China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Daos, n-ethyl-n - (2-hydroxy-3-sulfopropyl) - 3, 5-dimethoxyaniline sodium salt, the finished product is white or light blue powder, CAS number is 83777-30-4, molecular formula is c13h20nnao6s, molecular weight is 341.36, Daos is a new kind of Trinder's reagent, with high water solubility, stable reaction, wide pH range, as an excellent color reagent is widely used in diagnostic detection and biochemical experiments.   The detection principle is: in the presence of hydrogen peroxide and peroxidase, the new Trinder's reagent reacts with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazolylsulfonylhydrazone (MBTH) to form a very stable purple or blue dye, and then the substrate concentration is determined by spectrophotometry.   Daos chromogenic reagent   1、 The advantages of Daos in blood glucose measurement experiment are as follows   The determination of glucose in blood is an important test item in clinical medicine. At present, the commonly used detection method is glucose oxidase coupled with peroxidase method. This method uses God to catalyze the oxidation of glucose to gluconic acid and produce H2O2. H2O2 oxidizes colorless reduced chromogen under the catalysis of pod to produce colored oxidized pigment, and then calculates the content of glucose in the sample according to the color of oxidized chromogen.   The initial reaction of this method is specific, but the indicator reaction is nonspecific. The detection performance of this method changes with the different reduction chromogens in the indicator reaction. The common reduction chromogens are linaniline (which is rarely used because it is suspected to be carcinogenic), and the improved Trinder's reagent Daos is coupled with 4-aminoantipyrine (AAP) as the reducing chromogen The maximum absorption wavelength of the oxidized pigment formed by the oxidation and condensation of Daos and AAP is 592nm. Under this wavelength, bilirubin and other substances in blood do not interfere with the absorption, which can reduce the absorption interference of bilirubin and other interfering substances on blood glucose detection.   Therefore, this method does not need to separate blood into serum, which is simpler and more accurate than the method widely used in clinical enzymatic analysis with phenol as the reduced chromogen. The linear range of glucose is 1 ~ 20mmol / L, and the recovery is 96.3% ~ 97.7%.   2、 Instruments and reagents:   UV VIS spectrophotometer, glucose oxidase, peroxidase, Daos, AAP, anhydrous glucose, citric acid and trisodium citrate dihydrate, glycerin, bovine serum albumin, blood glucose detection kit, God and pod were prepared with pH = 6 buffer solution, and other reagents were prepared with distilled water.   3、 Methods: the experiment was carried out   In 1cm cuvette, add 0.5ml (25.6u) of God, 0.5ml (11.5u) of pod, 0.1ml (1.7mmol / L) of Daos, 0.1ml (2.9mmol / L) of AAP and 0.8ml of distilled water in turn, then add 40ul (8.3mmol / L) of glucose solution, stir well and use distilled water as reference to determine the absorption spectrum.   Desheng biochemical focuses on the development and production of in vitro diagnostic reagent raw materials, mainly including blood collection additive, chemiluminescent reagent, chromogenic substrate, enzyme substrate, antigen antibody and other products. The products are widely sold in domestic and foreign markets. Desheng's goal is not to be big, but to be a strong person in the precise field of the industry and win the market trust with its own professional.

Tris, CAS: 77-86-1. It is a white crystal or powder, soluble in ethanol and water, slightly soluble in ethyl acetate and benzene, corrosive to copper and aluminum. Tris base has high buffer capacity, high solubility in water and is inert to many enzyme reactions, which makes Tris a very satisfactory buffer for many biochemical purposes. It is used to stabilize the pH of the reaction system and has a strong buffer capacity between pH 7.5 and 9.0.   Desheng Tris packaging   Tris in glyphic acid buffer system was used to stabilize pH value in the electrophoretic buffer solution. The Tris-HCl buffer system was used to stabilize pH value in the gel. It was widely used as a solvent for nucleic acids and proteins. The low ionic strength of Tris buffer could also be applied to the formation of intermediate fibers of nematodes. EDTA buffer was added into Tris hydrochloric buffer to make TE buffer, which could be used for the stabilization and storage of DNA. The "Tae buffer" can be obtained by replacing the acid solution with acetic acid, and tbe buffer can be obtained by replacing it with boric acid. These two buffers are often used in nucleic acid electrophoresis experiments.   Tris is used in both TAE and tbe buffer (for nucleic acid dissolution) in biochemical experiments. It contains amino groups and can react with aldehydes. Tris is a weak base and its PKA is 8.1 at 25 ℃. The effective buffer range of Tris buffer is between pH 7.0 and 9.2.   The pH value of Tris base aqueous solution is about 10.5. Generally, hydrochloric acid is added to adjust the pH value to the desired value to obtain the buffer solution with this pH value. At the same time, we should pay attention to the effect of temperature on pKa of Tris. Because Tris buffer is a weak alkaline solution, DNA will be deprotonated in such a solution to improve its solubility.   People often add EDTA into Tris hydrochloric acid buffer to make "Te buffer", which is used for DNA stabilization and storage. If the acid solution of adjusting pH value is replaced by acetic acid, the "Tae buffer" (Tris / acetate / EDTA) is obtained, and the "tbe buffer" (Tris / borate / EDTA) is obtained by replacing it with boric acid. These two buffers are usually used in nucleic acid electrophoresis experiments.   TAE and tbe made from Tris are commonly used in DNA electrophoresis. Te (ph8.0) is mainly used to dissolve DNA. (TE is Tris plus EDTA.) 1mtris-hcl6.8 and 1.5mtris-hcl8.8 are commonly used in SDS-PAGE. Tris buffer has been used more and more in biochemical research, with the trend of more than phosphate buffer. Tris buffer has been used in SDS- polyacrylamide gel electrophoresis, and phosphate is rarely used. The common effective pH range of Tris buffer is in the "neutral" range.   In Tris medium, a certain microorganism can produce certain metabolites after growing in the medium, which can react with special chemicals in the medium and produce obvious characteristic changes. According to this characteristic change, this kind of microorganism can be distinguished from other microorganisms   In Tris HC, an amino group in it is a coordination group, which may replace the ligand in the original complex, thus changing the complex and affecting the absorbance. If you want to know whether there will be such an effect, you need to check their coordination constants and compare them.   Desheng has 15 years of experience in R & D and sales of biological buffers, and has generally received high praise from customers. There is still a long way to go in the future, and we will make persistent efforts to forge ahead!

