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Latest company new about 8 kinds of MOPS buffer uses and precautions you don't know
2021/04/09

8 kinds of MOPS buffer uses and precautions you don't know

MOPS is a zwitterionic biological buffer. It is a white powdery solid at room temperature, with high hydrophilicity and excellent water solubility (1000 g/L at 20°C). When MOPS is dissolved in water, the appearance of its aqueous solution is colorless. This is just its basic information, if you want to know more, then you have to look down. What is the recommended use of MOPS? 1. The operation that can separate RNA by agarose gel electrophoresis; 2. Used for protein purification in chromatography; 3. Measure absorption in ultraviolet/visible 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. In the control of medium pH value of 5, including cell culture medium for yeast, bacteria and mammalian cells; 7. It has been used as a buffer component of charcoal yeast extract culture medium; 8. It interacts with the peptide backbone of bovine serum albumin, resulting in a net stabilization of the protein.   What questions should you consider before choosing MOPS for your research? 1. When used for mammalian cell culture, the MOPS concentration should not be higher than 20mM 2. Although most studies have found that there is almost no complex between the mop and the metal, some studies have found that interference may occur due to the formation of metal complexes; 3. It can change the interaction of lipids; 4. MOPS can affect the thickness and barrier properties of the rat endothelial surface layer; 5. It interacts with DNA and forms a complex; 6. It can slightly affect the mRNA expression of bovine embryos produced in vitro; 7. It can be oxidized by H2O2, but due to its slow oxidation, it is not expected to have a significant impact on the biological system; 8. In the presence of glucose, autoclaving can partially degrade MOPS.
Latest company new about Chromogen substrate TOPS determination of free fatty acid steps
2021/04/09

Chromogen substrate TOPS determination of free fatty acid steps

The determination of free fatty acid (FFA) in serum is an important biochemical test index, and FFA is closely related to human health. Because serum components are complex and there are many types of FFA, the detection is affected by many factors, so the chromogen substrate TOPS is usually used to determine FFA. Chromogen substrate TOPS reagent Chromogen TOPS determination FFA steps: 1. In the container, first add the buffer solution weighed according to the formula ratio, and then add ATP, coenzyme A, 4-aminoantipyrine, ion activator (magnesium chloride), stabilizer (BSA), and preservative in sequence. After adding proper amount of water, add surfactant, adjust the pH to pH 6-9 with concentrated hydrochloric acid, add acyl-CoA synthase at last, then stir and filter, and add distilled water to the filtrate to obtain reagent A quantitatively. 2. Add buffer to the container, then add chromogen TOPS, water, surfactant in turn, adjust the pH to pH 6-9, finally add HRP and acetyl CoA oxidase, then stir and filter, and then add distilled water to the resulting filtrate to a quantitative amount Reagent B is obtained. 3. Fill the above reagents into vials and store them at 2-8°C. Take the reagent A and the sample and mix them in a certain ratio, incubate for a certain period of time, and read the absorbance value A1; add the reagent B and mix evenly, incubate for a certain period of time, and read the absorbance value A2. FFA concentration in the sample=standard solution concentration Χ(ΛΑ_/ΛΑ_#), ΛΑ_=Α2-A1.   Prepare buffer: In a clean glass container, first add HEPES buffer (Good's buffer, zwitterionic buffer, including HEPES, Tris, MES, MOPS, etc.) that has been weighed according to the formula ratio, add appropriate amount of water, and then add surfactant 5ml/ L TritonX-100, use concentrated hydrochloric acid to adjust the pH to pH 6-9, the amount is about 5ml/L, then stir and filter, and then add distilled water to the obtained filtrate to a quantitative amount.   The method of using TOPS as a chromogen substrate to detect serum or plasma FFA has high accuracy and small measurement error, and it is the most suitable color among the many Trinder's chromogens, which is low in acetyl CoA, high in stability, and large in molar absorption coefficient. original. In addition to TOPS, the chromogen substrates produced by Desheng include TOOS, MAOS, ADPS, etc., which are suitable for the detection of blood sugar and other biochemical indicators.
Latest company new about Tris (hydroxymethyl) aminomethane has other uses besides buffering
2021/04/09

