China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Recently, I received a complaint from a cooperating customer that the main reason is the bitter experience of purchasing carbomers before and his personal thinking. I feel that it is worth learning from peers. The original text is as follows: Not long ago, I received an arrangement from the company to let us purchase carbomer. The amount used was not very large and was fixedly supplied by foreign manufacturers. However, due to the epidemic situation, our raw materials were cut off. I am not very familiar with this raw material, so I repurchased it. There were many crashing problems in the process. During the procurement period, I asked many domestic carbomer suppliers, some were manufacturers, and some were trading companies. The first problem I encountered was that Carbomer's CAS number often didn't match up and Carbomer's different models were sometimes very confusing. Asking their sales staff, many of them also said it was confusing and ambiguous, which was really a headache. The following is my personal experience and insights, just for reference. Carbomer CAS number: 9003-01-4 139637-85-7 9007-17-4 9007-20-9 9062-04-8 54182-57-9 76050-42-5 The above are collected carbomer cas numbers, including but not limited to these. Although chemical substances and cas numbers correspond in principle, carbomers are acrylic polymers. Different polymerization degrees and different raw materials added in the polymerization reaction will make the reaction products different, and the accuracy of online information is not high. It leads to a lot of cas numbers and chaos, this need not be too tangled.   Undissolved Carbomer powder   Therefore, it is usually inconvenient to express the cas number as a polymer, and it is more common to distinguish by model. Such as Carbomer 940, Carbomer 980, Carbomer 941, Carbomer u20, Carbomer 340 and so on. So the more crazy question is, what does this model mean? There are two main types of network transmission: Does the Carbomer model indicate a different viscosity of Carbomer? This is obviously wrong. If the same carbomer is configured into gels of different concentrations, the difference in viscosity will be very large. The carbomer model is obviously not the number after the gel is configured. This can obviously be directly denied, the same The carbomer model represents the concentration used in different products is also wrong. Does the Carbomer model indicate its degree of polymerization? In a certain encyclopedia and a certain encyclopedia, it is said that the carbomer model represents a different degree of polymerization, the larger the number, the higher the degree of polymerization. At first glance, this statement seems to have a bit of truth, but this statement is also problematic, such as Carbomer 940 and Carbomer 941, the degree of polymerization is only 1 monomer apart, obviously knowing that industrial production is wrong, When the polymerization occurs, the polymer can hardly control the degree of polymerization at 940 or 941. To sum up, personally think that the number of carbomer number should be disassembled and understood. Carbomer is a resin, which may be similar to ion exchange resin. The model of the ion exchange resin is composed of three Arabic numerals, the first digit represents the classification of the product (codes from 0 to 6: strong acid weak acid strong alkali weak alkaline chelating amphoteric redox), the second digit Represents the difference of the skeleton (styrene acrylic acid acetate epoxy system, etc.), the third digit is the sequence number to distinguish the difference of genes, cross-linking agents, etc. Carbomer's model number may represent rheology, light transmittance, monomer difference, cross-linking agent difference, etc., viscosity and degree of polymerization are also included, but it is represented by a number code. Since I asked many companies and many websites, I didn’t find the exact difference between different carbomer models, so I directly asked many carbomer samples to come back for testing. Finally, I chose the carbomer from Desheng for our no-wash The effect in the disinfection gel is very good. In the end, the problem of the meaning of the carbomer model representative has not been completely resolved, and experienced seniors are welcome to give pointers!

Recently, the rebound of Beijing's new crown epidemic has sounded the alarm for our life in the post-epidemic period. The epidemic situation in the United States, Brazil, India, Africa and other regions is also intensifying. The new crown virus will inevitably leave a striking stroke in human history. In order to gain a deeper understanding of this RNA virus, we conducted a brief interview with the company's technology research and development department.   Hubei's new Desheng is a technology company specializing in the production of blood testing related reagents in the Optical Valley United Technology City. At the early stage of the outbreak, it began to invest heavily in the research and development of RNA virus Transport Medias, and eventually produced products approved by many companies.   So we made an appointment and interviewed the engineer Liu responsible for technology research and development. A series of interview questions are as follows:   Viruses and nucleic acids   Q: The company originally made blood test reagents. Why did it decide to make virus Transport Media? A: The company did start as a blood collection tube reagent, but that is only one of the main series in our products. The company has always produced a series of biochemical detection related reagents such as blood collection tube reagents, biological buffers, and sample tube Transport Medias, and even There are also some emerging reagent materials. Our advantage is R&D synthesis and innovation. And the virus Transport Media is an important part of the virus detection process. The market is in urgent need, and we are doing our best for the society. Q: The news now says that the nucleic acid test has false negatives. Is this related to the virus Transport Media? A: There are many cases of false negatives. Instead, the virus Transport Media is to reduce the occurrence of false negatives and increase the accuracy of detection. Because the virus will be quickly lysed in vitro, it is usually not detected in time after sampling. It can keep the original characteristics of the samples during transportation and storage to ensure the accuracy of the detection. Of course, if the virus Transport Media deteriorates or grows bacteria, it will not be able to protect viral proteins or viral RNA.   Q: How do you tell if the virus Transport Media has deteriorated or grown bacteria? Generally, it can be observed by the naked eye first. Usually, the non-inactivated virus Transport Media is easy to deteriorate or grow bacteria, and the inactivated type is not easy to deteriorate. Deteriorated storage solution is usually uneven in color, accompanied by turbidity or flocs, of course, the normal color is ultimately determined by testing to determine whether it is available.   Through the interview, we learned some common problems of virus Transport Media in the sampling tube. Finally, Engineer Liu also shared some suggestions for avoiding the deterioration of the Transport Media. The main reason is that the temperature is too high during transportation and the air during the packaging process. The contact is contaminated with bacteria and fungi, so be sure to keep strict low temperature and the product container is sealed tightly, especially the non-inactivated Transport Media.

