China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Glycerol, also known as glycerol, is colorless, sweet, clear, viscous liquid, odorless, warm and sweet. It can absorb moisture from the air, as well as hydrogen sulfide, hydrogen cyanide and sulfur dioxide. It is insoluble in benzene, chloroform, carbon disulfide, petroleum ether and oil. Glycerol is the backbone of triglycerides.   When the human body ingests edible fat, triglycerides are metabolized in the body to form glycerol and stored in fat cells. Therefore, the end products of triglyceride metabolism are glycerol and fatty acids.   At present, the main components of Virus Transport Media are Hank's solution, gentamicin, fungal antibiotics, BSA (the fifth component of bovine serum albumin), biological buffer Tris, amino acids, cryoprotectant, glycerol and other components. Among them, glycerol has the function of nutrition and desiccant. Virus resistance to the outside world is not strong, sensitive to temperature. Glycerol of 50% concentration makes the preservation in a relatively static state. Desheng has developed two kinds of preservative solutions according to market demand: inactivated and non inactivated, which can be used for the collection, preservation and transportation of specimens of nasopharyngeal pathogens such as new coronavirus, influenza, avian influenza, hand foot mouth disease, measles, etc. The inactivated type contains lysate, which can instantly cleave pathogens and release nucleic acid, and the protective agent can prevent nucleic acid from being degraded. At present, the inactivated type is commonly used in the detection of NCNA, which greatly reduces the risk of infection. The non inactivated type does not contain lysate, can maintain the activity and integrity of pathogens, and can be used for virus culture and isolation.   Inactivated Virus Transport Media can fully mix the collected samples with virus lysate and virus nucleic acid preservation solution to inactivate the virus in the samples, effectively ensure the integrity of virus nucleic acid in the samples, and the collected samples can be transported under normal temperature and stored for a long time. The preserved virus RNA samples can be widely used in gene detection, enzyme-linked immunosorbent assay (ELISA), PCR detection and so on.   On the basis of Hank's, the non inactivated Virus Transport Media is added with BSA (bovine serum albumin) amino acids, vitamins and other nutrients needed by the virus, which can maintain the activity of the virus in a wide temperature range and maintain the original sample to the greatest extent. It can be used for virus nuclear acid extraction detection, virus culture and isolation.   Desheng began to develop Virus Transport Media at the early stage of the epidemic. After the overtime work of the company's R & D personnel and many experiments, the product was finally developed successfully, and the product was highly praised by customers after use. Now we have reached a stable customer base of dozens. The temperature is gradually decreasing, and winter is coming. Experts predict that the new coronavirus may attack again. In order to strictly prevent the new coronavirus, the Virus Transport Media for nucleic acid detection is essential.

Before purchasing color reagent, let's distinguish the difference between color reaction and color reaction. Color reaction changes the color of chemical substances through chemical reaction, while color reaction of color reagent refers to the reaction of hydrogen peroxide (H2O2) produced by the tested substances through enzymatic reaction in the presence of 4-aminotripyrine (4-AAP) and peroxidase (POD) to make the chromogenic substances produce red quinone Imine compounds, the following listed under the purchase of color reagents need to pay attention to several issues. Pay attention to the parameters of different reagents Chromogenic reagents usually have various parameter values, such as molar absorbance, color reaction sensitivity, maximum absorption wavelength, purity, etc. the detection principle of chromogenic substrate is to use spectrophotometry to measure the absorbance change at a specific maximum absorption wavelength before and after reaction, so as to analyze the concentration of the substance to be measured. Therefore, it is necessary to select different types of chromogenic reagents We must make clear the requirements of the laboratory for each parameter. How to choose developer manufacturer