160results about How to "Shorten digestion time" patented technology

The invention discloses a complete medium and a human amnion-derived mesenchymal stem cell (hAMSCs) culture method. The complete medium is prepared by adding 3 to 10 percent of autologous umbilical cord blood serum into low-sugar Dulbecco minimum essential medium solution according to a volume ratio. The culture method comprises: (1) separation; (2) primary culture; and (3) subculture. The methodusing the complete medium in the hAMSCs culture has the advantages that: the risk of using fetal calf serum is avoided; although the need of adding L-glutamine, non-essential amino acid, 2-mercapitoethanol, pyruvic acid and the like is obviated, the high proliferation properties and phenotypic characteristics of the hAMSCs and expression of multilineage differentiation marker genes sand proteins of some stem cells can still be retained; and in subculture, the wall adherence fastness of the hAMSCs is much lower than that in fetal bovine serum (FBS) culture, the digestion time is reduced obviously, and the damage of trypsinization to cells and loss of cells are reduced.

The invention belongs to the field of solid waste treatment and relates to a method for reducing sludge by adopting ultrasound-magnetic field coupling to disrupt sludge. The method comprises the following units: an aerobic biochemical unit is to remove organic pollutants through microbes in a biochemical tank; a sedimentation unit is to separate mud from water in a sedimentation tank; an ultrasound- magnetic field treatment unit is to disrupt rest of sludge by adopting ultrasonic wave and a magnetic filed to cooperate for more than 1 minute, wherein the frequency of the ultrasonic wave is 16-200kHz, the density of sound energy is 0.1-1.0W / mL, and the magnetic field strength is 300-20000Gs; an anaerobic digestion unit is to anaerobically digest the sludge in a digestion tank; and a sludge dehydration unit is to carry out solid-liquid separation by adopting centrifugal dehydration. The method greatly reduces the sludge disruption energy consumption, and the sludge is reduced by more than 80 percent when aerobic digestion is carried out to disrupt the sludge; in anaerobic digestion, the digestion time is reduced by more than 60 percent, the methane yield is increased by more than 35 percent, the sludge is reduced by more than 30 percent. The method has obvious economic benefits, thereby having popularization and application value.

The invention discloses a pretreating and calibrating method for sequentially determining the content of lead and cadmium elements in rice, which comprises the following steps: (1) removing impurities of the rice, decorticating and crushing; (2) adding the processed rice into a concentrated nitric acid to be soaked for the night; moving the soaked rice into an electric hot plate to be heated and digested; adding deionized water for removing acid and obtaining a sample solution A by using the deinoized water for transferring and metering the volume; (3) using the national standard stock solution of the lead for being manufactured into series lead standard solution, determining the light absorption value of the lead and making a lead calibration curve; (4) determining the light absorption value of the sample solution A, fining the concentration of the lead in the sample solution A from the lead calibration curve, and obtaining the content of the lead in the sample by computing; (5) diluting the sample solution A by the deinoized water to obtain a sample solution B; (6) using the national standard stock solution of the cadmium for being manufactured into series cadmium standard solution, determining the light absorption value of the cadmium and making a cadmium calibration curve; and (7) determining the light absorption value of the sample solution B, fining the concentration of the cadmium in the sample solution B from the cadmium calibration curve, and obtaining the content of the cadmium in the sample by computing.

The invention relates to detection technology for element contents, and provides a method for simultaneously determining contents of arsenic, cadmium, lead, vanadium, zinc, manganese and phosphor in soil or deposits. The method mainly comprises the following steps: (1) 0.1g of a grinded drying soil sample is accurately weighed and placed in a TFM microwave digestion pot, a certain proportion of aqua regia and hydrofluoric acid are added, and a solution is allowed to stand; (2) an appropriate microwave digestion program is set, and microwave digestion is carried out for the solution in the step (1); (3) after the microwave digestion program ends, an acid-driving device is used for heating and evaporating the digestion solution in the step (2) to a dry state, and total transfer, volumetric flask preparation, and filtering are carried out; (4) ICP-OES is used for determining contents of arsenic, cadmium, lead, vanadium, zinc, manganese and phosphor in the clear liquor in the step (3); (5) ICP-MS is used for determining contents of elements in the clear liquor in the step (3) which do not reach detection limits in the step (4) once more. The method has the advantages of simple steps, simplified operation, saved soil samples, reduced personal error, minimized environment interference, and improved working environments.