Tris (hydroxymethyl) aminomethane has other uses besides buffering

As a common biological buffer, Tris is not only widely used as a solvent for nucleic acid and protein, but also one of the main components of protein electrophoresis buffer. In addition, Tris can also produce a variety of cosmetics, chemicals, pesticides, medicine, coating preparation and other products, and is an important intermediate for the preparation of surfactants, vulcanization accelerators, reducing agents and some drugs.   1. Used as medicine: if it is often used in acute metabolic and respiratory acidemia, Tris base is an amino acid buffer, which can absorb hydrogen ions and correct acidosis.   2. For synthesis: Tris is used to prepare surfactants, vulcanization accelerators and intermediates of some drugs. Because it has three equal hydroxyl groups, it can also be used as a good reducing agent. In the alkaline condition of sodium hydroxide, it can reduce chloroauric acid solution to prepare stable gold nanoparticles. This method is non-toxic and pollution-free, and belongs to green reduction method.   3. Tris as reducing agent: under alkaline condition, gold nanoparticles can be prepared by ultrasonic reduction of chloroauric acid solution without adding other stabilizers. The environmentally friendly and biocompatible gold nanoparticles were synthesized. Gold nanoparticles with different sizes can be prepared by adjusting the experimental conditions.   4. Neutralizer: the most common function of Tris in cosmetics is to adjust pH value (pH value). It can also be used as a neutralizer to neutralize Thickener (carbomer), so as to reduce the sticky feeling, improve the respiratory efficiency of skin cells, and prevent pore blockage. In addition, Tris can be used as an odor regulator in cosmetics containing amine salts to regulate the odor of amine produced by rubbing when applying cosmetics, so as to avoid the release of any residual or persistent odor.   5. Coating preparation: Tris mainly plays the following four roles in the coating preparation process: pH regulator, cross-linking accelerator, polyester coating raw material and phase change core material.   Desheng has 15 years of experience in developing and producing biological buffers, blood collection additives, color reagents and chemiluminescence reagents, and can provide high-quality Tris raw materials. In addition to Tris, HEPES, CAPS, MOPS and PIPES, our company is actively developing new fields, providing nucleic acid detection materials, virus preservation solution and gel free raw materials, Carbomer, and calls for detailed consultation.
Latest company new about The role of chemiluminescence analysis in environmental detection
2021/04/08

The role of chemiluminescence analysis in environmental detection

With the formation and continuous development of environmental science, a new environmental monitoring technology has emerged. Chemiluminescence analysis is a common analysis method, which is mainly used in modern testing technology in environmental monitoring. According to the intensity or total amount of radiation produced by chemical reaction, the corresponding component content can be determined by chemiluminescence analysis.   Chemiluminescence analysis is an independent analytical technology in atmospheric environmental monitoring, which can effectively analyze trace and trace amounts. In China, after years of in-depth research in chemiluminescence analysis. It is proved that this technology has become an important technology in many aspects, such as air pollutants research, atmospheric environment monitoring, etc.   Luminol is one of the earliest and most widely used chemiluminescence reagents. The chemiluminescence reaction of luminol needs to be carried out under alkaline conditions. For example, it can be oxidized by some oxidants, and the maximum emission wavelength of luminol is 425nm. Generally, the oxidant used is hydrogen peroxide. Luminol chemiluminescence system has been successfully used to determine the concentrations of SO2, Co, O3, HS and NOx in the air for a long time.   In addition, the chemiluminescence reaction between luminol and hydrogen peroxide is very slow in the absence of catalyst, otherwise it is very fast. The most commonly used catalysts are metal ions. In a large concentration range, the higher the concentration of metal ions, the stronger the luminous intensity. Therefore, the chemiluminescence analysis of some metal ions can be carried out. Using this reaction, the organic compounds containing metal ions can be analyzed, achieving high sensitivity.   Environmental monitoring involves many kinds of pollutants in the analysis gas, involving a wide range of aspects, so it needs high sensitivity, wide linear range, and the use of fast and simple detection method. Chemiluminescence analysis has its own unique advantages, which can well meet the above requirements and is widely used in atmospheric environmental monitoring. In order to be able to better adapt to atmospheric environmental monitoring, chemiluminescence analysis will have a good prospect in the following aspects.   The application research of chemiluminescence in environmental monitoring and analysis has been developing day by day. With the continuous development of chemiluminescence instruments with high degree of automation, sensitivity and selectivity, and the development and launch of commercial monitoring instruments, the application of chemiluminescence in environmental monitoring will be popularized and promoted rapidly.
Latest company new about Uncover the mystery of the new Trinder's reagent ADOS
2021/04/08