There is no big difference for the commonly used reagents required by the manufacturer, but for those that are not commonly used, especially those with high sensitivity demand such as chromogenic reagents, the manufacturer should choose the direct manufacturer rather than the foreign trader, the manufacturer with R & D and production capacity, and the manufacturer with standard and complete packaging should not choose the bulk self filling. Choose a formal purchase platform or channel, so that it will not affect the process of scientific research. It's easy to ignore the purity level required by the reagent. In some reactions, there will be great differences. Here are some common reagent levels, GR: superior purity. It is suitable for accurate analysis and research, and some can be used as reference materials. Ar: analytical pure. It is suitable for industrial analysis and chemical experiments. CP: chemical purity. It is suitable for chemical experiment and synthesis. LR: experimental pure. It is only suitable for general chemical experiments and synthetic preparation. Br: biochemical reagent. It is used for preparing biochemical test solution and biochemical synthesis. Quality indicators focus on bioactive impurities. It can replace indicator and organic synthesis. BS: biological dye. It is suitable for preparing the staining solution of biological samples. Quality indicators focus on bioactive impurities. It can replace indicator and organic synthesis. Desheng has been committed to the development and production of in vitro diagnostic reagents. There are a wide range of color reagents, including toos, tops, ADOS, ADPS, Alps, Daos, hdaos, MADB and other products. Compared with the color reagent products of other manufacturers, the reaction reagent is shorter, the accuracy is higher, and the accurate diagnosis can be made more quickly in the experiment.

Heparin sodium can be extracted from small intestine mucosa and lung tissue of pigs, cattle and sheep. However, the application of heparin sodium from cattle is limited due to the appearance of BSE. Studies have found that heparin sodium from different sources has different chemical structure and biological activity, and its adverse reactions are also different. The adverse reaction of thrombocytopenia induced by heparin sodium from cattle is about twice as much as that caused by heparin sodium from pig, which leads to the requirements and restrictions of raw material sources in various countries. It is safer to use heparin sodium from pig. In the newly developed low molecular weight heparin (LMWH) and ultra-low molecular weight heparin (ULMWH) products, most of the heparin sodium is required to come from pig intestinal mucosa. Studies have shown that the structure of heparin sodium from pig is the same as that of human endogenous heparin sodium. Heparin sodium is one of the most important biochemical drugs exported in China, accounting for more than 55% of the world's production. The control of raw material source and quality is the key to the long-term development of heparin sodium in the international market. At present, foreign manufacturers do not purchase heparin sodium from cattle, goats and sheep, but only purchase heparin sodium from pigs in order to prevent mad cow disease and pruritus. Heparin sodium mixed with bovine, goat and sheep is regarded as unqualified product, so it is important to distinguish heparin sodium from different species. At present, there are many ways to detect heparin sodium from different sources, such as PCR (polymerase chain reaction), NMR (nuclear magnetic resonance), ESI MS (electrospray ionization mass spectrometry), but these methods are usually expensive, and the detection steps are cumbersome and complex. Based on this, it is particularly important to find a simple and quick way to distinguish heparin sodium from different sources. Heparin sodium from different species was hydrolyzed by enzyme, and its disaccharide composition was analyzed by anion exchange high performance liquid chromatography (sax-hplc). Desheng is a professional manufacturer of blood collection reagent, with more than ten years of research and development, production experience, perfect quality detection and quality assurance system. Its heparin sodium comes from pig intestinal mucosa, mainly used as blood collection additive. Heparin sodium has good anticoagulant effect, effective price ≥ 150IU, high purity, fast delivery, welcome to consult and order!

