China Wuhan Desheng Biochemical Technology Co., Ltd Company News

The new coronary pneumonia in 2020 caused fear, not only claimed the lives of many people, but also disrupted the pace of life. Due to an epidemic, China's GDP has plummeted, and the economy has directly returned to a decade ago. Even though the epidemic is relatively under control, experts cannot guarantee that it has been completely controlled, and it will even make a comeback. Nucleic acid testing is currently the main method of diagnosis and control of new coronary pneumonia. However, nucleic acid testing also encounters endless problems. For example, the test results are a large number of false negatives. For this problem, RNA sample transport media provides great help.   Virus transport media (inactivated and non-inactivated)   Before extracting the sample nucleic acid, the common sample transport media needs to put the sample in an environment above 56°C to inactivate the virus. This inactivation process undoubtedly protects the personnel in the inspection from virus exposure, but it also destroys the integrity of the viral nucleic acid, causing some samples to not be detected normally, which is one of the reasons for the high false negative rate.   High temperature heating will increase the degradation of RNA and reduce the amount of sample detection. Using RNA transport media can effectively inhibit the degradation of RNA. Regarding the preservation after the virus sample is collected, for example, after the pharyngeal swab is sampled, the sample is packaged and then put into the sampling tube. Not all sterile sampling tubes can be used to store viruses, at least one RNA sample transport media is required to save. For virus storage, non-inactivated virus transport medias are generally used.   The components of the non-inactivated virus transport media are: Hanks liquid foundation, gentamicin, fungal antibiotics, BSA (V), cryoprotectant, biological buffer and amino acids. The combination of multiple antibiotics has anti-bacterial and anti-fungal effects. Bovine serum albumin (BSA) as a protein stabilizer can form a protective film in the virus protein shell, making it difficult to decompose and ensure the integrity of the virus. The neutral environment constructed by Hanks buffer helps increase the survival time of the virus and the stability of infection. Its advantage is that it can effectively preserve the activity of the virus. It is convenient for the subsequent isolation and cultivation of the virus, but the premise is that it must be stored at a low temperature.   RNA is easily degraded, and RNase is simply the natural enemy of RNA extraction. RNase has a wide range of sources and can include various organisms in nature. Therefore, it is difficult to guarantee that RNase will not be mixed in the samples you collect. RNase also degrades RNA at room temperature, so we need to store samples at 4° (short-term) or -70° (medium-long term). If we want to store RNA virus for a long time, we need to use liquid nitrogen. In many cases, the extraction experiment requires rapid lysis of the sample after recovery, and even operation on ice can reduce the rate of RNA degradation. If there are few viral RNA samples collected in the original sample, it will become less after a period of RNase degradation. After the temperature is heated to 56°, the activity of the enzyme increases. At 92°, the enzyme will not be denatured, but the efficiency will be further improved. Then the degradation phenomenon will be more serious.   Is there any way to save the virus without being broken down by RNase? The answer is the guanidine salt RNA virus transport media, which is the virus inactivation transport media.   Guanidine salts generally include guanidine hydrochloride, guanidine nitrate, cyanoguanidine and the like, which can effectively denature proteins. RNase is also a protease that will be denatured and lose its original role. The virus shell is also made of protein, so the guanidine salt can also inactivate the virus. The 56° heating process can be omitted. The virus inactivation transport media can inactivate viruses and reduce the infectivity of virus samples, while eliminating the process of high temperature heating greatly improves the accuracy of nucleic acid detection. Since the epidemic, Desheng has been working hard to develop virus transport medias to facilitate nucleic acid detection. Desheng virus transport medias are inactivated and non-inactivated, and nasal and pharyngeal swabs are also available.  

