China Wuhan Desheng Biochemical Technology Co., Ltd Company News

The EDTA anticoagulant blood routine test is the most basic test for blood testing, but whether it is better to use venous blood or peripheral blood for the test, there are different opinions in the industry. Blood routine involves the detection of multiple indicators, and it is necessary to compare the data of each indicator measured by two blood sampling methods.   The popularity and application of blood analyzers have greatly improved the level and efficiency of blood testing, laboratory science continues to develop, and the test results are more accurate. After comparing the data reproducibility and corresponding data of the two blood samples, it is found that the data of venous blood collection has good reproducibility, while the reproducibility of peripheral blood collection is relatively poor, and the data obtained by the two methods are not the same. https://www.vacutaineradditives.com/ Repeatability test results: There is no significant difference in the repeatability of the white blood cell (WBC), red blood cell (RBC), and hemoglobin (HGB) test results of venous blood sampling (P>0.05), while the difference in the repeatability of peripheral blood sampling is significant (P

In terms of detection, the higher the sensitivity, the better. The higher the purity of the reagent, the better the detection effect will be? The more expensive the reagent, the better the effect? Actually not. For diagnostic reagents, choosing the right reagent is the most important. In vitro diagnostic reagents   Does the higher the sensitivity of the reagent mean the best effect? Not entirely, usually the higher the sensitivity means that the analyte with a very small content can also be detected, but the detection index content in the sample to be tested is high, and there is no need to require high sensitivity of the reagent; if the composition of the sample to be tested is complex , Reagents with high sensitivity may also detect some interfering substances, resulting in inaccurate final data. Therefore, in biochemical detection, in order to eliminate interference, MAOS will be used as the chromogen substrate; for the low content analyte, TOOS with high sensitivity is used as the chromogen.   Is the purity of the reagent the better? No. Generally speaking, when purchasing diagnostic reagents, you usually pay attention to the purity data on the test report. The higher the purity, the better the quality. But for a specific experiment, the higher the purity, the better. Such as the simplest reagents, deionized water and ultrapure water. Some biochemical experiments can use deionized water. If ultrapure water is used, it means that all the reagents involved use ultrapure water, which increases the cost and the experiment operation becomes cumbersome.   As long as the reagent purity and impurity ion content can meet the needs of the experiment, the experiment can be carried out normally. It is not necessary to use high-purity reagent grade Tris for industrial synthesis of Tris, and injection grade heparin is not necessary for heparin used for anticoagulation. The purification cost of some reagents is relatively high, and the performance of some reagents can be improved by adding a small amount of other substances.   In vitro diagnostic reagents are used for scientific experiments in biochemical testing. It is a very rigorous work. The applied reagents need to be paid attention to, otherwise the test results will lose the significance of testing if they are inaccurate. Therefore, in the selection of reagents, it is necessary to choose the most suitable one to achieve the best results.

In a recent murder case in Hangzhou, the police used lumino technology to repeatedly wash blood stains to reveal the original shape, even if it was washed with strong acid, it would leave corresponding traces. DNA technology finds tissue DNA particles and blood traces, and other technologies find body tissues with victims’ DNA in pipes and septic tanks. It can be seen that no bloodstain can escape Rumilo's detection.     The luminol reaction is a classic chemiluminescence reaction. It is a yellow crystal or beige powder at room temperature, which is a relatively stable chemical reagent. In forensic medicine, the luminol reaction is also called the aminophthaloyl-hydrazine reaction. It is a chemical reaction that cannot be observed with the naked eye when detected at the crime scene. It can show a very small amount of blood stains (occult blood reaction), even after scrubbing. , Or bloodstains long ago can also be detected by luminol. Biologically, luminol is used to detect the presence of copper, iron and cyanide in cells.   The initial application of luminol reagent was to detect proteins. In western blotting, an enzyme-linked antibody is often used to bind to the protein to be detected, and the combination of luminol chemiluminescence reagent and enzyme (peroxidase) can make local luminescence and reduce the protein The position is displayed.   In addition, luminol derivatives such as isoluminol (ABEI) are labeled on carboxylic acid and ammonia compounds, and then separated by high performance liquid chromatography (HPLC) or liquid chromatography (LC), and then under alkaline conditions It reacts with hydrogen peroxide-potassium ferricyanide to perform chemiluminescence detection, such as labeling the newly synthesized chemiluminescence reagent isoluminol isothiocyanate to yeast RNA, separating it by centrifugation and dialysis, and then performing chemiluminescence detection.   But we should still pay attention to some issues that need to be paid attention to when using luminol and several things that need to be paid attention to when investigating:   1. Luminol fluoresces in the presence of iron, iron-containing alloys, horseradish or certain bleaching agents. Therefore, if the crime scene is thoroughly treated with bleach, the fluorescence from luminol will strongly mask any blood stains.   2. Luminol may interfere with other tests, but luminol does not interfere with DNA extraction.   3. The use of luminol needs to be in a dark environment, so that it is easier to make more accurate judgments with the naked eye.   4. Luminol has a limited amount of time to glow, so you must hurry up to take photos and record.   5. Luminescence lasts for about 30 seconds, which can be observed through long-exposure photos, and the surrounding environment should not be too bright.   In addition to luminol, the chemiluminescence reagents developed by Desheng also include acridine esters and other series. The effect is stable and the quality is guaranteed.