Chromogen substrates play an important role in in vitro diagnostic industry. The New Trinder's reagent is one of the most common in vitro diagnostic reagents, which mainly includes traditional Trinder's reagent and new Trinder's reagent. Traditional Trinder's reagents mainly include phenols such as phenol and aniline, while new Trinder's reagents are highly water-soluble aniline derivatives, which are widely used in clinical detection and biochemical experiments due to their high water solubility, high color sensitivity and high stability.   In the presence of hydrogen peroxide and peroxidase, the new Trinder's reagent can react with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazolylsulfonylhydrazone (MBTH) to form a very stable purple or blue dye. It can be used in both solution and test line detection system, and can be used in many detection items.   The New Trinder's reagents include Daos, toos, tops, Maos, Alps, ADOS, MADB, hdaos, etc., among which toos and tops are more commonly used.   Desheng is a new technology enterprise specializing in the research, development, production and sales of in vitro diagnostic reagents. We have excellent quality product system dominated by "in vitro diagnostic reagent raw materials", "blood collection additive", "biological buffer" and "chemiluminescence reagent", which can provide high purity and good stability in vitro diagnostic reagent products, including Daos, toos, tops, Maos and other new Trinder's reagents. Now expand the new products carbomer and nucleic acid detection core material virus preservation solution, customer response is also very good. Structure diagram of toos (cas82692-93-1)   Toos and tops are Desheng's "star products", with high color sensitivity, strong stability and good user experience. Toos Chinese name n-ethyl-n - (2-hydroxy-3-sulfopropyl) - 3-methylaniline sodium salt, CAS No. 82692-93-1, appearance of white crystalline powder. In the field of in vitro diagnosis, it is mainly used for the detection of blood glucose metabolism, such as the preparation of glucose detection kit, glycosylated albumin detection kit, etc. Structure diagram of tops (cas40567-80-4)   The Chinese name of tops is n-ethyl-n - (3-sulfopropyl) m-toluidine sodium salt. The CAS number is 40567-80-4. The appearance of tops is white powder. It is mainly used in uric acid determination, serum creatinine detection and other renal function diagnostic kits.

Tris is a widely used organic reagent with an effective buffer range of pH 7.0 to 9.2. It and its derivatives are widely used in the preparation of buffer solutions in biochemistry and molecular biology experiments, and can be used in the production of drugs, organic synthesis, biological buffers and so on.   In biochemical experiments, many protein and nucleic acid related experiments need Tris as a biological buffer. It even has a tendency to surpass phosphate buffer. This article will briefly describe its derivative buffer.     TBS buffer TBS is Tris buffer salt water, which is Tris HCl buffer salt solution. Because Tris base has strong alkalinity, it can only be used to prepare buffer solution with a wide range of pH from acidic to alkaline, which has little interference to biochemical process and does not precipitate with calcium, magnesium ions and heavy metal ions. However, the pH value of the buffer solution is greatly affected by the concentration of the solution, the temperature effect is also great, and it is easy to absorb CO2 in the air, so the prepared buffer solution should be tightly sealed, and this buffer solution has a certain interference effect on some pH electrodes, so the electrode compatible with tris solution should be used.   Tbst buffer Tbst contains Tris HCl, NaCl and Tween20, which is a common membrane washing buffer in Western blotting. The aim is to wash away non-specific proteins and maintain a close natural environment. Tween is an ionic surfactant, which can accelerate the separation of nonspecific antibody binding. Because the membrane used in Western blotting can bind to protein, the antibody can bind to the membrane nonspecificly during incubation. In order to prevent the film background from being too high due to later exposure, TBS mixed with Tween 20 can wash away the non-specific binding antibody after incubating the antibody to increase the specificity.   Te buffer Te buffer is made by adding EDTA into Tris hydrochloric acid buffer. Te buffer is weakly alkaline and has protective effect on DNA base. Therefore, DNA is stable in te, and it is not easy to damage its integrity or produce ring opening and breakage. Te buffer is used for DNA stability and storage.   Tae buffer The most widely used buffer system is TAS / acetate / EDTA. It is characterized by the fact that the super helix electrophoresis is more in line with the actual molecular weight, and the mobility of double stranded linear DNA in it is also faster. When electrophoresis fragments larger than 13KB, Tae buffer will achieve better separation effect. In addition, it is easy to use Tae buffer system for electrophoresis when recovering DNA fragments. However, the disadvantage of TAE is that the buffer capacity is small. Unless there is a circulation device to exchange the buffer solution between the two poles, long-time electrophoresis is not optional.   Tbe buffer Acrylamide experiments and agarose gel electrophoresis were used to convert the acid solution of pH to boric acid, and the "TBE buffer" (Tris/Borate/EDTA) was obtained. Tbe buffer is a common buffer in molecular experiments, which is composed of Tris, boric acid and EDTA, so it is called tbe buffer for short. The buffer is often used in the experiment of polyelectrophoresis. Tbe buffer is a colorless clear liquid, which can be stored at room temperature. The pH value of tbe buffer is 8.2 ~ 8.4 at 25 ℃. It should be noted that tbe buffer can not contain the activity of DNA hydrolase and RNA hydrolase.

