57 results about "Phenol red" patented technology

The invention discloses a high-sensitivity visual detection kit for the activity of human structure-specific nuclease FEN1 and application of the high-sensitivity visual detection kit. A turnup flap structure in FDP is specifically cut by FEN1 to generate a dumbbell-shaped DNA probe with a notch, the notch of the probe is connected under enzyme catalysis to generate a closed annular dumbbell-shaped DNA probe, rolling circle amplification is carried out in the presence of an amplification primer and enzyme, a urease modified signal probe is added into an amplification product, and the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows that the detection result shows. An amplification product and a signal probe complement are separated by virtue of magnetic microspheres and are added into a urease substrate solution, urea in the solution is efficiently catalyzed by urease in the complement to cause change of a pH value, so that the color of a phenol red indicator is changed, and the FEN1 activity is detected. The kit is high in sensitivity, simple and convenient to operate, free of additional instruments and equipment, low in cost and large in application potential, results can be observed by naked eyes, and the kit is used for screening FEN1 inhibitor candidate drugs, and the drug discovery efficiency is remarkably improved.

The invention discloses a method for simultaneously determining N-sodium laureth sarcosinate and phenol red residues in an injection based on a UPLC-MS / MS (Ultra Performance Liquid Chromatography-Mass Spectrometry / Mass Spectrometry) method. According to the method, on the basis of an ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometer, a 5mM ammonium acetate solution (containing 10% acetonitrile) is taken as a phase A, a 0.2% acetic acid acetonitrile solution is taken as a phase B, a Waters Acquity UPLCBEH C18 column is selected, ESI is taken as a mass spectrometry detection ion source, and the two process residues in the injection are accurately quantified at the same time in a negative ion scanning and multi-reaction monitoring mode. The method is simple in pretreatment, high in detection sensitivity and good in reproducibility, and can be used for corresponding injection process residue identification and quality control.

The present invention provides a visual indicator film for the freshness of fresh-cut fruits, a preparation method, the use and a detection method. The preparation method comprises the following steps: preparing a Co-based MOF; washing and activating the Co-MOF; preparing a CMC-Na-based thin film; and preparing a CMC-Na-based thin film, and thereby obtaining an indicator film for phenol red (PR) or an indicator film for bromothymol blue (BTB). In the present invention, an irregular spherical Co-based metal organic framework (Co-MOF) loaded with PR or BTB is prepared, and the nanocomposites Co-MOF / PR and Co-MOF / BTB are obtained after dyes and the MOF are adsorbed by means of the hydrogen bond interaction. Then, the nanocomposites are embedded into a sodium carboxymethyl cellulose (CMC-Na) base material to prepare CO2-responsive packaging materials, namely, a CMC-Na / PR / Co-MOF and a CMC-Na / BTB / Co-MOF, which are used for monitoring the freshness of fruits in real time and in situ. The Co-MOF-based composite thin film has good water resistance, time-temperature stability and mechanical properties, and also exhibits enhanced ultraviolet-visible light barrier properties, dye migration resistance and thermal stability. The visual indicator film for the freshness of fresh-cut fruits can effectively reflect the concentration of CO2, and is suitable for real-time and in-situ monitoring of the freshness of fruits.

The invention discloses a catecholamine substance multicolor visual detection kit and detection method based on synergistic catalytic reaction induction, and the method comprises the following steps: firstly, enabling catecholamine and AgNPLs to be subjected to a sufficient chemical adsorption reaction, and then adding hydrogen peroxide, so that the Ag NPLs are etched to different degrees and show different colors. According to the reaction of silver ions and urease and the cascade urease catalytic reaction, the color of pH indicator phenol red is changed, so that the colors of Ag NPLs and phenol red are compounded, the color recognition degree after the etching reaction is enhanced, and catecholamine substances are detected according to different colors. The method is simple, convenient, efficient, sensitive and high in naked eye recognition degree, and can be used for detecting diseases such as depression.

