China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Nowadays, as long as people have a headache and brain fever, they first go to the hospital for testing to find out where the problem lies, and then prescribe the right medicine. In fact, many people only know the test items, but they don't know much about the test materials. The DAOS in the new Trinder’s reagent is a very important test material, which has the advantages of good water solubility, high sensitivity, and strong stability. Let's take a look at the past of DAOS on the road of detection.     DAOS can be used for cholesterol testing   When measuring total cholesterol, the cholesterol ester is firstly hydrolyzed into cholesterol and fatty acid by cholesterol esterase CHE, and then it is catalyzed and oxidized to 4-cholestenone and hydrogen peroxide by cholesterol oxidase, and then it is through DAOS and 4-AAP Coupling with hydrogen peroxide to produce a color reaction under the catalysis of POD, the concentration of total cholesterol can be determined by measuring the absorbance.   DAOS can be used for triglyceride detection   When detecting triglycerides, triglycerides are hydrolyzed into glycerol and fatty acids in the presence of lipoprotein esterase (LPL); glycerol and ATP are catalyzed by glycerol kinase (GK) to generate glycerol-3-phosphate and ADP; glycerol-3- Phosphoric acid and oxygen are catalyzed by glycerol-3-phosphate oxidase (GPO) to generate dihydroxyacetone phosphate and hydrogen peroxide, and then use the color substrate to couple 4-AAP and hydrogen peroxide to produce color as in the above steps. In response, the TG concentration was measured.   DAOS can be used for high-density lipoprotein detection   When detecting high-density lipoprotein, a dual-reagent reaction is used. Reagent one contains polyanion and surfactant, which selectively binds to VLDL and LDL, and inhibits COD and CEH in reagent two on VLDH-CH and LDH-CH. , Thereby selectively acting on HDL-CH, through the action of CEH-COD-POD, and then measuring the absorbance to determine the concentration of HDL, and finally the LDL concentration can be obtained by calculation.   Cautions when using DAOS:   1. Divided packaging: When taking a small amount of mg DAOS, the product needs to be divided into the quantity needed each time to reduce the number of bottle openings and prevent the product from absorbing moisture. 2. Use: When using the product, you need to take out the product from the freezer half an hour in advance and place it at room temperature.   For the remaining, store the remaining DAOS in a sealed and light-proof container to avoid quality problems such as changes in color or properties of the product.   3. Preservation: Place DAOS in a 0-5 degree freezer, and record the time and batch number.   4. Transportation: Put ice cubes in the foam box for the packed products and wrap the products with foam glue. Take care to prevent the water from the ice cubes from getting the product wet (we put two more if the temperature is high, and the weather can be changed in winter. Temperature to decide)

Acridine ester (nsp-dmae-nhs), yellow powder, CAS No.: 194357-64-7, is an important chemiluminescence reagent. Its chemiluminescence quantum yield is higher than that of luminol. Moreover, the labeling conditions of acridine ester are mild, the labeling rate is high, and the labeling does not affect the separation.   In addition, the chemiluminescence process of acridine ester is rapid with low background, and can emit light in the presence of sodium hydroxide and hydrogen peroxide. In addition, acridine ester chemiluminescence reagents have good stability and are easy to store.   In addition to the application in immunoassay, acridine ester can also be used to label oligonucleotide fragment probes for gene detection or microbial detection. Acridine ester compounds are suitable for labeling DNA strand to make chemiluminescence DNA probes.   Modern medical research results show that many diseases such as cancer and genetic diseases are related to DNA mutation, and many infectious diseases are caused by viruses, bacteria or parasites in the environment. The analysis of specific sequence of virus DNA is conducive to the control of epidemic situation. The detection of DNA sequence and base mutation in its strand is of great significance in gene screening, early diagnosis and treatment of genetic diseases, and detection of pathogenic genes.   In nucleic acid hybridization analysis, the preparation of specific and sensitive labeled probe is the key to the success of nucleic acid hybridization analysis. Acridine ester derivatives can be directly labeled on the nucleic acid probe without catalyst and the luminescence quantum yield is not affected. In addition, under certain conditions, the acridine ester labeled on the unhybrid single strand DNA is hydrolyzed and destroyed, and only the double strand formed by hybridization is protected Only acridine ester can produce chemiluminescence, and the whole hybridization process can be monitored without separation.     The invention relates to a method for labeling nucleic acid with acridine ester, which comprises the following steps:   (1) The 5 'and 3' ends of DNA probe were protected;   (2) Acridine ester labeling: 25 mm NHS acridine ester was dissolved in DMSO, and 1 m HEPES buffer (pH = 8.0) was prepared. According to the molar ratio of nucleic acid probe: NHS acridine ester = 1:5, it was added into HEPES buffer and reacted at 37 ℃ for 1 h;   (3) Purified by HPLC. In the step (1), the protection of 5 'and 3' ends of DNA probe specifically includes: using s-ethyl trifluorothioacetate to protect 5 'end-nh 2; using s-ethyl trifluorothioacetate to protect 3' end-nh 2.   Desheng technology has been researching and developing chemiluminescence reagents for 12 years. After successful development, it has been put into the market and won the general recognition of customers. There are six different groups of acridine esters. Besides acridine esters, there are luminol and isoluminol. Acridine ester series have high luminous efficiency and belong to direct luminescence.