Uncover the mystery of the new Trinder's reagent ADOS

ADOS It is a kind of raw material for color development in the biochemical kit, CAS number: 82692-96-4, with high water solubility, is a stable aniline analog, the pH range of the color process and oxidation reaction is very wide, Suitable for diagnostic testing and biochemical tests. application 1. It has several advantages over conventional color-producing reagents in the colorimetric determination of hydrogen peroxide activity. 2. The new Trinder's reagent is stable enough, and can be used in both solution and test assembly line detection system; 3. In the presence of hydrogen peroxide and peroxidase, during the oxidative coupling reaction with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazole sulfone hydrazone (MBTH), very Stable purple or blue dye; 4. The molar absorbance of the dye coupled with MBTH is 1.5-2 times higher than that of the dye coupled with 4-AA; 5. The amount of substrate can be determined by the color development of the oxidative coupling reaction. Detection method 1. Prepare sample solutions for enzymatic oxidation reactions. The pH range of the buffer should be 5.5-9.5. 2. Use the same buffer to prepare a standard solution containing a known amount of substrate. 3. Add the appropriate unit of oxidase to the sample solution, and then add an equal volume of the detection solution. 4. Incubate the mixture at room temperature or 37°C for 30 minutes to 1 hour. 5. Prepare a standard curve and determine the concentration of the substrate in the sample solution. Precautions 1. This product needs to be sealed and stored in a dry and cool place, and it needs to be packaged in a dark brown bottle with a better protection against light; 2. ADOS is a white crystalline powder, if the color becomes darker, it may have grown bacteria or partially oxidized, so it cannot be used; 3. ADOS powder may adhere to the wall of the tube when it is dissolved. Use a centrifuge to centrifuge at low speed to reduce product loss; 4. The product has good solubility and can be directly dissolved in deionized water; double distilled water or ultrapure water can be used for higher experimental requirements.
Latest company new about The use of luminol chemiluminescence substrate liquid is enough to read this article
2021/04/08

The use of luminol chemiluminescence substrate liquid is enough to read this article

Recently, many customers have called to inquire about the instructions on the use of luminol chemiluminescence substrate solution. Although Desheng mainly sells luminol powder reagents, it has always been a case of customers’ problems. With the concept of morality-oriented" and "customer-oriented", the relevant product instructions are introduced here, and I hope it will be helpful to our customers.   【expected usage】 It is a luminescent substrate solution suitable for chemiluminescence experiments.   【Inspection principle】 The principle is to apply the basic principles of enzyme-linked immunology-the combination of the high specificity of the antigen-antibody reaction and the high sensitivity of enzyme catalysis, and the use of enzymes to catalyze the chemiluminescence reaction of the substrate to qualitatively or quantify specific substances in tissues or cells .   【Main components】 Substrate Luminescent Solution A (stored in the dark): Luminol, p-iodophenol, Tris-buffer, etc. Substrate luminescent solution B: hydrogen peroxide, Tris-buffer   [Storage conditions and validity period] Storage conditions: Store at 2 to 8°C, away from light. Validity period: 12 months.   【Instructions】 1. After adding the HRP enzyme marker for washing, prepare to add luminol luminescent substrate solution. 2. When using the substrate, add the chemiluminescence substrate solution A and the chemiluminescence substrate solution B in equal volumes. 3. According to the volume of the specific experimental system, add the corresponding amount of mixed substrate solution, and then place it in a dark place at room temperature for 5 minutes. 4. Detect and measure the result (luminescence value RLU).   【Analysis of test results】 1. The result of blank control without HRP-labeled antibody/antigen and negative control should be colorless. The positive control and HRP-labeled antibody/antigen emit blue light. 2. Detect the luminescence value of unknown concentration by drawing a standard curve, and find the concentration of the target substance to be measured corresponding to the standard curve.   【Precautions】 1. Laboratory supplies should be specific to avoid cross-contamination. 2. Avoid direct exposure to strong light during the experiment. 3. For your safety and health, please wear lab coats and disposable gloves for operation.   Luminol is a very important reagent in the chemiluminescence substrate solution. It is used in the color development stage of the chemiluminescence experiment. It can react with the sample and emit blue light. Luminol reagent is not only used for biochemical detection, carboxylic acid and ammonia compound labeling, metal ion detection, but also for criminal investigation blood stain detection, with very high sensitivity. Luminol produced by Desheng is a light yellow powder, which needs to be dissolved in lye when used. It is prepared now and stored away from light.
Latest company new about Advantages and disadvantages of Tris base
2021/04/08