The invention belongs to the technical field of biological medicine, and particularly relates to a mycoplasma synoviae culture medium capable of improving strain titer and a preparation method of the mycoplasma synoviae culture medium. The mycoplasma synoviae culture medium comprises a basic culture medium and auxiliary components, the basic culture medium is prepared from HEPES, milk protein hydrolysate, MEM, beef heart extract powder, coenzyme I, 1% phenol red, magnesium sulfate heptahydrate, L-cysteine hydrochloride, lactose-N-tetrasaccharide, disodium clodronate and water; the auxiliary components comprise porcine serum and penicillin. According to the mycoplasma synoviae culture medium obtained by the preparation method, the passage time of the mycoplasma synoviae is shortened, and the strain titer is improved. The inactivated vaccine prepared from the chicken mycoplasma synoviae cultured by the culture medium is good in safety and immunogenicity, can effectively prevent infection of the chicken mycoplasma synoviae, and has a good application prospect.

The invention discloses a method for detecting the concentration of halogen in liquid chloromethane, which comprises the following steps: S1, preparing an acetic acid-sodium acetate buffer solution, a phenol red solution, a chloramine-T solution and a sodium thiosulfate solution for later use, volatilizing the to-be-detected liquid chloromethane with a fixed volume at normal temperature, and then adding water to dilute the to-be-detected liquid chloromethane to the original volume so as to obtain a test solution A; taking the test solution A with the volume of W1, adding hydrochloric acid to adjust the pH value to 4.4-5, adding water to dilute until the volume is W2, and uniformly shaking to obtain a test solution B; s2, taking N groups of test solutions B, respectively adding an acetic acid-sodium acetate buffer solution with the volume of K1 and a phenol red solution with the volume of K2 into each group of test solutions B, uniformly shaking, adding a chloramine-T solution with the volume of K3, uniformly shaking, adding a sodium thiosulfate solution with the volume of K4, uniformly shaking, adding water to dilute until the volume is W0, uniformly shaking, and standing to obtain N groups of solutions to be detected, and respectively measuring the absorbance of each group of solution to be measured at the wavelength lambda. The method can accurately detect the concentration of the halogen in the liquid chloromethane.

The application belongs to the technical field of biological medicine, and particularly relates to a chicken synovial mycoplasma culture medium capable of improving strain titer and a preparation method thereof. The chicken synovial mycoplasma culture medium comprises a basic culture medium and auxiliary components; the basic culture medium comprises HEPES, milk protein hydrolysate, MEM, beef heart infusion powder, coenzyme I, 1% phenol red, magnesium sulfate heptahydrate, L-cysteine hydrochloride, lacto-N-tetraose, disodium chlormethine and water; and the auxiliary components comprise pig serum and penicillin. The chicken synovial mycoplasma culture medium obtained by the preparation method shortens the passage time of chicken synovial mycoplasma and improves the strain titer. The inactivated vaccine prepared from the chicken synovial mycoplasma cultured by the culture medium has good safety and immunogenicity, can effectively prevent chicken synovial mycoplasma infection, and has a good application prospect.

The present application relates to the technical field of metal content determination, and specifically discloses a long-lasting and stable liquid calcium indicator, comprising an indicator component A and a dilution component B; the indicator component A is obtained by compounding calcein, phenol red, and thymolphthalein; the dilution component B is a glycerol-triethanolamine mixture; the liquid calcium indicator is obtained by adding 1g of calcein, 0.15g of phenol red, and 1g of thymolphthalein to a 100mL glycerol-triethanolamine mixture; the liquid calcium indicator of the present application significantly extends the storage period compared to a solid calcium indicator; the newly prepared liquid calcium indicator can be stored at room temperature for 63 days without deterioration and can accurately indicate the titration endpoint; in addition, the amount of the liquid calcium indicator added can be accurately controlled, specifically by using a pipette, while the solid calcium indicator cannot be accurately controlled.

