China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Climbazole, CAS No: 38083-17-9, EC No: 253-775-4, English Name: clibazole, molecular formula: c15h17cln2o2, relative molecular weight: 292.76, is the most widely used second-generation anti dandruff agent developed by Bayer in 1977. It has broad-spectrum bactericidal properties. It is mainly used in anti itching and anti dandruff conditioning shampoo and hair care shampoo. It can also be used in antibacterial soap, shower gel, medicated toothpaste, mouthwash, etc.   The production of dandruff is caused by external and internal factors. The external factors are mainly affected by microorganisms (bacteria and molds). The effects of light, lipid peroxide and other stimulants produced by oxidation in the air, and various stimulants caused by environmental pollution accelerate the keratinization process of epidermal cells. The internal factors are mainly due to the body's nutritional status, excessive sebum secretion hormone or slightly nervous and other factors causing excessive dandruff. Climbazole has a unique antibacterial effect, especially on the oval dandruff, Candida albicans and other fungi. Climbazole powder Climbazole can block the production of dandruff through sterilization, inhibition of lipase, antioxidation and separation of oxides, So as to achieve the effect of effective anti dandruff, anti itching and hair care. It is different from simply eliminating dandruff temporarily by sterilization and degreasing. In a longer period of time, it can thoroughly protect the scalp and make the hair grow healthily. Therefore, it is welcomed by consumers. At present, active gambosol is widely used in Europe and the United States, in a variety of shampoo and conditioner, because of its inhibitory effect on Candida albicans, it is also used in medicated toothpaste, and has curative effect on gingivitis and oral endometritis.   Dandruff is like dirty things on clothes. It's not a serious disease, but it can make you embarrassed and irritable, and sometimes it can affect external communication. For dandruff, it is unnecessary to go to the hospital (unless there are symptoms such as redness, swelling or severe itching of the scalp). Most people choose anti dandruff hair products to solve the problem. In the hair products, Climbazole is the mainstream in today's market, which can also be called clomiprazole. Although Climbazole alone has limited anti dandruff ability, it can often achieve the best effect with ZPT, and is deeply consumed by the majority of consumers I love it.

Xanthine oxidase (XOD) is one of the important enzymes in nucleic acid metabolism, which can catalyze hypoxanthine to produce uric acid and hydrogen peroxide. It is a flavinase containing molybdenum, non heme iron, inorganic sulfide and fad. It is a form of xanthine oxidoreductase. Xanthine oxidoreductase is an enzyme producing reactive oxygen species. It is a kind of enzyme with low specificity, which can not only catalyze hypoxanthine to xanthine and then to uric acid, but also directly catalyze xanthine to uric acid.   The enzyme mainly exists in the liver, spleen and milk of mammals, but can not be detected in the serum of normal people. XOD is released into serum earlier than ALT in the process of hepatocyte injury. Therefore, the increase of XOD activity in serum can sensitively reflect acute liver injury.   XOD activity usually increased significantly in the early stage of jaundice, about 30-50 times of the upper limit of normal, and then decreased to the normal level as jaundice subsided. The positive rate of XOD was higher than that of ALT (90.4%) and AST (81.8%). In other liver diseases such as liver cirrhosis, amebic liver disease and hepatic echinococcosis, the serum XOD activity did not increase or slightly increased. Therefore, XOD can be regarded as a sensitive and specific index for the diagnosis of acute liver injury.   XOD is also helpful to distinguish the types of jaundice. Clinical observation showed that the serum XOD in patients with hepatocellular jaundice increased significantly, while the activity of XOD in patients with obstructive jaundice and hemolytic jaundice was almost normal or only slightly increased, generally less than 1 mu / L. The common diseases with high XOD are as follows: 1. Acute hepatitis is significantly higher than chronic hepatitis. 2. Infectious mononucleosis often increases. The activation of xanthine oxidase (XOD) can cause uric acid metabolism disorder and aggravate glucose metabolism disorder. When XOD is activated, it can also produce superoxide radicals and hydrogen peroxide, leading to oxidative stress.   Xanthine oxidase (XOD) uses molecular oxygen as electron acceptor to catalyze the oxidation of purine, pterin, aldehydes and other heterocyclic compounds, and produce reactive oxygen species (ROS) such as hydrogen peroxide and superoxide radicals. Reactive oxygen species can induce oxidative stress in cells.   