China Wuhan Desheng Biochemical Technology Co., Ltd Company News

HEPES solution is a weak acid, the Chinese name is hydroxyethyl piperazine ethylsulfonic acid, is an amphoteric buffer in organic chemical industry. However, compared with other buffers, the decomposition constant of HEPES does not change much with temperature, which makes HEPES buffer a buffer that can maintain the structure and function of enzyme at low temperature.   HEPES buffer can control the constant pH range for a long time and has no toxic effect on cells. It is often used in cell culture. In order to improve the culture environment of BHK-21 cells, maintain the stability of 146S antigen of foot-and-mouth disease virus, and increase the content of complete virus particles in vaccine, some experts studied the buffer system of culture medium. In the study, the stability of HEPES on virus antigen was compared to evaluate its protective effect.   Package of Desheng HEPES biological buffer in big barrel According to the experimental results, the virus titer of HEPES was higher than that of HEPES without biological buffer. At 37 ℃, TCID50 of virus without biological buffer changed more than that of virus with biological buffer. However, it should be noted that when HEPES is exposed to light, hydrogen peroxide will be produced, which is toxic to cultured cells or other bioactive substances. Therefore, HEPES should be used as a buffer as far as possible In dark condition.   Therefore, biological buffer can effectively improve the buffer capacity of virus culture medium, provide a suitable environment for virus and promote the stability of virus particles. If you need to buy HEPES buffer solution, please find Desheng technology, a biochemical reagent company integrating scientific research, production and sales. Direct sales from manufacturers can save you a lot of purchase costs.

Blood glucose detection should be familiar to all of us. It is a common project in the hospital. Blood glucose detection mainly depends on whether there is a rise in blood glucose, diabetes, and the severity of diabetes. In the process of blood glucose detection, appropriate anticoagulants must be selected to reduce errors, improve accuracy, and provide accurate diagnosis basis for clinic.   With the popularity of disposable vacuum blood collection vessel in China, blood glucose anticoagulant tube (containing sodium fluoride potassium oxalate) has been widely used, and greatly improved the quality of blood glucose samples and the accuracy of results. In practical work, the anticoagulant can be used to prepare blood glucose test samples with good preservation effect.   Sodium fluoride is a kind of weak effect anticoagulant. Its melting point is more than 990 ~ C. the anticoagulant tube can be dried at 100 ℃. It can effectively inhibit the enolase in the process of glycolysis, block the dehydration of monophosphoglyceric acid produced in the third stage of glycolysis pathway, lead to the energy redistribution within the molecule, and ultimately can not form high-energy phosphoenolpyruvate, so as to achieve effective inhibition of glycolysis and maintain the relative stability of blood glucose concentration, so it is considered to be an excellent method for blood glucose detection Good preservative.   Additives for blood collection vessels produced by Desheng Potassium oxalate can combine with calcium ions in blood to form insoluble calcium oxalate precipitation, thus preventing blood coagulation. But in the process of preparing anticoagulant tube, it can only be dried below 80 ~ C. If the temperature exceeds 80 ℃, carbon monoxide and potassium carbonate can be decomposed into anticoagulant.   EDTA dipotassium can chelate with calcium ion in blood to prevent blood coagulation, and has fast dissolution and good anticoagulant effect. In the process of preparing the anticoagulant tube, it can be dried at 100 ℃ just like sodium fluoride, and the anticoagulant effect can still be maintained without being decomposed. Compared with potassium oxalate, it is easier to produce and improve the efficiency.   Desheng is an old brand manufacturer in the field of vascular additive. Its main products are: dipotassium EDTA, Tripotassium EDTA, coagulant, blood separation gel, potassium oxalate, sodium fluoride, etc., which enjoy a high reputation both at home and abroad. Desheng has always put "customer first, symbiosis and win-win" in the first place of service, so that enterprises ordering Desheng vascular additives can have a more perfect after-sales service experience.