The speed of medical tests is of great clinical significance. Some tests require the separation of serum from blood concentration in order to perform. It usually takes one hour from blood clotting to hemorrhage extraction. Even if heated centrifugation is used, it takes half an hour, and it is easy to cause hemolysis. In case of emergency blood distribution or emergency diagnosis, delay time and delay treatment. Therefore, shortening the time of serum separation is an urgent problem to be solved in the current inspection work. In this case, blood coagulant was born. Blood coagulation: (1) The concept of promoting coagulation: The process of accelerating blood coagulation by introducing some substances is blood coagulation. (2) Blood coagulant: substances that can accelerate blood coagulation are called blood coagulants. Blood coagulants include silica powder, glass, fiber, hair, thrombin, snake venom, and rabbit brain powder. (3) The principle of blood coagulation: blood coagulation is referred to as coagulation, which is the process of changing blood from a flowing state to a gel state. It is an important part of the hemostatic function. The coagulation process is a process in which a series of coagulation factors are activated by successive enzymatic hydrolysis, and finally generates thrombin, forming a fibrin clot. There are 14 factors involved in coagulation. Among them, there are 12 numbered with Roman numerals (from I to VIII, of which factor VI does not exist). The coagulation process is usually divided into: ① endogenous coagulation pathway; ② exogenous coagulation pathway; ③ common coagulation pathway.   Vacuum blood collection tubes with coagulants sometimes have filaments and lumps precipitated by fibrin, which are caused by the lack of standardized use of coagulant blood collection tubes. In the preparation of vacuum blood collection tubes, the selection of procoagulants with too fast coagulation speed will cause fibrin to contract too fast and the fragile red blood cells to break easily, causing mild hemolysis. There are the following reasons for the precipitation of fibrin: the use of coagulant blood collection tubes or separation gel to promote coagulation blood collection tubes, if the coagulant is evenly distributed in the blood, it must be slightly inverted and mixed 4-5 times, so that the center of the blood collection tube and the surrounding The blood coagulates at the same time. If the blood is not completely coagulated, it is centrifuged, which can cause the precipitation of fibrin. A jelly sample or a lump sample appeared on the upper part of the serum, mixed with blood. Fibrin filaments are caused by fibrin that has not contracted completely. When using coagulant blood collection tubes, the spraying of coagulant is insufficient or the prepared water-soluble coagulant is not used up on the same day, and the continued use the next day leads to a decrease in the effectiveness of the coagulant. Fibrinogen in the blood is gradually transformed into insoluble fibrin under the action of a coagulant. If the dose of the coagulant is insufficient or fails to extend the coagulation time, centrifugation can cause fibrin precipitation.

3-(cyclohexylamine)-1-Propanesulfonic acid, referred to as CAPS, is an important chemical raw material. There are two types of manufacturers, one is for industrial purposes, the purity is relatively low, and the impurity content is too much. It is specifically for the field of biochemical reagents, with high purity and low impurity content. There are also two types involved.   English name) :3-(cyclohexylamine)-1-propanesulfonic acid Chinese name: 3-(cyclohexylamine)-1-propanesulfonic acid Abbreviation: CAPS CAS:1135-40-6 113-40-6 Molecular weight :221.32 Molecular formula :C9H19NO3S Storage conditions:Room temperature, protected from light and moisture Chemical structure: In the industrial field: It is mainly used to improve water-based coatings. In water-based polyisocyanate coatings, after adding CAPS, its sulfonic acid group reacts with the tertiary amine neutralizer to form sulfonic acid urea derivatives. The isocyanate coating after stability is better, the finished product is not turbid, and the dispersion state of forming latex in water is good.   In addition to being used in water-based coatings, CAPS is also often used in the manufacture of soldering fluxes, heat exchange carriers for air-conditioning equipment, raw materials for lithium metal manufacturing processes, pyrotechnics, dry batteries, etc., which are widely used. CAPS reagent In the field of biochemistry: Mainly used as a biological buffer, because it is a sulfamate, it has amphotericity and can maintain the pH of the reaction system, so it has a buffering effect. The buffer range is 9.7-11.1. CAPS itself is slightly acidic. Weigh a certain amount to make an aqueous solution during configuration, then mix it with sodium hydroxide solution in proportion, and adjust the proportion according to the required pH.   When used as a buffer, CAPS is mainly used in WB experimental protein electrophoresis buffer, and is suitable for high molecular weight proteins. CAPS electrophoresis buffer is composed of CAPS, EDTA and methanol. It can be used for protein separation, protein PVDF transfer membrane, protein sequencing. It is not suitable for nylon membrane. Tris electrophoresis solution for nylon membrane. In addition, CAPS is also used in buffers for HPLC separation of basic drugs.   Desheng Technology is a manufacturer specializing in the production of CAPS reagents. Its products are mainly used as buffers in the biochemical field. It can also provide industrial-grade CAPS. The reagent grade has high purity and low impurity content. It can be directly used in kits. Other buffers such as Bicine, Tris, MOPS, etc. are also widely recognized.