The invention relates to the field of medical jurisprudence inspection, in particular to a diatom inspection method in medical jurisprudence. The method at least comprises the following steps: (1) microwave digestion: adding concentrated nitric acid and hydrogen peroxide solution into the inspected sample to carry out microwave digestion; (2) vacuum filtration: carrying out vacuum filtration on the digestion solution, adding ultrapure water, carrying out vacuum filtration continually until the surface of the filter membrane is approximately neutral, adding absolute ethyl alcohol, and carrying out vacuum filtration to remove moisture from the filter membrane; (3) a scanning electron microscope automatically takes pictures and stores the pictures; and (4) qualitative and quantitative analysis on diatom: carrying out inspection, classification and statistic treatment on the diatom in the on-spot pictures in an artificial identification way or computer automated identification way. The invention has the advantages of high detection sensitivity, high accuracy of qualitative and quantitative analysis, simpleness, high efficiency and environmental protection, can effectively avoid pollution, greatly improves the working environment for diatom inspection technicians in medical jurisprudence, and reduces the labor intensity, thereby having wide application prospects in drowning diagnosis practice in medical jurisprudence.

The invention relates to a primary separation and culture method of human amniotic mesenchymal stem cells. The primary separation and culture method of the human amniotic mesenchymal stem cells comprises the following steps of: providing a human amniotic tissue, washing with PBS (phosphate buffer saline), shearing into pieces, adding 0.1-0.3% (by mass) trypsinase to digest, adding I-type collagenase and basal high-glucose DMEM until the final concentration of the I-type collagenase is 0.1-0.2%, digesting, separating the digested human amniotic tissue centrifugally to obtain a precipitate, resuspending the precipitate with PBS, filtering, separating centrifugally, and removing the supernatant to obtain the human amniotic mesenchymal stem cells. Compared with the prior art, the primary separation and culture method provided by the invention has the advantages that because a small amount of trypsinase is used to pretreat and loosen the human amniotic tissue, and further the I-type collagenase with good tissue specificity is used to treat the human amniotic tissue, the digesting time can be shortened greatly, the primary separation steps can be simplified, the human amniotic mesenchymal stem cells can be obtained at a high yield, and the viability of the obtained human amniotic mesenchymal stem cells can be improved greatly compared with that of the human amniotic mesenchymal stem cells in the prior art.

The invention discloses a pretreatment method for determining multiple heavy metal elements in soil simultaneously. The pretreatment method comprises steps as follows: step (1): sample weighing: the soil is air-dried, ground and screened with a nylon sieve, a soil sample is weighed and put into a microwave digestion tube through a polytetrafluoroethylene long-neck funnel, and the funnel is slightly flapped before the funnel is removed so that all the soil sample attached to the wall of the funnel enter the digestion tube; step (2): digestion: nitric acid, hydrochloric acid and hydrofluoric acid are added to the digestion tube, a cover is screwed down, and the digestion tube is put into a microwave digestion instrument for digestion; step (3): acid driving: after microwave digestion is finished, hydrogen peroxide is added to the digestion tube; then the microwave digestion tube is put into a temperature-controlling acid driver in a fume cupboard for direct acid driving until the volume is smaller than 1 mL, then a solution is directly transferred to a volumetric flask, the volume is constant, and a to-be-tested solution is obtained. With the adoption of the pretreatment method, the digestion speed of the sample can be increased, the pre-treatment step of the sample is simplified, and the accuracy of the detection analysis result is guaranteed.