In acridinium ester chemiluminescence immunization, acridinium ester is usually used as an indicator to label antibodies, but in fact, acridinium ester can also label antigen. So what is the difference between acridinium ester labeling antigen and labeling antibody?   The acridinium ester-labeled antigen and the labeled antibody are similar in the labeling principle and the final light detection. The difference is mainly in the immunoassay method. Usually acridinium ester-labeled antibody is used for double antibody sandwich assay, and acridinium ester-labeled antigen is used for competition assay. Chemiluminescence reagent acridinium ester labeled antibody   Double anti-sandwich method: The double-antibody sandwich method usually detects antigens. There are three immune components: solid-phase antibodies (specific antibodies bound to solid-phase carriers), test samples (ie, antigens that need to be tested), and antibodies labeled with acridinium esters. These three types will form an immune complex with two antibodies sandwiching the antigen. Since the antibodies in the complex are labeled with acridinium ester, the content of the antibody in the complex can be analyzed by chemiluminescence reaction of acridinium ester to calculate the antigen content in the sample to be tested.   Sometimes it is also possible to add a secondary antibody (secondary antibody, antibody of the antibody, which binds to the antigen and does not bind to the antigen) as a solid phase carrier. The primary antibody is fixed on the T line of the test line, and the second antibody is used as the control line C line (quality control line) ), so that when the acridinium-labeled antibody is excessive, it will continue to bind to the secondary antibody. The concentration of the antigen to be tested is analyzed and calculated by the ratio of the luminescence intensity of the acridinium-ester in the test line and the control line. For example: HIV-1p24, the antigen of AIDS, is the double-antibody sandwich method, which does not use acridinium ester to label the antigen, but to label the anti-p24 antibody.   Competition Law: The competition method can be used to determine the antigen, but also can be used to determine the antibody. For example, for the detection of antigens, the test antigen and the acridinium-labeled antigen can be combined with the solid-phase antibody in a competitive manner. These two antigens have the same chance to bind to the solid-phase antibody, so they are bound to the solid-phase acridinium-labeled antigen. The amount of antigen is inversely proportional to the amount of tested antigen. The acridinium ester-labeled antigen-antibody complex can be measured by chemiluminescence, and the content of the tested antigen can be calculated according to the inverse relationship.   It can be seen that the same is the detection of antigens, one is to label the antibody with acridinium ester, and the other is to label the antigen with acridinium ester. The detection method is different and the labeled objects are different. The antibody detection is similar, and the label is not what is detected. Desheng currently provides six acridinium esters, which can meet the labeling and detection of a variety of different antigens and antibodies.

What is trypsin Trypsin (C6H15O12P3) is a kind of protease. In vertebrates, it functions as a digestive enzyme. In the pancreas, it is synthesized as a precursor of the enzyme trypsinogen. It is secreted as a component of pancreatic juice and decomposed into activated trypsin under the restriction of enterokinase or trypsin. It is an endopeptidase that can cut the carboxyl side of lysine and arginine residues in the polypeptide chain. It not only functions as a digestive enzyme, but also limits the decomposition of precursors of other enzymes such as chymotrypsinogen, carboxypeptidase, and phospholipase, and has an activating effect. It is the most specific protease, and it has become an indispensable tool in determining the amino acid sequence of a protein.   Introduction of porcine trypsin The relative molecular mass of porcine trypsinogen is about 24 000. According to the difference in isoelectric point, porcine trypsinogen can be divided into anionic (pl6.8). Because the cationic type not only has a larger specific gravity, but also has better stability than the anionic type, the cationic porcine trypsinogen was selected for construction and expression. Porcine trypsinogen contains 12 cysteines, which can form 6 pairs of disulfide bonds (30-160, 48-64, 132-233, 139-206, 171-185, 196-220), which greatly Increased the difficulty of denaturation and renaturation of inclusion bodies in subsequent experiments. Application of porcine trypsin Porcine trypsin is a kind of trypsin, which can be used as an additive for the removal of surface adherent cells, the production of influenza virus vaccines, insulin and other proteins, the rapid hydrolysis of proteins, and the pretreatment of animal cells and tissues. There is a large demand for trypsin with high purity and strong activity. At present, a preparation process of recombinant porcine trypsinogen has been established, and the obtained recombinant porcine trypsin has good enzyme activity and does not contain other animal source pollution, which provides a certain experimental basis for industrialized research and production.   Characteristics of porcine trypsin Porcine trypsin is unstable in nature and prone to autolysis. When constructing a recombinant porcine trypsinogen expression system, this autolysis feature makes it difficult for the eukaryotic expression system to obtain complete trypsinogen, and the activated product will affect the host. Cells can also be toxic, so consider choosing a prokaryotic expression system. In addition, the autolysis characteristics require that the activation conditions of porcine trypsinogen also need to be strictly controlled.   Preparation method of porcine trypsin In the traditional preparation method, there are many separation and purification steps and a long time, which is easy to cause damage to the protein and cause inactivation. Resulting in low yield. Therefore, the preparation and production of porcine trypsin has gradually shifted from extraction from animal pancreas to recombinant expression production. The production of trypsin by constructing a recombinant porcine trypsinogen-derived Escherichia coli expression system can also avoid the risk of related pathogen contamination and the risk of carrying unknown viruses due to the animal origin of the donor.

