetic liquid to obtain chromatographic peak response values of nicotinamide, ascorbic acid and VC ethyl ether; wherein, the positive ion and the negative ion are alternately ionized in the mass spectrometry, and multiple reaction monitoring is performed on the nicotinamide, the ascorbic acid and the VC ethyl ether; and the concentrations of the nicotinamide, the ascorbic acid and the VC ethyl ether in the cosmetic liquid are obtained according to the chromatographic peak response values. The method improves the detection precision of low-concentration and multi-target component.

The application relates to an LC-MS / MS method for detecting neurotransmitter metabolites in a biological sample, comprising the following steps: S1, constructing a mass spectrum database containing neurotransmitter metabolites and isotope internal standards; S2, preparing a mixed standard solution containing neurotransmitter standards and drawing standard curves of each neurotransmitter metabolite standard; S3, extracting a biological sample by a protein precipitation method to obtain a sample solution to be detected; S4, separating the sample solution to be detected by using liquid chromatography, wherein a mobile phase A of the liquid chromatography is an aqueous solution containing ammonium fluoride and formic acid, and a mobile phase B is an organic phase containing formic acid; and S5, performing mass spectrum detection on the sample separated by the liquid chromatography. The method can realize baseline separation of 57 metabolites within 9 minutes.

The application provides a method for quantitatively detecting the concentration of dapsone in human plasma by using liquid chromatography-tandem mass spectrometry (LC-MS / MS). By optimizing the chromatography and mass spectrometry conditions, the detection specificity and sensitivity are improved. The protein precipitation pretreatment and rapid chromatography separation technology are adopted, the analysis time is shortened, the sampling amount is reduced, and the automation adaptability is good. The method can be used for efficient and accurate quantification, and is suitable for clinical pharmacokinetic research and treatment monitoring.

The invention belongs to the technical field of reutilization of palm shells, and particularly relates to a method for preparing xylose by taking palm shells as a raw material. Comprising the following steps: (1) pretreatment: carrying out crushing and steam explosion pretreatment on an air-dried palm shell raw material to obtain palm shell steam explosion slag; (2) enzymolysis: mixing the steam explosion slag with a compound enzyme solution, stirring, preserving heat, performing enzymolysis, and filtering to obtain enzymolysis slag; (3) hydrolysis: adding acid into the enzymolysis residues for hydrolysis to obtain hydrolysate; (4) salting-out: adding alkali into the hydrolysate to precipitate protein, and filtering to obtain salting-out liquid; and (5) purification: carrying out activated carbon decoloration, electrodialysis and ion exchange desalination on the salting-out solution to obtain a purified solution. Hard palm shell cell walls are broken through steam explosion pretreatment, and hemicellulose and lignin are better separated during steam explosion through dilute acid soaking, so that more hemicellulose is released, and a better hydrolysis effect is obtained.

The invention provides a method for determining D-psicose in processed food and application of the method. The method specifically comprises the following steps: extracting a sample with warm water at 50-60 DEG C, precipitating protein by adopting a Carrez reagent, and removing interference impurities; chromatographic conditions are defined as follows: a calcium type strong cation exchange column is adopted, pure water containing 50 mg / L of EDTA-Ca is adopted as a mobile phase, the flow rate is 0.4-0.6 mL / min, and the column temperature is 80 DEG C. The result shows that the linear relation of the D-psicose is good in the concentration range of 1.0 mg / mL to 20.0 mg / mL, and the correlation coefficient is 0.999999; according to the method, the LOD is 0.002 g / 100g, and the LOQ is 0.005 g / 100g. Under the experimental conditions of standard addition before simulation processing, the average recovery rate of 18 matrixes including dairy products, bakery products and the like is 81.5-128.1%, and the RSD is less than 3.0%. The determination method provided by the invention is simple in pretreatment, high in sensitivity, strong in interference resistance and good in accuracy, effectively solves the ubiquitous problems of matrix wrapping, matrix interference, difficulty in isomer separation and the like when the D-psicose in the processed food is detected, can realize rapid and accurate detection of the D-psicose in all dosage forms of processed food, and has a wide prospect.