Advantages and disadvantages of Tris base

Tris is known in Chinese as trimethylol aminomethane, aminobutanol, bradykinine, 2-amino-2 - (hydroxymethyl) - 1,3-propanediol. It is a white crystal or powder. It is soluble in ethanol and water, slightly soluble in ethyl acetate and benzene, insoluble in ether and carbon tetrachloride, corrosive to copper and aluminum, and irritating chemicals.   Tris 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. Generally used to stabilize the reaction system, pH has a strong buffer capacity between 7.5-9.0.   Advantages of Tris buffer: 1. Because Tris base is more basic, we can only use this kind of buffer system to prepare the buffer with a wide range of pH from acidic to alkaline; 2. It has little interference to biochemical process and does not precipitate with calcium, magnesium and heavy metal ions.   Disadvantages of Tris buffer: 1. The pH value of the buffer is greatly affected by the concentration of the solution. When the buffer is diluted ten times, the pH value changes more than 0.1; 2. The temperature effect is large, and the temperature change has a great influence on the pH value of the buffer. The pH value of the buffer at 4 ℃ is 8.4, and the pH value at 37 ℃ is 7.4. The tris HCl buffer prepared at room temperature can not be used for 0-4; 3. It is easy to absorb CO2 in the air, so the prepared buffer should be tightly sealed; 4. This buffer has a certain interference effect on some pH electrodes, so the electrode compatible with tris solution should be used.   Application of Tris buffer: In the electrophoretic buffer, glycine buffer system is used to stabilize pH value; Tris-HCL buffer system is used to stabilize pH value in gel; it is widely used as solvent for nucleic acid and protein; the low ionic strength characteristic of Tris buffer can also be applied to the formation of intermediate fiber of nematode; EDTA buffer is added into Tris hydrochloric acid buffer to form "TE buffer", which can be used for stabilization and storage of DNA. The "Tae buffer" can be obtained by changing the acid solution of pH value into acetic acid, and the "tbe buffer" can be obtained by changing it into boric acid. These two solutions were used for electrophoresis.
Latest company new about How to remove dandruff and relieve itching in cosmetics with gambol
2021/04/07

How to remove dandruff and relieve itching in cosmetics with gambol

Climbazole, CAS No: 38083-17-9, EC No: 253-775-4, English Name: clibazole, molecular formula: c15h17cln2o2, relative molecular weight: 292.76, is the most widely used second-generation anti dandruff agent developed by Bayer in 1977. It has broad-spectrum bactericidal properties. It is mainly used in anti itching and anti dandruff conditioning shampoo and hair care shampoo. It can also be used in antibacterial soap, shower gel, medicated toothpaste, mouthwash, etc.   The production of dandruff is caused by external and internal factors. The external factors are mainly affected by microorganisms (bacteria and molds). The effects of light, lipid peroxide and other stimulants produced by oxidation in the air, and various stimulants caused by environmental pollution accelerate the keratinization process of epidermal cells. The internal factors are mainly due to the body's nutritional status, excessive sebum secretion hormone or slightly nervous and other factors causing excessive dandruff. Climbazole has a unique antibacterial effect, especially on the oval dandruff, Candida albicans and other fungi. Climbazole powder Climbazole can block the production of dandruff through sterilization, inhibition of lipase, antioxidation and separation of oxides, So as to achieve the effect of effective anti dandruff, anti itching and hair care. It is different from simply eliminating dandruff temporarily by sterilization and degreasing. In a longer period of time, it can thoroughly protect the scalp and make the hair grow healthily. Therefore, it is welcomed by consumers. At present, active gambosol is widely used in Europe and the United States, in a variety of shampoo and conditioner, because of its inhibitory effect on Candida albicans, it is also used in medicated toothpaste, and has curative effect on gingivitis and oral endometritis.   Dandruff is like dirty things on clothes. It's not a serious disease, but it can make you embarrassed and irritable, and sometimes it can affect external communication. For dandruff, it is unnecessary to go to the hospital (unless there are symptoms such as redness, swelling or severe itching of the scalp). Most people choose anti dandruff hair products to solve the problem. In the hair products, Climbazole is the mainstream in today's market, which can also be called clomiprazole. Although Climbazole alone has limited anti dandruff ability, it can often achieve the best effect with ZPT, and is deeply consumed by the majority of consumers I love it.
Latest company new about Xanthine oxidase level can be used to detect physical condition
2021/04/07