In chemiluminescence immunoassay, we need to label the antibody protein with acridine ester before we can detect the tested substance after the immune reaction, so how to label the antibody is very important.   Acridine salts and related compounds have been widely proved to be very useful chemiluminescence markers. Their stability, labeling specificity and detection sensitivity surpass those of radioisotopes. We now compare the six acridine esters of Desheng, so that you can make clear the difference between them, so as to find what you need.   Package picture of Desheng acridine ester 1、 Name and number of acridine ester Acridine 0: ae-nhs (traditional acridine ester) Acridine 1: dmae-nhs Acridine 2: me DMAE NHS Acridine 3: nsp-dmae-nhs Acridine 4: nsp-sa-nhs Acridine 5: nsp-sa Acridine 6: nsp-sa-adh 2、 Structural differences of acridine esters There are six kinds of acridine esters, among which No.1-3 are acridine esters; no.4-6 are acridine sulfonamides; No.1-4 are NHS active esters; No.5 is acridine carboxylic acid containing carboxyl group; no.6 is acridine hydrazide containing free amino group.   3、 Hydrolysis resistance and stability Traditional acridine ester No.0 (ae-nhs) and No.1-3 were modified on their structures to increase the steric hindrance and enhance the hydrolysis resistance. No. 0 is stable only in acidic solution, and it is easy to hydrolyze when pH value is higher than 6.3, but no. 1-3 is not. At room temperature, it is stable in Pb buffer solution with pH 7.0. After 16 days, the luminescent activity only decreases by 3.6%.   The reason is that the bond order of C-N bond is different from that of C-O bond, and the C-N bond is larger than that of C-O bond. Acridine amides (No. 4-6) were more resistant to hydrolysis than acridine esters (No. 0-3). No.4-no.6 was stable in acidic solution (pH < 4.8). The photoquantum yield of protein conjugates did not decrease when they were stored at room temperature for 4 weeks. The lyophilized products could be stored at - 20 ℃ for more than one year   4、 Hydrophilicity On the basis of No.   5、 Differences in marking methods Because the essence of antibody is protein, which contains amino group, it can directly react with No.1-4 (NHS active ester) and conduct coupling. No. 5 is acridine carboxylic acid, which needs to add the condensation agent EDCI to react with amino protein. No. 6 is acridine hydrazide, containing free amino group. The terminal of acridine hydrazide is suitable for direct coupling of polysaccharide, nucleic acid or protein containing aldehyde group.   6、 Comparison of luminescent properties Because of no.1-no.6 acridine, their luminescent matrix and mechanism are consistent, and their luminescent properties should have little difference.