Hubei New Desheng was established in 2017. It is a new technology-based enterprise established on the basis of Wuhan Desheng Biochemical Technology Co., Ltd. (2005). It is specialized in the research, development, production and sales of blood collection tube additives and blood test reagents. In terms of blood collection tube additives, it has formed its own intellectual property rights and professional production research and development capabilities. Has accumulated rich knowledge and experience in the pretreatment of blood specimens and has professional technical service advantages.     The company mainly includes: anticoagulant products of blood samples: heparin sodium and lithium heparin; materials used for pretreatment of blood samples: separation gel; raw materials for diagnostic reagents 1. Types of blood collection tube additives: Blood collection tube additives are divided into anticoagulants, coagulants, siliconizing agents, separating gels, anti-blood glucose decomposers, and blood cell preservation solutions. (1) Anticoagulant: EDTA salt (disodium, dipotassium, tripotassium), heparin salt (heparin sodium, lithium heparin), sodium citrate, potassium oxalate, etc. (2) Accelerator: There are coagulant powder and coagulant (solution type). It is usually a compound of silica powder and various inorganic materials, and some manufacturers use a compound of inorganic powder and thrombin. Thrombin promotes fast coagulation, but its stability is relatively poor, and it requires relatively harsh storage conditions. Generally, it is good to be stable for half a year. Therefore, some institutions improve their stability by modifying thrombin. In addition, thrombin has an effect on some detection indicators and is only used in emergency biochemical tests. (3) Silicide: Our company's silicide is divided into oily and water-based silicide. The oily silicifying agent has good silicidation effect, but the outer wall of the test tube is easy to stick, which makes it difficult to label or the label is easy to fall off. In addition, it is required to be used in conjunction with petroleum ether, which has a large taste and high risk; The outer wall can be washed with water to remove the silicide from the outer wall. (4) Separation gel: It is the substance that separates serum (plasma) and blood cells. The separation gel can be used in combination with heparin salt, EDTA salt, sodium citrate, etc. The separation gel is used to prepare high-quality specimens and to store and transport specimens. (5) Anti-glycemic decomposition agent: sodium fluoride or potassium fluoride is generally used. (6) ACD solution: blood preservation solution, which is a compound of sodium citrate, citric acid and glucose, etc. It is mainly used for the preservation of blood in blood banks.   2 Blood anticoagulants: including EDTA salt, heparin salt, sodium citrate, potassium oxalate, etc. (1) EDTA salt: EDTA disodium, dipotassium, tripotassium, etc. Generally, EDTA salt is used for anticoagulation in routine blood tests. It is an excellent complexing agent that can combine with calcium ions in the blood, thereby preventing blood from clotting. Because of its poor solubility, EDTA sodium salt is basically no longer used. EDTA salt requires analytical purity, no impurities and heavy metal ions exceed the standard, dipotassium and tripotassium contain two crystal water, dipotassium molecular weight 404.6, PH value between 3.8-5.8, tripotassium molecular weight 464.4, between 5.8-7.8 between. Potassium salt has good solubility, fast dissolution rate, strong complexing ability, and can quickly play an anticoagulant effect. It is an ideal anticoagulant. The industry standard stipulates that 1.5-2.2 mg EDTA salt is added per ml of blood for anticoagulation. (2) Heparin salts: including sodium heparin and lithium heparin. The principle of heparin salt anticoagulation is that heparin salt molecules can combine with lysine in the blood to prevent it from activating thrombin and achieve the purpose of anticoagulation. Blood electrolyte testing uses heparin anticoagulation, adding 9-24IU heparin per ml of blood, and the amount of heparin anticoagulation required for micro blood collection tubes is 14IU per ml of blood. For blood gas detection, lithium heparin is generally used for anticoagulation, because lithium heparin has the least interference with blood gas detection. (3) Sodium citrate: alias sodium citrate. The chemical name is sodium citrate dihydrate, molecular formula Na3C6H5O7·2H2O, molecular weight 294.1, is a complexing agent, it can complex with calcium ions in the blood to form stable calcium citrate, thus preventing the start of blood coagulation mechanism, To achieve the purpose of anticoagulation. Sodium citrate was used as the anticoagulant in the determination of the four items of coagulation and erythrocyte sedimentation rate. (4) Potassium oxalate: It is also a complexing agent that can combine with calcium ions in the blood to form a stable complex, thereby preventing blood coagulation. Molecular formula: (COOK) 2. H2O, molecular weight 184.23, analytically pure reagent, white crystals, easily soluble in water. It is used with sodium fluoride when measuring blood sugar, and the dosage is 1.5-2.2mg per ml of blood. After anticoagulation, the blood is centrifuged, and the resulting supernatant is plasma. The main difference between plasma and serum is that plasma contains fibrinogen, while serum does not contain fibrin.   3 Blood coagulant: When performing blood biochemical testing, serum is used as the test object, and blood coagulant is used to rapidly coagulate the blood to improve the detection efficiency. (1) Accelerating powder: The main component is a compound of silica powder and other inorganic powders. The principle of promoting coagulation is to activate the blood coagulation mechanism through the introduction of calcium ions and promote the rapid coagulation of blood. (2) Accelerator: The coagulant powder is formulated as a liquid accelerator. The accelerator is more convenient for customers to use automated production lines for production, and can add the accelerator to the test tube more accurately and quickly.   4 Silicide: It is divided into water-soluble silicide and oily silicide.   5 Separation glue: There are several kinds of separation glues on the market. According to different systems, they are divided into silicone rubber system (represented by Jiean and the company's first generation separation glue), acrylic system (taken by the company's second generation separation glue and Yangpu separation Glue as the representative) and resin system (represented by the company's fourth-generation separation glue, water-separating separation glue and Fuji-Shanghai separation glue). Several types of separation gels have their own advantages and disadvantages. Resin system separation gels represent the future development direction of separation gels.   (1) Key performance indicators of separation gel: A. Specific gravity: 1.045-1.065g/cm3, between the specific gravity of serum (plasma) and blood cells. PRP test tubes have two specific gravity of 1.055 and 1.078, which are used to separate platelet and serum components respectively;   B. Viscosity: between 100,000 and 200,000 yuan (dynamic viscosity measured by rotary viscometer). C. Thixotropy: When the object (such as paint) is sheared, the consistency becomes smaller. When the shear stops, the consistency increases or when the shear stops, the consistency becomes larger. When the shear stops, the consistency becomes smaller. The nature of a touch. This is the key to the separation gel that can form an isolation layer under the action of centrifugal force.   