HEPES is 4-hydroxyethyl piperazine ethanesulfonic acid in Chinese, CAS number is 7365-45-9, pH buffer range is 6.8-8.2, pKa value is 7.5 at 25 ℃. HEPES Na is n - (2-hydroxyethyl) piperazine-n '- (2-ethanesulfonic acid) sodium salt, its CAS number is 75277-39-3. HEPES buffer and HEPES Na are very important biological buffers, which are widely used in biopharmaceutical, medical diagnosis and other fields.   Packaging of biological buffer series products HEPES is a kind of amphoteric buffer, which is used in cell culture medium and protein research for various types of organisms. It can also be used in biochemical diagnostic kit, DNA / RNA extraction kit and PCR diagnostic kit. Because of its non-toxic effect on cells and the ability to control the constant pH range for a long time, HEPES is often used as cosmetic additive, active agent, peeling agent and promoter Through the role of the agent. Difference between HEPES and HEPES Na: HEPES Na, also known as organic HEPES base, is a conjugated acid-base relationship with HEPES. They are essentially the same, but the pH of the two substances after dissolution is different.   The preparation methods of HEPES were as follows About the preparation of HEPES buffer solution, according to the use of preparation, one is pure HEPES + NaOH, the other is HEPES + salt. Various preparation methods are summarized as follows:   1、 Preparation of 500 ml 1 m HEPES, pH = 7.0, stock solution Dissolve 119.15 g HEPES in 400ml distilled water, add 0.5 ~ 1m NaOH aqueous solution to adjust at least the required pH (the effective pH range of HEPES is 6.8 ~ 8.2), then fix the volume to 500ml with distilled water and store at 4 ℃.   2、 HEPES buffer formula with small amount of salt (500ml) HEPES 6.5g, NaCl 8.0g, na2hpo4.7h2o 0.198g, adjust the pH value with 0.5m NaOH solution, and finally fix the volume.   3、 Preparation of 2 × HEPES buffer salt solution Dissolve 1.6g NaCl, 0.074g KCl, 0.027g na2hpo4.2h2o, 0.2g dextran and 1g HEPES in 90ml distilled water, adjust to the required pH value with 0.5m NaOH, and then fix the volume to 100ml with distilled water.   The preparation method of HEPES Na was as follows HEPES Na can be synthesized by 4-hydroxyethyl piperazine and sodium vinyl sulfonate, or by high pressure synthesis of hydroxyethyl sulfonic acid, sodium hydroxide and 4-hydroxyethyl piperazine. At present, the most widely used preparation method that meets the requirements of biological buffers is the reaction of HEPES with NaOH to produce HEPES Na. The specific preparation steps are as follows:   Under the protection of nitrogen, HEPES with purity between 90-99% and NaOH solid or solution were reacted for 0.2-1 hour at 20-100 ℃. After the reaction, the obtained product was decolorized, filtered, concentrated, dehydrated, crystallized, washed and dried to obtain HEPES Na.   This method is simple and easy to operate, and the yield and purity of HEPES Na product are high, which can meet the purity requirements of biological buffer.   Desheng has 20 years of experience in developing and producing series products of biological buffers (Tris, HEPES, caps, mops, pipes). Desheng has deep research on blood vessel additives (heparin lithium, heparin sodium, dipotassium, Tripotassium), chromogenic reagents (toos, Maos, tops, Alps), chemiluminescence reagents (luminol, isoluminol, acridine ester). Desheng has checked the production and packaging of selected materials layer by layer, and insisted on improving the quality of products for customers Provide high quality raw materials for products.