The invention discloses a pharmacodynamic test method for a cough relieving mixture, which comprises the following steps: constructing four core pharmacodynamic test sub-models containing ammonia water to cause young mouse cough, citric acid to cause young guinea pig cough, rabbit in-vitro trachea cilia mucus movement and young mouse trachea phenol red excretion and a body model of a test result analysis sub-model; each pharmacodynamic test sub-model is provided with a plurality of groups of test arrays and test individuals; pathogen data is imported to generate a simulated disease scene, and a corresponding drug sequence is called to intervene and collect physiological index change data; and multi-dimensional pharmacodynamic parameters are evaluated through the analysis sub-model, and a dose-effect relation curve and an evaluation report are generated. According to the invention, a parallel verification system for antitussive and expectorant tests is formed, the antitussive effective dose, the expectorant effective dose and the effective dose range under the dual action of the medicine are determined through multi-model cross validation, the accuracy degree of judging the effectiveness of the medicine is greatly improved, and a reliable method support is provided for evaluating the efficacy of the cough-stopping mixture.

The invention relates to a helicobacter pylori staining solution for rapid detection, which consists of a staining solution and a diluent, the staining solution comprises the following components in percentage by weight: 0.4-0.6% of phenol red, 30-40% of ethanol and 60-70% of purified water, and the pH range of the staining solution is 6.4-6.6. The diluent comprises the following components in percentage by weight: 10%-14% of urea, 0.01%-0.03% of Triton X-100 and the balance of purified water, and the pH range of the diluent is 6.4-6.6. The volume ratio of the staining solution to the diluent is (1: 4.5)-(1: 5.5). The staining solution is simple and rapid in operation process, and one-step staining is achieved, so that personnel operation is facilitated; the reaction is efficient, color development can be completed within 5-10 minutes, and the method is suitable for rapid detection of scenes and convenient to popularize; the staining solution is high in staining efficiency, easy to observe, low in staining cost and high in market competitiveness; the staining solution is stable in performance, easy to transport and store at normal temperature and beneficial to long-term use of reagents; the staining solution is safe and non-toxic in formula, and is safe to operators and environment.

The invention belongs to the field of molecular biology and biomedical engineering, and particularly relates to an LAMP colorimetric detection system, application of the LAMP colorimetric detection system and a method for detecting nucleic acid through an LAMP colorimetric method with the synergistic enhancement effect of an indicator. The LAMP colorimetric detection system contains a magnesium ion indicator and a pH indicator; wherein the volume ratio of the magnesium ion indicator to the pH indicator is 1: 1. According to the LAMP colorimetric method disclosed by the invention, the use of an indicator is improved, the change of a Mg < 2 + > compound and H < + > is detected depending on the synergistic effect of a pH indicator phenol red and a magnesium ion indicator chrome black T, which represents that the DNA target is successfully amplified, and a colorimetric result is quantized into a delta Hue value which is increased to 300 degrees from original 100 degrees, so that the accuracy of the result is improved, and the detection time is shortened. And the function of a qPCR instrument is simulated to quantify the delta Hue value in real time, so that the capability of the method in outdated regions and field detection is greatly improved.

The present invention provides a bovine sex-sorted sperm sorting solution mediated by a small molecule compound and its application. The sperm sorting solution comprises a sperm sorting protection solution and a sex control functional component. The sperm sorting protection solution contains sodium chloride, potassium chloride, calcium chloride dihydrate, sodium dihydrogen phosphate, glucose, sodium pyruvate, sodium bicarbonate, penicillin-streptomycin, and phenol red. The sex control functional component includes creatine and a 24e drug. The concentration of creatine is 450 μM-550 μM, and the concentration of the 24e drug is 0.27 μM-0.33 μM. The 24e drug is a pyrido [3,2-d]pyrimidine-based TLR7&8 dual agonist. The present invention can meet the large demand for sex-sorted semen in production. Moreover, the sorting process is carried out under the suitable conditions for sperm and does not require complex treatment of sperm. It takes less time for sorting and causes less damage to sperm.