Pre receptor and post receptor defects are the main pathogenesis of insulin resistance. The former is mainly manifested by the abnormal binding of insulin to target tissue receptors, including the relative deficiency of insulin and its receptors, the structural changes of insulin and its receptors, etc.; the latter is mainly manifested by the dysfunction of insulin signaling pathway, etc.   Under oxidative stress, it interferes with the signal transduction of insulin binding to receptor mainly by stimulating the inflammatory signal transduction pathway and c-Jun N-terminal kinase pathway. The main reactive oxygen species produced by xanthine oxidase activation is O2, which can inhibit the functional expression of insulin receptor.   The sensitivity of insulin receptor and the integrity of its structure and function are shown by the consumption of glucose. When the number or structure and function of insulin receptors change, the sensitivity of insulin receptors will change accordingly.   In recent years, the incidence of gout and diabetes is increasing year by year. With xanthine oxidase (XO) and α - glucosidase as the main enzyme targets of hyperuricemia and hyperglycemia, exploring the inhibitory effect and mechanism of natural plant ingredients with low toxicity and little side effect on XO and α - glucosidase has gradually become a research hotspot. XO inhibitors can reduce the content of uric acid in the body by inhibiting the activity of xanthine oxidase, which is widely used in clinical treatment.   Therefore, some xanthine oxidase inhibitors can effectively reduce the level of uric acid. However, patients with hyperuricemia do not fully develop gout. Therefore, the development of gout in patients with hyperuricemia can be predicted by regular detection of xanthine oxidase, uric acid and erythrocyte sedimentation rate.

The determination of free fatty acids in serum or plasma usually adopts Trinder chromogen enzyme photometric method. However, due to the characteristics of this test, the detection of fatty acids is affected by many factors, and the detection method needs to be optimized and improved to improve the accuracy of the detection.   Trinder chromogen detection FFA principle: The detection method has three reaction steps: free fatty acids (FFA or NEFA) react with excess CoA to generate acyl-CoA under the action of acetyl-CoA synthase (ACS), and react with oxygen under the action of acetyl-CoA oxidase (ACO). The reaction generates 2,3-trans-enoyl CoA and hydrogen peroxide, and the Trinder reaction is used to detect hydrogen peroxide, and the content of FFA can be obtained. TOPS is recommended for FFA determination of chromogen Problems in FFA determination and optimization methods: 1. Excessive Coenzyme A in the reaction will interfere with the reaction of hydrogen peroxide and Trinder chromogen, making the whole test result low. N-ethylmaleimide (NEM) can be used to remove excess Coenzyme A. The stability of NEM is very affected. Limited, only one week. 2. The acetyl CoA synthetase and acetyl CoA oxidase used have different substrate specificities for different free fatty acids, causing differences in the determination results. Different enzyme sources have different substrate specificities for free fatty acids with different C chain lengths. That is, the response capacity is different. There are 6 kinds of FFA in human serum, and only enzymes with high specificity to them can make no difference in the measurement results.   3. Due to the influence of CoA on the reaction, the linear range of the data results is narrow. The color of FFA measured on the market is MEHA, TBHB, TOOS, etc., but it is greatly interfered by CoA, and it must be excessive, so interference is required. Less chromogen. SCEP is not interfered by Coenzyme A but is unstable. ADOS and TOPS are less interfered by CoA, and TOPS has a higher molar absorption coefficient, so it is a better chromogen substrate.   4. Add sulfhydryl complex DTNB and MIT to reduce the amount of NEM. The sulfhydryl group of DTNM can react with the sulfhydryl group of CoA to remove the interference to chromogen. A small amount of MIT can remove the sulfhydryl group of CoA and also acts as a preservative. Based on the use of TOPS chromogen, the interference of CoA can be completely eliminated, and the stability is greatly improved.   If you have higher requirements for FFA determination results, you can choose a better quality kit based on the above points. Desheng produces the raw materials for the FFA and other index determination kits. If TOPS is used to determine FFA directly, due to the poor stability of the solution, it is recommended to prepare a working solution for immediate use before use.