The new crown is an acute respiratory infectious RNA virus. It is spherical in shape, with crowned spikes on the surface, ribonucleic acid strands (RNA) inside, and shells composed of multiple proteins on the outside.   Early diagnosis of infected persons is an important prerequisite for controlling the spread of the epidemic and for active treatment. At present, two technologies are mainly used to diagnose whether they are infected by the new coronavirus, one is nucleic acid detection technology, and the other is antibody detection technology.   Nucleic acid testing is a direct detection of viruses, requiring respiratory samples, including pharynx, nasopharynx secretions, sputum, bronchus, lavage fluid, lung biopsy, etc. The collection process is very complicated. The storage conditions of nucleic acid samples are harsh, RNA is easy to lyse, and can only be stored for 24 hours at 4°C. It uses the unique gene sequence of the virus as the detection target. Through PCR amplification, the target DNA sequence we choose increases exponentially. Each amplified DNA sequence can be combined with a pre-added fluorescent labeled probe. Combined to produce a fluorescent signal. The more target genes that are amplified, the stronger the accumulated fluorescent signal. In samples without virus, since there is no target gene amplification, no increase in fluorescence signal can be detected.   The antibody test is an indirect test, which can also be said to be a blood test. It can be collected by peripheral blood or venous blood. The sample collection method is more convenient and safer, and the sample can be stored for 72 hours. It is not against the virus itself, but the specific antibody produced by the immune response after the human body is infected with the virus. The human body gradually produces antibodies about a week after being infected with the virus and then rapidly rises. Generally, the human body first produces an antibody called IgM, which does not last long; then a large number of IgG antibodies appear, which may last for several months. several years.   IgM and IgG antibodies can be used for the auxiliary diagnosis of the new coronavirus, which is complementary to nucleic acid detection, reduces the missed detection of patients, and can assist in monitoring the progress of the patient's disease. It should be noted that in the early stage of the disease, it may not be detected due to less antibody production, which is the "window period." However, due to differences in pathogenicity and immune function of the organism, there are individual differences in the appearance time and expression level of specific antibodies in different patients.   The nucleic acid detection raw material Virus Transport Media developed and produced by Desheng has high detection sensitivity and is favored by customers. It can also provide the raw material luminol and acridinium esters for antibody detection developed and produced by itself.