Carbomer 940, like 980, is one of the most commonly used carbomer gels. Its chemical structural formula is an acrylic polymer cross-linked with polypropylene ether. It has strong hygroscopicity and becomes weakly acidic after neutralization. Forming a high-transparency gel, it is used in pharmaceutical excipients in addition to the skin care products most commonly used.   Note: Carbomer used in pharmaceutical excipients does not have sterilization and disinfection effect: Carbomer has many examples of application in pharmaceutical excipients, such as the currently used no-clean disinfectant gel, carbomer eye drops, carbomer intracavitary adhesive preparations, bioadhesives, cards Pom skin antiseptic gel, etc. It should be noted that carbomer is used as a pharmaceutical excipient and does not have a sterilizing effect. It is only used as a carrier medium for drugs, such as gels, thickeners, dispersants or suspending agents. It does not have the effect of other drugs, but it has no toxic effect on the body or skin without impurities, which is why it can be widely used in cosmetics.   Carbomer and its gel   Carbomer 940's performance difference with other gels when used in pharmaceutical excipients: Different carbomers have different performances in pharmaceutical excipients. Carbomer 940 is also the same. After carbomer gel is made, the adhesion of 940 is lower than that of carbomer 934 or 934P, so it is given in some cavity The drug system needs to increase adhesion and prolong the drug release time. Instead of 940, use 934P or 934 with stronger adhesion.   When preparing a water-soluble gel, the amount of carbomer used is 0.5%-2% according to the viscosity of the desired gel. When preparing an emulsion gel, the concentration is 1%. In terms of gel transparency and thickening rate, the Carbomer 940 effect is significantly better. Carbomer 940 is used as an auxiliary material for external medicine, easy to apply, and can absorb tissue solution, which is conducive to discharge of secretions, good stability, smooth and comfortable skin feel, easy to clean and good breathability. Some oral medicines are made into gels for transdermal administration, which are used as external medicines, reducing the irritation of internal organs. Carbomer also has moisturizing properties when applied to skin externally, it can lubricate the skin, protect the skin from pollution and irritation, and has an anti-infective effect.   At present, due to the severely limited supply of imported carbomer raw materials in China, it is almost interrupted. Domestic high-quality carbomers are in short supply. The same is true of Desheng's carbomers. Now the factory has added a large number of equipment and the carbomers production capacity has been further upgraded. .

There are two types of Virus Transport Media added in the virus sampling tube, one is the inactivated preservation solution of the modified lytic virus protein extraction nucleic acid, and the other is the maintenance of the virus in vitro activity, its nucleic acid and antigen modified based on the transport medium Complete non-inactivated preservation solution. For inactivated preservation solutions, it is important to inactivate viruses efficiently and prevent secondary infection.   Different from the non-inactivated type, the inactivated Virus Transport Media is added with a high concentration of lysis salt, which can inactivate the virus efficiently and can effectively prevent the operator from secondary infection. But it also contains Rnase inhibitors, which can protect the viral nucleic acid from degradation, so that it can be subsequently detected by NT-PCR. The inactivation effect is experimentally verified below. 1. Inactivation verification materials 1 SPF chicken embryo (and hatched to 10 days old by itself) 2 Chicken infectious bronchitis virus IBV QXL87 strain 3 Normal saline (0.9% NaCl), autoclaved 4 Inactivated sample storage solution, 3 batches. 5 RNA extraction kit   Virus Transport Media inactivates viruses   2. Experimental methods 1. Add the prepared chicken infectious bronchitis virus QXL87 strain to the preservation solution, according to the ratio of 1 (viral solution): 10 (preservation solution), and set the room temperature at 18-26℃ for 45min. The virus fluid was inoculated into SPF chicken embryos, and allantoic fluid was harvested.   2. Inoculate the allantoic fluid harvested in 1 into 10 days old SPF chicken embryos according to the allantoic cavity inoculation method. Each sample is inoculated with 10 chicken embryos, 0.1 mL/piece, placed in a 37°C incubator for 144 h and discarded. After 24 h of dead chicken embryos, observe and record 24-44 h of chicken embryo deaths and the number of diseased live embryos after inoculation. Observation of chicken embryo lesions, and the detection of chicken infectious bronchitis virus nucleic acid on the harvested allantoic fluid, referring to GB/T 23197-2008 chicken infectious bronchitis diagnostic technology, using RNA extraction kit to extract RNA, and using one-step method Real -Time RT-qPCR for virus detection. Group 1/2/3 added virus (100ul) + preservation solution (900ul); Group 4 added virus (100ul) + physiological saline (900ul); Group 5/6/7 added preservation solution (1000ul). Among them, the Virus Transport Media is in three batches.   3. Experimental results According to the above experimental results, groups 1, 2 and 3 were inoculated with virus-containing preservatives, which showed that chicken embryos grew normally; group 4 was inoculated with virus-added physiological saline, and chicken embryo lesions; groups 5, 6, and 7 were inoculated with preservatives, showing No inhibition of chicken embryo growth. This indicates that the inactivated preservation solution can inactivate viruses.   Through this experiment, we can finally show that the three batches of random sampling of Desheng inactivated preservation solution can effectively inactivate the virus, and it has no inhibitory effect on the normal physiological function of the cells. Therefore, this inactivated Virus Transport Media It can efficiently inactivate various viruses and extract nucleic acids, which is suitable for RT-qPCR nucleic acid detection experiments. Of course, in view of the faster testing, which is directly used for the detection of patients diagnosed with New Crown, few companies in China will do so, because after all, New Crown virus is not so easy to obtain!