Carbomer is a kind of acrylic crosslinking resin crosslinked with acrylic acid by pentaerythritol and so on. It is a very important rheological regulator. After neutralization, Carbomer is an excellent gel matrix with thickening, suspension and other important uses. The process is simple, and its stability is good. It is widely used in emulsion, cream and gel. We ourselves are not very familiar with Carbomer, and we know it was in the eyes of the public when it was used as a raw material for hand washing gel during the epidemic. At that time, because the purchase of this raw material was imported from abroad, the epidemic situation led to a very severe foreign form, unable to carry out normal import and export trade, and also directly led to the shortage of many manufacturers in the production of hand sanitizer series products. It also made it explode overnight. There are all kinds of information about cabom, which has skyrocketed from tens of dollars to hundreds of dollars, but it is still unable to supply domestic demand. If you can't import it, you have to produce and sell it yourself. So there was a boom in the production of carbomer. As long as you ask, you say you are a manufacturer of Carbomer, but how many are there? It's really hard to find a real and reliable manufacturer of carbomer. To tell the truth, it's either not available, or there are too many, so you can't tell the true from the false. Then why do you have to find a manufacturer? As long as you have the goods, isn't it OK? Yes, as long as the goods are available, it is the ultimate goal. But where did the goods come from? Is there a guarantee and after-sales service? I believe that every purchasing staff is most concerned about this issue. As long as we pay attention to the product of Carbomer, we all know that the explosion of this product has led to a lot of bad businesses replacing inferior products with good ones. There are many problems with the product, and there are very few products that can be used, which has led to an unprecedented strange appearance in the whole market. But if you are looking for a regular manufacturer to provide you with samples and after-sales and technical support, are these problems still problems? Desheng, as a manufacturer, although it appeared relatively late in the cabom project, they did not follow suit and only made products, because only the products were finished, all problems were not problems. They don't look at the high price and sell the incomplete products with no guarantee of quality to customers. Instead, they deal with a series of problems encountered in the products in a low-key way. Only when they really achieve the products in their mind can they go to the market. Even when the price and market demand decrease at that time, they will not change their determination to make good products at all. They will let you see the products first Quality, when you encounter any problem to help you solve the problem. Isn't such a manufacturer what you are looking for?

