Wuhan Desheng Biochemical Technology Co., Ltd

Biological buffer solution is a kind of solution which can keep pH value relatively stable when adding a small amount of acid or base. It is usually composed of weak acid and its conjugated base or weak base and its conjugated acid buffer pair. Most cells can only move in a narrow pH range, so a buffer system is needed to resist the pH change in the metabolic process. Buffer is widely used in biochemical field. How to distinguish the quality of buffer solution? What characteristics should they have? Package drawing of biological buffer First of all, let's take a closer look at what a buffer is? Buffer is an aqueous solution containing conjugated acids or bases. The pH range of the buffer is determined by its pKa value. The pKa value is defined as the pH value when 50% of the molecules are acidic and 50% are basic. A conventional principle of buffer solution is that its pH value should be within the range of 1 pH value unit about pKa value, so as to ensure its good buffer capacity. In this way, it can be ensured that there are enough molecules in both acid and basic structure to neutralize them when H + or Oh - is added. In this way, the buffer can prevent the change of protein stability caused by pH change.   Good buffer must have the following characteristics: 1. Water solubility 2. Chemical stability 3. Good buffering capacity in the required pH range 4. It has good compatibility with analytical and experimental conditions 5. It has good compatibility with other solutes   Many substances can be used in biological buffers. The most commonly used buffer components usually have a near neutral pKa value and can be used around the physiological pH range. Table 1 lists the four most commonly used biological buffers, their respective pH ranges, and their advantages and disadvantages that may affect the protein purification process. To ensure adequate buffer capacity, the concentration of these buffers is usually 25mm.   The effect of buffer solution is as follows The function of buffer solution is to adjust the pH value of the solution within a limited range, so that the acidity of the solution to be measured meets the range specified by the analytical method. For example, phenol can react with 4-aminoantipyrine in alkaline medium and the presence of potassium ferricyanide to produce orange red antipyrine dye. In order to prevent the interference of aromatic amines, the pH value of 10 ± 0.2 is the most suitable. Therefore, it is necessary to add ammonia money chloride buffer solution into the solution to be tested, and adjust and control the pH value of the solution to be measured to 10.0 ± 0.2.   Where can I buy a good buffer? Desheng can provide high-quality buffer for customers. Desheng has been focusing on the R & D and production of biological buffer, blood collection additive and chemiluminescence reagent for 15 years, and can freely adjust the concentration of buffer required according to customer demand.   In practical work, some analysts do not understand the mechanism of buffer solution. When the buffer solution prepared and used is not in accordance with the specified value, in order to make the buffer solution meet the requirements, the strong acid and alkali such as hydrochloric acid or sodium hydroxide are used to adjust the buffer solution, thinking that this can make the buffer solution reach the required pH value as soon as possible. However, the results obtained are counterproductive Although the pH value of such a solution is adjusted correctly, its buffer system is destroyed and its function is lost. Generally, the buffer solution is a pair of conjugates composed of weak acid and its weak acid salt or weak base and its weak base salt.

Heparin is common in clinical blood test with sodium salt and lithium salt, which has unique application value. Heparin has low chelating force, little influence on water molecule movement, less interference on blood components, no influence on red blood cell volume and no hemolysis. Therefore, heparin is recommended as anticoagulant in a variety of tests based on whole blood or plasma.   It is suitable for erythrocyte fragility test, blood gas analysis, hematocrit test, hemorheology and emergency biochemical determination. In the detection of pH value, blood gas, electrolyte and calcium ion, heparin is the only anticoagulant that can be used, and heparin lithium has the least possibility of interference in the detection of non lithium ions, so it is recommended to use heparin lithium as anticoagulant. At present, heparin lithium is gradually replacing heparin sodium in blood test. Heparin lithium is a chemical substance and an important member of blood anticoagulant. The appearance is white to nearly white powder with CAS No. 9045-22-1. The titers were divided into 150u, 160u, 170u and 180u. Heparin anticoagulants commonly used include sodium, potassium, lithium and ammonium salts of heparin, among which heparin lithium is the first.   Application of heparin lithium anticoagulant 1. Biochemical test for patients after hemodialysis: the blood sample of patients after hemodialysis is a special sample faced by the laboratory departments of many hospitals, and many inspectors often feel helpless when facing such samples. This is because hemodialysis patients use anticoagulant drugs containing heparin, such as low-molecular-weight heparin calcium, etc. in the process of hemodialysis, because there is a certain amount of heparin anticoagulant drugs in the blood, it is very difficult to coagulate and separate the bleeding clear after blood extraction in the common tube or separation gel / coagulant tube.   It has been reported that the detection of blood K with heparin lithium anticoagulant plasma and serum is biased, which may be caused by the high rotation speed of blood sample during centrifugation, the red blood cells in the blood clot of fibrin silk mesh are crushed, hemolytic, and the K ions in the red blood cells are released to the serum. In addition, a small amount of red blood cells will inevitably be destroyed during the transportation and coagulation of blood samples, resulting in slightly higher blood K. It is also reported that there are significant differences in CK-MB, LDH, Glu between heparin lithium anticoagulant plasma and serum, which may be due to hemolysis or long storage time of blood glucose decomposition. On the contrary, heparin anticoagulant has the advantages of not affecting the cell volume and causing hemolysis easily. It does not need to be placed in a water bath and can be centrifuged directly. The blood K, Glu, LDH measured by heparin lithium anticoagulant plasma are more close to the real concentration of patients. Therefore, establishing the reference value system of plasma biochemical test as soon as possible is helpful for clinicians to make accurate judgment on patients' condition.   2. For routine biochemical tests: the results show that heparin lithium anticoagulant plasma can be used to replace serum in most routine biochemical test items, but the reference range of plasma should be established for Glu, K +, Na +, CI -, P3 -, and other items can be used to explain the results of plasma test with serum reference range; LP (a), PA, HBDH, LDH, CK, CKMB, IgM Plasma Lp (a) increased with the increase of heparin concentration.   Desheng has 15 years of rich experience in the development and production of blood anticoagulants. It is an old manufacturer of blood collection additives. The product has high purity of heparin lithium and heparin sodium, and the packaging can be made according to the needs of customers. Desheng biochemical insists on providing customers with high quality products and professional services.