D. Physiological inertness: The separation gel is in direct contact with the blood and cannot react with the blood. Otherwise, it will affect the blood composition and cause a significant difference in the test results, leading to misdiagnosis. Blood cells are a particularly delicate substance, and a little carelessness will most likely cause hemolysis and affect the accuracy of the test results. E. Irradiation resistance: The blood collection tube requires sterility, and it is generally sterilized by gamma irradiation. After the separation gel is irradiated with gamma rays, its performance cannot change significantly, including specific gravity, viscosity, thixotropy, and physiological inertness. Generally, gamma rays are generated by the cobalt 60 radioactive element, and the radiation dose is generally in the range of 8-25KGY; the radiation dose is determined by the initial number of colonies in the blood collection tube. G. Stability: On the one hand, it requires the stability of the separation gel for long-term storage, and it needs to be stable for at least two years. In addition, there can be no reaction between the separation gel and the various additives in the blood collection tube, which affects the effectiveness of the reagent and thus affects the blood test.   In addition, there are other properties, such as separation gel bubbles, volatile small molecules, impurities, etc., must meet the requirements, otherwise it will cause trouble to customers. Usage and dosage of separating gel: In the past, separating gel was mainly used for serum biochemical detection, that is, separating gel and blood coagulant were used together. With the development of blood collection tube technology and inspection requirements, more and more blood collection tubes are beginning to use separation gel test tubes. At present, there are already blood test tubes (separation gel + potassium salt anticoagulation tube), electrolyte test tubes (separation gel + heparin salt), blood coagulation test tubes (separation gel + sodium citrate) and other types of blood collection tubes using separation gel. These aspects have driven the increasing use of separation gels.   Generally, 0.8-1.2g of separation gel is added to each blood collection tube to form a separation layer of at least 5mm between different components of blood to ensure the high quality of blood samples. Each kilogram of separation gel can produce 800-1200 blood collection tubes, and one ton of separation gel can produce 800-1.2 million blood collection tubes. For a blood collection tube enterprise with an annual output of 500 million tubes, the proportion of separation gel test tubes is about 30%, which requires about 190-220 tons of separation gel, and an average of about 15 tons of separation gel per month. Enterprises with an annual output of 100 million blood collection tubes have an annual separation gel consumption of 35-40 tons, and a monthly separation gel consumption of 3-3.5 tons, and this demand is still increasing.   Now, the vast majority of blood collection tube manufacturers use automatic glue machine to add glue. The procedure of adding glue is: add blood from blood collection tube-stand for 3-5 days-evacuate-centrifuge to remove bubbles-irradiation sterilization-detect bubbles-re-centrifuge   Desheng is positioned as a professional manufacturer and service provider of blood test reagents and polymer materials, and provides professional services and high-quality products for blood collection tubes, diagnostic reagent manufacturers and polymer material companies at home and abroad.

Carbomer 940 is a high-molecular polymer cross-linked with acrylic acid and propylene sucrose or propylene pentaerythritol. Carbomer was first produced by Goodrich Company of the United States under the trade name Carbopol. The appearance is white loose powder with moisture absorption Sexual and characteristic slight odor, soluble in water, ethanol, glycerin, because the molecule contains 56%-58% carboxyl group, so it is weakly acidic, carbomer is an excellent medicinal auxiliary, widely used in cosmetics In the production of pharmaceuticals, carbomer is mainly used as a thickener, adhesive, gel, suspension base and matrix material for controlled-release preparations in pharmaceuticals. There are many models of carbomer, the most widely used is carbomer 940. When we prepare carbomer 940 gel, various problems will occur. The most common thing is to generate a lot of bubbles. Many people take it for granted that defoamers can be added, but we have to consider from the perspective of drug safety. Don't use the auxiliary materials that may have safety risks to solve the problems that are solved by improving the production process. Use stirring and vacuum emulsifiers to solve them first. It is really impossible to use other methods.   carbomer 940   common problem: 1. Bubbles: The swelling carbomer first disperses the powder in water with a high-speed mixer, and there are also two methods of stirring while adding, but in the experiment, it was found that both will generate a large number of bubbles. In addition, when the carbomer swells into a colloid Later, when dissolving the related drugs, a large number of bubbles will also be introduced. We can use the following methods to solve: ①Pre-soaking method: 24 hours in advance, first add carbomer in deionized water to dissolve according to the actual production requirements, without stirring, after carbomer naturally absorbs water, there is no white powder on the surface, and no white solution The agglomerates are subject to mixing. After mixing, add a neutralizer to adjust the PH value to about 7 to achieve a thickened state. Stir evenly with a disperser at a low speed. ②Homogenizer: Add to the homogenizer according to the actual production ratio to homogenize so that no white balls can be seen, then add a neutralizer and wait for the gel to form, then use a vacuum emulsifier to evacuate the air from the gel.   2. Produce flocculation and affect transparency: In some gels, in order to increase permeability, antiseptic, and solubilization, ethanol is often added as an additive, such as disinfection and no-clean gel, in which ethanol is the main component, the content may be up to about 75% . Carbomer gel is essentially an aqueous polymer solution. The reason why the polymer solution is stable is because of the presence of 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 gels are prepared by different operating processes. The ethanol concentration of the finished product has different high limits. When the ethanol concentration is too high, the finished gel will produce a little opalescence, which reduces the transparency of the gel. However, if the ethanol content is 70%, In the finished rubber product, slowly add 2% purified water and stir. Compared with the finished product before the addition, the opalescence is significantly reduced. This method has a certain effect on improving the appearance transparency of the finished product.   Desheng warm reminder: The dispersion time of carbomer 940 in water is related to the water temperature and water quality. It is recommended to use deionized water to make the product more stable. It will take longer to dissolve in organic solutes. The carbomer 940 takes about 8 hours to soak. The specific dissolution time is related to the amount of dissolution.