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.

Caps, the full name of 3-cyclohexylaminopropane sulfonic acid, is known by more people as a biological buffer to stabilize the pH value. You may not know that caps is not only widely used in biochemical analysis and in vitro diagnosis industry, but also in nucleic acid extraction and water-based coating market.   3-cyclohexylaminopropane sulfonic acid (CAPS) is mainly used in biochemical diagnostic kits, DNA / RNA extraction kits and PCR diagnostic kits. 3-cyclohexylaminopropane sulfonic acid (CAPS) can also support alkaline phosphatase activity and inhibit the growth of Aeromonas at pH 10.5, and can be dissolved in deionized water and adjusted to pH 11.0 for purification of fibronectin.   Desheng biological buffer caps   In nucleic acid extraction, 3-cyclohexylaminopropane sulfonic acid (CAPS) and 3 - [(3-cholamidopropyl) dimethylammonium] - 1-propanesulfonate (chaps), 3 - (cyclohexylamino) - 2-hydroxy-1-propanesulfonate (capso), and 2 - (cyclohexylamino) ethanesulfonate (ches) were used to prepare the solution for nucleic acid hybridization, which could reduce the yield of non-specific hybridization products, improve the specificity of nucleic acid hybridization, and maintain the stability of nucleic acid hybridization The yield of the target hybrid product was determined. It has important value in the identification of specific pathogens, the diagnosis of genetic diseases and the analysis of gene sequences.   In addition, caps can also be used in a variety of environment-friendly high-quality waterborne two-component polyurethane coatings. Many coatings do not perform well in terms of dryness, curing and chemical resistance, while caps performs well. It can be used as water-based isohydric ester curing agent and can coexist with resins containing active groups (hydroxyl, carboxyl, amine, epoxy, etc.) for a long time at room temperature. This is one of the reasons why caps is more and more favored by the water-based coatings market.   Desheng has rich experience in the production and research of cyclohexylaminopropane sulfonic acid and other biological buffers. Caps buffer is not only widely praised in the field of biochemical industry, but also widely used in the new paint market. Its application in the chemical industry is also rising with the rapid development of the medical industry.

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.     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. .

The new Trinder's reagent is a highly water-soluble aniline derivative, which is widely used in diagnostic detection and biochemical tests. In the colorimetric determination of hydrogen peroxide activity, it has several advantages over conventional chromogenic reagents. The new Trinder's reagent is stable enough to be used in both solution and test line detection system. In the presence of hydrogen peroxide and peroxidase, the new Trinder's reagent formed very stable purple or blue dyes in the oxidative coupling reaction with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazolylsulfonylhydrazone (MBTH). The molar absorptivity of the dye coupled with MBTH is 1.5-2 times higher than that of the dye coupled with 4-AA; however, 4-AA solution is more stable than MBTH solution. The substrate is oxidized by its oxidase to produce hydrogen peroxide, and the concentration of hydrogen peroxide corresponds to the concentration of the substrate. Glucose, alcohol, acyl coenzyme A and cholesterol can be used to detect those substrates coupled with the new Trinder's reagent and 4-AA. Trinder's reaction, also known as "coupling end-point colorimetry", or enzyme method, is mainly used for the detection of uric acid, creatinine, blood glucose, cholesterol, triglyceride and so on in blood test. Trinder's reaction is the basis of enzymatic determination of glucose, cholesterol, triglyceride and uric acid. In Trinder's reaction, the chromogen or chromogenic agent is Trinder's reagent, also known as chromogen substrate or hydrogen donor. Phenols include phenol, 4-chlorophenol or sodium 3,5-dichloro-2-hydroxybenzenesulfonate; aniline includes N, n-dialkylaniline, N, n-dialkyl-m-toluidine, etc. Desheng company has made its own way in the industry in the past 15 years. In the small branch of in vitro diagnostic reagents, Desheng also plays its own R & D ability, taking the existing chromogen substrates (the New Trinder's reagents) such as toos, tops, ADOS, ADPS, Alps, Daos, hdaos, MADB, Maos, todb and other reagent products as a separate R & D field, and constantly developing them Innovative research has been in production capacity since 2012. After years of exploration, the in vitro diagnostic reagent products have been continuously improved. Compared with the previous new reagents, it has more advantages: such as high water solubility, UV absorption of color reaction products > 540nm; color reaction requires a wider pH range, which can ensure the activity of a variety of enzymes; color reaction has higher sensitivity, It can be used for the determination of very small amount of analytes.