Serum is an important sample for clinical biochemical detection. At present, the main way to obtain serum samples is to collect venous blood and centrifuge after blood coagulation. Under normal circumstances, blood samples in vitro need more than 60 minutes to complete coagulation, or even no coagulation, which is difficult to meet the needs of laboratory rapid detection. At this time, blood samples need to be processed to speed up the speed of blood coagulation. The commonly used method to promote blood coagulation is to add some coagulants, such as clay and cephalin, into the collected blood samples. When these coagulants are added into the blood appropriately, they can provide the active surface for coagulation factors to contact with foreign bodies and activate coagulation factors.   Several factors affecting the effect of coagulation promotion are as follows 1. Coagulation rate: blood coagulation mechanism is a process in which a series of coagulation factors are activated successively and finally form fibrin clots. Sometimes, there are filaments and lumps of fibrin in the vacuum blood collection vessel containing coagulant, which is caused by the lack of standardized use of coagulant promoting blood collection vessel.   In the preparation of vacuum blood collection vessel, the selection of coagulant with too fast coagulation speed will lead to the rapid contraction of fibrin, and the fragility of red blood cells will be broken, resulting in mild hemolysis. The proportion of blood clot is greater than that of serum, so the serum is under the upper blood clot, and the lower end of serum is still in contact with the upper end of blood cell. The cells can still use the nutrients in the serum to reduce the blood glucose measurement value, lactate dehydrogenase and serum potassium determination When using the gel accelerating tube, the specific gravity of the gel is higher than that of the blood clot. Therefore, the upper layer is the serum, the middle layer is the separation gel, and the lower layer is the blood clot. Therefore, the various components in the serum maintain physiological levels.   2. Coagulation temperature: the natural coagulation of blood is related to temperature. Blood can coagulate in a glass tube in a 37 ° water bath for 30 minutes. However, it should be pointed out that if the blood and coagulant are not fully mixed or the blood is not completely coagulated, it is easy to form fibrin gel like coagulation or fibrin filaments, whose specific gravity is smaller than the blood clot, so it remains in the serum layer and partially adheres to the separation gel. If the blood is directly used at this time, the blockage of the automatic analysis blood sampling needle can be caused.   3. Dosage of coagulant: the relative amount of coagulant needed to make blood reach the best coagulation effect. When the coagulant was used up on the next day, the coagulant was not prepared well on the next day. Fibrinogen in the blood gradually changes into insoluble fibrin under the action of coagulant. If the coagulation time is prolonged due to insufficient or ineffective coagulant dosage, centrifugation can lead to the precipitation of fibrin.   4. Whether the operation is standard or not: there are the following reasons for the precipitation of fibrin: the coagulant should be slightly reversed and mixed 4-5 times in order to make the coagulant evenly distributed in the blood, so that the center of the blood collection vessel and the surrounding blood coagulate at the same time. If the blood is not completely coagulated, that is, centrifugation can cause the precipitation of fibrin. Gel like and fragment like appeared in the upper part of serum and mixed with blood. Fibrin filaments are caused by the incomplete contraction of fibrin.   The coagulant should be sprayed quantitatively and dried under the condition of less than 45 ° C; if it is higher than 50 ℃, the coagulant effect may decrease. The coagulant prepared with distilled water or anhydrous ethanol should have standard quality management and be sprayed quantitatively. Only by using the coagulant tube containing neutralizing heparin to separate serum can high quality serum samples be separated correctly.   Desheng biochemical brand products for blood collection additives, has 15 years of R & D and production experience, coagulant, high efficiency coagulant powder, heparin sodium, heparin lithium, serum separation gel these products are our main products for so many years, high quality, stable performance, guaranteed after-sales service, welcome to exchange cooperation.