With the arrival of an epidemic, let us understand how terrible the invasion of the virus is, our understanding of it is limited to know that it is highly infectious, will lead to our loss of life, but that is to say, let us smell pale. So we should learn more about it and take corresponding measures to reduce its harm to us. The virus does great harm to us in the human body. Either we can defeat it or it can defeat us. How long will it survive after it leaves our body?   According to the NHS website, the survival time of the virus after leaving the human body depends on the surface condition of the object it is attached to, as well as environmental conditions such as temperature and humidity. on the whole:   The virus has a relatively long survival time on non permeable (waterproof) surfaces such as stainless steel and plastic.   The survival time of the virus on the permeable surface such as fiber fabric and paper towel is relatively short. The survival time of different kinds of viruses is also different. Some viruses can survive on the surface of indoor objects for more than 7 days, but their pathogenicity will be significantly reduced within 24 hours. Therefore, the elevator buttons, door handles and other places need to be more careful!   Influenza virus can survive in the form of droplets in the air for several hours, low temperature will increase its viability.   Influenza virus in the hands of survival time is very short, about five minutes the number of viruses on the hands will drop to a very low level.   Elevator button risk is relatively high, because these places are high frequency contact.   There are three corresponding strategies First, increase the frequency of disinfection appropriately; Second, it can be separated with tissue paper or disinfectant tissue, hands do not directly touch it; Third, after touching it, use hand disinfectant to rub hands and do a good job in hand hygiene. There are many community elevators more tissue or disposable gloves, so that fingers do not directly touch the elevator button. Does it really work?   Some experts said that if the paper towel is exposed in the closed space for a long time, if there is a virus carrier going in and out of the elevator, the exposed part of the paper towel will still have the risk of virus attachment, which will become a new source of infection. Washing hands in time after taking the elevator is the most scientific protective measure. It is also very important to disinfect the elevator as many times a day as possible. Take the elevator to pay attention to: avoid crowding, avoid long-time ride, reduce joking and phone calls in the elevator.   We should learn to protect ourselves and others, so that we can eliminate these viruses faster. Don't let others pay for your mistakes.

MOPS sodium salt is a buffer used in biochemistry and molecular biology, and also belongs to a zwitterionic morpholine buffer. MOPS interferes with the determination of Folin protein. When autoclaved in the presence of glucose, MOPS will be partially decomposed. MOPS can be used as Good's buffer because it has low UV absorption, minimal reactivity, stable pH and soluble in water. The pH buffer range is 6.5-7.9. It is commonly used in cell culture media, electrophoresis buffer in electrophoresis, and protein purification in chromatography. MOPS lacks the formation of complexes with most metal ions, so it is recommended to be used as a non-coordinating buffer in metal ion solutions. In the following, I will share some information about the application of MOPS buffer, I hope it can help everyone. MOPS buffer application: 1. Used for denaturing RNA electrophoresis; 2. Used for protein purification in chromatography; 3. Measure absorption in ultraviolet/visible light spectrophotometry and use cyclic voltammetry to study redox characteristics; 4. The electron transfer mechanism in nitrogenase; 5. Separate nucleic acid and protein by electrophoresis; 6. Control the pH value of the culture medium, including the cell culture medium used for yeast, bacteria and mammalian cells; 7. Used as a buffer component of charcoal yeast extract culture medium; 8. Interact with the peptide backbone of bovine serum protein to make the protein more stable;   In the current market, there are not many professional manufacturers of MOPS buffers, and our company is one of the most professional MOPS manufacturers in China. Among them, our products are traded in many regions around the world and are widely accepted by the industry. And get a great praised. Hubei New Desheng Material Co., Ltd. Desheng company specializes in the production of MOPS buffers. Since the establishment of the company, it has produced biological buffers for more than ten years. It has independently developed Tris, Mops, Hepes, Taps and other products, and has a professional team to manage R&D and production. If you are interested in Desun’s products, you can enter the company’s official website to contact customer service for more information.