Tris: trimethylol aminomethane Trismethylaminomethane (Tris) is an organic compound with the formula (HOCH 2) 3CNH 2. Tris is used to prepare buffers in biochemistry and molecular biology experiments. Both TAE and TBE buffers (used to dissolve nucleic acids) used in biochemical experiments require Tris, which can condense with aldehydes when it contains amino groups. Buffering characteristics Tris is a weak base. At room temperature (25°C), its pKa is 8.1. According to buffering theory, the effective buffering range of Tris buffer is between pH 7.0 and 9.2. The pH of the aqueous solution of Tris base is about 1 0.5. Generally, hydrochloric acid is added to adjust the pH value to the desired value, and then the buffer solution with this pH value can be obtained. But at the same time, the influence of temperature on the pKa of Tris should be controlled. Since Tris buffer is a weak alkaline solution, DNA will be deprotonated in such a solution, thereby improving its solubility. People often add EDTA to Tris hydrochloric acid buffer to make "TE buffer". TE buffer is used for DNA stabilization and storage. If the pH-adjusted acid solution is replaced with acetic acid, then "TAE buffer" (Tris/Acetate/EDTA) is obtained, and if it is replaced with boric acid, then "TBE buffer" (Tris/Borate/EDTA) is obtained. These two buffers are used in nucleic acid electrophoresis experiments. 1 M Tris-HCl (pH7.4, 7.6, 8.0)   Component concentration 1M Tris-HCl Preparation volume 1L Preparation method: 1. Weigh 121.1g Tris into a 1L beaker. 2. Add about 800ml of deionized water and stir to dissolve. 3. Add the amount of concentrated HCl as shown in the table below to adjust the required pH value. pH Concentrated HCl 7.4 about 70ml 7.6 about 60ml 8.0 about 42ml 4. Bring the solution to 1 L. 5. After high temperature and high pressure sterilization, store at room temperature. Note: Allow the solution to cool to room temperature before adjusting the pH value, because the pH value of the Tris solution varies greatly with the temperature. When the temperature increases by 1°C, the pH value of the solution decreases by about 0.03 units.   1.5 M Tris-HCl (pH8.8)   Component concentration 1.5M Tris-HCl Preparation volume 1L Preparation method 1. Weigh 181.7g Tris in a 1L beaker. 2. Add about 800ml of deionized water and stir to dissolve. 3. Adjust the pH to 8.8 with concentrated HCl. 4. Bring the solution to 1 L. 5. After high temperature and high pressure sterilization, store at room temperature. Note: The solution should be cooled to room temperature before adjusting the pH value, because the pH value of Tris solution varies greatly with temperature, For every 1°C increase in temperature, the pH of the solution decreases by approximately 0.03 units.   The advantages of Tris-HCl buffer are: ①Because Tris base is more alkaline, you can use this buffer system to prepare a buffer solution with a wide range of pH values ​​from acidic to alkaline; ② Little interference to biochemical process, no precipitation with calcium, magnesium ions and heavy metal ions.   The disadvantages are: ① The pH value of the buffer solution is greatly affected by the concentration of the solution, the buffer solution is diluted ten times, and the change in pH value is greater than 0.1; ②The temperature effect is large, and the temperature change has a great influence on the pH value of the buffer solution, namely: △pKa/℃=－0.031, for example: the pH of the buffer solution at 4℃=8.4, then the pH value at 37℃= 7.4, so it must be prepared at the use temperature, the Tris-HCl buffer prepared at room temperature cannot be used at 0 ℃ ~ 4 ℃. ③ It is easy to absorb CO2 in the air, so the prepared buffer should be tightly sealed. ④ This buffer solution will interfere with certain pH electrodes, so use an electrode compatible with Tris solution. Tris solution can absorb carbon dioxide from the air, pay attention to sealing during storage, if you require sterility, you can add sodium azide.   TE is Tris-EDTA buffer (10mM Tris, 1mM EDTA, pH7.4 pH7.6 pH8.0). Commonly used molecular biology reagents for DNA dissolution. Prepare 10×TE Buffer (pH7.4, 7.6, 8.0) Component concentration: 100mM Tris-HCl, 10mM EDTA Preparation volume: 1L Preparation method: 1. Measure the following solution and place in a 1L beaker. 1M Tris-HCl Buffer (pH7.4, 7.6, 8.0) 100 ml 500 mM EDTA (pH8.0) 20ml 2. Add about 800ml of deionized water to the beaker and mix evenly. 3. After adjusting the volume to 1L, sterilize at high temperature and high pressure. 4. Store at room temperature.