In 2020, people are full of fear. The epidemic that has lasted for half a year has not been effectively controlled. Whether it is a natural disaster or a human disaster, we must actively face it and solve it. The new coronavirus is a new type of complex RNA virus. SARS in 2003 has already devastated us, and COVID-19 is a mutation based on SARS. To solve it, it is really difficult. The first task is to fully understand the virus and use each. A method to detect its gene sequence, viral RNA preservation solution provides a convenience for subsequent virus detection.   Viral RNA Transport Media-viral   The traditional virus Transport Media used for virus sample collection is an isotonic saline solution or phosphate buffer solution that can preserve virus activity. Its component is mainly sodium chloride, which can preserve virus activity, but cannot inhibit the degradation of RNA. There are two problems with this virus Transport Media. The first problem is that the active virus puts transportation and testing personnel at risk of infection, especially the collection of highly infectious and highly pathogenic viruses (such as new coronaviruses) ); The second problem is that the Transport Media cannot avoid the degradation of RNA. It needs to be transported at low temperature after sampling, and can not be repeatedly frozen and thawed. Otherwise, the RNA is very susceptible to degradation by the RNA enzyme. These harsh conditions make detection more difficult. The degradation is one of the reasons for the high negative test rate. Therefore, the development of a viral RNA storage solution that can inactivate viruses and protect RNA from degradation by RNA enzymes is the key to optimizing the collection of viral samples and the key to providing quality-assured nucleic acids for subsequent fluorescence quantification or sequencing tests.   Desheng Company has overcome the shortcomings of the existing technology, and has conducted multiple experiments with clinical technicians and repeated verification. Finally, it has successfully developed an inactivated virus RNA Transport Media. Its advantages are: 1. It is easy to use and can store virus samples at room temperature with a shelf life of 1 year; 2. Virus samples do not need to be refrigerated and inactivated. The virus samples can be inactivated by entering the Transport Media, which can protect the transportation and testing personnel from the risk of infection, and effectively avoid RNA degradation at room temperature;

HEPES buffer is 4-hydroxyethylpiperazine-ethanesulfonic acid (N’-a-hydroxythylpiperazine-N’-ethanesulfanic acid), a white crystal powder, hydrogen ion buffer, which can control a constant pH range for a long time. The effective buffer range is pH6.8-8.2. Commonly used to prepare protein extraction lysis buffer, cell culture buffer, etc.   The dissociation constant of HEPES is 7.5. When equimolar mixing of HEPES and its Na-HEPES, the pH of the solution is 7.5. Generally, a fixed molar concentration of HEPES is prepared first, and then the pH is adjusted to the specified value with a strong base (generally commonly used NaOH). Here, NaOH only serves to provide OH. It is also possible to use other strong bases such as KOH. When the pH difference is large, use concentrated NaOH. For fine-tuning, use dilute NaOH. If NaOH solid is added directly, the error is too large, and when NaOH is dissolved Exothermic and changing the temperature may affect the accuracy of the pH electrode.     HEPES lysis buffer preparation:   Lysis Solution A: Lysis Solution B: HEPES 10mmol/L，pH7.9 HEPES 20mmol/L，pH7.9 KCl 10mmol/L NaCl 420mmol/L MgCl2 1.5mmol/L MgCl2 1.5mmol/L DTT 1mmol/L DTT 0.5mmol/L 甘油 5% glycerin 25% EDTA 0.2mmol/L EDTA 0.2mmol/L NP-40 1%     PMSF (Add before use) 1mmol/L PMSF （Add after use） 0.5mmol/L aprotinin 3mg/L aprotinin 5mg/L leupeptin 3mg/L leupeptin 5mg/L pepstainA 2mg/L pepstainA 3mg/L   Steps:   1. Collect the cells into an EP tube and centrifuge (4000r/min, 5min, 4 degrees).   2. Wash three times with PBS, centrifuge as above, discard the supernatant.   3. Add 100 μl of buffer A, incubate on ice for 10 min, centrifuge (14000 r/min, 1 min), and discard the supernatant.   