4-Hydroxyethylpiperazine ethanesulfonic acid, English abbreviation HEPES, CAS number: 7365-45-9, color is white crystalline powder, PH value range is 6.8-8.2, its most common application is as a biological buffer adjustment PH value and its application in skin care products are also loved by major manufacturers. Its application in rabies virus detection is often unknown. Today, the editor of Desheng will popularize relevant knowledge for everyone.   Rabies virus generally does not produce cytopathic (CPE) when it reproduces in infected cells, and it is not easy to form plaques under conventional culture conditions. Although many scholars at home and abroad have established rabies virus erosion on chicken embryo cells and BHK-21 cells. Spot methods, but these methods require strict experimental conditions, or the operations are complicated and difficult to master, which affects their popularization and use. After the researchers found that 4-hydroxyethylpiperazine ethanesulfonic acid HEPES can enhance the pathogenic effect of rabies virus on infected cells, they used this characteristic of HEPES to establish a simple and rapid HEPES plaque method for rabies virus. The effect of HEPES on the formation of rabies virus plaque After the infected cells were cultured at 37°C for 3 to 5 days, the infected cells treated with HEPES developed obvious cytopathic changes at the bottom of the covering. After staining with crystal violet, clear plaque formation was seen, while the infected cell group not treated with HEPES showed no signs of plaque formation. There is no cytopathic effect, and no plaque formation. It can be seen that HEPES can obviously promote the formation of rabies virus plaque on BHK cells.   Observation on the sensitivity of HEPES plaque method The HEPES plaque method can be used for the titer of virus infection. Experiments show that there is an obvious titer relationship between the number of plaques formed after virus infection and virus dilution. The infective titers of the same rabies virus CTN-BHK strain were measured by the HEPES plaque method and the mouse method. The results showed that the number of plaques obtained by the HEPES plaque method for 4 consecutive determinations ranged from 1.0×10° to 4.0× 10*PFU/m1. The infection titer obtained by the mouse method for 4 consecutive determinations is 6.0～6.8log or 1.0×10°～6.3×10/ml. This shows that the rapid HEPES plaque method has the same sensitivity as the mouse method. Advantages of HEPES plaque method Using rabies virus CTN-181 strain and CTN-BNK strain to study the infection titer titration method, the results show that HEPES can induce and enhance the pathogenic effect of the canine virus on the infected cells. When the virus infects the cells, they are cultured at 37°C for 3～5 Just add 50～00mmol/L HEPES on the cover of methylcellulose semi-solid medium on the first day, stain with crystal violet solution after 24 hours, and calculate the number of plaques by naked eyes after drying at room temperature. Compared with the insect spot method reported in the previous literature, this plaque method has the advantages of fast, simple, economical, sensitive and easy to master.   The HEPES produced by Desheng is reagent grade with a purity greater than 99%. Our products perform well. There are many cooperative manufacturers and can provide samples for free trial. Desheng will continue to provide customers with high-quality products as always. If you have any questions or needs, you can go to the official website to consult customer service staff  

In the nucleic acid detection of the new coronavirus, the very key technology is the real-time fluorescent quantitative PCR experiment of nucleic acid, which is the core technology of the new coronavirus detection. So what effect does the virus transport media used for virus sampling joints have on the PCR amplification of nucleic acids? This article makes a brief discussion. Does the virus transport media affect nucleic acid PCR amplification? Judging the result from the PCR amplification curve: The fluorescent quantitative PCR instrument in the new crown detection has become a routine equipment for molecular biology research. The rapid development of this detection method and the urgency of the detection task have also put forward higher requirements for the detection personnel, requiring them to be proficient in judging the results of the data. For the judgment of the result of fluorescence quantitative PCR, the most intuitive judgment is to see whether the amplification curve is normal. In normal experiments, you will encounter problems with abnormal amplification curves, such as discounted amplification curves, poor repeatability between multiple wells, and uplifted amplification curves of negative samples.   