When we use products, we don't pay much attention to what substances are in its ingredients. Why is Carbomer 940 concerned by us? I think the main reason is because it appears too frequently in our lives, it will prompt us to discover its value, so where is it basically used?   Desheng carbomer   Carbomer 940 is white, loose, acidic, hygroscopic and slightly odorous, soluble in water, ethanol and glycerin. Commonly used concentration is 0.1% ~ 3.0%. Carbomer 940 contains a large number of carboxyl groups in its molecule, so the aqueous solution should be used after neutralization with alkali to reduce irritation to the skin and mucous membrane. The carbomer 940 neutralizer can be sodium hydroxide, potassium hydroxide, potassium bicarbonate, borax, amino acids, polar organic amines such as triethanolamine. Laurylamine and stearylamine can be used as neutralizers in non-polar systems. The neutralized carbomer hydrogel is most viscous between pH 6 and 11, such as pH12, the viscosity decreases, and the presence of strong electrolytes can also reduce the viscosity. The gel is unstable. It is easy to grow mold and lose viscosity quickly when exposed to sunlight. Adding antioxidants can slow down the reaction. 1. Function: Carbomer 940 has an efficient thickening effect and can produce clear and transparent water or ethanol-hydrogel with very short rheology. Low ion resistance and shear resistance. Very suitable for all kinds of cosmetics. Such as: moisturizing creams, lotions, cleansing products, sunscreen products, non-alcoholic perfumes, fragrance hair conditioners (enhance gloss, easy to comb), etc. Carbomer 940 can produce high-efficiency thickening effect at very low dosage (conventional dosage 0.25-0.5%), thus preparing emulsions, creams, gels and transdermal preparations with a wide viscosity range and different rheological properties .   Carbo resin exists in water in acidic form, and swells easily in water and polar organic solvents (such as ethanol and glycerin). It contains acrylic polymers crosslinked with polyalkenyl polyether and contains 56-68% hydroxy acid groups in the molecule, making these resins weakly acidic, but it is easy to neutralize with inorganic bases and organic bases to form salts. Due to its weak acidity and swelling, it is a very important rheology modifier. Carbopol resin after neutralization with alkali is an excellent gel matrix with thickening and suspending properties, and is widely used in the transparent gel industry , Cosmetic gel growth.   Second, the method of use: 1. Direct method · Sift the carbomer slowly into the rapidly stirring water to make it fully dispersed ·Continuously stirring and pouring the water phase into the oil phase ·Neutralization with suitable alkali (in some cases, neutralization is best done after the fourth step) ·Quick mixing reduces the size of particles to obtain shiny products. Homogeneous method can be used, but high-speed shear will make the emulsion unstable 2. Indirect method ·Disperse the polymer emulsifier in the oil phase and continue stirring until a smooth and uniform dispersion is formed ·Add an appropriate amount of alkali as a neutralizer to water · With vigorous stirring, add the oil phase (containing the polymer) to the water phase and continue stirring until a white emulsion is formed..   Three, carbomer 940 matters needing attention: ·After carbomer neutralization, long-term stirring or high-shear stirring will cause viscosity loss ·Ion presence-electrolyte will reduce the thickening efficiency, not resistant to acids, electrolytes, salts and other substances, it will decompose into water when it encounters salt ·Ultraviolet--long-term ultraviolet irradiation will reduce the viscosity of carbomer gel when pH>/=10, it is not sensitive to ultraviolet irradiation ·Temperature change--Carbomer gel is not affected by temperature · Microorganisms-Carbomer does not support the growth of bacterial mold, which does not affect the gel properties. The conventional dosage is 0.2-0.4%, which can replace 3-7% of the conventional emulsifier. Carbomer polymers hardly have the properties of surfactants. Adding 0.1-0.5% surfactants with low HLB value can adjust the oil phase particles to be smaller to prepare white and delicate cream products.   Carbomer 940 is far more than what we know. It has many unknown potentials waiting for us to discover it. Desheng is such a digger, using our way to develop more value, and also achieved good results, we will not stop, we will continue to move forward.

Every time we go to the hospital for examination, blood tests are indispensable, and many causes of our bodies will be shown through blood tests. Serum is one of the main specimens for clinical biochemical and immune tests. At present, the means for medical institutions to obtain serum specimens are mainly obtained by collecting venous blood and centrifuging after the blood is completely coagulated. Under normal circumstances, it takes more than 60 minutes for the blood sample after coagulation to completely coagulate, or even not coagulate, which is difficult to meet the needs of rapid laboratory testing.     The blood coagulation mechanism is a process in which a series of coagulation factors are activated one after another and finally form a fibrin clot. If the blood coagulation rate is too fast, fibrin contraction also accelerates, and it is easy to squeeze the fragile red blood cells, causing them to rupture and cause mild hemolysis. The blood clot has a larger specific gravity than the serum, so the serum is above the blood clot. At this time, the lower end of the serum is still in contact with the upper end of the blood cell. The cells can still use the nutrients in the serum to lower the blood glucose measurement value, and the lactate dehydrogenase and serum potassium measurement values ​​increase. In this case, the respective coagulant products came into being. The main function of the blood coagulant is to accelerate blood coagulation, that is, to shorten the blood coagulation time in vitro without affecting the necessary components of the blood and promote the separation of serum. When using serum separation gel to promote coagulation blood collection tubes, the separation gel has a larger specific gravity than serum and is smaller than a blood clot, resulting in the upper layer being serum, the middle layer being separation gel, and the lower layer being blood clots, so that various components in serum maintain physiological levels.     The natural coagulation of blood is related to temperature. Blood can coagulate in a glass test tube at 37°C in a water bath for 30 minutes. If the blood and the coagulant are centrifuged after the blood collection is not fully mixed or the blood is not completely coagulated, it is easy to form a fibrin jelly-like coagulation or the fibrin filaments have a smaller specific gravity than the blood clot, so they remain in the serum layer and partially adhere to Around the separation gel, if directly on the machine at this time, it will cause clogging of the analysis blood collection needle. Vacuum blood collection tubes for coagulants sometimes have filaments and lumps precipitated by fibrin. The main reason is that there is no standard use of blood collection tubes for coagulation.   Most accelerators use substances with physical and chemical properties as accelerators, such as silica powder, glass powder, silicon carbon, and snake venom, etc., which are made into powder through special processing and are evenly sprayed on the inner wall of the vacuum blood collection tube with a quantitative sprayer to achieve rapid acceleration. The purpose of condensation. The accelerator used in some imported accelerator tubes is composed of silica gel particles and biological additives. Different types of accelerators have different mechanisms.   Different kinds of procoagulants can act on endogenous coagulation pathway, exogenous coagulation pathway, and common coagulation pathway. Different types of coagulants have their own advantages and disadvantages, and their variety, performance, and concentration directly affect the characteristics of blood samples and test results. When manufacturers prepare coagulation tubes, they should be consistent in terms of variety and concentration, and can temporarily maintain their effectiveness, so as to minimize the effect of coagulants on the test results. Before the laboratory is used, it is necessary to understand the detailed information of the accelerator used by various manufacturers and select high-quality products, so as to achieve good control of the quality before analysis. We should also pay attention to the following points when using blood coagulant: 1) coagulation time: the time required for the blood to reach full coagulation after contact with the coagulant. 2) Promoting coagulation efficiency: the relative amount of coagulant needed to achieve the best coagulation effect. 3) Coagulation effect: the amount of serum oozing after blood clotting. 4) Separation effect: After centrifugation, the blood after coagulation can achieve complete and clear separation of serum and whether hemolysis occurs. 5) Influence on essential components of blood: The use of coagulants cannot have a harmful effect on the clinical test results of blood and the performance and quality of blood products. 6) When it is found that there are impurities, foreign smells, abnormal colors and exceeding the expiration date in the accelerator;   7) This product is an organic solvent liquid, has a certain smell, is flammable, and has slight anesthetic properties.   Since its establishment, Desheng has been devoted to the research, development, production and sales of blood test reagents, and has won the trust of many companies.