4. Resuspend the pellet in 60 microliters of Buffer B, mix well, centrifuge on ice for 30min, centrifuge (14000r/min, 15min, 0 degree), collect the supernatant and discard the pellet.   Among them, the role of lysate A is mainly used to release cytoplasmic proteins and membrane proteins, lysate B is used to release nuclear proteins, NP-40 is both a surfactant and a detergent, its role is both It destroys the cell membrane (mild), and can combine with the released protein to prevent precipitation, so most of the cytoplasmic protein and membrane protein can be removed after the supernatant is removed by centrifugation in the first step. After the nuclear protein is extracted, it can be dialyzed with lysate A for 2h and combined for IP; or diluted with other solutions and replaced with concentrated centrifuge tubes for IP or other experiments.   The main raw materials of Desheng's in vitro diagnostic reagents are: 1. Biological buffer Tris, BICINE, HEPES, CAPS, MOPS, TAPS, EPPS, MOPSO, PIPES, PEP; 2. Chemiluminescent reagents luminol, isoluminol, Acridine ester DMAE-NHS, Acridine ester NSP-DMAE-NHS, Acridine salt NSP-SA, Acridine salt NSP-SA-NHS, Acridine hydrazide NSP-SA-ADH, Acridine ester ME-DMAE-NHS ; 3. New Trinder's reagents TOOS, TOPS, ADOS, ADPS, ALPS, DAOS, HDAOS, MADB, MAOS; 4. Anti-irradiation separation gel for blood collection tube additives, sodium heparin, lithium heparin, EDTA-2K3K, EDTA-2NA, promote Coagulant, coagulation powder, etc. In addition, it also produces Virus Transport Media and carbomer 940/980. Welcome friends to come to buy.

Recently, I always receive customers' inquiries about Good's buffers, but many times even the customers themselves are not able to express their exact products exactly. Because there are still a few people who really understand, I will briefly introduce Good's buffer and the difference between PIPES and HEPES in Good's buffer.     Good's buffers, also known as zwitterionic buffers, are a type of buffer system dedicated to life science research. They do not participate in or interfere with the biochemical reaction process, and have no inhibitory effect on enzyme chemical reactions. Therefore, they are specifically used for organelles and electrodes. Research work on volatile, pH-sensitive proteins and enzymes. These buffer systems should have the following characteristics:   1. The pKa value is between 6-8;   2. High solubility in water;   3. Not easy to penetrate biofilm;   4. Little salt effect;   5. The ion concentration, solution composition and temperature have little effect on dissociation;   6. No complex or precipitation with metal ions;   7. The buffer is chemically stable;   8. Small absorption of light in the ultraviolet and visible wavelength range;   9. Easily produce high-purity salt.   The PIPES buffer and HEPES buffer in Good's buffer are our commonly used buffers, and they are inextricably linked. To a certain extent, they have the function of acquaintance, but they also have their own functions and advantages. After we understand Good's buffer, let’s take a look at PIPES and HEPES, let us slowly penetrate into their respective fields, so that we can be more Good choices use their respective characteristics:   PIPES   The pH buffer range is 6.1-7.5, insoluble in water, and soluble in aqueous NaOH solution. PIPES is different from buffers containing bis(2-hydroxyethyl)amino groups (such as Bis-tris, Bicine), and cannot form stable complexes with most metal ions. It is suitable for buffers in solution systems containing metal ions. According to the existing research results, PIPES can be applied to the purification of tubulin using phosphocellulose chromatography, the purification of recombinant GTP-binding proteins ARF1 and ARF2 by gel filtration, and as a buffer to crystallize transketolase from E. coli. In addition, because PIPES can form free radicals, it is not suitable for use in redox systems. In cation exchange chromatography, a low concentration of PIPES buffer should be used, because PIPES has a relatively large ionic strength, and its pKa value is concentration-dependent.    