Reasons for abnormal PCR amplification curve: 1. Confirm whether the software settings are correct. Check the kit instructions to check whether the time, temperature, cycle number, fluorescence collection, etc. are set correctly, and whether the selected reagent contains ROX as a reference fluorescent dye. Some results show that the amplification curve of the multi-component graph is not uplifted, which is obviously a negative sample, but the amplification graph curve is uplifted, so that it crosses the threshold line, and instead has a CT value. This is because the software makes a mistake in the automatic deduction of the baseline. The method of manually adjusting the baseline can be normal by redefining the baseline.   2. Make sure that the consumables and instrument accessories are used correctly. Consumables are more important for real-time PCR. Many abnormal amplification curves are caused by improper use of consumables.   3. To determine whether the reagents used are normal, first determine whether the reagents are effective, including checking whether the reagents are within the validity period, whether they are repeatedly frozen and thawed many times, and whether the transportation conditions are normal. If all of the above are normal, then you have to consider whether there is any negligence in the operation details.   From the above points, it can be seen that the virus transport media will not directly affect the amplification curve, it will only affect the virus samples, but this can be done through a control experiment with positive samples to determine whether the virus preservation solution has an impact on the virus samples. . There are two types of Desheng virus transport media, both the inactivated type and the activated type are suitable for nucleic acid PCR experiments.

Carbomer 940 is a thickening agent, and ordinary consumers are quite unfamiliar with this raw material, but it is used in personal care products and disinfectants, lotions, shampoos, toothpastes and other products for a short time. It is difficult to find substitutes. During the epidemic last year, the demand for carbomers surged, and the supply of domestic carbomers was insufficient. Imported carbomers have high purity and good viscosity, and are very popular with customers. However, the price of imported carbomers is very high. Can you find a carbomer with high quality and low price?   Of course, the answer is yes. During the epidemic, Desheng has "circled many fans" with its good quality and competitive price, and as a supplier of Carbomer 940 with production strength, it produces a wide range of products. Well received by the market, let’s talk about 3 reasons why customers choose Desheng   In terms of price, Desheng can give customers the greatest discount. If the customer needs a relatively large amount of Carbomer 940, they can enjoy a price discount, and the room for profit is very large. You can compare with other products on the market. Desheng always believes that good products can withstand the test of the market. In addition to the quality and quality of the products, Desheng also impresses you with the price.   In terms of quality, Desheng guarantees the product content of Carbomer 940 and the accuracy of various parameters. All parameters are accurate data obtained by the production and R&D department through a series of inspections and experiments. The parameter table is provided. , Customers can compare and verify, and in addition, ensure that the continuous spot supply within customer needs will not affect the normal use of customers. The company has the quality inspection report of Carbomer 940, and customers can buy with confidence.   Secondly, Desheng also conducted a survey of intentions for Carbomer customers. Customers commented that Desheng’s supply speed is very fast. The products can meet the buyer’s requirements in terms of appearance, light transmittance, viscosity range and other parameters. Demand, the most important thing, Desheng’s after-sales service is very strong, no matter what kind of problems arise, professional after-sales service will provide reasonable solutions, so that customers can feel Desheng’s professionalism and dedication.   The three reasons for choosing Desun Carbomer 940 are mentioned here. Although Carbomer 940 has a large domestic demand, many manufacturers cannot meet quickly due to tight supply of raw materials or too many orders for a long period of time. According to the needs of every purchaser, Desun, as one of the manufacturers of Carbomer 940, has a daily output of up to 3-5 tons. It can meet the needs of customers in large quantities and is a manufacturer worthy of cooperation!