With the emergence of various junk foods and the prevalence of staying up late, the disease has gradually begun to rejuvenate, and even hypertension and diabetes patients have concentrated in the age of 20-30 years old. The blood test is a fast, simple and universal method for detecting diseases. Because of the rapid development of the times and the advancement of technology, all rhythms have been accelerated, and the speed of blood testing has also accelerated, and this main core raw material is the coagulant. Serum is one of the main specimens for clinical biochemical and immune tests. At present, the means for medical institutions to obtain serum specimens are mainly obtained by collecting venous blood and centrifuging after the blood is completely coagulated. Under normal circumstances, the blood sample after isolation needs more than 60 minutes to completely coagulate, or even not coagulate, which is difficult to meet the needs of rapid laboratory testing.   The containers currently used by medical institutions for collecting venous blood samples mainly include vacuum blood collection tubes or blood samples collected with disposable syringes and then injected into non-vacuum containers. The materials of the containers are divided into glass and plastic. Under normal circumstances, it takes a long time for the collected blood samples to naturally coagulate at room temperature (2-35°C). Generally, the glass tube needs more than 60 minutes, and the plastic tube needs more than 90 minutes. Due to the clinical need for laboratories to provide rapid and accurate laboratory biochemical and immune testing indicators, if the collected blood samples are not processed, it is difficult to meet the clinical needs in time, especially for emergency patients, it is necessary to obtain fast and accurate test results . The traditional method of promoting blood coagulation is mainly to add materials such as white clay and cephalin to the blood samples after collection to promote blood coagulation. However, with the advancement of clinical laboratory testing methods, some automated, intelligent biochemical and immunological testing instruments are continuously updated and used for clinical testing and analysis. The sensitivity and accuracy of these automatic analysis instruments are constantly improving, and the requirements for specimens are also increasing.   The blood clotting process includes three basic biochemical reactions: 1. Formation of prothrombin activator; 2. Prothrombin activator turns prothrombin into active thrombin with the participation of calcium ions; 3. Soluble fibrinogen is converted into insoluble fibrin under the action of thrombin. The visible blood clot formation is both a physical phenomenon of fibrin formation and the end point of a series of enzymatic biochemical reactions. The whole process involves many clotting factors. Under physiological conditions, clotting factors are generally in an inactive state. When these clotting factors are activated, a series of enzymatic reactions that are still known today as the "coagulation mechanism waterfall theory" occur and cause blood clotting. Tissue factor, tissue thromboplastin or factor Ⅲ, is the only coagulation factor that does not exist in the blood of animals. It is a lipoprotein, and its main component is phospholipid. Tissue factor lipoproteins are widely present in animal tissues such as brain, lung, and placenta. They are released after tissue damage, act on the exogenous coagulation system, and promote the co-production of endogenous coagulation system products under the catalytic action of thrombin. Sexual coagulation pathway to achieve coagulation effect.   Accelerator (suspending agent)   The main function of blood coagulants is to accelerate blood coagulation, that is, to shorten the blood coagulation time in vitro without affecting the necessary components of blood, and to promote the separation of serum.   Blood coagulant performance should be considered: 1. coagulation time: the time required for the blood to reach full coagulation after contact with the coagulant. 2. Promoting coagulation efficiency: the relative amount of coagulant needed to achieve the best coagulation effect. 3. Coagulation effect: the amount of serum oozing after blood clotting. 4. Separation effect: After centrifugation, the blood after coagulation can achieve complete and clear separation of serum and whether hemolysis occurs. 5. Impact on essential blood components: The use of coagulants cannot have a detrimental effect on the clinical test results of blood and the performance and quality of blood products.   Desheng has 15 years of rich experience in research and development and production of blood collection tube additives. It can provide high-quality raw material products such as coagulant, sodium heparin, lithium heparin, dipotassium EDTA and tripotassium EDTA. Blood test reagent products have always been trusted by customers.