According to news reports, autumn and winter is the season of rapid spread of the new coronavirus, and the epidemic may continue to spread rapidly in this winter and next spring. In the special period of epidemic prevention and control, rapid and efficient detection, diagnosis and isolation of virus infected patients are the key to overcome the epidemic.   New Coronavirus pneumonia was detected by real-time fluorescence RT-PCR kit and virus gene sequencing in two ways. Among them, nucleic acid detection (fluorescent PCR) has become the main means of new coronavirus detection because it can get the detection results faster, has greater flexibility and universality, and is more suitable for epidemic prevention and control and management.     The principle of New Coronavirus nucleic acid detection kit is basically: by extracting RNA from patient samples, and performing reverse transcription polymerase chain reaction (RT-PCR), amplifying the virus information in the sample to amplify it, and finally reading the signal in fluorescence. If the signal is positive after PCR, it can be said that there is virus in the sample (already infected), otherwise it means that there is no infection.   Affected by the epidemic, the rapid increase in the production capacity of nucleic acid detection kits has also brought a sharp increase in the demand for reagent raw materials. Overnight, the virus preservation solution has become a hot product. According to the published reports, the reagents used in the coronavirus nucleic acid detection kit include Tris, HEPES, Tris HC, guanidine hydrochloride, BSA, guanidine isothiocyanate, EDTA, edta-2na, etc.   Among them, Tris, Tris HC and HEPES are similar in their functions as buffers, which are used to form PCR reaction solution / RT-PCR reaction solution / thermostatic amplification buffer, etc.; BSA is mostly used as a stabilizer in the preservation solution and reaction solution of restriction enzyme or modified enzyme;   Guanidine hydrochloride and guanidine isothiocyanate are commonly used reagents for nucleic acid extraction. Guanidine hydrochloride is a strong inhibitor of nuclease, which is conducive to extracting complete RNA from RNase rich tissues. Guanidine isothiocyanate is a powerful protein denaturant, which can quickly separate nuclear protein from nucleic acid; EDTA and edta-2na are mainly used as chelating agents to prevent metal ions such as Mg and Ca from activating protease. In order to prevent the rapid degradation of RNA, ensure the integrity of RNA and improve the accuracy of detection, virus preservation solution plays an important role.   The novel coronavirus pneumonia and the virus preservation solution play an important role in the diagnosis of diseases. In the very period of epidemic prevention and control, it is necessary to diagnose the new crown pneumonia.   Desheng is a new scientific and technological enterprise with "in vitro diagnostic reagent raw materials", "blood vessel additive", "biological buffer" and "pharmaceutical intermediates" as the leading, integrating R & D, production, sales and service.   At present, Desheng can provide nearly 100 kinds of in vitro diagnostic reagent materials, including Tris, Tris HC, HEPES, EDTA, acridine ester and other reagents, as well as virus preservation solution, the core material for detection. The average daily production of Tris can reach 1 ton, hoping to provide basic raw materials for the development of new crown vaccine, neutralizing antibody and rapid immunodiagnostic reagent.

Desheng, as an old manufacturer of vascular additive, has developed from a small workshop to a large factory. In the world of ups and downs, it can keep its progress all the time, which only means that it has been keeping up with the pace of the times, striving to do well in every product, so that all the individuals and enterprises who have contacted their products applaud. I think the success of an enterprise in the final analysis is inseparable from the quality of products and services.   Since it is an old manufacturer of vascular additive, what are their vascular additive products? Serum gel, heparin sodium, heparin lithium, dipotassium EDTA, Tripotassium EDTA, coagulant, silicide, sodium citrate, potassium oxalate, etc. Every product has its own characteristics and uses, but who is one of them? From the use, sales and production point of view, serum separation gel is worthy of the title.     Serum gel is a substance used to separate serum (plasma) and blood cells (blood cells). The separation gel can be used not only with accelerator, but also with anticoagulants such as heparin salt, EDTA salt and sodium citrate. The purpose of using separation glue is to prepare high-quality specimens and to store and transport specimens.   If separation gel is not used in coagulant blood collection vessel, although it can also accelerate blood coagulation and form blood clot and serum separation, there will still be material exchange when blood clot contacts with serum for a long time, and blood cells are very fragile and easy to hemolysis and interfere with serum samples. Using separation gel separation layer can solve the problem. In general, 0.8-1.2g separation glue is added to each blood collection vessel to form a separation layer of at least 5mm between different blood components, so as to ensure the high quality of blood samples.   The pure EDTA additive is the blood routine tube, while the EDTA dipotassium and serum gel are used together for the collection, transportation and storage of venous blood samples for nucleic acid detection. It is aimed at the DNA amplification detection of HBV, HCV and HIV. The serum gel can well block the interference of hemoglobin in red blood cells to the nucleic acid detection experiment.   We invest a lot of manpower and material resources in the serum separation gel every year. Last year, we obtained a patent due to the improvement of the separation gel technology, which increased our output from 500 tons to 800 tons per year in the early stage. The sales volume is also greatly increased, and it is sold at home and abroad. No matter from which aspect, serum separation gel is one of the blood vessel additives. And our other products are only relative to the separation glue, may not be so brilliant, but the market share is also praiseworthy.