The invention discloses a compound stabilizer and a milk coffee beverage, and relates to the technical field of food additives, the compound stabilizer is used in the milk coffee beverage, and the compound stabilizer comprises the following components in parts by mass: 5-8 parts of an emulsifier, 1.2-2.5 parts of a thickener and 1.2-2.5 parts of phosphate. Meanwhile, the mass parts of the emulsifier, the thickening agent and the phosphate are controlled within the range, so that a stable beverage system can be formed after the compound stabilizer is added into the milk coffee beverage, and the aroma and taste stability of the milk coffee beverage after high-temperature sterilization and the system stability after high-temperature storage are improved; the quality problems of protein precipitation, water separation, product layering, oil slick and the like after the milk coffee beverage is placed for a long time are reduced, and the storage stability and consumption experience of the product are remarkably improved.

The invention provides a method for simultaneously detecting dichloroacetic acid and trichloroacetic acid in urine, and belongs to the technical field of analysis detection and occupational health / environmental health. According to the method disclosed by the invention, a synergistic pretreatment strategy of acidic sample loading, WAX / reversed-phase mixed mode solid-phase extraction, water / low-proportion organic phase step-by-step leaching and ammonia-water-containing organic phase elution is adopted; a technical route of protein precipitation, acidification pH regulation, purification and enrichment by adopting WAX / reversed-phase mixed mode solid-phase extraction on a 96-well plate and stable isotope internal standard isotope dilution LC-MS / MS quantification is adopted, the method can effectively reduce the matrix effect and realize high-throughput analysis in a high-salinity urine matrix, the quantitation limits of DCEA and TCAA are not higher than 0.30 g / L and 0.20 g / L respectively, and the method has the advantages that the method is simple and convenient to operate, and the method is suitable for large-scale popularization and application. The method is suitable for biological monitoring and risk assessment of occupational and environmental low-level exposure crowds.

The invention relates to the technical field of food detection, discloses an efficient detection method for six sugar alcohol compounds in dairy products, and aims to solve the problems that in the prior art, dairy product protein precipitation and high-efficiency dissolution of strong-polarity sugar alcohol are difficult to consider at the same time, and toxic precipitants, high-temperature treatment or complex solid-phase extraction are often depended on. The problems of tedious operation, high equipment threshold and poor detection stability exist in the prior art, trichloroacetic acid with optimized concentration is used for constructing a water phase system, and dissolution of six sugar alcohols and preliminary precipitation of protein are synchronously realized; the high-protein matrix of the milk powder is supplemented with precise supplementary precipitation, and the liquid milk is simplified; a specific chromatographic column and gradient elution are combined, linear correlation is established by adopting an external standard method, synchronous detection of six sugar alcohols is completed, high-temperature and solid-phase extraction consumables are not needed, two matrixes of milk powder and liquid milk are adapted, the operation time is short, the detection recovery rate is high, the precision is excellent, the existing pain point is effectively solved, and the batch detection requirement of a conventional laboratory is met.

The present application relates to the technical field of plant extraction, and particularly relates to a preparation method of sweet tea extract and application thereof. The preparation method of the sweet tea extract comprises the following steps: extraction, concentration, fermentation, decolorization, cold precipitation and extraction. By controlling the alcohol concentration in the extraction step, the protein precipitation and the reduction of pectin substance precipitation are facilitated, and by combining with the step of air oxidation in the extraction process, the bitter and astringent taste of the prepared sweet tea extract in the prepared cigarette can be removed, and the yield of the sweet tea extract is greater than or equal to 90%.

The invention relates to the technical field of in-vitro detection, in particular to a sample pretreatment method and a method for detecting VK2 and VD in serum. According to the specific technical scheme, the method comprises the following steps: carrying out protein precipitation after carrying out enzymolysis on serum, taking supernate, mixing the supernate with activated magnetic beads, enabling the magnetic beads to adsorb a target object, finally eluting the magnetic beads adsorbed with the target object by using eluent, collecting the eluent, and detecting the eluent to obtain vitamin K2 (VK2) and 25-hydroxy vitamin D (VD) at the same time. The problems that pretreatment operation is tedious, health is harmed and flux is low are solved by adopting an automatic magnetic bead method; the problems that detection equipment is expensive and difficult to popularize are solved by adapting to a conventional mass spectrum platform; the technical path is not only suitable for detection of vitamin K2 and 25-hydroxyvitamin D, but also provides a solution normal form with popularization value for detection of trace micromolecular markers which are difficult to popularize due to complex pretreatment or high equipment threshold.