The application discloses a rapid detection method for the cleanliness of a slide for chromosome preparation for visual analysis, and relates to the technical field of chromosome detection, and comprises the following steps: step one, phenol red is added to anhydrous methanol and glacial acetic acid, the mixture is uniformly mixed, sealed and left to stand, after undissolved particles are precipitated, the supernatant clear orange liquid is taken as a detection reagent; step two, the system sampling method is used to screen and detect pathological slides in a whole box, and the same batch of pathological slides without defects and pollution are detected; step three, a plurality of pathological slides that pass the detection are selected and placed obliquely, and the detection reagent is added dropwise; and step four, the cleanliness of the pathological slides is judged. The visual rapid cleanliness detection method has the advantages of simple process, intuitive interpretation, effective satisfaction of the daily quality control demand of the slide for chromosome preparation in a laboratory and popularization value.

The invention relates to the technical field of molecular biology, in particular to an LAMP (Loop-Mediated Isothermal Amplification) double-signal visual detection indicator based on SYTO 9 and application of the LAMP double-signal visual detection indicator. SYTO 9 is adopted as a fluorescent indicator, a phenol red and hydroxynaphthol blue mixture is adopted as a color indicator, and it is found that after SYTO 9 is added, the visual sensitivity is increased from 20 cfu / reaction to 2 cfu / reaction; by means of the method, the low copy number can be detected, the false positive rate is reduced, and the problem that weak positive caused by too low template concentration is difficult to distinguish during photographing retention or visual distinguishing can be perfectly solved. The color indicator provided by the invention can simultaneously use a direct visual method and a real-time fluorescence amplification method, has the characteristics of high resolution, high sensitivity and low false positive rate, realizes the effect of judging whether a sample is positive or negative by naked eyes in combination with double signals of a fluorescence amplification curve, and is high in judgment result accuracy.

A culture medium for testing drug resistance of H. pylori as well as a preparation method and use thereof are characterized in that 10% to 15% of calf serum, 1.2 mg / mL to 2.4 mg / mL of urea, 0.004 mg / mL to 0.016 mg / mL of phenol red, 10 μmol / L to 100 μmol / L of nickel chloride and H. pylori selective additive accounting for 1% of the total volume of the culture medium are added on the basis of a Columbia culture medium, and meanwhile, antibiotics for testing drug resistance are added, and the pH value is adjusted to 7.15 to 7.35. The present invention provides a method for a rapid testing of H. pylori resistance in culture media.

The present invention relates to the technical field of adhesives, with the classification number IPC C09J123 / 26, and discloses a heat-curable adhesive and a preparation method thereof. By mass fraction, the raw material composition includes: 5-20 parts of functional rubber, 1-15 parts of modified phenolic resin, 1-15 parts of special vulcanizing agent, 1-15 parts of metal salt, 1-15 parts of metal oxide, 1-15 parts of filler, and 70-75 parts of solvent. The present invention prepares a heat-curable adhesive with excellent bonding performance, aging resistance, impact resistance and stability by carrying out phenol red modification on phenolic resin, controlling the phenol content in the phenol red-modified phenolic resin, compounding the special vulcanizing agent, functional rubber and phenol red-modified phenolic resin, and compounding the filler carbon black N642 with the functional rubber.

The present invention provides a method for preparing a phenol red-containing trypsin solution with uniform color distribution after cryopreservation, comprising the following steps: weighing buffer components and phenol red, mixing them, and ball-milling to obtain a pretreated buffer component powder; weighing the pretreated buffer component powder, trypsin powder, and ultrapure water, mixing them, stirring, and performing sterile filtration to obtain the phenol red-containing trypsin solution; wherein the passing rate of the pretreated buffer component powder through a 100-mesh sieve is ≥95%. By determining reasonable grinding conditions and adopting the method of grinding first and then dissolving, the present invention makes the material particle size uniform, the particle size small, and the dissolution speed faster, and it is easier to form a uniform solution during the dissolution and stirring process, ensuring that the prepared phenol red-containing trypsin solution remains a uniform light yellow color after being cryopreserved at -20°C for 24 hours.