What is HEPES? The full chemical name of HEPES is N-(2-hydroxyethyl)-piperazine ethane sulfonic acid. It is a zwitterionic biological buffer. Its physical properties include a white powdery appearance at room temperature and its excellent water solubility. 40 grams of HEPES can be completely dissolved in 100 ml of pure water at 20°C. Therefore, it is very easy to use and only needs to be dissolved in water. Application of HEPES: 1. Research on most metal ions; 2. It can be a good substitute for Tris and phosphate in the research of metal ions; 3. For environmental, analytical and biological research; 4. As the binding buffer and eluent in cation exchange chromatography; 5. As a grinding buffer in plant research; 6. As the running buffer in gel electrophoresis; 7. As a buffer for electroporation; 8. Buffer mammalian cell culture; 9. As a buffer for in vitro fertilization and embryo culture; 10. For Bradford or bicinchoninic acid (BCA) analysis; 11. For research on cartilaginous amphibians, because it is non-toxic to this algae; 12. It has been introduced into the extraction buffer to prevent damage to the proteins in red blood cells.   Precautions: 1. It affects the membrane potential of neuronal cells; 2. It will interfere with the determination of Lowry protein; 3. It is not suitable for redox research; 4. It is toxic to small crustaceans (water fleas); 5. It will interfere with the phenol oxidation of peroxidase; 6. It will affect the self-oxidation rate of iron; 7. It is not recommended to use Folin reagent for protein determination; 8. HEPES powder has high temperature resistance and melting point as high as 200℃, so it will not be degraded by autoclaving; 9. If the HEPES water solution is exposed to light for three hours, it will produce cytotoxic H2O2, so it must be kept away from light.   Advantages of Desheng HEPES: 1. The application range of HEPES is pH6.8-pH8.2, which is in line with the characteristics of pH value needed for cell culture; 2. The purity reaches ≥99%, the water solubility is good, the process is stable, and the constant pH range can be controlled for a long time; 3. There is a professional R&D and production team, with a daily output of 1-2 tons, and there will be no long supply cycle or out of supply; 4. Have strong logistics capabilities and rich export experience; 5. A full range of product testing and special testing services can be provided according to your application requirements; 6. We can pack in quantities according to customer needs. Generally, there are 500g small bottles and 25kg cardboard drums. The large packaging is lined with plastic bags. The white powder is packed in the belt and the tie is tight.

Blood analysis is a routine test item in clinical medicine. The vast majority of outpatients or inpatients are subject to this test. From the beginning of the development of manual detection to automatic detection. EDTA is an anticoagulant commonly used in hematology analyzer. It has good anticoagulant effect and little effect on blood cell morphology. Potassium ethylenediaminetetraacetate (edta-k2)   Ethylenediaminetetraacetic acid (EDTA) is an amino polybasic acid. Because it can form complex with most metal ions, it has become a general strong chelating agent. In the past, the research on EDTA chelate and chelation mainly focused on three aspects 1. The most stable metal chelates of EDTA are transition elements and rare earth elements.   2. It is a group of vegetative compounds with medium complexing strength, such as alkaline earth metal complexes. Because it is difficult for common reagents to realize the complexation of alkali metals, EDTA has attracted special attention;   3. The affinity of EDTA to protons was studied through the sequence of EDTA itself and its co alkali metal salt.   Edta-k Ψ is a kind of amino polycarboxylic acid, calcium chelating agent, which has a great affinity for calcium in blood. It can effectively chelate calcium in blood samples, chelate calcium or remove the calcium reaction site. The decrease of calcium content will block and terminate the endogenous or exogenous coagulation process, so as to prevent the coagulation of hemostatic fluid samples. Every 0.8 mg can anticoagulate 1 ml of blood. It can not be used for the determination of Ca, Na and N in plasma. It is also suitable for anticoagulation. Edta-k Ψ can also complex some ions in plasma to make some proteins or nucleic acids more stable, but the interference of chromium complex formation on samples and experiments should be considered.   