In the vast field of molecular biology, polymerase chain reaction (PCR), as a revolutionary technology, has greatly promoted the development of genetics, disease diagnosis, forensic identification and other fields. PCR technology achieves efficient amplification of trace DNA samples by replicating specific DNA fragments in vitro, greatly facilitating subsequent analysis and research. However, the success of PCR reactions depends not only on high-quality DNA templates, primer design, and polymerase activity, but also highly on the buffer environment in the reaction system. Among numerous biological buffering agents, MES buffer (2-morpholinoethanesulfonic acid) plays a crucial role in PCR kits due to its unique properties. This article will delve into the application of MES as a biological buffer in PCR kits, including its characteristics, mechanism of action, and optimization strategies. Basic characteristics of MES buffer MES, also known as 2-morpholinoethanesulfonic acid, is an important zwitterionic buffer with excellent buffering capacity and stability. In biological experiments, the pKa value of MES is close to the physiological pH range, making it an ideal choice for many biochemical processes. MES buffer not only stabilizes the pH value of the solution, but also reduces adverse effects on biological molecules such as cells and enzymes, thereby maintaining efficient buffering in complex biological reaction systems. In addition, the low ion strength of MES means that it has less interference with other components in the reaction system, which is beneficial for maintaining the sensitivity and specificity of PCR reactions. The Mechanism of MES in PCR Kit 1. Stable pH value: During the PCR reaction, as the DNA strand extends and the primer binds, a large amount of hydrogen ions (H+) and hydroxide ions (OH -) are generated, causing a change in the pH value of the reaction system. MES buffer maintains the pH stability of the reaction system by accepting or releasing hydrogen ions, ensuring that the activity of DNA polymerase and other enzymes is not affected, thereby ensuring the smooth progress of PCR reaction. 2. Protecting enzyme activity: DNA polymerase is a core enzyme in PCR reactions, and its activity is highly sensitive to conditions such as pH, salt concentration, and temperature. The low ionic strength and physiological pH range of MES buffer can reduce the risk of enzyme denaturation, protect the active conformation of enzyme molecules, and ensure their sustained and efficient catalysis of DNA strand extension in the PCR cycle. 3. Reduce non-specific amplification: Non specific amplification is a common problem in PCR reactions, which can lead to false positives in results or reduce the amplification efficiency of target DNA. MES buffer helps reduce non-specific binding between primers and template DNA by maintaining the stability of the reaction system, thereby reducing the risk of non-specific amplification.   Optimization Strategy of MES in PCR Kit 1. Concentration selection: The concentration of MES buffer has a significant impact on PCR reaction. Excessive concentration may cause the reaction system to become too stable, affecting the activity of DNA polymerase; However, low concentrations may not effectively maintain pH stability. Therefore, in PCR kits, the concentration of MES needs to be optimized based on specific experimental conditions and the characteristics of the target DNA. 2. pH adjustment: The pH range of MES buffer is crucial for the success of PCR reaction. Generally speaking, the optimal pH value for PCR reaction is between 7.0-8.5. By adjusting the pH value of MES buffer, the reaction system can be ensured to be in the optimal state, thereby improving the efficiency and specificity of PCR reaction. 3. Compatibility with other components: In PCR kits, MES buffer needs to be compatible with other components (such as DNA templates, primers, polymerases, dNTPs, etc.) to ensure the stability and efficiency of the reaction system. Therefore, when preparing PCR kits, it is necessary to conduct in-depth research on the interactions between MES buffer and other components to avoid potential interference and inhibitory effects. 4. Temperature stability: PCR reactions are usually carried out at high temperatures, which places high demands on the stability of MES buffer agents. High quality MES buffer should be able to maintain a stable pH value and buffering capacity at high temperatures to ensure the smooth progress of PCR reactions. Practical Application Case of MES in PCR Kit Many commercial PCR kits use MES as a buffer component. For example, in DNA/RNA extraction kits and PCR diagnostic kits, MES buffer not only stabilizes the pH value of the reaction system, but also improves extraction efficiency and amplification specificity. By optimizing parameters such as concentration and pH of MES, these kits can achieve faster, more accurate, and more sensitive PCR amplification results. Conclusion MES, as an excellent biological buffer, plays an irreplaceable role in PCR kits. By stabilizing the pH value of the reaction system, protecting enzyme activity, and reducing non-specific amplification, MES ensures the smooth progress and efficient amplification of PCR reactions. As an advantageous supplier of MES, Desheng can provide high-purity raw material powders with a complete range of types for selection and personalized customization. If you are interested, please feel free to contact us!