Carbomer wins the hearts of many people because of its powerful application functions. However, in the process of using, there are always problems like this and occasionally irritate you and make you crazy. If you encounter the following problems, that's great. I hope these can help you solve the problems you have encountered and liberate your hair. Solubility issues Due to the special structure of carbomer, it is easy to swell in contact with water, and it has strong hydrophilicity. The carbomer of dry powder is very hygroscopic. Like other hygroscopic powders, it should be treated improperly. When thrown into water or other polar solvents, it tends to form agglomerates or is not completely wetted. Other powders will eventually decrease and dissolve after forming agglomerates, but the carbomer will not dissolve easily after forming agglomerates, because once the outer layer of the agglomerates is completely infiltrated, the water will not easily penetrate into the internal dry part. Gel viscosity problem Temperature has a certain effect on carbomer gel. As the temperature rises, the kinetic energy of molecular motion increases, and the speed of motion increases. Due to the difference in the volume of gel molecules and water molecules, the movement frequency of the two is inconsistent. As the temperature increases, the hydrogen bond between the gel molecules and the water molecules weakens, and some of the hydrogen bonds are broken, which leads to the system’s failure. The viscosity is reduced. However, this effect is reversible, heating within 100 degrees and then returning to room temperature will restore the viscosity; if heated to 260 degrees, it will decompose completely in half an hour. Color problem There are residual polymerization inhibitors, the type and amount of initiator, and the drying temperature. If the drying temperature is too high, the product is easy to change color. Studies have found that if the drying temperature exceeds 120°C, the product is more or less slightly yellowish. Therefore, drying should be dried under reduced pressure below 80°C. Transparency issues In some gel products, such as disinfectant and disposable gels, ethanol is often added as an additive in order to increase permeability, corrosion protection, and solubilization, and the content may be as high as about 75%. Carbomer gel is essentially a polymer solution. The reason why the polymer solution is stable is that there is a hydration film on the surface of the particle. The addition of a strong hydrophilic non-electrolyte (such as ethanol) will cause the polymer solution to flocculate. Carbomer ethanol gel is prepared by different operation processes, and the ethanol concentration of the finished product is different. When the ethanol concentration is too high, the finished gel will produce a little opalescence, which reduces the transparency of the gel. Stability issues When carbomer dissolves in water to prepare a gel, it is best to soak it in deionized water for 24 hours, and then mechanically stir it for half an hour. Neutralizing carbomer usually uses triethanolamine and EDTA-2Na as gel stabilizers. The presence of the hydration film on the surface of the carbomer gel makes the gel relatively stable. The greater the degree of dissociation of the carboxyl group, the less free water content in the gel, and the less prone to bacteria growth. The degree of hydration of the gel can be judged by the sliding time of the gel on the wall of the beaker. Products with the same viscosity but different hydration speeds indicate that the stability of the gel is different. The stability of the gel can be determined by the degree of hydration. Judge, adjust and control.