HEPES   The pH buffer range is 6.8-8.2. It is soluble in water. It is a hydrogen ion buffer that can control a constant pH range for a longer period of time. The final concentration is 10-50mmol/L, and the general culture medium contains 20mmol/L HEPES to achieve buffering capacity. It does not form stable complexes with metal ions, and in most cases, does not interfere with biochemical processes. HEPES is commonly used in cell culture media of various types of organisms; in protein research, PIPES is often used as a combination in cation exchange chromatography Buffer components and eluent; reaction buffer, pre-hybridization buffer, hybridization buffer for separation and analysis of RNA nuclear components; 3′-terminal labeling for RNA and T4RNA ligase; used in biochemical diagnostic reagents In the kit, DNA/RNA extraction kit and PCR diagnostic kit. In DNA research, PIPES is used as a buffer for calcium phosphate and DNA precipitate formation systems, AFM and buffer for electroporation experiments. In addition, HEPES interferes with the reaction between DNA and restriction enzymes, and is not suitable for Lowry's method to determine protein content.   It can be seen that neither PIPES nor HEPES can form stable complexes with metal ions, which is suitable for solution systems containing metal ions. However, there is also a certain difference between them. In terms of solubility, PIPES is insoluble in water, while HEPES buffer has good water solubility; in terms of buffer range, PIPES is acidic to neutral, and HEPES is neutral to alkaline. These are the same and different All tell us that to choose them better, we must first understand them. Desheng already has extensive experience in Good's buffer. It provides you with technology products, teaches you how to choose the right choice to distinguish what you need. Why don't you choose such a company!

4-Hydroxyethylpiperazineethanesulfonic acid, referred to as HEPES, CAS No. 7365-45-9, is usually used as a biological buffer in biochemical experiments. It has properties similar to EPPS and is commonly used for pH-sensitive proteins and enzymes. research work. Physical and chemical properties: HEPES Molecular formula: C8H18N2O4S Molecular weight: 238.31 Status: crystalline powder pKa:7.45-7.65 Buffer range: 6.8-8.2 Structure: Purity: greater than 99% Use concentration: 10-50mmol/L   Depending on the application, HEPES buffers are subject to two commonly used buffer systems: HEPES buffer solution: HEPES + NaOH (500mL): 119.15g HEPES is dissolved in 400mL distilled water, add 0.5~1M NaOH aqueous solution to adjust at least the required pH, pay attention to the effective pH buffer range is 6.8-8.2, and then use distilled water to make volume To 500mL; 2. HEPES buffered salt solution: HEPES 6.5g, NaCl 8.0g, Na2HPO4·7H2O 0.198g, adjust the pH value with 0.5M NaOH aqueous solution, and make the volume to 500mL. 3.2×HEPES buffered salt solution: Dissolve 1.6g of NaCl, 0.074g of KCl, 0.027g of Na2HPO4.2H2O, 0.2g of glucan or dextran and 1g of HEPES in 90ml of distilled water, and adjust to the required pH with 0.5M of NaOH Value, then dilute to 100ml with distilled water. In the cell-cell adhesion experiment, it contains calcium and magnesium ions; HA cell culture solution does not contain calcium and magnesium ions, but contains BSA.   The advantages of HEPES buffer: 1. Unlike PEcine, HEPES does not contain coordination groups and cannot form stable complexes with most metal ions. It is suitable for buffers in solution systems containing metal ions. 2. HEPES has very good water solubility, and the buffer range is close to neutral. Although PIPES does not form a complex with most metal ions, PIPES can form free radicals, so it is not suitable for redox systems and has relatively large ions. Strength, PIPES is more acidic. 3. HEPES has no toxic and side effects on cells at low concentration, and can control a constant pH range for a long time. The final concentration is 10-50mmol/L, and the general culture medium contains 20mmol/L HEPES to achieve buffering capacity. Therefore, it is commonly used in HA solution, cell culture solution, virus preservation solution and even skin care products.   Among the biological buffers, EPPS and PIPES are similar in properties to HEPES. They are used as buffers for different experiments, and sometimes can be replaced with each other. Desheng is a manufacturer of buffers. It has more experience in the production and sales of various buffers. Partners are welcome to visit and guide!