Edta-k Ψ is suitable for general hematological examination, especially for platelet count. Because it affects platelet aggregation and phagocytic function of blood cells, it is not suitable for coagulation and platelet function examination. It is also not suitable for determination of Ca +, K +, Na +, Fe +, alkaline phosphatase, creatine kinase and leucine aminopeptidase and PCR test.   Additives for vacuum blood collection: the additives for vacuum blood collection are edta-k2 aqueous solution, and 4mg edta-k Ψ is needed for anticoagulation of 2ml blood.   Because the concentration is small, in order not to dilute the blood, 20 μ l of water solution containing 200 g / L edta-k Ψ is usually preset in each blood collection vessel. Because the blood collection vessel is valid for two years, when the use environment changes slightly, such as the temperature changes, the water is easy to evaporate to the tube wall (especially the water in the solvent of plastic pet tube can seep through the tube wall and leak out), resulting in tube leakage Edta-k Ψ crystallizes quickly in the blood sample. When collecting blood, it is required that edta-k Ψ be reversed for at least 8 times, so that the crystallized edta-k Ψ can be fully dissolved and mixed in the blood. If the action is a little bigger, the red blood cells will be destroyed and hemolyzed, and the platelets will be aggregated, adhered and broken.

Luminol, the luminescent substrate of horseradish peroxidase HRP, is chemically named 3-aminophthalic acid hydrazide, and sometimes also contains isoluminol and its derivatives such as ABEI, ITCI, etc., which are the reagents of this type of reagent Collectively. The synthesis process of this kind of reagent directly affects its luminescence performance, which in turn affects the detection result. The synthesis process of luminol, isoluminol and its derivatives are all based on 3-aminophthalic hydrazide. The synthesis steps are divided into three steps. Here is a brief introduction to their synthesis trilogy:   1. Synthesis of 3-nitrophthalic acid Luminol and isoluminol are both prepared by the reaction of nitrophthalic acid and hydrazine, and it is an important raw material for the synthesis process. Raw materials can be purchased directly, the cost will be higher, or they can be produced on their own. Mix 12 mL of concentrated sulfuric acid and 12 g of phthalic anhydride and heat, slowly add 10 mL of fuming nitric acid dropwise, and control the temperature at 100-110°C. After the reaction is completed, it is cooled to obtain the product 3-nitrophthalic acid and the by-product 4-nitrophthalic acid. Using different water solubility, add water and filter to obtain the crude 3-nitrophthalic acid solid, and then use water for the solid Recrystallize to obtain the product. Three steps of luminol synthesis 2. Synthesis of 3-nitrophthalic hydrazide Put 1.3 g of 3-nitrophthalic acid and 2 mL of 10% hydrazine hydrate in a 100 mL two-necked flask, heat to dissolve, add 4 mL of triethylene glycol, fix the two-necked flask, add zeolite, The catheter connects the flask to the water pump through a safety bottle. Turn on the water pump and heat the flask to maintain the temperature at 210-220°C. After the reaction is complete, stop heating and pumping. Cool to 100°C, heat water, cool to room temperature and filter, collect light yellow crystals to obtain 3-nitrophthalic acid hydrazide.   3. Synthesis of luminol 3-aminophthalic hydrazide The product from the previous step was transferred to a beaker, and sodium hydroxide solution was added to dissolve it. Add 4 g of sodium dithionite dihydrate, heat and stir, and keep boiling for 5 minutes. After a little cooling, 2.6 mL of glacial acetic acid was added, and the mixture was cooled to room temperature in a cold water bath to precipitate light yellow crystals, which were washed with suction and water for three times to obtain the final product luminol.   The above is the synthesis steps of luminol. Similarly, the by-product 4-nitrophthalic acid can be made into isoluminol, or the synthesis of isoluminol derivatives can be continued. The luminescent substrates currently synthesized by Desheng include luminol, isoluminol, and acridinium ester, a direct chemiluminescence reagent.