Since the company makes heparin products, we always receive a lot of calls asking for heparin sodium. Customers should think that the price difference is too big to even understand. In fact, there are several reasons for the price misunderstanding. Here we introduce The reason:   Heparin Sodium Reagent   1. Unfractionated heparin: It is a mixture of sulfated glycosaminoglycans (GAGs). It is a mucopolysaccharide sulfate composed of alternating D-glucosamine, L-iduronic acid and D-glucuronic acid. Prepared from the lungs of cattle or the intestinal mucosa of cattle, sheep and pigs. After the medicine is made, it is usually used for patients with renal insufficiency or pregnant women. 2. Low molecular weight heparin: It is a short-chain preparation isolated from ordinary heparin or degraded by ordinary heparin. Due to different molecular sizes, anticoagulant activities, preparation methods, manufacturers, etc., clinically used low molecular weight heparins include enoxaparin, dalteparin, natraparin, etc. 3. Vacuum blood collection tube anticoagulant sodium heparin: It is an additive in blood collection tube used for anticoagulation tube, which can prevent blood from coagulating in vitro quickly after blood collection for a certain period of time. This heparin is usually not injection-grade, unlike Heparin drugs, but their potency is relatively high. 4. Heparin, a raw material for cosmetics: It can be added to cosmetics such as nutrition creams, eye creams, acne-removing products, and hair restorers. It has many functions: increase the permeability of the skin's blood vessels; improve the role of local blood circulation; promote the supply of skin nutrients and Excretion of metabolic waste; plays a good role in skin care and maintenance. 2. Different origin of heparin sodium This is mainly the difference between domestic and imported heparin, especially for drugs, and the price difference is up to double. 3. Limited sources of heparin sodium Although many organs of pigs, cows and sheep can extract crude heparin, the most important thing is the small intestine extraction of pigs. Only 1300 can be used to extract 1 kg. Therefore, the price of pork and the plague of pigs will directly affect the price of heparin sodium. Cause an impact. In summary, when you purchase heparin sodium again, don’t think it is particularly outrageous because of the large price difference of heparin sodium. You should first ask for specific details, including types, places of origin, and market conditions. Desheng is a manufacturer specializing in the production of high-quality sodium heparin and lithium heparin. You can consult and visit the factory for related questions.

The new coronary pneumonia in 2020 caused fear, not only claimed the lives of many people, but also disrupted the pace of life. Due to an epidemic, China's GDP has plummeted, and the economy has directly returned to a decade ago. Even though the epidemic is relatively under control, experts cannot guarantee that it has been completely controlled, and it will even make a comeback. Nucleic acid testing is currently the main method of diagnosis and control of new coronary pneumonia. However, nucleic acid testing also encounters endless problems. For example, the test results are a large number of false negatives. For this problem, RNA sample transport media provides great help.   Virus transport media (inactivated and non-inactivated)   Before extracting the sample nucleic acid, the common sample transport media needs to put the sample in an environment above 56°C to inactivate the virus. This inactivation process undoubtedly protects the personnel in the inspection from virus exposure, but it also destroys the integrity of the viral nucleic acid, causing some samples to not be detected normally, which is one of the reasons for the high false negative rate.   High temperature heating will increase the degradation of RNA and reduce the amount of sample detection. Using RNA transport media can effectively inhibit the degradation of RNA. Regarding the preservation after the virus sample is collected, for example, after the pharyngeal swab is sampled, the sample is packaged and then put into the sampling tube. Not all sterile sampling tubes can be used to store viruses, at least one RNA sample transport media is required to save. For virus storage, non-inactivated virus transport medias are generally used.   The components of the non-inactivated virus transport media are: Hanks liquid foundation, gentamicin, fungal antibiotics, BSA (V), cryoprotectant, biological buffer and amino acids. The combination of multiple antibiotics has anti-bacterial and anti-fungal effects. Bovine serum albumin (BSA) as a protein stabilizer can form a protective film in the virus protein shell, making it difficult to decompose and ensure the integrity of the virus. The neutral environment constructed by Hanks buffer helps increase the survival time of the virus and the stability of infection. Its advantage is that it can effectively preserve the activity of the virus. It is convenient for the subsequent isolation and cultivation of the virus, but the premise is that it must be stored at a low temperature.   RNA is easily degraded, and RNase is simply the natural enemy of RNA extraction. RNase has a wide range of sources and can include various organisms in nature. Therefore, it is difficult to guarantee that RNase will not be mixed in the samples you collect. RNase also degrades RNA at room temperature, so we need to store samples at 4° (short-term) or -70° (medium-long term). If we want to store RNA virus for a long time, we need to use liquid nitrogen. In many cases, the extraction experiment requires rapid lysis of the sample after recovery, and even operation on ice can reduce the rate of RNA degradation. If there are few viral RNA samples collected in the original sample, it will become less after a period of RNase degradation. After the temperature is heated to 56°, the activity of the enzyme increases. At 92°, the enzyme will not be denatured, but the efficiency will be further improved. Then the degradation phenomenon will be more serious.   Is there any way to save the virus without being broken down by RNase? The answer is the guanidine salt RNA virus transport media, which is the virus inactivation transport media.   Guanidine salts generally include guanidine hydrochloride, guanidine nitrate, cyanoguanidine and the like, which can effectively denature proteins. RNase is also a protease that will be denatured and lose its original role. The virus shell is also made of protein, so the guanidine salt can also inactivate the virus. The 56° heating process can be omitted. The virus inactivation transport media can inactivate viruses and reduce the infectivity of virus samples, while eliminating the process of high temperature heating greatly improves the accuracy of nucleic acid detection. Since the epidemic, Desheng has been working hard to develop virus transport medias to facilitate nucleic acid detection. Desheng virus transport medias are inactivated and non-inactivated, and nasal and pharyngeal swabs are also available.