China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Chemical agents or substances that can prevent blood coagulation are called anticoagulants or anticoagulants, such as natural anticoagulants (heparin, hirudin, etc.), Ca2 + chelating agents (sodium citrate, potassium fluoride). Commonly used anticoagulants are heparin, EDTA, citrate, oxalate, etc. in practical application, we should choose according to different needs, in order to obtain the ideal effect. Their application characteristics are summarized as follows:   1、 Heparin   Heparin is the preferred anticoagulant for the detection of blood chemical composition. Heparin is a kind of mucopolysaccharide containing sulfate group, which is a kind of dispersive phase material with an average molecular weight of 15000. Its anticoagulant mechanism is mainly through the combination with antithrombin III to cause the change of antithrombin III configuration and accelerate the formation of thrombin thrombin complex to produce anticoagulant effect.   In addition, heparin can inhibit thrombin by plasma cofactor (heparin cofactor II). The commonly used heparin anticoagulants are sodium, potassium, lithium and ammonium salts of heparin, among which heparin lithium is the best, but its price is more expensive. Sodium and potassium salts will increase the content of sodium and potassium in blood, and ammonium salts will increase the content of urea nitrogen. The dosage of heparin anticoagulation is usually 10.0-12.5 IU / ml blood.   Heparin has less interference on blood components, does not affect the volume of red blood cells, and does not cause hemolysis. It is suitable for red blood cell permeability test, blood gas, plasma permeability, hematocrit and ordinary biochemical determination. However, heparin has antithrombin effect and is not suitable for hemagglutination test.   In addition, excessive heparin can cause leukocyte aggregation and thrombocytopenia, so it is not suitable for leukocyte classification and platelet count, let alone hemostasis test. In addition, heparin anticoagulant can not be used to make blood smear, because Wright staining appears dark blue background, which affects the production reduction of microscope. Heparin anticoagulant should be used in a short period of time, otherwise the blood can coagulate if it is placed too long.   2、 Ethylenediamine tetraacetate (EDTA salt)   EDTA can combine with Ca2 + in blood to form a chelate, the coagulation process is blocked, and the blood can not coagulate. EDTA salts include potassium, sodium and lithium. EDTA-K2 is recommended by the International Committee for standardization of Hematology, which has the highest solubility and the fastest anticoagulation speed. EDTA salt is usually prepared into 15% aqueous solution, adding 1.2mg EDTA per ml blood, that is, adding 0.04ml 15% EDTA per 5ml blood. EDTA salt can be dried at 100 ℃, and its anticoagulant effect remains unchanged.   The anticoagulant does not affect the count and size of white blood cells, has the least effect on the morphology of red blood cells, and can inhibit platelet aggregation, so it is suitable for general hematological detection. But if the concentration of anticoagulant is too high, the osmotic pressure will rise, which will cause cell shrinkage.   The pH of EDTA solution has a great relationship with salts, and low pH can make the cells expand. EDTA-K2 can slightly expand the volume of red blood cells, the average platelet volume is very unstable in a short time after blood collection, and tends to be stable after half an hour. EDTA-K2 can decrease Ca2 + and Mg2 +, and decrease creatine kinase and alkaline phosphatase. The optimal concentration of EDTA-K2 is 1.5mg/ml blood. If the blood is less, neutrophils will swell and disappear, platelets will swell and disintegrate, and normal platelet fragments will be produced, which makes the analysis results wrong.   Because EDTA can inhibit or interfere with the polymerization of fibrin monomer during fibrin clot formation, it is not suitable for the detection of blood coagulation and platelet function, nor for the determination of calcium, potassium, sodium and nitrogenous substances. In addition, EDTA can affect the activity of some enzymes and inhibit lupus erythematosus factor, so it is not suitable for making blood smear for histochemical staining and examination of lupus erythematosus cells.     