Recently, Jiujiang Jiangzhou, Nanchang Xinjian and other places have successively issued calls for the reverse flood resistance of young and middle-aged people. Due to the continuous heavy rains, many places in the middle and lower reaches of the Yangtze River are also suffering from floods. Therefore, companies or laboratories related to biochemical reagents have stored a large amount of biochemical reagents. , Unlike some popular commodities, in addition to daily waterproof and electricity proof, it also needs some special attention. Generally speaking, except for areas with severe flooding, most companies will prepare some emergency plans, but there will still be some omissions in details. Doing good details can also avoid the loss of many biochemical reagents and further strengthen safety precautions. . Due to continuous heavy rains and even floods, the air humidity is very high, which means that there is a lot of water in the air, and the clothes that are dried are even wet, let alone some biochemical reagents. The reagents that usually require special attention are as follows: EDTA potassium salt, sodium citrate and other hygroscopic salts Salts such as  EDTA K2, disodium EDTA, and sodium citrate are very easy to absorb moisture. These salts usually absorb water and easily form crystal hydrates containing crystal water. As long as the sealing is not good, they will quickly absorb water. . In the cabinet containing these reagents, you can put some desiccants, such as anhydrous calcium chloride (itself can easily absorb moisture in the air to form crystalline hydrates). Carbomer and other gels Carbomer type gels, although not miscible with water, are very easy to absorb water and swell to form a gel. This is also the carbomer can be widely used in gels. After it absorbs water, the molecules are fully expanded and the volume will increase a lot This in turn may cause the bag or cardboard barrel containing carbomer to be broken, further increasing moisture absorption. A variety of biochemical reagents High-nutrient reagents such as enzyme preparations and protein preparations Enzymes and protein are nutrient-rich substances, which are very conducive to the growth of microorganisms. The high temperature and high humidity environment in summer is easy to breed bacteria and fungi. This type of reagents are usually expensive, so you must ensure that the storage environment is dry, ventilated, and dehumidified. Peroxide, sulfuric acid and other reagents This type is relatively dangerous in normal times, and storage conditions need to be strictly controlled. For example, peroxide initiators and concentrated sulfuric acid may cause a lot of heat or even explosion risk even if they do not directly contact water but absorb moisture in the air. Protect against moisture. Although only a few reagents will absorb moisture and cause violent reactions to cause danger, many reagents will affect their use or rapidly grow bacteria and deteriorate. These are no small losses. Finally, Desheng wishes everyone an early escape from the influence of the flood and return to normal work.

DAOS, one of the new Trinder's reagents, the full Chinese name is N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline sodium salt, commonly used in uric acid and renal function detection The detection kit has the advantages of good water solubility, high sensitivity, and strong stability. It is a white or light blue powder with CAS number 82692-97-5. This product is sensitive to light and humidity. Features: As a member of the new Trinder's reagent, DAOS has high water solubility compared with other chromogenic substrates. It is a stable aniline analogue. The pH range of the chromogenic process and oxidation reaction is wide, and it is widely used Diagnostic testing and biochemical tests. It has several advantages over conventional color-producing reagents in the colorimetric determination of hydrogen peroxide activity. The new Trinder’s reagent is stable enough to be used both in solution and in test line detection systems.   Preparation of DAOS detection solution:   1. Dissolve 23 mg DAOS in 10 ml PBS buffer to prepare a 6.6 mM DAOS solution. (The specific solubility can be adjusted as needed)   2. Dissolve 14 mg 4-aminoantipyrine (4-AA) with 10 ml PBS buffer to prepare a 6.6 mM 4-AA solution.   3. Prepare 2 U/ml horseradish peroxidase solution with PBS.   4. Mix equal volumes of each solution to prepare the test solution. Store the detection solution in the dark at 4°C.   Detection steps:   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. Determine the O.D. value at 593 nm.   6. Prepare a standard curve and determine the concentration of the substrate in the sample solution.   Detection principle: In the presence of hydrogen peroxide and peroxidase, the new Trinder's reagent is oxidatively coupled with 4-aminoantipyrine (4-AA) or 3-methylbenzothiazole sulfone hydrazone (MBTH) During the process, a very stable purple or blue dye is formed. The molar absorbance of the dye coupled with MBTH is 1.5-2 times higher than that of the dye coupled with 4-AA. The substrate is enzymatically oxidized by its oxidase to produce hydrogen peroxide, and the concentration of hydrogen peroxide corresponds to the concentration of the substrate. The amount of the substrate can be determined by the color development of the oxidative coupling reaction.   Precautions:   1. Sub-packaging: When taking a small amount of mg DAOS, the product needs to be sub-packed into the quantity needed each time to reduce the number of bottle openings and prevent the product from absorbing moisture.   2. Use: When using the product, take out the product from the freezer half an hour in advance and place it at room temperature. If there is any remaining after use, store the remaining DAOS in a sealed and light-proof container to avoid quality problems such as color or property changes. .   3. Preservation: Place DAOS in a 0-5 degree freezer, and record the time and batch number.   4. Transportation: Put the packed product with ice in the foam box and wrap the product with foam glue. Take care to avoid the water from the ice cubes to wet the product (we put two more if the temperature is high, and the temperature can be changed in winter. To decide)   Desheng is an established company focusing on the production and sales of in vitro diagnostic reagents for 19 years. Years of production experience has made our products have considerable advantages in quality. The reputation in the industry is also the result of the joint efforts of all members of the company. I cherish the hard-won results, and will serve every friend who chooses our products wholeheartedly.