Cyclohexylpropanesulfonic acid CAPS, CAS No. 1135-40-6, is an important chemical raw material. It is usually used as a biological buffer in biochemical experiments to maintain the pH of the reaction system. There are many types of biological buffers, so which experiments can CAPS be used for? This requires first understanding how to choose a buffer.   1.Selection of buffer pH range: The buffering range of the buffering agent must first conform to the pH value of the reaction system, such as the reaction condition pH value, protein activity, or enzyme catalyst pH value. The buffer range of the buffer depends on its ionization equilibrium Changshu pKa value. The pH value of the buffer solution is related to the ionization equilibrium constant of the acid and the concentration of salt and acid. The formula for calculating the pH value of the solution is: pH=pKa-lg(Na/Nb ), Na and Nb respectively represent the amount of conjugated acid and alkaline substance. The buffer range of the buffer is between the plus and minus 1 of the negative logarithm of its power balance constant, and pH=pKa±1. The pKa of CAPS is equal to 10.4, the theoretical buffer range is 9.4-11.4, in order to ensure accuracy in biochemical experiments The upper and lower limits are reduced by 0.3 to use 9.7-11.7, so the pH of the experimental system that can use CAPS as a buffer must be in this weakly alkaline pH range. Common buffer buffer range   2. the ionization balance of commonly used buffers Changshu and buffer range In many reactions such as complexometric titration, spectrophotometry, and enzymatic reaction, the pH of the solution is required to be kept within a range to ensure the color change of the indicator, the color development of the color reagent, and the optimal pH value for enzyme catalysis, etc. These conditions are achieved by adding a certain amount of buffer solution, so the buffer solution is a reagent often required in analytical tests.   Using the potentiometric titration method to determine the titration curve of added acid or alkali to the same buffer solution with different ratios, not only helps to understand the concept of buffer solution and buffer capacity (range) but also to correctly select the preparation method and dosage of buffer solution in analytical testing Instructive. It can be seen from the chart that CAPS is higher among buffers and belongs to weak alkaline buffer.   3. Restrictions on the use of buffers In the case where the buffer range meets the reaction system, it is also necessary to consider the limiting conditions of the reaction system, for example, phosphate buffer will complex metal ions calcium, enzymes, etc., and the activities of enzymes and proteins in some reactions are affected by metal ions. Phosphate buffer cannot be used. CAPS buffer is suitable for the electrophoresis buffer of high molecular weight proteins (greater than 20KD); if it is a low molecular weight protein blotting experiment, Tris + glycine is usually used, and Tris-Tricine + EDTA is used to exclude glycine for protein sequencing.   In addition to being used as a biological buffer, CAPS reagents are also commonly used in waterborne coatings and other industries. Desheng has extensive experience in the production and development of cyclohexylamine propanesulfonic acid and other various biological buffers, which is worthy of the majority Customer trusted partner!

Tris(hydroxymethyl)methyl-3-aminopropanesulfonic acid or TAPS, CAS: 29915-38-6, is a zwitterionic buffer, widely used in the field of biochemistry and molecular biology, usually white crystals or Powder is a Good's biological buffer mainly produced by the company.   In clinical diagnostic biochemical testing, TAPS is mainly used as a biological buffer. Its molecular structure contains a sulfonic acid group and an amino group substituted by a polyhydric alcohol, the sulfonic acid group is weakly acidic, and the amino group is weakly basic, so as to maintain the pH value of the reaction system, the buffer range is 7.7-9.1; Good, the solubility can reach 50g per 100g of water; therefore, it is often used in biochemical diagnostic kits, DNA/RNA extraction kits and PCR diagnostic kits.   Tris(hydroxymethyl)methylaminopropanesulfonic acid TAPS   In addition to the kit, TAPS is also used to protect oxyhemoglobin during freeze-drying, as a protective agent to prevent the oxidation of hemoglobin to methemoglobin. This is very important, because traditional blood transfusions have many drawbacks, such as blood-borne infectious diseases, complicated blood type matching, and viral infections. Hemoglobin oxygen carriers can be used as good blood substitutes. However, hemoglobin is easily oxidized to methemoglobin without oxygen carrying capacity during the freeze-drying process, so it is necessary to add a protective agent to prevent hemoglobin degeneration, TAPS is one of the important components.   At present, a domestic TAPS synthesis method is: Tris methylaminomethane Tris and 1,3-propane sultone (1,3-PS) in n-butanol solvent, Tris amino nitrogen atom and Hydrogen atoms are added to the carbon and oxygen in which propane sultone is broken and ring-opened to form TAPS. In this reaction, n-butanol can be recycled to improve product yield and purity.   TAPS, a buffer used in biochemical testing and molecular diagnostics, has very high requirements on reagent purity and impurity ion content. Desheng Technology has done a lot of research and improvement in this area, and many biological buffers produced by the company have obtained a large number of Recognized by biochemical testing companies and medical device companies.