The invention relates to the technical field of microorganism culture and screening, and discloses a culture medium for screening mineralizable microorganisms and a screening method, and the culture medium for screening mineralizable microorganisms contains L-arginine, yeast extract powder, seawater salt, beta-sodium glycerophosphate, sodium silicate, phenol red and ferric sodium ethylene diamine tetraacetate. The culture medium is high in mineralizable microorganism screening pertinence and extremely low in infectious microbe content. According to the culture medium disclosed by the invention, L-arginine is taken as a main nutrient substance, and mineralizable microorganisms often preferentially utilize L-arginine (agmatine is produced through a decarboxylation reaction, the pH is indirectly increased, and the combination of Ca < 2 + > and CO3 < 2-> is promoted); beta-sodium glycerophosphate is added into the culture medium, so that'carbonate mineralizing bacteria '(utilizing Ca < 2 + > + CO3 < 2->) and'phosphate mineralizing bacteria' (utilizing Ca < 2 + > + phosphate radical) can be screened at the same time; the added sodium silicate is only utilized by silicate mineralizing bacteria. The types of mineralization bacteria screened by the culture medium cover three mineralization types of carbonate, phosphate and silicate.

The invention relates to the field of microbiological detection, in particular to an LAMP (loop-mediated isothermal amplification) primer group for visual rapid detection of Brucella as well as a kit and application of the LAMP primer group. The LAMP primer group for visual rapid detection is designed aiming at a bcsp31 gene sequence and comprises a forward outer primer (F3), a reverse outer primer (B3), a forward inner primer (FIP-T), a reverse inner primer (BIP-T), a forward loop primer (LF) and a reverse loop primer (LB). When the kit is used, DNA of a sample to be detected is extracted, the primer group is added, a fluorescent dye or methylphenol red is added, an amplification reaction is carried out, and whether the sample to be detected contains brucella or not is judged according to a color development result. The invention provides an LAMP (loop-mediated isothermal amplification) primer group, a kit containing the primer group and application of the LAMP primer group, wherein the LAMP primer group takes a bcsp31 gene as a reference sequence, is shorter in response time, high in sensitivity, good in compatibility and suitable for visual detection of Brucella in daily frequent public health.

The invention discloses a visual paper-based cancer miRNA marker detection kit, the kit comprises an integrally formed foldable T-shaped filter paper, and a DNA probe TEprobe, urease and a color developing agent dropwise added on the filter paper, and the principle of the kit is as follows: the TEprobe is combined with a cancer nucleic acid marker (miRNA) to release Ag < + > to inhibit the activity of the urease; the composite signal response of the pH response probe phenol red and fluorescein is triggered, and the detection sensitivity is as low as 10-12 M. The kit provided by the invention can significantly shorten the detection time and reduce the sample demand, and realizes zero false positive rate and 97.10% specificity by combining with machine learning algorithm classification during result analysis. The performance is successfully verified in real samples of prostatic cancer, liver cancer and colorectal cancer, and a cheap and convenient means is expected to be provided for family self-inspection and cancer screening and diagnosis in resource-deficient areas.

The present invention relates to a culture medium for efficiently and rapidly culturing primary mouse pulmonary artery endothelial cells, belonging to the technical field of culture medium preparation, and well solving the problems such as high price, slow cell crawling speed and poor cell state of the primary mouse pulmonary artery endothelial cell culture medium on the current market. The culture medium comprises the following components: glucose, L-glutamine, sodium pyruvate, sodium bicarbonate, fetal bovine serum, heparin, vascular endothelial growth factor, epidermal growth factor, vasopressin, endothelin, phenol red, Earle's balanced salt solution, and ultrapure water. This culture medium can culture primary mouse pulmonary artery endothelial cells economically, rapidly and efficiently, and has the characteristics of good cell growth, stable phenotype and meeting the requirements of subsequent experiments.