Recently, the news of Urumqi’s closure of the city was swept away, and Urumqi, which had 40 million people, was ordered to blockade again. Some time ago, an epidemic was diagnosed in Beijing, and the epidemic was controlled within a short period of time. According to news, Beijing has seen 0 new additions in 11 days, and the control capability is very good. According to news at noon on the 17th, the official website of Tianshan in Xinjiang announced that the number of confirmed cases in Urumqi has increased again. According to the latest report of the Health Commission of the Autonomous Region, from 0:00 on July 16 to 12:00 on the 17th, Xinjiang (including the Corps) added 5 newly diagnosed cases and 8 asymptomatic infections, all in Urumqi. As of 12:00 on the 17th, Xinjiang (including the Corps) had 6 confirmed cases and 11 asymptomatic infections, all in Urumqi. There are currently 135 people under medical observation. In view of the continuous phenomenon of the new coronavirus, will the virus exist for a long time? Next, Desheng will answer for you.   The core material of nucleic acid detection-Virus Transport Media   Question: There are some asymptomatic infections around us. Some cases have an incubation period of more than 14 days. Some people have been retested after being discharged and found positive. In addition, some people have a negative throat swab test, but there are still in the stool Keep the virus. How should we interpret a situation like this now? Answer: We now use a throat swab test (negative) as a standard, but some patients still have virus fragments detected in the feces, not live viruses have been detected. These are two different things. In addition, there are a small number of patients who have been re-examined after being discharged from the hospital and the calculated fragments are found to be positive. This is not surprising to me because they need to be isolated for two weeks after being discharged from the hospital, and the re-examination will continue after the end.   Q: Is this a special case? Answer: A few, can not be said to be a case. Our current discharge standards: throat swabs are negative twice, there are no symptoms, the body temperature is normal, and the CT is normal, then you can be discharged from the hospital and be isolated for another two weeks. If anal swabs are required to be normal, then our patients will have a backlog and the bed will not be able to turn over! Therefore, we still need to observe closely and implement a hierarchical management of all patients.   Question: On July 20, Beijing lowered its emergency warning and adjusted the second-level response to the third-level response. Do you think this notice is reasonable? What is the basis for Beijing to lower the epidemic warning? Answer: I think it is appropriate. On the morning of the 18th, the last three high-risk patients recovered and were discharged, and Beijing high-risk patients were cleared. Beijing has not reported newly confirmed local cases for 13 consecutive days, which is a prerequisite. The other is that the masses' awareness of prevention and control has been greatly strengthened. Therefore, it is not appropriate to adopt a secondary response. It is more appropriate to adopt a hierarchical, zoning and classification method for epidemic prevention, which is beneficial to the development of production.   Q: Is it possible that the new coronavirus will exist for a long time like the flu? Answer: SARS has appeared sporadically in 17 years, but no climate has formed. Will COVID-19 exist for a long time in the future, but will not form an outbreak situation? Also a possibility. The key is to control it to the minimum. I don't think it will be like flu. Flu occurs every year. This possibility should be less.   Nucleic acid testing is important before vaccines are successfully developed The epidemic is still spreading, and a vaccine has not yet been developed. To control the spread of the epidemic, nucleic acid testing is still an important presence. Although nucleic acid testing is very helpful, more importantly, we should take the initiative to protect it. The WHO mentioned in its COVID-19 prevention guidelines updated in June that the public needs to maintain basic hand and respiratory hygiene, avoid touching the mouth and nose, and eat and drink safely to avoid contracting or spreading the virus; avoid going to crowded places and try It is possible to avoid close contact with anyone showing symptoms of respiratory diseases and keep a distance of more than 1 meter from them. I hope that countries that have not been able to control the epidemic will learn about epidemic prevention and control, examine their own problems, and make active and effective decisions.