HEPES is an important biochemical preparation in biochemical industry. It is considered to be one of the important buffers in the field of biological research. The chemical name of HEPES is: N-hydroxyethylpiperazine-1-ethanesulfonic acid, the character is white crystalline powder , Is a weak acid, often used as zwitterionic buffer and pharmaceutical intermediate in organic chemical industry. It is often selected as a buffer for cell culture because of its advantages:   Desheng's location and buffer products   1. The decomposition capacity of HEPES can be enhanced with the increase of temperature and weakened with the decrease of temperature, but compared with other buffers, its decomposition constant does not change much with temperature, which makes HEPES buffer become A buffer that better maintains the structure and function of the enzyme. The buffer can control a constant pH range for a longer period of time and has no toxic effect on cells.   2. The pH required for most cells is 7.2-7.4, HEPES has a good buffer capacity in this range, but the optimal pH value varies with the type of cell cultured. Fibroblasts prefer higher pH (7.4-7.7), while subcultured cell lines require acidic pH (7.0-7.4). Most culture medium relies on sodium bicarbonate (NaHCO3) and CO2 system for buffering. The CO2 concentration in the gas phase should be balanced with the sodium bicarbonate concentration in the culture medium. In this case, the cell culture bottle cap should not be screwed too tight to ensure gas exchange.   However, after storage for a certain period of time, the pH of the buffer system will increase with the CO2 volatilization. At this time, the culture solution quickly becomes purple when the cell is subcultured and blown, making the cells cultured with this culture medium difficult to survive. Even if it survives, the activity It is also very low, and the proliferation rate is very slow. Adding HEPES to the culture solution can avoid this problem. HEPES can be used as a buffer to replace bicarbonate to eliminate the limitation of the high-concentration CO2 culture environment. The final concentration of HEPES buffer used is generally 10-25mM.   How to use HEPES:   1. HEPES can be directly added to the prepared culture solution at the required concentration, and then sterilized by filtration. Add 2.38 grams of HEPES per 1000ml of culture solution, adjust the pH to 7.2 with lN NaOH after dissolution, filter and sterilize and use At this time, the use concentration of HEPES is 10 mmol/L.   2. It can also be prepared into 100 x storage solution (l mol/L). Before use, 99ml of culture solution is added to lml storage solution, and the final application concentration is still 10mmol/L. l mol/L (100 x) HEPES stock solution preparation method: dissolve 23.8g HEPES in 90ml double-distilled water, adjust pH to 7.5-8.0 with 1N NaOH, then dilute to 100ml with water, filter and sterilize, and dispense vials ( 2ml/bottle), store at 4℃ or -20℃.   Desheng Biochemical reminded that when used as a buffer for cell culture, HEPES in the culture medium exposed to visible light for more than 3h will produce hydrogen peroxide that is toxic to the cells. It is recommended that the culture medium be stored in the dark.