With the outbreak of the epidemic, Carbomer raw material has always been an important raw material in short supply. It is mainly used in daily chemical products. Because of the need of epidemic prevention, hand sanitizer is widely used, and carbomer is an important raw material of the product. Therefore, the shortage of carbomer once led to the shortage of hand sanitizers. At that time, cabom went crazy overnight. There are people everywhere asking about cabom. It is conceivable that the price has soared all the way, but it is not satisfactory. There is an unprecedented phenomenon that there is no goods at all. This also led to the behavior of some unscrupulous businessmen shoddy. The quality of carbomer's products was once suspected, and the price difference of middlemen was raised, which caused great losses to those enterprises that really needed carbomer's raw materials.   In this severe situation, it is very difficult to find a reliable and quality guaranteed manufacturer of carbomer. Because people's habitual thinking always feel that the wolf is not worth believing, even if it is true to meet you, there will be all kinds of distrust and suspicion. Just in this case, we met it -- Desheng technology, an enterprise that depends on products. It doesn't talk nonsense with you. It sends samples directly for testing. If it's true or not, you can tell by a try. No matter how much exquisite language there is no real product effect to experience, people are convinced.   Product packaging   [character] white loose powder; characteristic slight odor; hygroscopicity.   [identification] take this product 0.1g, dispersed in 20ml water, add 10% hydrogen Sodium Chloride Solution 0.4ml, that is gel form.   [inspection]   Acidity: take 0.10g of this product, evenly disperse and swell in 10ml water, and check according to law, the pH value should be 2.5-3.5.   Viscosity: take 0.5g of this product, evenly disperse it in 98ml water, after full swelling, mix it well, adjust the pH value to 7.3-7.8 with 15% sodium hydroxide solution (test with precision pH test paper), add water to 100ml, mix it well (avoid bubbles), and determine according to law, the dynamic viscosity at 25 ℃ should be 15-30pa · s.   Benzene: take about 1g of this product, weigh it accurately, put it in a tube with plug, add 10.0ml p-xylene, shake it to disperse, add 10.0ml 0.1mol/l sodium hydroxide solution, shake it tightly for 1 hour, and take the supernatant as the test solution. Take an appropriate amount of benzene, weigh it precisely, add p-xylene to make a solution of 10 μ g per 1ml as the reference solution. 1 μ l of the test solution and 1 μ l of the control solution were measured by gas chromatography (Appendix V E). A 3M glass chromatographic column with 201 red support (60-80 mesh) was used. Dinonyl phthalate and organic bentonite were mixed as the fixed solution. The coating concentration was 10%. The column temperature was 100 ℃. The benzene content should not exceed 0.01%.   Weight loss on drying: take this product and dry it under reduced pressure at 80 ℃ for 1 hour. The weight loss shall not exceed 2.0%.   Burning residue: take 1.0g of this product and check it according to the law. The residue shall not exceed 2.0%.   Heavy metal: the residue left under the item of burning residue shall be inspected according to law, and the content of heavy metal shall not exceed 20 parts per million.   [content determination] take about 0.4g of this product, accurately weigh it, evenly disperse it in 400ml water, stir to dissolve it, titrate it with sodium hydroxide titrant (0.25mol/l) according to potentiometric titration (Appendix VII a) (at the end point, stir at least 2 minutes after each drop). Every 1 ml sodium hydroxide titrant (0.25 mol / L) is equivalent to 11.25 Mg - COOH.   In the production process, DeSheng has passed through the numerous checkpoints and tests, and now has the quality of carbomer 940. The powder is white and flawless, and the gel liquid is crystal clear.

Acridine ester DMAE-NHS is a luminescent chemical reagent with a yellow solid powder appearance. Because no catalyst is needed, the reaction conditions are mild, and the reproducibility is good, the application field is very wide. Acridinium Ester-DMAE-NHS is mainly used for: chemiluminescence and immunoassay, receptor analysis, nucleic acid and peptide detection, etc. It also plays an important role in the TSH screening test items and can also detect the thyroid. Understand its four main characteristics.   