Just yesterday, the National Health Commission issued an announcement, which was madly reposted in the circle of friends because of the sentence "nucleic acid must be extracted for dilution and mixed sample detection, and the "one-step method" is prohibited.   From a technical point of view, there is nothing wrong with this sentence. The one-step method mostly uses direct lysis, and then amplifies after centrifugation or without centrifugation. The reason why this method cannot be used for mixed sample detection is also mixed sample The reason why the test was dissed by many examiners at the beginning, mixing multiple specimens means that the sample is diluted, and dilution also means that there is a risk of missed testing. To   However, as many places in the country began to carry out large-scale nucleic acid screening, a large number of samples followed, and then mixed sample testing was once again put on the discussion table. In disease control, blood stations, etc., blood samples were mixed. In fact, it is a relatively common method, but the blood sample is a homogeneous sample after all, and the new crown is a non-homogeneous swab sample, which is also the culprit of the current epidemic. Can a mixed sample of the new crown work?                                               I don’t know if you have read this document of the Health Commission carefully. In this document, the recommended number of mixed samples is 5, each 200μl, which adds up to exactly 1mL. I think this is why it is recommended to mix 5 with 1 The reason is that the mixed liquid volume is too large or the single volume is too small. Don't say that it can be enriched by centrifugation, this is a virus, and no one can be centrifuged at a speed of tens of thousands of speeds.   This version of the technical guidelines for mixed sample testing basically takes into account all the issues that can be considered. It is currently the most complete technical solution for mixed sample testing. Regarding the reason why the "one-step method" cannot be used, I think it is probably because the one-step method is common. The sample volume is relatively small and direct lysis is used. The purity of the nucleic acid is not high, and the presence of protein and polysaccharides will affect the results.   The purpose of mixed sample detection is to improve the detection efficiency and reduce the detection cost. If the cost factor can be put later, there is also a mixed sample detection scheme that is also good, that is, nucleic acid extraction through a single sample and magnetic bead transfer mixing method Concentrate. This solution uses multiple extraction reagents + 1 detection reagent combination, which can reduce the cost of detection reagents, but the cost of extraction reagents does not decrease much.   The inactivated Virus Transport Media developed by Desheng provides a strong guarantee for nucleic acid detection. The company has also specially tested whether the samples stored in the company’s Virus Transport Media are more suitable for one-step detection or magnetic bead detection. In short, two kinds of detection Each method has its own advantages. If you need more professional and detailed knowledge about the product, you can call our customer service or direct online consultation on the official website, and Desun will have professional technology to answer you.

In-vitro diagnostic reagents are a subdivision of the in-vitro diagnostic industry. They are part of medical devices and play an important role in disease prevention, diagnosis, treatment monitoring, and health status evaluation. There are many classification methods for in vitro diagnostic reagents, and there are different types according to different classification principles. The following Desheng introduces you the classification methods and classification principles of in vitro diagnostic reagents.     The most common classification principle is according to the "In Vitro Diagnostic Reagent Registration Management Measures", according to the order of the degree of product risk from high to low. Mainly divided into the third category, the second category, the first category, and implement classified registration management.   According to the management principle, it is also an important classification method for in vitro diagnostic reagents. First, according to the principle of in vitro diagnostic reagents for drug acceptance and review, in vitro diagnostic reagents can be divided into seven categories, including blood type, tissue matching reagents; microbial antigens, Antibody and nucleic acid detection reagents; tumor marker reagents; immunohistochemistry and human tissue cell reagents; human gene detection reagents; biochips; allergy diagnosis reagents. Secondly, according to the in vitro diagnostic reagents accepted and reviewed by medical devices, it includes a total of nine types of clinical hematology and humoral test reagents, clinical chemistry test reagents, clinical immunological test reagents and microbiological test reagents.   The management classification method needs to be specially pointed out that the in vitro diagnostic reagents managed in accordance with the medical device production supervision and management methods, excluding the in vitro diagnostic reagent products that are legally used for blood source screening and radionuclide labeling by the state.   Another is to classify in vitro diagnostic reagents according to the detection principle, which is the current mainstream classification method. According to this classification principle, in vitro diagnostic reagents can be divided into biochemical diagnostic reagents, immunological diagnostic reagents, molecular diagnostic reagents, microbial diagnostic reagents, urine diagnostic reagents, blood coagulation diagnostic reagents, hematology and flow cytometry diagnostic reagents.   Biochemical, immunological and molecular diagnostic reagents are the three main types of diagnostic reagents in my country. At present, nucleic acid diagnostics in molecular diagnostics occupy the main market.   Since its establishment in 2005, Desheng has been focusing on the R&D and production of in vitro diagnostic reagent raw materials. The raw materials of diagnostic reagents include: biological buffers, chromogen substrates, and current chromogen substrates (new Trinder's reagents) include TOOS, TOPS, ADOS, ADPS, ALPS, DAOS, HDAOS, MADB, MAOS, TODB, etc. Buffers include Tris, Bicine, Caps, Mops, Taps, EPPS, etc.