With the rapid development of China's economy in the 21st century, people's living conditions have made a qualitative leap compared to the 20th century. However, while the material conditions are extremely rich, due to excess nutrition, lack of exercise and other reasons, rich diseases such as diabetes, hypertension and hyperlipidemia have also begun to spread. In order to better and more convenient for people to monitor and diagnose these diseases, a variety of diagnostic and therapeutic instruments that can be used for bedside diagnosis, such as blood glucose meters, multiple lipid test cards, and triglyceride test strips, have been developed in succession. Today we are going to talk about MAOS is a core material that can be used with blood glucose test paper, total cholesterol test paper and the other two test papers mentioned above.   The maximum absorption wavelength and molar absorbance of the new Trinder’s reagent   MAOS(CASNo.:82692-97-5)full name: N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate, is a new Trinder's A very important member of the reagent family. It is not as commonly used as TOOS, but it also has an absolutely irreplaceable role. As can be seen from the figure below, the maximum absorption wavelength of MAOS is 630nm, which has a larger absorption wavelength than other Trinder’s reagents. Since Trinder's reaction principle is the hydrogen peroxide produced by the tested substance under the action of the enzyme, then 4-aminotepyrine and catalase oxidize the chromogen substance to a red quinoid substance, and then use light absorption method to determine the Measured substance concentration.   The scope of application of MAOS and other Trinder's reagents is almost the same, between PH 5.0 and 9.5, but the maximum absorption wavelength of MAOS makes it can greatly reduce the interference of other components in the sample to be tested, so it is widely used in the need for relatively accurate Numerical applications such as blood glucose test strips.   MAOS product description Product Chinese name N-乙基-N-（2-羟基-3-磺丙基）-3,5-二甲基苯胺钠盐一水合物 English name N-Ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethylaniline sodium salt monohydrate CAS　No. 82692-97-5 Customs code 2922199090 Molecular formula C13H20 NNaO4S, H2O Molecular formula 327.37 Exterior White or light yellow pink powder Storage conditions Room temperature（20-25℃），Protect from light and moisture Transport conditions Room temperature（20-25℃） Maximum absorption wavelength 630 nm Molar absorbance (pH10) ≥10,000 （about 257 nm） Oxidation reaction application Hydrogen peroxide reaction, colorimetric method   Desheng's MAOS has the characteristics of high purity, good crystal form and pure white color. In addition, MAOS produced by Desheng has also passed the verification of the five major domestic biochemical diagnostic reagent giants, and more than 100 companies have selected Desheng as their reliable supplier. Welcome to consult!

The full name of TOPS (CAS No.: 40567-80-4) is N-Ethyl-N-(3-sulfopropyl)-3-methylaniline sodium salt, which is a white to light brown powder, also A member of the new Trinder's reagent family. Maybe you think the name sounds humongous, and it is a vocabulary that a fully professional pharmacist only understands. It is even more difficult to relate to your life. If you think so, you are wrong. You may not have heard of this name, but I think most of you or people around you have done biochemical tests in the hospital, that is, liver function, kidney function, uric acid, cholesterol and other tests. Most of these tests are performed by automatic biochemical analyzers, uric acid analyzers, etc. in conjunction with the corresponding kits. And one of the core materials in these kits is the TOPS we talk about today.   Desheng TOPS reagent   In humans and primates, uric acid is the final product of purine metabolism. It is produced by the oxidation of xanthine and hypoxanthine by xanthine oxidase and is excreted in the urine. High serum uric acid and hyperuricemia are associated with insulin resistance, cardiovascular disease and gout. The mechanism leading to hyperuricemia is usually increased uric acid production or decreased urine excretion. Increased serum uric acid may be a sign of kidney disease, so the early diagnosis of kidney disease can be indirectly through the test of uric acid.   TOPS product description Product Chinese name N-乙基-N-(3-磺丙基)-3-甲基苯胺钠盐 English name Sodium 3-(N-ethyl-3-methylanilino)propanesulfonate CAS No. 40567-80-4 Customs code 2922199090 Molecular formula C12H18NNaO3S, H2O Molecular formula 297.34 Exterior White or light brown powder Storage conditions 0-5℃，Protect from light and moisture Transport conditions Room temperature（20-25℃） Maximum absorption wavelength 550 nm Oxidation reaction application For colorimetric determination of uric acid and cholesterol. Good water solubility, high sensitivity and strong stability. Cholesterol colorimetric determination; water-soluble reagent, used for catalase photometric determination     In the presence of hydrogen peroxide and peroxidase, TOPS reagent is formed during the oxidative coupling reaction with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazolone hydrazone (MBTH) Very stable purple or blue dye. The substrate is enzymatically oxidized by its oxidase to produce hydrogen peroxide. The concentration of hydrogen peroxide corresponds to the substrate concentration. Therefore, the amount of substrate can be determined by the color of the oxidative coupling reaction to obtain a relatively accurate test result of the concentration of the analyte. TOPS produced by Desheng has obtained the quality certification of over 100+ manufacturers nationwide. Because of its color rendering sensitivity, color rendering stability and anti-interference, as well as the accuracy and precision of specific measurement items, it has been well received by customers. You are welcome to inquire, the company will provide you with quality products and excellent services, so that your products rank among the industry's leading level!