China Wuhan Desheng Biochemical Technology Co., Ltd Company News

Routine blood testing is already a very important routine testing item. Platelet count is an important basis for the diagnosis and identification of hemostasis and thrombotic diseases. However, in daily testing, the platelet count using a blood cell counter may sometimes be falsely increased or Lower, why is this?   The role of platelets   Platelet is abbreviated as PLT, which belongs to blood cell like red blood cell and white blood cell. It is dimpled, oval or disk-shaped on both sides, but much smaller than red blood cell and white blood cell. The average diameter is only 2 to 4 microns. It is formed by fragments of bone marrow megakaryocyte cytoplasm shedding. . When blood vessels are damaged, platelets aggregate into clusters to form thrombus; and also release substances that promote vasoconstriction and blood clotting. Platelet count refers to the number of platelets contained in a unit volume of blood. Certain diseases can lead to a decrease or increase in the number of platelets.     Causes of false elevation of platelets   1. In some hemolytic diseases, hemolysis occurs in the blood vessels, and then the fragments generated by the rupture of red blood cells will be divided into the platelet area by the hemocytometer, which will cause errors in the instrument and falsely increase the count. For example, hemoglobinopathy and G-6-PD deficiency can cause intravascular hemolysis.   2. After the treatment of chronic granulocyte patients, a large number of fragments will appear in the blood vessels. These fragments will also be divided into the platelet area by the hemocytometer, which will cause interference and falsely increase the platelet count.   3. Take venous blood for routine blood testing within a short period of time after transfusion of fat emulsion, chylo particles will also be counted into platelets by the blood cell counter, resulting in high falsehood. All the above three types can be corrected by observing the morphology of platelets and red and white blood cells through artificial blood smears.   Causes of false reduction in platelets   1. EDTA-K2 anticoagulant causes platelet aggregation, which is related to the presence of cryptic antigens on the surface of platelets, causing the blood cell counter to treat the adhered platelets as non-platelets, resulting in a false decrease in counts. At this time, citrate can be used instead of EDTA-K2 as an anticoagulant, or platelets can be manually counted to correct.   2. Cold agglutinin can agglutinate red blood cells, nucleated cells, and platelets, thereby making the platelet count falsely lower. When encountering the interference of cold agglutinin in the body, the specimen can be incubated at 37 degrees for a period of time to eliminate the interference caused by cold agglutinin.   3. The invisible aggregation of platelets in hypercoagulable blood will make the count falsely lower. For example, hypermagnesium, hypercholesterolemia, and high triglycerides will all increase platelet aggregation.   The instrument used for blood cell analysis has the advantages of speed and simplicity, but it is also easy to cause errors. As an established blood test reagent company, Desheng recommends that when the platelet count does not match the clinical practice, it must be corrected by manual recheck to avoid unnecessary disputes between doctors and patients.

As the weather becomes hot, all chemical companies are in great danger. It is necessary to strictly pay attention to the storage conditions of raw materials and the temperature control during equipment operation to avoid safety accidents. According to the recent notice issued by the Jiangsu Provincial Emergency Management Department, chemical (hazardous chemicals) companies are required to implement eight major risk management and control measures, and do a good job in safe production of hazardous chemicals in summer and flood seasons, and make every effort to prevent and contain production safety accidents.     The eight control measures are as follows:   One is to earnestly implement monitoring measures for major hazard sources, strengthen the temperature and pressure monitoring of hazardous chemical production equipment and storage facilities, prohibit over-temperature, over-pressure, and overload production, pay close attention to the working conditions of heat exchange equipment and cooling water, and handle temperature in a timely manner , Liquid level, pressure and other abnormal conditions.   The second is to strengthen the maintenance of equipment and facilities. All automatic control and safety instrument systems, flammable and toxic gas detection and alarm systems, etc. should be put into normal operation, and buildings (structures), production equipment, storage facilities, electrical equipment, safety instruments, etc. Lightning protection and grounding conditions completely eliminate hidden dangers and effectively prevent production safety accidents caused by lightning.   The third is to improve ventilation and cooling facilities. In places involving the production, storage, and use of flammable, explosive, toxic, harmful and other hazardous chemicals, it is necessary to ensure that the ventilation, cooling, detection and alarm facilities are intact and in a normal applicable state.   The fourth is to reasonably adjust the work and rest time, arrange the time reasonably according to the weather forecast and weather changes, reduce outdoor outdoor work activities at noon high temperature, and equip heatstroke prevention and cooling drugs to prevent personnel from heatstroke. Enterprises should strictly implement the safety management regulations for the loading and unloading of hazardous chemicals in summer. When the temperature exceeds 35°C, all hazardous chemical loading and unloading operations shall be stopped from 10 am to 15 pm.   The fifth is to strengthen the safety management of inspection and maintenance, fully identify the risks of special operations such as hot work, operations in restricted spaces, temporary electricity use, and climbing operations, conduct inspection and analysis, standardize the approval of work permits, and effectively confirm the implementation of safety measures.   The sixth is to do a good job in flood prevention. Enterprises should inspect the drainage facilities in the plant area, dredge drainage, flood drainage ditches, arrange flood control materials, and implement flood control rescue teams. It is necessary to clarify the responsible personnel and regularly monitor the flammable and toxic gases in the sewage pipe network to prevent leaked materials from entering the sewage pipe network and ensure the safe operation of the pipe network. Enterprises along the river, lake, and river should pay close attention to flood forecasts, inspect flood discharge isolation gate facilities such as the river, lake, and river, arrange flood control personnel on duty, and be ready to close the gate at any time to prevent rivers, lakes, and rivers from flowing. Backflow.   The seventh is to inspect and test the fire sprinkler system, and conduct a start-up test on the sprinkler cooling water system installed in the hazardous chemical tank area to ensure that the water pressure and cooling effect meet the design requirements.   The eighth is to pay attention to the safety of enterprises that stop production, and urge enterprises to fully understand the situation of hazardous chemicals in storage tanks and installations, and properly handle, recover and transfer hazardous materials. Strengthen the monitoring and control of out-of-service production installations and storage facilities that contain hazardous chemicals, and shall not dismantle or disable safety facilities without authorization.   Desheng specializes in the research and development, production and sales of blood collection tube additives, in vitro diagnostic reagents, buffers, and luminescent substrates. The storage of raw materials, equipment monitoring, and mental state supervision of production personnel are all strictly supervised to avoid safety accidents. In the scorching summer, Desheng hopes that all chemical companies will attach great importance to safe production.