Various exogenous and endogenous factors, such as environmental pollutants, ionizing radiation, drug chemotherapy, and cell metabolism, can cause various forms of DNA damage. Among them, DNA double-strand breaks have the most serious damage to genome stability and can threaten the survival of cells. Establishing a simple, rapid and sensitive method for detecting DNA hybridization and genotoxicity effects is a very meaningful research topic. Here is a brief introduction to the method of DNA damage detection.   What are the types of DNA damage detection DNA damage detection methods include gel electrophoresis, ultraviolet spectrophotometry, fluorescence and electrochemistry, and chemiluminescence analysis. Chemiluminescence analysis (CL) has been widely used in the fields of environment and life sciences due to its high sensitivity, wide linear range, convenient operation, fast analysis, and easy automation. Formaldehyde and acetaldehyde are both environmental pollutants. To a certain extent, it can cause DNA damage. Study the amount of acridinium esters embedded in DNA before and after the damage of formaldehyde and acetaldehyde, causing changes in the chemiluminescence intensity of acridinium esters, and study the damage behavior of formaldehyde and acetaldehyde on DNA. Establish a simple chemiluminescence analysis method to evaluate the degree of DNA damage caused by formaldehyde and acetaldehyde. Acridine esters method for detecting environmental damage to DNA 1. First, soak the glass luminescence cell used in a certain amount of concentrated nitric acid for several hours, acidify, and then rinse with water. Add 20 μL of 1mg/mL calf thymus DNA to the acidified luminescence cell, and place it for 1 hour to make The DNA is adsorbed on the bottom of the light-emitting pool, and then the unadsorbed calf thymus DNA is washed with secondary water to obtain the light-emitting pool with DNA adsorbed.   2. Add 50μL of 9.6×10-7g/mL acridinium ester to the luminescent cell, and the chimerization reaction is for 1h to embed the AE in the DNA double-stranded structure, and wash away the unchimeric AE with secondary water. Finally, in the luminescent cell Add luminescence initiation reagents in sequence to detect the chemiluminescence generated by AE chimerized in DNA. When detecting the damage of calf thymus DNA by formaldehyde and acetaldehyde, add damage reagent to the DNA after AE chimerization, and use it after a certain period of time. The second water washes away the AE released after the DNA is damaged, and the luminescence initiation reagent is added to detect the chemiluminescence intensity of the AE chimeric in the DNA.   Studies have shown that acridinium ester can be used as a chemiluminescence indicator with a good structure of intercalating DNA double helix. This detection method is feasible for DNA break damage and chemiluminescence detection method. It has the advantages of simplicity and sensitivity. Damage studies provide a simple research method. Desheng acridine ester luminescent markers have the properties of good hydrolytic stability, thermal stability and high signal-to-noise ratio, and the labeling conditions are mild, the labeling rate is high, and the separation does not affect the separation after labeling. , So it is considered to be an ideal chemical marker.