Tris, cas77-86-1, also known as tromethamine, is a common reagent, which is widely used in industrial synthesis, biochemical detection and biopharmaceutical fields. In addition, Tris can also be used to prepare gold nanoparticles.   Tris (hydroxymethyl) aminomethane is widely used in biochemistry and molecular biology experiments as a common raw material for buffer preparation. Tris is also an intermediate for the preparation of surfactants, vulcanization accelerators and some drugs. Because it has three equal hydroxyl groups, it can also be used as a good reducing agent. In the alkaline condition of sodium hydroxide, it can reduce chloroauric acid solution to prepare stable gold nanoparticles. This method is non-toxic and pollution-free, and belongs to green reduction method.   At present, the classical synthesis methods of gold nanoparticles are sodium citrate reduction method, phase transfer method and seed growth method. These methods are the easiest to modify the surface of gold nanoparticles, but the preparation and modification of these methods have certain toxicity. In order to reduce the toxicity of gold nanoparticles to organisms in experiments and make them better used in biomedical field, researchers have been continuously developing new green reduction methods in recent years. For the first time, Tris was used as a reducing agent to reduce chloroauric acid solution under alkaline condition by ultrasound without adding other stabilizers. The environmentally friendly and biocompatible gold nanoparticles were synthesized. Gold nanoparticles with different sizes can be prepared by adjusting the experimental conditions.   Compared with other green synthesis methods, the experimental conditions are more mild and the operation is simple. This provides a new research idea and theoretical basis for the synthesis of green, pollution-free, low toxicity, low cost and high biocompatibility gold nanoparticles.   Since 2005, Desheng has developed and produced biological buffers, blood collection additives, color reagents and chemiluminescence reagents. The biological buffers include Tris, HEPES, caps, mops, etc. Desheng has always been adhering to the concept of quality first, products from the selection of raw materials to production and packaging layer upon layer, only to provide customers with quality products, do not forget the original intention can Zhiyuan.

In the field of in vitro diagnostics, enzyme colorimetry is a common method for quantitative or qualitative testing of target components, and it is widely used in China, such as the detection method of the color reaction of the enzyme HRP catalyzed by the chromogenic substrate TOOS in the Trinder reaction. Because of the participation of enzymes, it is very valuable to improve the stability of the enzyme activity color substrate.   Some reaction products with high molar absorbance chromogenic substrates, such as TOOS, TOPS, etc., can be used in wet chemical methods as well as dry chemical methods: the required reaction reagents (TOOS, 4-AAP) and the required enzymes (HRP) Etc.) It is fixed on the membrane carrier, and the sample is added dropwise to generate H2O2 and then release new ecological oxygen, oxidize the color substrate, and indirectly determine the target component through the amount of the reaction product. Enzymes are highly specific and highly efficient in catalysis. However, they have poor stability under the influence of temperature, pressure, and light in dry chemical methods. In wet chemical methods, enzymes are easily inactivated when they are in a liquid state or at low concentrations. Chromogenic substrate TOOS powder On the other hand, most chromogenic substrates, such as TOOS, MAOS, TMB, etc., are also easily oxidized slowly, so their solutions cannot be exposed to the air for a long time. There are many ways to improve the stability of biologically active enzymes and chromogenic substrates: 1. Adding enzyme solution protective agent can make the activity of various enzymes such as ALT, AST, LDH, ALP, CK in aqueous solution or serum matrix stable for 2 weeks at room temperature, but the effect on dry chemical test paper is not significant. 2. The color-developing substrate stabilization method uses surfactants and flavonoid pigment substances with an alkyl group with 8 to 16 carbon atoms, but the formula is complicated, the reagents are difficult to buy, and the protective agent interferes with the test results. 3. There is a protective agent that is more reducible than the color-developing substrate, but the added protective agent contains primary amino groups and often causes non-specific reactions. 4. The use of azo dyes as stabilizers of the color-developing substrate has a good stabilizing effect and does not cause interference, but the maximum absorption wavelength of the dye is sometimes close to that of the color-developing agent, which makes the blank control a bit higher. 5. A protective agent for polymer and its composition, which can improve the stability of enzymes and chromogenic substrates. Applicable chromogenic substrates include TOOS, 4-AA, TOPS, MAOS, etc., suitable for HRP, CHO, etc. Enzyme, suitable for the detection of glucose, creatinine, uric acid, cholesterol, triglyceride and other indicators.   It can be seen that various existing protective agents for enzymes or chromogenic substrates, some of which are defective, such as high cost, biased detection, and only suitable for wet chemical methods, etc., thus improving the stability of enzymes and chromogenic substrates The method needs further research. Desheng is a manufacturer of chromogenic substrates and enzymes. It is recommended that you pay more attention to the use of chromogenic substrates and enzymes.