Methods for measuring chemical oxygen demand, a composition and a kit useful for measuring chemical oxygen demand, a method for calibrating a chemical oxygen demand analysis method, and a method for determining carbonaceous chemical oxygen demand are disclosed.

The invention provides a detection method of total phosphorus content in water. The detection method comprises the following steps: (1) determining the absorbance of a phosphate standard solution by adopting a spectrophotometric method and drawing a working curve; (2) providing a water body test sample to be detected and adding a potassium persulfate solution into the water body test sample to be detected; carrying out microwave sealed digestion; oxidizing all total phosphorus in the water body test sample to be detected into orthophosphate, so as to obtain a digestion solution; (3) adding ascorbic acid into the digestion solution and uniformly mixing for 30s to 60s; adding a molybdate solution and carrying out color development reaction to obtain a reaction solution; (4) providing a blank water sample and referring to operation of steps (2) and (3) to obtain a blank reaction solution; (5) carrying out spectrophotometric absorbance determination on the reaction solution and the blank water sample to obtain test sample absorbance and blank absorbance respectively; referring to the working curve and calculating to obtain the total phosphorus content in the water body test sample to be detected.

The invention provides a method for determining iron content in nori with a flame atomic absorption spectrometry. The method comprises the following steps: dyeing a sample at a high temperature to remove water; immersing the sample into a digestion solvent for long time and then pre-treating under high-temperature, high-pressure and closed conditions, so as to rapidly transfer iron in the sample into the digestion solvent at maximum, wherein the digestion solvent is a mixed acid of nitric acid and perchloric acid at a volume ratio of 4:1; heating and digesting by using a microwave oven so as to achieve a high temperature instantly and shorten the digestion time. According to the method provided by the invention, the problems of a traditional method that the consumed time is long and the use amount of solvents is great when the flame atomic absorption spectrometry is used for determining microelements and the environmental pollution caused by the solvents is serious are solved; the method has the advantages of rapidness and convenience, good repeatability and good accuracy, and is applicable to determining the microelements of similar materials.

The invention discloses a method for treating sludge through the refluxing of acidified fermentation liquor and application of the method. The method comprises the following steps of: performing hydrolytic acidification on the sludge, refluxing the acidified fermentation liquor of the sludge, performing acidification pretreatment on the sludge, and performing hydrolytic acidification fermentation on the pretreated sludge and producing methane by using a product. The sludge is subjected to acidification pretreatment by using the fermentation liquor of the sludge, so that the time required by anaerobic digestion is shortened, the gas yield is improved, and the operating cost is reduced.

The invention relates to an advanced dry anaerobic digestion method based on sludge modification pretreatment. The method comprises the following steps: pre-treating dehydrated sludge for 10-60 minutes at a certain temperature and pressure, and cooling to a certain temperature value at the fermentation temperature of 35-42 DEG C or 50-60 DEG C so as to obtain modified sludge; fully mixing the modified sludge with inoculated sludge at a volume ratio of (1:10)-(1:1), putting the mixed sludge in an anaerobic fermentation tank, and starting a temperature control device so that the material temperature is controlled at the fermentation temperature to stand for 3-10 days; then carrying out continuous feed and discharge, controlling feed and discharge amount each day so as to gradually improve operation load, carrying out feed by using the modified sludge with the feed amount of 0.5-1m<3> / d, maintaining the operation for 12-30 days under the load level when the load is improved once, improving the load again after a digestion parameter discharge VS and daily gas production amount are stable until a planned load is reached; after starting the anaerobic digestion process, performing a stable operation stage; carrying out continuous feed and discharge, and controlling material retention period to 12-20 days so that the digestion load is maintained at a set level; and treating biogas residue. By using the method, the viscosity of the sludge can be reduced, dry digestion speed and gas production amount are improved; and compared with the wet fermentation, equipment investment and occupied soil are saved.