3、 Citrate   Citrate is mainly sodium citrate. Its anticoagulant principle is that it can combine with Ca2 + in blood to form chelate, which makes Ca2 + lose coagulation function, and the coagulation process is blocked, so as to prevent blood coagulation. Sodium citrate has two kinds of crystals, na3c6h5o7 · 2H2O and 2na3c6h5o7 · 11h2o. The former is usually used to make 3.8% or 3.2% aqueous solution, which is mixed with blood according to the volume of 1:9.   Most coagulation tests can be anticoagulated with sodium citrate, which is helpful to the stability of factor V and factor VIII, and has little effect on mean platelet volume and other coagulation factors, so it can be used for platelet function analysis. Sodium citrate is one of the components of blood maintenance fluid in blood transfusion. However, sodium citrate 6mg can anticoagulate 1ml blood, strong alkaline, not suitable for blood tests and biochemical tests.   4、 Oxalate   Oxalate is also a commonly used anticoagulant, which has the advantage of high solubility. Its principle of action is that the dissociated oxalate after dissolution forms calcium oxalate precipitation with Ca2 + in the sample, which makes Ca2 + lose the coagulation function and blocks the coagulation process.   The commonly used oxalate anticoagulants are sodium oxalate, potassium oxalate and ammonium oxalate. The concentration of sodium oxalate is 0.1 mol / L, and the ratio of sodium oxalate to blood is 1:9. However, high concentration of K + or Na + is easy to make the blood cells dehydrate and shrink, while ammonium oxalate can make the blood cells expand. Therefore, the anticoagulant with appropriate proportion of ammonium oxalate and potassium oxalate or sodium oxalate does not affect the shape and volume of red blood cells. It is often used in blood biochemical determination, but it is not suitable for the determination of K + and Ca2 +.   Due to the formation of calcium oxalate precipitation, red blood cells will appear serrated, white blood cells will appear vacuoles, lymphocytes and monocytes will be deformed, it is not appropriate to do blood test. Oxalate can cause platelet aggregation and affect the morphology of leukocytes, so it can not be used for the differential count of leukocytes and platelets. Product packaging   Desheng is an old manufacturer of vascular additives. It has formed its own intellectual property rights and professional production and R & D capabilities in the aspect of vascular additives. It has provided products and raw material solutions for more than 100 domestic and foreign manufacturers.   The anticoagulant series products of blood samples include heparin sodium, heparin lithium, trisodium citrate, EDTA dipotassium, EDTA Tripotassium, potassium oxalate, etc.; the anticoagulant series products of blood samples include blood coagulant powder, blood coagulant, etc.; the pretreatment materials of blood samples include separation gel, silicide, etc. A variety of raw materials for you to choose, need to click the official website to consult our professional customer service.

CLIA was born in 1977. According to the basic principle of radioimmunoassay, chemiluminescence immunoassay was established by combining high sensitive chemiluminescence technology with high specific immune response. CLIA has the advantages of high sensitivity, strong specificity, wide linear range, simple operation and no need of expensive equipment.   CLIA is widely used in the detection of antigens, haptens and antibodies of different molecular sizes, as well as nucleic acid probes. Compared with RIA, IFA and EIA, CLIA has the advantages of non radiation, long validity period and full automation.   Chemiluminescence immunoassay consists of two systems: immunoassay and chemiluminescence analysis. Immunoassay system uses chemiluminescent substances or enzymes as markers, which are directly labeled on the antigen or antibody. After the reaction of antigen and antibody, antigen antibody immune complex is formed.   Chemiluminescence analysis system is after the end of the immune reaction, add oxidant or enzyme luminescent substrate, chemiluminescence material after oxidation by oxidant, form an excited state intermediate, will emit photons to release energy to return to the stable ground state, the luminous intensity can be detected by luminous signal measuring instrument. According to the relationship between chemiluminescent markers and luminous intensity, the content of the measured substance can be calculated by standard curve.   Chemiluminescent immunoassay (CLIA) is a kind of immunoassay method which uses chemiluminescent agent to label antibody or antigen directly. At present, luminol and acridine esters are the most common chemiluminescent agents.   