When it comes to biochemical experiments, especially in the field of protein separation and purification, the role of biological buffers cannot be underestimated. A high-quality buffer solution can exhibit strong capabilities in the presence of trace amounts of acid or alkali, as well as the addition of water, greatly suppressing pH fluctuations and creating a stable chemical environment for experiments. This ability is mainly attributed to its unique composition, such as a mixed solution of weak acids and their salts (such as acetic acid HOAc and sodium acetate NaOAc) or a mixed solution of weak bases and their salts (such as ammonia NH3 · H2O and ammonium chloride NH4Cl), which together form what we call a buffer.   The role of buffer is crucial in the separation and purification process of proteins. The purification of proteins is a complex and delicate task, as each protein has its unique properties and requires specific purification methods. In this process, the stability of proteins often depends on the multi-component buffer system used. A good buffer system can not only maintain the solubility of proteins during the experimental process, but more importantly, it can provide the most suitable environment for proteins without damaging their biological activity.   We know that the purification process of most proteins is carried out in vitro, which means they are detached from their original physiological environment. Therefore, the buffer systems corresponding to recombinant proteins in the market are particularly important. These buffer systems can simulate the environment of natural proteins in the body, providing the possibility for stable storage and transportation of proteins.   When choosing and using buffer solutions, we must consider several key factors. Firstly, the composition of the buffer solution. Ideally, the components of the buffer should not interact with proteins in any form as this may affect their function. For example, some enzymes may be inhibited by phosphate groups in phosphate buffer, leading to their loss of function. Therefore, when choosing a buffer, we should try to choose components that are well compatible with proteins and refer to the recommendations in relevant manuals.   In addition, the pH value of the buffer solution is also an important consideration factor. The choice of pH value depends on the actual application of the protein. If proteins are used for biological assays such as enzyme assays, we should choose the pH values that enable enzymes to exhibit optimal activity. When preparing proteins for purification technology, we need to choose an appropriate pH value based on experimental conditions to ensure maximum purification efficiency. Of course, in situations where a specific pH value is not required, we should choose pH values that can enable proteins to exhibit optimal stability.   In this field, Desheng Company has provided us with a wealth of buffer products with its professional technology and rich experience. They specialize in the research and development, production, and sales of blood collection additives, in vitro diagnostic reagents, biological buffers, and luminescent matrices. They can provide us with various buffer materials (such as TRIS, HEPES, MOPS, etc.), and can configure buffer solutions of different concentrations according to our specific needs. This customized service undoubtedly provides us with more convenience and choices for our experiments.   In summary, buffer plays an irreplaceable role in biochemical experiments, especially in protein separation and purification processes. By selecting the appropriate buffer, we can provide the protein with the most suitable environment, ensuring its stability and activity during the experimental process.