The invention provides a method for pretreating excess sludge by adopting a bio-augmentation technology, relates to a method for pretreating the excess sludge, and solves the problem of low hydrolysis speed during anaerobic digestion of the sludge. The method comprises the steps as follows: I, activated bacillus subtilis is taken; II, the activated bacillus subtilis is inoculated into a starch-containing beef extract peptone solid culture medium to be cultured, and then bacillus subtilis A is obtained; and III, the bacillus subtilis A is added into the excess sludge produced during secondary biological treatment of wastewater to react with the excess sludge, and then the method is completed. The method for pretreating the excess sludge by adopting the bio-augmentation technology has the characteristics of harmlessness and low energy consumption, is simple to operate and achieves a good municipal sludge pretreatment effect, wherein, the volatile suspended solid (VSS) removal rate is increased by 15.1 percent, the chemical oxygen demand (COD) in a supernatant of the treated sludge is increased by 2734mg / l and the volatile fatty acid (VFA) content is increased by 1080mg / l. The sludge treated by adopting the method has the advantage that further anaerobic digestion treatment to the sludge is facilitated.

The invention discloses an online COD water quality detection method which is a spectrophotometric method for determining COD in water by utilizing potassium hydrogen phthalate as a standard solution. The online COD water quality detection method comprises the following detection steps: configuring the standard solution of the potassium hydrogen phthalate, configuring a detection reagent, drawing a standard curve and treating waste liquid. The online COD water quality detection disclosed by the invention has the benefits that the analysis efficiency is improved, and the test cost is reduced.

The invention relates to a method for measuring COD in high-chlorinated water by a chlorine oxygen consumption curve correction-sealed digestion method. The method comprises the following steps: (1) preparing sodium chloride solutions of different concentrations; (2) adding the sodium chloride solution to In the pressure dissolution bomb, add MnSO4, potassium dichromate solution, and concentrated sulfuric acid in sequence, and digest it together with the distilled water blank in a drying oven at a constant temperature; (3) Take out the pressure dissolution bomb, and after cooling, titrate with ferrous ammonium sulfate solution to calculate the COD (4) take Cl-concentration as the abscissa and COD (Cl) as the ordinate, draw the chlorine oxygen consumption curve; (5) process the high chlorine water sample to be tested according to step (2) and step (3) successively , to obtain the apparent COD value; according to the Cl- content in the high-chlorinated water sample to be tested, the COD(Cl) value is obtained from the chlorine oxygen consumption curve, and the apparent COD value is subtracted from the COD(Cl) value to obtain the high-chlorinated water sample to be tested. The actual COD value of the water sample. The invention has the advantages of simple operation, good reproducibility, good accuracy, saves time, reduces pollution, and is easy to realize batch measurement.

The invention discloses a complete formula feed for domesticated snakes. The complete formula feed is prepared from the following raw materials in parts by weight: 40 to 90 parts of fish meat, 5 to 40 parts of chicken meat, 5 to 40 parts of duck meat, 5 to 20 parts of flour, 0.1 to 0.5 part of hawthorn fruit powder, 0.05 to 0.5 part of coptis chinensis powder, 0.01 to 0.5 part of astragalus membranaceus powder, 0.05 to 0.5 part of pericarpium citri reticulatae powder, 0.01 to 0.1 part of compound enzyme, 0.001 to 0.01 part of decavitamin, 0.001 to 0.01 part of microelement, 0.001 to 0.005 part of wild silkworm spore fungus, 1 to 5 parts of wheat plant protein powder, 2 to 10 parts of sodium alginate and 2 to 10 parts of calcium chloride. After the domesticated snakes are fed by the complete formula feed, the domesticated snakes have the characteristics of rapid growth, few disease suffering times, good digestive absorption and low parasite infection rate. Thus, the survival rate and the fecundity of the domesticated snakes are obviously improved.