Xanthine oxidase level can be used to detect physical condition

Xanthine oxidase (XOD) is one of the important enzymes in nucleic acid metabolism, which can catalyze hypoxanthine to produce uric acid and hydrogen peroxide. It is a flavinase containing molybdenum, non heme iron, inorganic sulfide and fad. It is a form of xanthine oxidoreductase. Xanthine oxidoreductase is an enzyme producing reactive oxygen species. It is a kind of enzyme with low specificity, which can not only catalyze hypoxanthine to xanthine and then to uric acid, but also directly catalyze xanthine to uric acid.   The enzyme mainly exists in the liver, spleen and milk of mammals, but can not be detected in the serum of normal people. XOD is released into serum earlier than ALT in the process of hepatocyte injury. Therefore, the increase of XOD activity in serum can sensitively reflect acute liver injury.   XOD activity usually increased significantly in the early stage of jaundice, about 30-50 times of the upper limit of normal, and then decreased to the normal level as jaundice subsided. The positive rate of XOD was higher than that of ALT (90.4%) and AST (81.8%). In other liver diseases such as liver cirrhosis, amebic liver disease and hepatic echinococcosis, the serum XOD activity did not increase or slightly increased. Therefore, XOD can be regarded as a sensitive and specific index for the diagnosis of acute liver injury.   XOD is also helpful to distinguish the types of jaundice. Clinical observation showed that the serum XOD in patients with hepatocellular jaundice increased significantly, while the activity of XOD in patients with obstructive jaundice and hemolytic jaundice was almost normal or only slightly increased, generally less than 1 mu / L. The common diseases with high XOD are as follows: 1. Acute hepatitis is significantly higher than chronic hepatitis. 2. Infectious mononucleosis often increases. The activation of xanthine oxidase (XOD) can cause uric acid metabolism disorder and aggravate glucose metabolism disorder. When XOD is activated, it can also produce superoxide radicals and hydrogen peroxide, leading to oxidative stress.   Xanthine oxidase (XOD) uses molecular oxygen as electron acceptor to catalyze the oxidation of purine, pterin, aldehydes and other heterocyclic compounds, and produce reactive oxygen species (ROS) such as hydrogen peroxide and superoxide radicals. Reactive oxygen species can induce oxidative stress in cells.   Pre receptor and post receptor defects are the main pathogenesis of insulin resistance. The former is mainly manifested by the abnormal binding of insulin to target tissue receptors, including the relative deficiency of insulin and its receptors, the structural changes of insulin and its receptors, etc.; the latter is mainly manifested by the dysfunction of insulin signaling pathway, etc.   Under oxidative stress, it interferes with the signal transduction of insulin binding to receptor mainly by stimulating the inflammatory signal transduction pathway and c-Jun N-terminal kinase pathway. The main reactive oxygen species produced by xanthine oxidase activation is O2, which can inhibit the functional expression of insulin receptor.   The sensitivity of insulin receptor and the integrity of its structure and function are shown by the consumption of glucose. When the number or structure and function of insulin receptors change, the sensitivity of insulin receptors will change accordingly.   In recent years, the incidence of gout and diabetes is increasing year by year. With xanthine oxidase (XO) and α - glucosidase as the main enzyme targets of hyperuricemia and hyperglycemia, exploring the inhibitory effect and mechanism of natural plant ingredients with low toxicity and little side effect on XO and α - glucosidase has gradually become a research hotspot. XO inhibitors can reduce the content of uric acid in the body by inhibiting the activity of xanthine oxidase, which is widely used in clinical treatment.   Therefore, some xanthine oxidase inhibitors can effectively reduce the level of uric acid. However, patients with hyperuricemia do not fully develop gout. Therefore, the development of gout in patients with hyperuricemia can be predicted by regular detection of xanthine oxidase, uric acid and erythrocyte sedimentation rate.
Latest company new about Optimization of TOPS Method for Determination of Free Fatty Acids
2021/04/02