The invention relates to a selective enrichment medium for staphylococcus aureus. The selective enrichment medium comprises tryptone, soy peptone, sodium chloride, glucose, sodium pyruvate, phenol red and the like. The invention further relates to application of the culture medium to separation and identification of staphylococcus aureus. Finally, the invention relates to a method for identifying Staphylococcus aureus, according to which a color change of Staphylococcus aureus during growth due to metabolic action is detected in order to detect the target strain. The culture medium disclosed by the invention can be used for enriching target bacteria and inhibiting non-target bacteria, and the preparation method of the culture medium disclosed by the invention is simple to operate, good in specificity and high in accuracy.

The present invention relates to the technical field of biomedical materials, and discloses a method for preparing a CO2 antibacterial dressing with a pH indication function. First, a phenol red (PR)-grafted PCN-SF composite material PR-PCN-SF is prepared, followed by preparing a mesoporous silica MSN@FeCO loaded with carbonyl iron (FeCO), and finally loading MSN@FeCO onto the PR-PCN-SF composite material to obtain a composite aerogel MSN@FeCO-PR-PCN-SF. The present invention indicates the wound infection condition by the color change of the loaded phenol red indicator, controls the temperature of the near-infrared (NIR) light source on / off control system, adjusts the release amount of CO2, realizes the CO2 antibacterial efficacy started on demand, and then achieves an efficient and controllable wound treatment effect. The present invention is simple to prepare, safe and controllable, and is not prone to bacterial resistance, and has potential application prospects in the field of biomedicine.

The invention belongs to the technical field of traditional Chinese medicine, and particularly relates to a cough relieving and phlegm reducing pill and a preparation method thereof.The cough relieving and phlegm reducing pill is prepared from basic medicinal materials and auxiliary medicinal materials; the basic herbs comprise radix asteris, rhizoma anemarrhenae, radix ophiopogonis, radix scutellariae, lily, radix scrophulariae, angelica sinensis, fructus perillae, schisandra chinensis, radix rehmanniae, radix stemonae, exocarpium citri rubrum, flos farfarae, fermented pinellia, radix asparagi, radix trichosanthis, cortex mori radicis, bulbus fritillariae cirrhosae, radix peucedani, inula flower, platycodon grandiflorum, liquorice, fructus gardeniae and semen armeniacae amarae; the auxiliary medicinal materials comprise at least four of gingko, rhizoma arisaematis, trichosanthes kirilowii maxim, snow lotus herb, cynanchum glaucescens, momordica grosvenori, rhodiola rosea, azalea leaf, mulberry leaf, boat-fruited sterculia seed, loquat leaf and artemisia dubia. The cough-relieving and phlegm-reducing pill provided by the invention can obviously prolong the cough latency period, reduce the cough frequency and effectively increase the phenol red excretion amount of trachea, has obvious cough-relieving and phlegm-reducing effects, is black brown in appearance and uniform in color, and has the yield of 90% or above.

The invention relates to the technical field of biological medicines, and discloses application of urolithin A in a culture solution for reducing fragmentation of aged oocytes. The culture solution comprises NaCl, KCl, KH2PO4, MgSO4. 7H2O, glucose, NaHCO3, sodium pyruvate, sodium lactate, CaCl2. H2O, gentamicin, phenol red and urolithin A. The final concentration of the urolithin A is 25 mu M-50 mu M. The invention provides the culture solution for improving the quality of the oocytes, a feasible scheme is provided for obtaining more and better oocytes, and help is provided for improving the assisted reproduction efficiency clinically.

The invention relates to a method for measuring fluorine content in copper and copper alloy. According to the method for determining the fluorine content in the copper and the copper alloy, alkali fusion hot water extraction is not needed, phenol red is taken as an indicator, acetic acid-sodium acetate-sodium citrate-sodium chloride is taken as a total ion strength regulator, and the fluorine ion selective electrode method is adopted for determining the low-content fluorine in the copper and the copper alloy, so that the acidity and the ion strength of a solution can be adjusted; and elements such as iron and aluminum in the solution can be masked. The analysis method for measuring the low-content fluorine in the copper and the copper alloy through the fluorine ion selective electrode is high in sensitivity, high in measuring speed, easy and convenient to operate, small in interference compared with other methods, good in selectivity and capable of providing accurate data.