THAM, or tris(hydroxymethyl)aminomethane, is a weak base and is often used as a biological buffer; hydrochloric acid and sulfuric acid are two essential acids in the laboratory, but concentrated sulfuric acid is very easy to absorb water, concentrated hydrochloric acid is easy to volatile, and their concentration is not Stable, usually calibrated by soda ash (sodium carbonate); now it has been found that it is more advantageous to use THAM instead of soda ash to calibrate the acid concentration in potentiometric titration.   The significance of titrating acid concentration: In many experiments, the required acid (hydrochloric acid, sulfuric acid) concentration is different, or sometimes it is necessary to use different concentrations of acid at the same time. At this time, in order to ensure the exact concentration, it is necessary to titrate with sodium carbonate. The price of sodium carbonate is relatively cheap, but the high-purity sodium carbonate reference substance is easy to absorb moisture, and some of it will be converted into sodium bicarbonate (baking soda) to affect the titration. Need high temperature treatment and need to boil and then cool before the end of titration. This process requires manual titration, which is not conducive to automatic potentiometric titration. THAM Tris(hydroxymethyl)aminomethane reagent   Advantages of THAM Potentiometric Titration: Manual titration is actually easy to cause errors and poor repeatability. For example, the personnel operation requirements are very high, the analysis steps are relatively large, and because it is judged by the color change that different people will have differences. Modern potentiometric titration is different. It does not require people to judge by color change, only the instrument records the potential mutation point.   Potentiometric titration of acid with soda ash can eliminate the boiling and cooling steps before the end point. It is more accurate to judge the end point by the potential mutation point than when the indicator changes color. The disadvantage is that the potential mutation point of sodium carbonate is small, and there are multiple mutation points before the end point that are not conducive to judging the end point (caused by not heating before the end point). Using THAM instead of soda ash potentiometric titration, the obtained potential jump is sharp and single, the titration end point is obvious, and the calibration result is consistent with soda ash, and there is no other influence.   THAM potentiometric titration calibration of acid concentration is not only used to calibrate the concentration of hydrochloric acid and sulfuric acid, but also applicable to other acids. While the automatic potentiometric titration data is consistent with the results of manual titration indicator method, it also reflects the simplicity of instrument analysis and operation. Heating like soda ash titration, faster efficiency and good parallelism. Desheng is a specialized manufacturer of biochemical reagents, which can supply large quantities of high-quality THAM reagent raw materials.

Luminol, also known as luminol, is a kind of yellow crystal or beige powder at room temperature, which is a relatively stable chemical reagent. At the same time, luminol is a kind of strong acid, which can stimulate eyes, skin and respiratory tract. It is one of the oldest and most commonly used reagents. It can be oxidized by peroxide under alkaline conditions and emit light at the same time.   The redox reaction between luminol and peroxide needs catalyst, which is usually multivalent metal ions, peroxidase such as iron, horseradish peroxidase, etc. this method is often used to detect the content of peroxide, heavy metal, peroxidase, as well as the derived free radical detection, toxicological analysis and based on peroxidase and glucose oxidase The method of analysis is introduced.   In general, the chemiluminescence reaction between luminol and hydrogen peroxide is very rapid in the presence of some catalysts. The most commonly used catalysts are metal ions. In a large concentration range, the concentration of metal ions is directly proportional to the luminous intensity, so the chemiluminescence analysis of some metal ions can be carried out. Using this reaction, the organic compounds containing metal ions can be analyzed, achieving high sensitivity. The second is to use the inhibition of organic compounds on luminol chemiluminescence reaction to determine the organic compounds with quenching effect on chemiluminescence reaction. Third, indirect determination of inorganic or organic compounds by coupling reaction.   Luminol luminescent principle First, sodium hypochlorite oxidizes luminol to make it luminescent; Second, hydrogen peroxide reacts with sodium hypochlorite to form oxygen to oxidize luminol and make it luminescent   The first is the reaction equation of sodium hypochlorite and hydrogen peroxide: NaClO + H2O2 = = NaCl + O2 + H2O   Secondly, luminol reacts with hydroxide to form a dianion, which can be oxidized by oxygen decomposed by hydrogen peroxide to form an organic peroxide. The peroxide is very unstable and immediately decomposes into nitrogen (after luminol is oxidized by organic oxidants such as dimethyl sulfoxide, it does not generate nitrogen, but nitrogen-containing organic compounds), and forms excited 3-aminophthalic acid. During the transition from excited state to ground state, the released energy exists in the form of photons, and the wavelength is located in the blue part of visible light.   Luminol (luminol ammonia) as a chemiluminescence reagent is often used in the detection, however, some people will ask, luminol in the application of the general will choose which luminescent detection method? The three methods that Desheng told you were accelerating the luminescence of catalyst, indirect determination of inhibitor and indirect determination by coupling.   It is estimated that the luminescent speed of luminol detection is too slow, so some catalysts are often added to accelerate the detection. In chemiluminescence immunoassay, peroxides, especially horseradish peroxidase, are often used as catalysts. In addition to horseradish peroxidase, catalysts also include some metal complexes, transition metal ions, such as hemoglobin, iron ions, manganese ions, etc. If there is acceleration, there will be inhibition. Some organic compounds will inhibit luminol luminescence by inhibitors, such as reducing compounds containing phenolic hydroxyl groups. This can be used for indirect determination of such organic compounds. This is the second method.   Indirect determination by coupling is to combine one reaction that can produce or consume chemiluminescence reactants with another chemiluminescence reaction, so as to realize Indirect Chemiluminescence Determination of some substances. This method is used to determine the purity of some substrate enzymes.