The invention relates to the technical field of medicines, and discloses an application of a traditional Chinese medicine composition in serum neurotransmitter, which comprises the following steps: selecting 6-8 weeks old mice to establish a normal model, a chronic fatigue syndrome model and a functional dyspepsia model; the method comprises the following steps: sampling blood from mice of a normal model, a chronic fatigue syndrome model and a functional dyspepsia model to respectively obtain a normal blood sample, a CFS blood sample and an FD blood sample, and performing protein precipitation operation to obtain normal deproteinized supernatant, CFS deproteinized supernatant and FD deproteinized supernatant; separating by using a reversed-phase chromatographic column, and then carrying out mass spectrometric detection to respectively obtain a normal serum neurotransmitter mass spectrogram, a CFS serum neurotransmitter mass spectrogram and an FD serum neurotransmitter mass spectrogram; and carrying out concentration value calculation and rhythm fluctuation analysis to respectively obtain a neurotransmitter function index and a rhythm stability quantitative score. Therefore, the action mechanism of the serum neurotransmitter of the traditional Chinese medicine composition can be clearly and quantitatively represented.

The invention discloses a method for synchronously detecting L-asparagine monohydrate and L-alanyl-L-glutamine in an assisted reproduction culture solution. The L-asparagine monohydrate and the L-alanyl-L-glutamine in the assisted reproduction culture solution are used as a detection reagent. According to the method, a pretreatment mode of combining protein precipitation with diluted hydrochloric acid extraction is adopted, a target object is separated through ion exchange chromatography, and a ninhydrin post-column derivatization technology is adopted to establish an external standard method quantitative analysis system. The method has the following advantages: (1) synchronous and efficient separation and accurate quantification of two amino acid substances are realized; (2) methodology verification shows that good repeatability (RSD (Relative Standard Deviation) is 1.05) and high sensitivity (the detection results of L-asparagine monohydrate and L-alanyl-L-glutamine are 0.00038 mg / mL and 0.00036 mg / mL respectively); (3) the operation is simple and convenient, and the single analysis time is about 60 minutes; and (4) the recovery rate is stabilized in a range of 93%-105%. The method provides a reliable analysis means for quality control of the assisted reproduction culture solution, and is particularly suitable for quantitative determination of key amino acid components in the assisted reproduction culture solution.

This invention belongs to the field of medical materials, specifically relating to a patterned bio-barrier membrane with self-adhesive function and its preparation method. The preparation method includes: dissolving the adhesive matrix in a buffer solution, then adding reactive amino acids and a stabilizer to obtain a first mixture; adding ethanol and a hydrophobic agent to the first mixture, and stirring under heating conditions to obtain a second mixture; adding a thickener, a calcium supplement, and a reinforcing agent to the second mixture, continuing stirring, and then adding a protein precipitation reagent to precipitate the mixture, obtaining a hydrogel; covering a collagen membrane with a patterned porous mold, and adding the hydrogel to allow it to flow into the pores and solidify. This invention achieves precise adhesive loading through patterned design, combining advantages such as simple operation, reliable fixation, good biocompatibility, and high osteogenic efficiency, effectively solving the barrier membrane fixation problem in GBR technology, and is suitable for bone defect treatment in dental implant prosthesis restoration.

The utility model discloses a liquid treatment system which comprises a liquid working station, the liquid working station is provided with a working platform, the top end of the working platform is provided with a liquid transferring mechanical arm used for transferring liquid and a plate transferring mechanical arm used for transferring a pore plate, one end of the working platform is provided with a CO2 incubator, and the other end of the working platform is provided with a film sealing machine and a positive pressure module. The positive pressure module comprises a liftable base as well as a protein precipitation plate placing area and a sample receiving plate placing area which are positioned on the base, the protein precipitation plate placing area and the sample receiving plate placing area are respectively used for placing a protein precipitation plate and a sample receiving plate, and a pressurizing part is arranged at the top end of the protein precipitation plate placing area; a sample receiving plate placing area is arranged at the bottom end of the protein precipitation plate placing area and is used for collecting the to-be-analyzed liquid purified by the protein precipitation plate. According to the liquid treatment system disclosed by the utility model, the functions of sample adding, incubation, termination and solid-liquid separation are realized at the same time, and complicated liquid transfer operation is not needed.