Optimization of TOPS Method for Determination of Free Fatty Acids

The determination of free fatty acids in serum or plasma usually adopts Trinder chromogen enzyme photometric method. However, due to the characteristics of this test, the detection of fatty acids is affected by many factors, and the detection method needs to be optimized and improved to improve the accuracy of the detection.   Trinder chromogen detection FFA principle: The detection method has three reaction steps: free fatty acids (FFA or NEFA) react with excess CoA to generate acyl-CoA under the action of acetyl-CoA synthase (ACS), and react with oxygen under the action of acetyl-CoA oxidase (ACO). The reaction generates 2,3-trans-enoyl CoA and hydrogen peroxide, and the Trinder reaction is used to detect hydrogen peroxide, and the content of FFA can be obtained. TOPS is recommended for FFA determination of chromogen Problems in FFA determination and optimization methods: 1. Excessive Coenzyme A in the reaction will interfere with the reaction of hydrogen peroxide and Trinder chromogen, making the whole test result low. N-ethylmaleimide (NEM) can be used to remove excess Coenzyme A. The stability of NEM is very affected. Limited, only one week. 2. The acetyl CoA synthetase and acetyl CoA oxidase used have different substrate specificities for different free fatty acids, causing differences in the determination results. Different enzyme sources have different substrate specificities for free fatty acids with different C chain lengths. That is, the response capacity is different. There are 6 kinds of FFA in human serum, and only enzymes with high specificity to them can make no difference in the measurement results.   3. Due to the influence of CoA on the reaction, the linear range of the data results is narrow. The color of FFA measured on the market is MEHA, TBHB, TOOS, etc., but it is greatly interfered by CoA, and it must be excessive, so interference is required. Less chromogen. SCEP is not interfered by Coenzyme A but is unstable. ADOS and TOPS are less interfered by CoA, and TOPS has a higher molar absorption coefficient, so it is a better chromogen substrate.   4. Add sulfhydryl complex DTNB and MIT to reduce the amount of NEM. The sulfhydryl group of DTNM can react with the sulfhydryl group of CoA to remove the interference to chromogen. A small amount of MIT can remove the sulfhydryl group of CoA and also acts as a preservative. Based on the use of TOPS chromogen, the interference of CoA can be completely eliminated, and the stability is greatly improved.   If you have higher requirements for FFA determination results, you can choose a better quality kit based on the above points. Desheng produces the raw materials for the FFA and other index determination kits. If TOPS is used to determine FFA directly, due to the poor stability of the solution, it is recommended to prepare a working solution for immediate use before use.
Latest company new about Application of 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES) in rabies virus detection
2021/04/01

Application of 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES) in rabies virus detection