This invention relates to the field of traditional Chinese medicine research technology, specifically a method for discovering and identifying quality markers for the antitussive and expectorant effects of Ke Ning granules. This application evaluates the antitussive and expectorant effects of Ke Ning granules using concentrated ammonia-induced cough and phenol red excretion assays. Plasma pharmacochemistry studies of Ke Ning granules were conducted using UHPLC-Q-Exactive Plus Orbitrap HRMS technology, identifying 26 prototype blood-entering components. Through network pharmacological analysis of these blood-entering components, 11 potential active ingredients for antitussive and expectorant effects of Ke Ning granules were screened, involving 40 common targets including IL6, TLR4, and STAT3, and mainly participating in signaling pathways such as PI3K-Akt, HIF-1, and EGFR. Seven prototype blood-entering components were quantitatively analyzed using pharmacokinetic methods. Azelaic acid, caffeic acid, and vanillin were selected as quality markers for the antitussive and expectorant effects of Ke Ning granules based on efficacy, transmissibility, and measurability. The results of this study are of great significance for further clarifying the pharmacodynamic material basis of Ke Ning granules, optimizing quality standards, and promoting its clinical application.

This application discloses a serum-free cryopreservation solution for cells and its applications. The serum-free cryopreservation solution comprises: 1-2% recombinant human albumin, 5-10 μM (-)-Blebbistatin, 50-100 μM antioxidant, 5-10% permeable cryoprotectant, and a basic culture medium free of phenol red indicator. This serum-free cryopreservation solution is suitable for the cryopreservation of various cell types, particularly muscle cells, especially human induced pluripotent stem cell (iPSC) differentiated cardiomyocytes. It can significantly improve the survival rate, structural integrity, and effective preservation of the physiological functions of cardiomyocytes after resuscitation. It is applicable to basic scientific research, disease modeling, drug screening, and clinical treatment related to cardiomyocytes.

The invention belongs to the technical field of biological detection, and particularly discloses a system for targeted quantitative detection of breast cancer cells in blood and a preparation method and application thereof. The system comprises a magnetic nanoparticle composite material, Ag nanoparticles, a first modified nucleic acid chain, a second modified nucleic acid chain, a hydrogen peroxide solution, a phosphate buffer salt solution, a urease solution, a urea solution and a phenol red solution, wherein the magnetic nanoparticle composite material comprises magnetic Fe3O4 nanoparticles and polydopamine which grows on the surfaces of the Fe3O4 nanoparticles in an auto-polymerization manner; the nucleotide sequence of the first modified nucleic acid chain is used for modifying the magnetic nanoparticle composite material; the nucleotide sequence of the second modified nucleic acid chain is used for modifying the Ag nanoparticles. The method has the advantages of high sensitivity, low detection limit, low cost and simplicity in operation, realizes sensitive detection of breast cancer cells in blood, solves the problem of complex matrix interference, and has a good application prospect.

The application discloses a kind of based on olfactory visualization chip beef freshness rapid detection method, comprising the following steps: selecting tetramethoxy phenyl porphyrin iron (III) chloride and phenol red as gas-sensitive material, and preparation is obtained with two sensors olfactory visualization chip;Different storage time under the representative beef sample is set, freshness index data is combined with the response characteristic matrix obtained corresponding storage time, to establish the back propagation neural network quantitative model of beef freshness.The response characteristic matrix of the olfactory visualization chip of the beef sample to be measured is input into the quantitative model established in beef, to obtain the predicted value of TVB-N content and the predicted value of TVC content of the beef sample to be measured.The application can realize rapid, simple, accurate quantitative detection of beef freshness;To solve the shortcomings of the prior art detection process, high detection cost, easy to be disturbed by environment and unable to detect visualized etc.