Chemiluminescence technology is widely used in clinical practice. Chemiluminescence is a type of immunodiagnosis, which uses the specific reaction between antigen and antibody to determine the concentration of disease markers in the body to determine the body state of the human body. It is widely used in infectious diseases, heart diseases, tumors, pregnancy detection, etc. Compared with other immunodiagnostic methods, chemiluminescence has become the mainstream of immunodiagnosis due to its systematic advantages in safety, automated operation, test accuracy, and test speed. It surpasses other technologies in performance.  chemiluminescent-reagent While chemiluminescence products have been widely used in clinical practice, they also encountered some difficult development problems, mainly in the following aspects. The biggest reason is the low concentration of markers and the difficulty of detection. 1. The fundamental reason is that the concentration of the test substance (antigen, antibody) in the sample is low, which requires more precision and standardization from R&D, production to use-the content of carbohydrates, fats, etc. in biochemical diagnostic tests are common in the human body It is the g/L-μg/L level, while the immunodiagnostic target antigens and antibodies are only at the μg/L-pg/L level, and the difference between the two is about 106 times. 2. The instrument and reagents are closed, and the development capabilities of the enterprise's instruments and reagents are very high. The instrument determines the lower limit, and the reagent determines the upper limit; 3. Cutting-edge technologies in various fields are required: mechanical automation, optics, materials, statistics, etc. There are obviously insufficient talents in the field, and it is difficult to train; 4. High R&D cost and long cycle. Compared with the differences in different types of technologies, domestic manufacturers are more important to product development and quality control capabilities. As one of the leading manufacturers of chemiluminescence reagents, Desheng should have higher requirements for the quality of products. Desheng’s chemiluminescence reagent products mainly include acridinium esters, luminol and isoluminol, and rely on super high Cost-effective, professional scientific research and technical team, and strong after-sales service have been unanimously recognized by many customers.

People basically use in vitro diagnostic reagents (IVD) when they go to the hospital or go for a physical examination. In vitro diagnostic reagents are the "doctor's eyes", which can assist clinicians in diagnosing the condition, observing curative effects, and adjusting treatment plans. Product quality and safety level are an important basis for ensuring the correctness of relevant test results and diagnosis.   As people’s demand for health and disease prevention and treatment services grows, in the process of medical and health services, the public’s awareness of the quality and safety of diagnostic reagents is getting stronger and stronger. For the test results of one item in multiple hospitals, for one item The comparison of test results in different time periods in the same hospital has begun to require knowledge and attention to quality control, which also requires high attention and common progress from all aspects of society! Different colors of in vitro diagnostic reagents At present, most of the in vitro diagnostic reagents in my country are regulated in accordance with medical device standards, and some are regulated in accordance with drug standards. The popular science knowledge introduced here is mainly aimed at how to buy correctly, understand the technical parameters that need to be paid attention to when purchasing products, transportation requirements, and storage requirements during use. It has certain guidance and help for readers to understand, correctly understand and apply in vitro diagnostic reagents. Here are a few frequently asked questions and answers.   1. How to judge the technical performance of in vitro diagnostic reagents? Answer: The performance of in vitro diagnostic reagents is mainly reflected in three aspects: 1. Analytical performance: mainly includes precision, accuracy, sensitivity, specificity, linear range or measurement range, etc., which may be reflected in some technical indicators in the product manual There is not a complete agreement. 2. Diagnostic performance: the degree of sensitivity and specificity to the tested substance. 3. Stability: the production date, expiration date, expiration date, and calibration requirements of the product.   The raw materials and processes used in the reagents should have clear quality requirements and have been verified. The performance of the final product meets the requirements for clinical use. The main factors affecting product performance include the establishment of raw materials, processes and reaction systems, performance evaluation methods and methods, the establishment of internal reference products, and clinical evaluation.   2. What are the special requirements for the storage of in vitro diagnostic reagents? Answer: The storage of in vitro diagnostic reagents is quite special and requires certain conditions. According to the types and performance of in vitro diagnostic reagents, product partitioning and classified storage management should be implemented. The product storage warehouse shall meet the requirements of temperature and humidity, dustproof, ventilation, protection from light, and storage period regulations, and shall be equipped with temperature and humidity monitoring and control facilities or equipment, and maintain monitoring records. Most in vitro diagnostic reagents need to be stored in a low temperature between 2-8℃, a few varieties need to be frozen, and some varieties can be stored at room temperature. The specific requirements are clearly marked in the product manual.   3. Are there special requirements for the transportation of in vitro diagnostic reagents? Answer: The transportation of IVD reagents should meet the requirements of transportation conditions and product packaging. Product manuals and labels that require low temperature and refrigeration shall be transported and stored in low temperature and refrigeration facilities in accordance with relevant regulations.

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.