The invention provides an online analyzer for total phosphorus of water quality and a detection method thereof. The analyzer comprises a reagent metering assembly, a digestion reaction assembly, a reaction cell assembly, a colorimetric photoelectric detection assembly and a single chip microcomputer, wherein the reagent metering assembly is connected to the digestion reaction assembly and the reaction cell assembly through a liquid conveying channel, the digestion reaction assembly is connected to the reaction cell assembly through the liquid conveying channel, the reaction cell assembly is also connected to the colorimetric photoelectric detection assembly through the liquid conveying channel, and the single chip microcomputer is used for connecting with the electronic components in eachassembly. The online analyzer for total phosphorus of water quality and the detection method thereof fully automate the steps such as injection, digestion, reaction and colorimetric measurement, can realize automatic, rapid and accurate analysis of total phosphorus content in water, have the advantages such as accurate measurement, good stability and relatively low digestion temperature, and provide reliable guarantee for long-term accurate monitoring of total phosphorus of water quality.

This invention relates to one rapid resolving photometric analysis water medium chemical oxygen volume testing method, which comprises the following steps: making H2SO4-H3PO4 mixture with proportion as 3:1-5:1; making catalytic agent MnSO4-CuSO4 with weight proportion as1:1-1:3; adding catalytic agent into the mixture of 100ml with catalytic agent weight as 0.25-0.40g with oxidation K2Cr2O7 concentration as0.10-0.25mol / L to make resolving liquid; adding the liquid into the dirty water with proportion 1:2-1:3 with resolving temperature as 150-170DEG C and time as10-20min; Measuring the water medium oxygen volume by adopting photometric meter online monitor through Cr on 590-610nm light.

The invention relates to a method for measuring content of total nitrogen in a urea-ammonium nitrate solution containing 27%-33% of nitrogen. According to the method, concentrated sulfuric acid is added to the urea-ammonium nitrate solution, amide nitrogen is converted into ammonium nitrogen, a nitrogen-fixation alloy is added, nitrogen in various forms is sequentially converted into ammonium nitrogen, sodium hydroxide is added, ammonium nitrogen is converted into ammonia to be distilled, ammonia is absorbed with a boric acid solution, a standard sulfuric acid titration solution is used for direct titration, and the content of total nitrogen is calculated. Compared with an existing method of back titration after distillation and a method of direct titration after distillation, the method has the advantages that the steps are reduced, the operation is simpler, more convenient and more fast, the analysis procedure is greatly shortened, coexisting complicated matrix components, manual operation and other factors cause little influence on measurement, the interference capability of the method is enhanced, the accuracy and the precision of a result are improved, and the analysis and checking cost is very low.

The invention discloses a method for mixed fermentation of sludge disintegrated by low-strength ultrasonic wave and crop straws pretreated by fermentation broth and application of the method in improving mesophilic two-phase anaerobic digestion. The method comprises the following steps: mixing the sludge and the straw to perform hydrolytic acidification, wherein the sludge is pretreated by the low-strength ultrasonic wave; refluxing the straws with the hydrolytic acidified fermentation broth after the sludge and the straw are mixed; and mixing the straws treated by the fermentation broth with the sludge again, and performing hydrolytic acidification. The method provided by the invention improves mesophilic two-phase anaerobic digestion performance of the sludge, increases the gas yield and stability of the sludge, and shortens the anaerobic digestion time.

The invention relates to an aquaculture feed feeding technique which is characterized in that when fish fingerlings are bred, bean cakes, peanut cakes, wheat bran, bran, silkworm chrysalis, fish meals and the like are fed, and the feeding rate is about 3%. After the fish fingerlings are bred for 15-30 days and grow to certain specifications, full rate artificial particle feeds are fed, and the feeding rate is 1-1.5%. Feeds are fed through automatic feeding machines. One to two automatic feeding machines are arranged on each pond, feeds are fed once every day, feeding time is from 9 o'clock to 14 o'clock, the speed of spraying particle feeds of the feeding machines is controlled, feeds are fed discontinuously, and the range of feeding feeds is enlarged as possible. The aquaculture feed feeding technique improves utilization rate of feeds, reduces feed cost, improves growth speed of pond fishes, guarantees water quality of ponds and improves pond yield and economic benefits.