Carbomer 940 is white, loose, acidic, hygroscopic and slightly odorous, soluble in water, ethanol and glycerol. The common concentration is 0.1% ～ 3.0%.   Carbomer 940 contains a lot of carboxyl groups in its molecule, so the aqueous solution should be used after neutralization with alkali to reduce the irritation to skin and mucous membrane.   The neutralizer of Carbopol 940 can be sodium hydroxide, potassium hydroxide, potassium bicarbonate, borax, amino acids and polar organic amines such as triethanolamine. Laurylamine and Stearylamine can be used as neutralizers in nonpolar systems. The carbomer hydrogel after neutralization is thicker between pH6 and 11, such as pH < 3 or pH > 12, viscosity decreases, and strong electrolyte can also reduce viscosity. The gel is unstable. It is easy to grow mold and lose its viscosity rapidly when exposed to sunlight. Adding antioxidants can slow down the reaction.   Desheng Carbopol 940 sample Usage and precautions of Carbopol 940 (acrylic resin) 1. PH value: the best pH value range of Carbopol 940 system is 4-10, higher or lower than this range will lead to the change of system viscosity.   2. The ingredients in the formula that are not easy to be compatible: protein, PVP resin, polyethylene glycol (PEG), polyethoxylated surfactant will interact with non neutralized Carbopol 940, so it is necessary to partially neutralize Carbopol 940 before adding. Desheng is specialized in providing raw materials and technical formula support for Kapo 940 and other cosmetics.   3. Salt and soluble cation: Carbopol 940 is sensitive to salt and cation. When the concentration of soluble ion exceeds 0.1%, the dosage of Carbopol 940 should be controlled. If possible, acidic, neutral or alkaline materials should be used as the matrix of the main drug, deionized water should be used, and salt should be added after neutralization to master the influence of salt on the system. High valence ions (CA, Mg, Fe, AI) will cause serious damage to the system and should be eliminated.   Self transformed pollutants (such as Fe, Cu, etc.) will gradually reduce the viscosity of the system and lead to the instability of the system. In addition, adding EDTA to chelate metal ions can also achieve good results. In addition to the above two aspects, we can also choose the appropriate model of Carbopol 940 (such as Carbopol 9401342ge resin), which is less sensitive to soluble salts.   4, insoluble matter: when there are insoluble components, carbo 940 system is difficult to present clear and transparent gel.