4-Hydroxyethylpiperazine ethanesulfonic acid, English abbreviation HEPES, CAS number: 7365-45-9, color is white crystalline powder, PH value range is 6.8-8.2, its most common application is as a biological buffer adjustment PH value and its application in skin care products are also loved by major manufacturers. Its application in rabies virus detection is often unknown. Today, the editor of Desheng will popularize relevant knowledge for everyone.   Rabies virus generally does not produce cytopathic (CPE) when it reproduces in infected cells, and it is not easy to form plaques under conventional culture conditions. Although many scholars at home and abroad have established rabies virus erosion on chicken embryo cells and BHK-21 cells. Spot methods, but these methods require strict experimental conditions, or the operations are complicated and difficult to master, which affects their popularization and use. After the researchers found that 4-hydroxyethylpiperazine ethanesulfonic acid HEPES can enhance the pathogenic effect of rabies virus on infected cells, they used this characteristic of HEPES to establish a simple and rapid HEPES plaque method for rabies virus. The effect of HEPES on the formation of rabies virus plaque After the infected cells were cultured at 37°C for 3 to 5 days, the infected cells treated with HEPES developed obvious cytopathic changes at the bottom of the covering. After staining with crystal violet, clear plaque formation was seen, while the infected cell group not treated with HEPES showed no signs of plaque formation. There is no cytopathic effect, and no plaque formation. It can be seen that HEPES can obviously promote the formation of rabies virus plaque on BHK cells.   Observation on the sensitivity of HEPES plaque method The HEPES plaque method can be used for the titer of virus infection. Experiments show that there is an obvious titer relationship between the number of plaques formed after virus infection and virus dilution. The infective titers of the same rabies virus CTN-BHK strain were measured by the HEPES plaque method and the mouse method. The results showed that the number of plaques obtained by the HEPES plaque method for 4 consecutive determinations ranged from 1.0×10° to 4.0× 10*PFU/m1. The infection titer obtained by the mouse method for 4 consecutive determinations is 6.0~6.8log or 1.0×10°~6.3×10/ml. This shows that the rapid HEPES plaque method has the same sensitivity as the mouse method. Advantages of HEPES plaque method Using rabies virus CTN-181 strain and CTN-BNK strain to study the infection titer titration method, the results show that HEPES can induce and enhance the pathogenic effect of the canine virus on the infected cells. When the virus infects the cells, they are cultured at 37°C for 3~5 Just add 50~00mmol/L HEPES on the cover of methylcellulose semi-solid medium on the first day, stain with crystal violet solution after 24 hours, and calculate the number of plaques by naked eyes after drying at room temperature. Compared with the insect spot method reported in the previous literature, this plaque method has the advantages of fast, simple, economical, sensitive and easy to master.   The HEPES produced by Desheng is reagent grade with a purity greater than 99%. Our products perform well. There are many cooperative manufacturers and can provide samples for free trial. Desheng will continue to provide customers with high-quality products as always. If you have any questions or needs, you can go to the official website to consult customer service staff  
Latest company new about Is the abnormal PCR amplification curve caused by the virus transport media ?
2021/03/30

Is the abnormal PCR amplification curve caused by the virus transport media ?

In the nucleic acid detection of the new coronavirus, the very key technology is the real-time fluorescent quantitative PCR experiment of nucleic acid, which is the core technology of the new coronavirus detection. So what effect does the virus transport media used for virus sampling joints have on the PCR amplification of nucleic acids? This article makes a brief discussion. Does the virus transport media affect nucleic acid PCR amplification? Judging the result from the PCR amplification curve: The fluorescent quantitative PCR instrument in the new crown detection has become a routine equipment for molecular biology research. The rapid development of this detection method and the urgency of the detection task have also put forward higher requirements for the detection personnel, requiring them to be proficient in judging the results of the data. For the judgment of the result of fluorescence quantitative PCR, the most intuitive judgment is to see whether the amplification curve is normal. In normal experiments, you will encounter problems with abnormal amplification curves, such as discounted amplification curves, poor repeatability between multiple wells, and uplifted amplification curves of negative samples.   Reasons for abnormal PCR amplification curve: 1. Confirm whether the software settings are correct. Check the kit instructions to check whether the time, temperature, cycle number, fluorescence collection, etc. are set correctly, and whether the selected reagent contains ROX as a reference fluorescent dye. Some results show that the amplification curve of the multi-component graph is not uplifted, which is obviously a negative sample, but the amplification graph curve is uplifted, so that it crosses the threshold line, and instead has a CT value. This is because the software makes a mistake in the automatic deduction of the baseline. The method of manually adjusting the baseline can be normal by redefining the baseline.   2. Make sure that the consumables and instrument accessories are used correctly. Consumables are more important for real-time PCR. Many abnormal amplification curves are caused by improper use of consumables.   3. To determine whether the reagents used are normal, first determine whether the reagents are effective, including checking whether the reagents are within the validity period, whether they are repeatedly frozen and thawed many times, and whether the transportation conditions are normal. If all of the above are normal, then you have to consider whether there is any negligence in the operation details.   From the above points, it can be seen that the virus transport media will not directly affect the amplification curve, it will only affect the virus samples, but this can be done through a control experiment with positive samples to determine whether the virus preservation solution has an impact on the virus samples. . There are two types of Desheng virus transport media, both the inactivated type and the activated type are suitable for nucleic acid PCR experiments.
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