Luminol is a chemiluminescent reagent. Among the many chemiluminescent reagents, luminol reagents have high luminescence quantum yield and good water solubility, and can chemically react with various oxidants and have become The most widely used chemiluminescent reagent. Its luminescence mechanism is that of oxidative reaction. They are catalyzed by horseradish peroxidase under alkaline conditions and oxidized by hydrogen peroxide to produce their excited intermediates that return to aminophthalic acid. When they return to the ground state, they emit Photon. Therefore, Luminol reagents have good application value and broad market demand prospects. The advantages and disadvantages of several Luminol synthesis methods are briefly described here.   The current method of preparing luminol mainly has the following synthetic routes:   (1) Using 3-nitrophthalic acid as a raw material, it undergoes a cyclization reaction with hydrazine hydrate, and is reduced with an insurance powder to obtain luminol (J. Chem. Educ., 1934, II: 142～145). This synthetic method has a simple process route, but the disadvantages are: 1. The reaction temperature in the first step is high, requiring 225 degrees; 2. The purification is difficult. The first step requires the use of high-boiling substance triethylene glycol as a solvent, which is difficult to remove. The reducing agent safety powder used in the second step will decompose during the reaction to produce several inorganic impurities, which are difficult to remove; 3. The yield is low, only about 30%.   (2) Using 3-nitrophthalic acid as a raw material, it undergoes a cyclization reaction with hydrazine sulfate, and is reduced with an insurance powder to obtain luminol (Org. Synth. 1949, 29, 78 and Org. Synth. 1949, 29, 8). The synthesis method has made some improvements on route one, but the disadvantages are: 1. The highly toxic hydrazine sulfate is used; 2. The reaction temperature in the first step is 170 degrees, the temperature is too high, and the equipment requirements are high; 3. The reaction produces a lot of The waste liquid and the reducing agent safety powder used in the second step will decompose during the reaction to produce several inorganic impurities, which are difficult to remove.   (3) Monophthalic anhydride is used as the raw material to nitrate with mixed acid to obtain 3-nitrophthalic acid, dehydrate with acetic anhydride to obtain 3-nitrophthalic anhydride, then hydrazine decompose, and finally reduce iron powder Get Lumino. The shortcomings of this synthesis method are: 1. Long synthetic route; 2. Mixed acid nitrification, which generates a large amount of acidic waste liquid; 3. Iron powder reduction, a large amount of iron slag waste, and greater environmental pollution.   Another method of synthesizing luminol or isoluminol using the one-pot method has obvious advantages and beneficial effects compared with the prior art.   1) The method realizes the completion of the three-step reaction in the same pot, without any purification treatment of the intermediate product, and finally obtains the product directly.   2) The method has simple synthesis route, mild reaction conditions, simple operation, and the required reagents are all conventional reagents, and the required equipment is conventional equipment, so the price is low, therefore, the cost required for synthesis is low, suitable for industrial large-scale production .   3) The yield and purity of luminol and isoluminol synthesized by this method are high. The yield of luminol and isoluminol are both above 80%, and the purity of HPLC is above 98%, which can fully meet the industrialization of products. Production and market demand.

Since the discovery of heparin, it has been widely used to prevent and treat various thromboembolic diseases because of its rapid onset, definite curative effect, and anticoagulant effect can be reversed. However, there are many types of heparin drugs with similar names, such as heparin, low-molecular-weight heparin, enoxaparin, natraheparin, etc., which can easily lead to confusion. What exactly are heparin drugs, what types are they, and how are heparins different?  How is heparin extracted? In 1916, Jay Mclean of John Hopkins University in the United States first discovered a substance with anticoagulant effect from animal liver, so the substance was named "heparin". Later, heparin was found in many organs of mammals. At present, most of the medicinal heparin is extracted from the intestinal mucosa of pigs and lungs of pigs and cattle. What are the types of heparin? Heparin is mainly divided into ordinary heparin (UFH), low molecular weight heparin (LMWH), heparin derivatives (such as fondaparinux), heparin analogs (such as danaparin). What does unfractionated heparin mean? Unfractionated heparin is a mixture of sulfated glycosaminoglycans (GAGs). It is a mucopolysaccharide sulfate composed of alternating D-glucosamine, L-iduronic acid, and D-glucuronic acid. Or made from the intestinal mucosa of cattle, sheep and pigs. What are the low molecular weight heparins? Low molecular weight heparin is a short-chain preparation isolated from ordinary heparin or degraded by ordinary heparin. Due to differences in molecular size, anticoagulant activity, preparation methods, manufacturers, etc., clinically used low molecular weight heparins include enoxaparin, dalteparin, natraparin, etc. What are heparin analogues? Heparin analogue actually refers to a substance similar to heparin, which is somewhat similar in chemical structure to heparin, an acidic substance with anticoagulant activity, heparin analogue danaparin sodium is a mixture of sulfated aminodextran , Also prepared from pig intestinal mucosa, the main components are heparan sulfate, dermatan sulfate and chondroitin sulfate. Indana heparin sodium is rarely used clinically.