There are many kinds of anticoagulants. Although they are all for anticoagulation, the anticoagulants to be selected in different tests are also different. How to choose the right anticoagulant in the process of use is very important. Otherwise, the wrong choice may lead to the deviation of test results, which may be very different for patients. Now Desheng takes you to understand the anticoagulant mechanism of different anticoagulants.   Heparin is widely distributed in almost all tissues such as lung, liver, spleen and the granules of mast cells and basophils around blood vessels. It is a mucopolysaccharide with sulphuric acid group, with an average molecular weight of 15000 (2000-40000).   Heparin is the best anticoagulant in the determination of blood chemical composition. Its anticoagulant mechanism is to inhibit the interaction between factor IX a, VIII and PF3 at low concentration together with anticoagulant II, and to enhance the inactivation of serine protease by antithrombin III, so as to prevent the formation of thrombin; it also inhibits the self catalysis of thrombin and the inhibition of factor X. Heparin anticoagulant should be used in a short period of time, otherwise the blood can coagulate if it is placed too long.   Ethylenediaminetetraacetic acid (EDTA) has disodium, dipotassium and Tripotassium salts. EDTA salt had little effect on the morphology of red blood cells and white blood cells.   EDTA is one of the most common and important anticoagulants and reagents in clinical work. Its mechanism is to prevent blood coagulation by forming a stable chelate with calcium ion in water phase. EDTA can also affect platelet aggregation and leukocyte phagocytosis, and is not suitable for hemostatic test and platelet function test. The salts of EDTA include potassium, sodium and lithium, which are soluble in water. The solubility of potassium is higher than that of sodium. The potassium salt of EDTA is the best for whole blood cell count.   Citrate can form a soluble chelate with calcium ions in blood, thus preventing blood coagulation. It was used with blood in the ratio of 1:9 or 1:4.   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 6mg can anticoagulate 1ml blood, strong alkaline, not suitable for blood test and biochemical test.   Oxalate is also a common anticoagulant with the advantage of high solubility. 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.   After oxalate dissolves, the dissociated oxalate and Ca2 + in the sample form calcium oxalate precipitation, which makes Ca2 + lose the coagulation function and block the coagulation process. 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.

Sodium citrate, also known as sodium citrate, is an organic compound, a sodium salt, its chemical formula is na3c6h5o7, the appearance is white to colorless crystal, with the taste of soapy water. It is soluble in water and glycerin, but insoluble in alcohols and other organic solvents. Deliquescence, weathering in hot air.   In terms of structure, citric acid is a kind of tricarboxylic acid compound, which has similar physical and chemical properties with other carboxylic acids. When heated to 175 ℃, citric acid will decompose to produce carbon dioxide and water, leaving some white crystals. Citric acid is a kind of strong organic acid, with three H + ions which can be ionized. It can be decomposed into a variety of products by heating, and react with acid, alkali and glycerol. When it comes to sodium citrate, people's first reaction is to use it for anticoagulation in vitro. When fresh blood is taken in clinic, some sterilized sodium citrate needs to be added to prevent blood coagulation, so sodium citrate is called anticoagulant. Sodium citrate has other applications in addition to anticoagulation in vitro. Next, Desheng will take you to know about it.   1. Used in chemical industry Citric acid can be used as chemical analysis reagent, as experimental reagent, chromatographic analysis reagent and biochemical reagent, as complexing agent and masking agent, and as buffer solution.   2. For environmental protection Sodium citrate buffer is used for flue gas desulfurization. China is rich in coal resources, which is the main part of energy. However, there has been a lack of effective flue gas desulfurization process, resulting in serious air SO2 pollution. It is urgent to study effective desulfurization process. Citric acid sodium citrate buffer solution is a valuable desulfurizer because of its low vapor pressure, non toxicity, stable chemical properties and high SO2 absorption rate.   3. For cosmetics Citric acid is a kind of fruit acid, its main role is to accelerate the regeneration of keratin, commonly used in emulsion, cream, shampoo, whitening products, anti-aging products, acne products, etc. The renewal of cutin is helpful to the peeling off of melanin in the skin, the thinning of pores and the dissolution of blackheads.   4. Used in medicine Calcium must be involved in the formation of prothrombin activator and subsequent coagulation. Citrate ion and calcium ion can form a soluble complex which is difficult to dissociate, thus reducing the concentration of calcium ion in blood and blocking blood coagulation. It is often used as anticoagulant in vitro in blood transfusion or laboratory.   Desheng specializes in R & D, production and sales of vascular additives, in vitro diagnostic reagents, biological buffers and luminescent substrates. In the aspect of blood vessel additive, it has formed independent intellectual property rights and professional production and research capacity. Can produce a variety of additives, blood samples anticoagulant series products include heparin sodium, heparin lithium, sodium citrate, EDTA dipotassium, EDTA Tripotassium, potassium oxalate, etc.; blood samples anticoagulant series products include blood coagulant powder, blood coagulant, etc.; blood samples pretreatment materials include separation gel, silicide, etc.