Luminescence properties of acridinium ester-DMAE-NHS   The luminescence of acridinium ester-DMAE-NHS is flash type, the luminous intensity reaches the maximum at 0.4s, the luminous intensity decreases rapidly in the first 2s, and the luminous intensity decreases slowly after that. The luminous half life is about 0.9s. Changing the concentration of acridinium ester-DMAE-NHS only affects the size of the luminous intensity, but does not affect the time and half-life of the maximum luminous intensity.   Product packaging   Thermal stability of acridinium ester-DMAE-NHS   The thermal stability of acridinium ester-DMAE-NHS decreases with increasing pH and temperature. At room temperature, DMAE-NHS is relatively stable in PB buffer with pH of 5.8, 7.0, and 8.0. After 16 days, the luminescence activity decreased by 1.6%, 3.6%, and 8.3%, respectively. At 37℃, the luminescence activity of DMAE-NHS in PB buffer with pH 5.8, 7.0 and 8.0 decreased by 8.9%, 22% and 42% respectively after 16 days.   Hydrolysis rate of acridinium ester-DMAE-NHS   The reason why the luminescence activity of DMAE-NHS in PB buffer decreases with time is due to hydrolysis, which is beneficial to hydrolysis in an alkaline environment. Increasing temperature is also beneficial to hydrolysis, that is, the hydrolysis rate of DMAE-NHS varies with the pH of the solution. Increase and speed up with temperature rise.   Advantages of Desheng Acridine Ester DMAE-NHS   Compared with traditional acridine esters, DMAE-NHS has higher luminous efficiency, better thermal stability, and stronger hydrophilicity. The chemiluminescence reagent has high photon yield and low background. It is compatible with proteins, antigens, and antibodies. After coupling, the luminous efficiency is almost unaffected, making it an excellent chemiluminescence immunoassay labeling reagent.   Desheng acridine ester DMAE-NHS is a golden yellow powder under normal conditions. The texture is very fine and bulky. The purity of the HPLC method is greater than 98%, no peculiar smell, high sensitivity, high luminous efficiency, and strong stability. .

Pharmaceutical intermediates refer to chemical raw materials or chemical products used in the process of pharmaceutical synthesis. From the development history of China's pharmaceutical intermediates industry, after nearly 30 years of development, pharmaceutical intermediates have developed from a small branch of the chemical industry to a new industry with an output value of billions of yuan, and its market competition is becoming increasingly fierce. Now Desheng Xiaobian will introduce several common pharmaceutical intermediates for you.   Tris base(trimethylol aminomethane) Tris actually has another name, tromethamine, which is also related to its role in the field of medicine. In the field of medicine, Tris is also widely used in medicine. Tris is the intermediate of fosfomycin tromethamine. Fosfomycin tromethamine is a kind of broad-spectrum antibacterial drug which was launched in the late 1980s. Its bioavailability is 3 ~ 6 times of that of fosfomycin calcium, which is more suitable for the treatment of urinary tract infection and other diseases. Tris, as an organic amine, can form water-soluble double salt with insoluble substances with acidic groups. The most common eye drops containing Tris are ketorolac tromethamine eye drops.     Methyl 4,4 '- dimethoxyacetoacetate Methyl 4,4 '- dimethoxyacetoacetate is an important intermediate of nifedipine for the treatment of cardiovascular and cerebrovascular diseases. It is the leading drug for the treatment of cardiovascular and cerebrovascular diseases in the international market, but it has not been produced in China. Methyl 4,4 '- dimethoxyacetoacetate was synthesized from glyoxylic acid and trimethyl orthoformate in the presence of concentrated sulfuric acid. The latter reacted with methyl acetate and sodium methoxide to obtain methyl 4,4' - dimethoxyacetoacetate.   Pazopanib Pazopanib is a new oral angiogenesis inhibitor developed by GlaxoSmithKline company, which can interfere with the angiogenesis required for the survival and growth of refractory tumors. It targets vascular endothelial growth factor receptor (VEGFR) and works by inhibiting the angiogenesis of tumor blood supply. It is suitable for the treatment of advanced renal cell carcinoma (a type of renal carcinoma with cancer cells found in renal tubules), soft tissue sarcoma (STS), epithelial ovarian cancer and non-small cell lung cancer (NSCLC).   To sum up, Tris can be used as pharmaceutical intermediates. In addition to pharmaceutical applications, it can also be widely used in in vitro diagnosis, biopharmaceutical, cosmetics, paint and other industries. Desheng is a professional Tris reagent manufacturer, and its customers are the most in the application of buffers. Due to its high buffering efficiency and guaranteed quality, there are more than 50 stable cooperation customers at home and abroad .