Serum separation gel, a kind of raw material commonly used in hospital laboratory, is indispensable for many biochemical analysis. It is an inert polymer, insoluble in water, and has the characteristics of high temperature resistance, low temperature resistance, oxidation resistance and high stability. Some manufacturers such as Desheng also have the characteristics of anti irradiation.   Packing and delivery of serum separation gel   The main purpose of serum separation gel is to form an isolation layer between blood cell components and serum, which can effectively prevent the material exchange between blood cells and serum, ensure the stability of serum components within a certain period of time, and make the test results closer to the biochemical level. The separation gel collecting vessel with coagulant can shorten the blood coagulation time, quickly get the serum and the processed blood The blood sample can withstand the shaking and bumping of long-distance transportation. The isolation layer of separation glue can adhere to the test tube tightly after centrifugation. The serum can be directly drawn from the automatic analyzer in the original state or stored in cold storage. The long-distance transportation does not affect the test results, and also avoids the influence of fibrinogen and hemolysis.   In addition, a series of processes such as blood sample injection into blood collection vessel, serum separation, analyzer direct serum collection, blood sample preservation and waste disposal are carried out in the same branch pipe, which can avoid the contamination of blood samples, prevent the infection of virus in blood, and ensure the biological safety of the test process.   With the improvement of people's health awareness, blood testing has become more common. Serum separation glue is favored by various medical institutions, and there are many manufacturers of separation glue. Due to the different requirements of medical institutions for separation glue, the components of separation glue produced by each manufacturer are different, no matter from the transparency, color, viscosity, specific gravity and other aspects of performance. High quality serum separation gel can shorten the time of serum separation, and the separation gel is between serum and blood cells, which can effectively protect the serum components, so as to realize the original tube on the machine, save the serum in the original tube for future reference, and reduce the possibility of error caused by re tube transfer.   However, the influence of inferior separation gel on the test items can not be ignored. The use of inferior separation gel can make the triglyceride (TG) in the test results increase abnormally. Therefore, the comparative test must be done before the use of serum separation gel. Triglyceride can be detected by the following method, which is fast, simple and easy to operate   1. Instruments and reagents: automatic biochemical analyzer, triglyceride (trig) reagent and calibration solution, 5ml disposable sterile syringe, Desheng serum separation gel blood vessel, inferior serum separation gel blood vessel of a certain brand, traditional common blood vessel, 0.9% sodium chloride injection.   2. Methods: traditional common blood collecting vessels were used as control group A, Desheng serum separated blood collecting vessels were used as control group B, and inferior serum separated blood collecting vessels of a certain brand were used as experimental group C. each group randomly selected 10 tubes of blood collecting vessels, each tube added 5ml 9% sodium chloride injection, placed in 37 ℃ water bath for 15min, centrifuged at 3000r / min for 10min, the above tubes were measured on the automatic biochemical analyzer, and the test results were recorded. Compared with the results, TG could not be detected in the blood collection vessels of group A and group B, but different concentrations of TG could be detected in each tube of group C. through this method, the contrast test can be done quickly and accurately The quality of separating glue in blood collection vessel was evaluated.

Blood testing has become an indispensable means to detect diseases. At this time, patients often say, "I took several tubes of blood today, yellow, green, purple and blue. I just checked blood. Why do I take so many tubes?" Actually, it's about the items you need to check. For general physical examination, such as blood routine, blood glucose, blood lipid, liver function, renal function, various tumor markers, etc., all need to be analyzed through blood detection, and different colors of blood collection vessels represent different kinds of additives and test purposes. Therefore, the items that cannot be detected together should be divided into multiple blood collection vessels. What do the colorful blood vessels represent? Here is to introduce the significance of various colors of blood vessels. 1. Yellow head cap tube (coagulation promoting tube): mainly used for serum biochemical (liver function, renal function, blood glucose, blood lipid, myocardial enzyme, electrolyte, amylase, etc.), thyroid function, drug detection, tumor markers, PCR, serum immunology detection, etc. 2. Purple head cap tube (EDTA-K2 anticoagulant tube): used for general Hematology (blood routine) examination, partial PCR items and glycosylated hemoglobin detection. 3. Green head cap tube (heparin anticoagulant tube): heparin tube is generally used for emergency biochemical and hemorheological tests. 4. Blue head cap tube (sodium citrate hydrochloride 1:9 anticoagulant tube): it is mainly used for the examination of coagulation items (prothrombin time, thrombin time, activated partial thrombin time, fibrinogen, etc.). 5. Black head cap tube (sodium citrate 1:4 anticoagulant tube): generally used for ESR detection. 6. Red cap tube (without additives): used very rarely, similar to yellow cap tube, mainly used for serum biochemical drug detection, serum immunology detection, etc. Desheng biochemical specializes in the 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. To provide 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 materials used in the pretreatment of blood samples include separation gel, silicide, etc., and the anticoagulant tubes can also be provided for customers.

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 buffer 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.