When we use the good's buffer, we always inadvertently confuse the HEPES and pipes in the good's buffer, thinking that they are the same, which makes it impossible to distinguish them very accurately. In fact, there are similarities between them, but there are also many different characteristics.   Especially in the process of our experiment, a little difference may lead to the failure of the experiment. So we need to know what buffer is and what it does? In order to distinguish between HEPES and pipes in buffer, what is the difference between them? What should we pay attention to when using?   Buffer solution is a kind of special buffer system for life science research. In biochemical experiments, buffer solution plays an indispensable role. It can resist the influence of a small amount of strong acids and bases, and maintain the pH value closest to the physiological environment for the system. HEPES and pipes buffers are commonly used in biological experiments. Package picture of Desheng biological buffer The pH buffer range of HEPES is 6.8-8.2, which is a kind of zwitterionic biological buffer. It is soluble in water and does not form stable complexes with metal ions. In most cases, it does not interfere with biochemical processes. It can be widely used in a variety of biochemical reactions and used as a buffer reagent in some cell culture media.   HEPES is commonly used in cell culture media of various types of organisms; in protein research, it is often used as the component and eluent of binding buffer in cation exchange chromatography; in DNA research, it is used as the buffer of calcium phosphate and DNA sediment formation system, AFM and electroporation experiment.   In addition, HEPES interferes with the reaction between DNA and restriction enzyme and is not suitable for Lowry's method. HEPES buffer is often used in the research of organelles and pH sensitive proteins and enzymes, as well as in biochemical diagnostic kits, DNA / RNA extraction kits and PCR diagnostic kits. It is a hydrogen ion buffer, which can control the constant pH range for a long time. When the final concentration is 10-50 mmol / L and the culture medium contains 20 mmol / L HEPES, the buffer capacity can be achieved.   The pH buffer range of pipes is 6.1-7.5, insoluble in water and soluble in NaOH solution. Different from buffers containing bis (2-hydroxyethyl) amino groups (such as bis Tris, bicine), pipes can not form stable complexes with most metal ions, so it is suitable for buffers containing metal ions.   According to previous studies, PIPES can be used to purify tubulin by using cellulose phosphate chromatography, and to purify recombinant GTP binding protein ARF1 and ARF2 by gel filtration as a buffer to crystallize ketoenzyme from E. coli. In addition, due to the formation of free radicals, pipe is not suitable for redox system. In cation exchange chromatography, low concentration of pipes buffer should be used because of its relatively high ionic strength and concentration dependent pKa value.   It can be seen that neither pipes nor HEPES can form stable complexes with metal ions, which is suitable for the solution containing metal ions. However, there are some differences between them. In terms of solubility, pipe is insoluble in water, while HEPES has good water solubility. In terms of buffer range, pipe is acidic to neutral, and HEPES is neutral to alkaline. This is mainly due to the structural differences between them. Pipe has two sulfonic groups, and HEPES contains one sulfonic group and hydroxyl group.   In addition, pipes and HEPES have some limitations in the application of some systems. Therefore, when we choose the above buffers, we need to consider the suitability of the experimental system and the difference of their properties.   We should learn to distinguish and understand the similarities and differences in these reagents, so as to better promote the R & D and production of our different products. Desheng consistently adheres to this kind of subtle difference, so as to continuously develop and produce better products.