The invention belongs to the technical field of biology, and specifically discloses an SD thoracic rat artery smooth muscle cell separation and culture method. The method comprises the following steps: (1) cutting SD rat thoracic artery in a sterile condition; (2) cutting the thoracic artery into long sections with a length of 3 to 5 centimeters, placing the sections in a PBS solution, cutting the thoracic artery in the vertical direction, removing the fat and connective tissues around the blood vessels, then soaking thoracic artery in collagenase (II); (3) taking out processed thoracic artery, and removing the external membrane; (4) incubating the thoracic artery in digestive juice, and then transferring thoracic artery to a DMEM culture medium; (5) transferring thoracic artery to a centrifuge, carrying out centrifugation, collecting the precipitate (namely thoracic artery smooth muscle cells), then placing the obtained thoracic artery smooth muscle cells into a fetal calf serum DMEM culture bottle, then transferring thoracic artery smooth muscle cells to an incubator, culturing the thoracic artery smooth muscle cells in the incubator, and then carrying out subculture. The provided method can greatly increase the number of obtained cells and improves the material utilization rate. Furthermore, the operation is simple and convenient.

The invention discloses a fast and efficient biological technical method for separating and amplifying umbilical cord mesenchymal stem cells. According to the method, umbilical cord tissues from full-term fetus born by cesarean section are utilized to obtain a large amount of mesenchymal stem cells through a mixed enzyme digestion method combined with an explant method, in a short period of time. This method effectively shortens enzyme digestion time, reduces loss of cell number to a largest degree, and improves the influence on biological activity of mesenchymal stem cells in a long enzyme digestion process. The method also optimizes in vitro amplification conditions; and the amplified cells have the biological characteristics of mesenchymal stem cells and high proliferation ability. The invention creates a fast and efficient biological technology for separation, purification and amplification of human umbilical cord mesenchymal stem cells, and provides an adequate seed cell source for research and clinical application of stem cells.

The invention discloses a method for rapidly determining the COD of sewage and a tester thereof. The method comprises the following steps that: a sample is heated to be digested by oil which is 170 DEG C to 180 DEG C, a calculation formula is then utilized to work out the chemical oxygen demand of a water body, the tester is built, and under different COD concentrations, corresponding potassium dichromate and ferrisulphas are prepared in order to rapidly determine the COD. The invention has the advantages of environment-friendliness, mass determination, high COD determination accuracy, wide measuring range, short time and easiness in operation, and can be used for rapidly testing the COD in municipal sewage and industrial sewage samples.

The invention discloses a method for quickly separating and culturing fibroblast from human skin tissues. The method comprises the following steps of cleaning and shearing fresh foreskin tissues afteroperation of adults or children, and sequentially adopting solutions of dispase II and dispase I to digest under the condition of oscillation in a water bath at the temperature of 37 DEG C; and collecting skin tissue blocks through centrifuging; enabling a culture medium to resuspend, and culturing in a culture box with CO2 (carbon dioxide) volume concentration of 5% at the temperature of 37 DEGC. The method has the advantages that the temperature of the digestion function of the dispase I and the dispase II is increased from 4 DEG C to 37 DEG C, the activities of the dispase I and the dispase II are respectively improved, the contact areas between the dispase I as well as the dispase II and a corresponding primer are increased by the oscillation in the water bath, the enzymatic reaction is favorably performed, the digestion time of the dispase I as well as the dispase II is greatly shortened, and the separating and culture speed of the fibroblast is improved; the damage of enzyme to tissue cells is decreased, the wall attaching rate of the cells is improved, and the primary fibroblast can complete passage after culturing for 6 to 8 days.

The invention relates to a method for preparing clinical-level adipose-derived stem cells. Specifically, the method includes the steps of firstly, washing adipose tissue with double-resistance salinecontaining mycillin mixed liquid, and cutting off and removing adipose; secondly, conducting chylosis on the adipose tissue obtained in the first step; thirdly, adding the adipose tissue subjected tochylosis in the second step to an a-MEM containing an enzyme mixture to be digested, wherein the enzyme mixture contains I-type collagenase, hyaluronidase, deoxyribonuclease I and trypsin; fourthly, centrifuging digested liquid in the third step, and removing supernate to obtain the adipose-derived stem cells.