1 chemiluminescence immunoassay of luminol: luminol is an oxidative reaction. Luminol can be oxidized by many oxidants in alkaline solution, among which H2O2 is the most commonly used. Due to the slow reaction rate, some enzymes or inorganic catalysts need to be added. The main enzymes are horseradish peroxidase (HRP), and the inorganic ones include O3, halogen, Fe3, Cu2, CO2 and their complexes.   In the early stage, it was mainly used for the determination of inorganic and organic biological small molecules, and the sensitivity decreased due to the decrease of the luminous intensity after labeling. It has been found that the addition of Some Phenols and their derivatives, amines and their derivatives, and phenylboronic acid derivatives can significantly enhance the luminescence of the system. The luminescence intensity can be increased by 1000 times, and the "background" luminescence is significantly reduced, and the luminescence time is also prolonged. The use of these enhancers makes chemiluminescence immunoassay widely used in protein and nucleic acid analysis.   2 acridine ester labeled chemiluminescence immunoassay: acridine ester was used in CLIA. Because of its poor thermal stability, more stable acridine ester derivatives were synthesized. Under the condition of H2O2 and oh -, acridine esters can emit light rapidly with high quantum yield. For example, the quantum yield of acridine aromatic esters can reach 0.05. When acridine esters are used as markers for immunoassay, the luminescence system is simple, rapid, and does not require the addition of catalyst. Moreover, the labeling efficiency is high and the background is low. These characteristics arouse the great interest of the majority of analysis and diagnosis workers.

Toos, n-ethyl-n - (2-hydroxy-3-sulfopropyl) - 3-methylaniline sodium salt, is a widely used color reagent, which is most commonly used in the new Trinder's reagent. Toos has been used in many clinical biochemical test items. This article will introduce the specific test items for which the chromogenic reagent toos can be used. Through Trinder reaction, toos is widely used in diagnostic detection and biochemical tests. Trinder reaction is also known as "coupling end point colorimetry". The principle is that hydrogen peroxide (H2O2) produced by enzyme reaction can generate red quinoline imine compound in the presence of 4-aminoantipyrine (4-AAP) and peroxidase (POD). The specific detection application of toos mainly includes blood glucose detection And liver function test, the following is a brief introduction to the detection principle of these two methods. TOOS, the substrate of Desheng chromogen 1. Blood glucose detection project: toos is used to prepare glucose detection reagent and glycosylated albumin detection reagent in blood glucose metabolism project. According to the description of patent cn105572065a, glucose oxidase is used to catalyze the oxidation of glucose to hydrogen peroxide, and platinum bismuth nano mimetic peroxidase is used to catalyze the oxidation of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and sodium salt of n-ethyl-n - (2-hydroxy-3-sulfopropyl) - 3-methylaniline (toos) by hydrogen peroxide. The color of the color developing product solution is purple, and with the concentration of glucose increasing The maximum absorption wavelength of the color system is 590 nm, and the content of glucose can be obtained from the absorbance at 590 nm. 2. Routine examination items of liver function: adenosine deaminase (ADA) activity is a sensitive index reflecting liver injury, and is one of the routine examination items of liver function. The detection reagent of adenosine deaminase composed of toos, bovine serum albumin, disodium ethylenediamine tetraacetate, etc., has the advantages of good color effect, rapid response, stability and high precision. In addition, toos is also used in the diagnostic reagents for triglyceride and other blood lipid detection items and cholesterol detection items, which has important value in clinical diagnosis. The toos chromogenic reagent produced by Desheng is not only of high purity, but also of high quality, High sensitivity, and in the absorption wavelength, color reaction intensity and fading have good performance, welcome the majority of scientific research workers and dealers colleagues to consult and purchase!

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.