Biological buffers are of great significance in biochemical research, and are widely used in immunoblotting, biochip, biological hybridization and in vitro diagnosis.   Biological buffer system includes 20-30 varieties, and Desheng's main business covers the most important products. Such as Tris base , HEPES, mops, caps, Tris HCl, etc. This article will introduce the advantages and precautions of Tris buffer.   Tris (hydroxymethyl) aminomethane, CAS 77-86-1, PKA 8.06 at 25 ° C, buffer range 7.0-9.0. The common Tris buffers are Tris HCl buffer, Tris phosphate buffer and various derivative buffers, such as TBS, Te, etc. Tris buffer is a very important biological buffer   1. Tris base has strong alkalinity, so we can only use this buffer system to prepare a wide range of pH buffer from acidic to alkaline;   2. It has little interference to biochemical process and does not precipitate with calcium, magnesium and heavy metal ions;   3. It has high solubility in water and is inert to many enzymes;   4. It has high buffering capacity and is generally used to stabilize the pH of reaction system. It has strong buffering capacity between pH 7.5 and 9.0;   5. Tris buffer is widely used in biochemistry, molecular biology, in vitro diagnosis, cosmetics, coatings and other fields.   Precautions when using Tris buffer:   1. The pH value of Tris buffer is greatly affected by temperature and concentration, so the use environment should be considered in the preparation process;   2. To some extent, Tris reacts with various molecules, including RNase inhibitors, aldehydes, enzymes, DNA and common metals such as Cr3 +, Fe3 +, Ni2 +, CO2 + and Cu2 +, which can act together with heavy metals, but also inhibit in some systems;   3. It is easy to absorb CO2 in the air, and the prepared buffer should be sealed tightly;   4. Some pH electrodes are interfered, so it is necessary to use the electrode compatible with tris solution;   5. Tris is not suitable for the determination of biquinolinic acid (BCA);   6. Inhalation, ingestion or skin absorption can cause injury. Gloves and goggles should be worn during operation.   Desheng's main product biological buffer is a kind of alcohol ammonia fine chemicals with special characteristics. It does not participate in or interfere with the biochemical process. It can be used in the buffer system of life science research and provide a stable pH environment for experiments. Desheng's biological buffer is widely used in in vitro diagnosis, biopharmaceutical, biological beauty, paint and other industries because of its high buffering efficiency and high quality There are dozens of stable customers. Desheng provides one-stop purchasing service. If necessary, you can click the official website to consult customer service.

Acridine ester chemiluminescence reagent is a commonly used detection reagent in the field of in vitro diagnostics. Its chemiluminescence is not like the substrate of HRP or ALP and can directly chemiluminescence. So what is the difference between the chemiluminescence of acridinium ester and the fluorescence in fluorescence immunity? What's the difference?   Chemiluminescence is a molecular luminescence phenomenon in which the product returns from the excited state to the ground state when a substance produces a chemical reaction. In fact, there are three types of molecular luminescence: chemiluminescence, fluorescence, and phosphorescence. Their luminescence principles are different:     1. Principles of Chemiluminescence   For example, the chemical reaction between acridine ester and hydrogen peroxide produces another acridinium ester derivative. The energy released by the reaction is absorbed by the molecules of this product and transitions to an excited state, and the excited molecule returns to the ground state. Light radiation is generated during the process. The product here is a luminous body, and the luminescent product directly participates in the reaction during this process, so it is called direct chemiluminescence. Luminol's luminescence principle is similar, but requires HRP or POD catalysis, so it is called enzymatic chemiluminescence.   2. The principle of fluorescence   When light irradiates certain atoms, the energy of the light makes some electrons around the nucleus transition from the original orbit to a higher energy orbit, that is, transition from the ground state to the first excited singlet state or the second excited singlet state. The first excited singlet state or the second excited singlet state is unstable, so it will return to the ground state. When the electron returns from the first excited singlet state to the ground state, energy will be released in the form of light, so fluorescence is generated.   3. The principle of phosphorescence   When a certain room temperature substance is irradiated with incident light of a certain wavelength (usually ultraviolet or X-ray), it absorbs the light energy and enters an excited state (usually with a spin multiplicity different from the ground state), and then slowly de-excites and emits a ratio. Outgoing light with a long wavelength of incident light.   Seeing this, many people may still not be able to distinguish, but it doesn't matter. For example, the luminescence of fireflies belongs to bioluminescence or chemiluminescence, phosphorous fire or "ghost fire" is also chemiluminescence, and fluorescent sticks are also chemiluminescence; ultraviolet rays illuminate RMB anti-counterfeiting signs to emit fluorescence; luminous pens and luminous watches belong to phosphorescence. In daily life, people usually call all kinds of faint light fluorescence in a broad sense.   In the field of analysis and detection, chemiluminescence immunoassay and fluorescence immunoassay are two different detection methods, which need to be distinguished. Luminol and acridine esters of Desheng belong to chemiluminescence reagents, and the reagents for fluorescence immunity are reagents of different systems.

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!