The invention discloses a method for preparing sodium alginate based on powder form absorption and separation. The method comprises the following steps: S1, carrying out pretreatment; S2, carrying outabsorption and separating; S3, carrying out digestive foaming; S4, filtering; S5, carrying out calcification and decalcification; S6, neutralizing for realizing replacement. According to the method,silicon dioxide aerogel powder is added into powdered kelp liquid, the powdery kelp liquid is enabled to stand still so as to form a layered state by means of the absorption characteristics of the silicon dioxide aerogel powder, and a filtering membrane is cooperatively used for realizing filtration and separation; the method is ingenious in process, and enables the extraction of the powdered kelpnot to be affected while enabling the kelp to fully absorb formaldehyde for realizing fixation. The absorption way of the method provided by the invention is more convenient and quicker than that ofsponge.

The invention discloses a human placenta chorionic mesenchymal stem cell separation method, which comprises: 1) taking healthy human placenta chorionic tissue, cutting into strip blocks, and completely rinsing with physiological saline; 2) adding a proper amount of physiological saline, chopping the chorion into fine particles by using a homogenizer, and rinsing with physiological saline until the solution is clarified; 3) treating again with the homogenizer to achieve micro-particles, and carrying out centrifugation to remove the upper layer blood cells; 4) adding an enzyme to the precipitate, digesting, carrying out centrifugation, and separating the precipitate; 5) carrying out centrifugal washing with physiological saline twice, adding a culture medium to the precipitate, inoculating, and culturing; and 6) discarding the tissue blocks and the culture medium at the 7th day, rinsing the bottom of the culture flask by using physiological saline, adding a fresh culture medium, changing the culture medium every 3 days until the cell fusion degree achieves 80-90%, and carrying out digestion passage with trypsin to obtain the human placenta chorionic mesenchymal stem cells. According to the present invention, the operation is simple and rapid, and the high-quality human placenta chorionic mesenchymal stem cells can be obtained.

The invention relates to a culture and cryopreservation method of amniotic mesenchymal stem cells. The culture method comprises amniotic tissue separation, amniotic mesenchymal stem cell separation, P0 generation amniotic mesenchymal stem cell culture and amplification culture. According to the culture method of the amniotic mesenchymal stem cells, at a separating stage of the amniotic mesenchymalstem cells, a special mixed enzyme digestive juice system (the final concentrations of components in the digestive juice are as follows: 1.5-2U / mL of neutral protease, 0.5mg / mL of deoxyribonuclease Iand 1mg / mL of collagenase IV) is adopted for digestion, so that the amniotic mesenchymal stem cells can be more effectively separated from amniotic tissues, and then the yield of P0 generation cellsis obviously improved. Compared with conventional two-step digestion, the culture method provided by the invention has the advantages that a one-step digestion method is adopted, operation is more convenient, and the cultured amniotic mesenchymal stem cells have good activity, high yield, high purity and good repeatability.

The invention relates to a determination method of the protein content in foodstuff in the technical field of food detection, comprising the following steps of: digesting a sample by using a digestive juice of hydrogen peroxide and concentrated sulfuric acid so as to obtain a mixed solution; taking the mixed solution, using methyl red as an indicator, and adding a NaOH aqueous solution; adding a formaldehyde solution, shaking, adding a phenolphtalein indicator, titrating by the use of a NaOH aqueous solution at the concentration of C until the mixed solution shows reddish and does not fade in color within half a minute, recoding the volume V of the consumed NaOH aqueous solution, and calculating the protein content by the use of a formula. The digestive juice used in the method can help accelerate the digestive speed of the sample, shorten the digestive time and accelerate the analysis speed; in addition, the formaldehyde method is adopted for titration so as to simplify the operation.