Sweat aerosol in monkey clothes is always threatening

Virus investigator judges "yin" and "yang" within seven hours

Winning the fight against epidemic prevention and control

After the sample was collected, how was the new crown virus detected? Nucleic acid testing is an important part of the determination of new coronary pneumonia. Every sampled person has been waiting for a "declaration": whether the nucleic acid test is negative or positive. In the microbiology testing laboratories of the CDCs at all levels, there are such a group of "virus investigators" who are looking for the virus in the microscopic world invisible to the naked eye. They do not directly contact patients, but they are trying to peel off the true face of the virus and provide scientific, effective and powerful "big data" support for the treatment of the epidemic. One sample involves the overall situation of the epidemic prevention and control, and they are responsible for each sample. From January 20 to the present, 15 "fighters" in the Microbiology Laboratory of Fengtai District Center for Disease Control and Prevention have been fighting for more than 40 days, 7 × 24 hours a week, and tested thousands of samples ... The reporter put on protective clothing, followed the "virus investigators" to go deep into the front line of virus detection, and unveiled their mystery.

At a room temperature of 25 ° C, and with her sealed protective clothing, Wang Zhao'e could feel the sweat dripping from her body, and a layer of fog had already formed on her goggles.

Test results are related to personal and global psychological pressure

At more than 16:00 on March 2, Fengtai District Center for Disease Control and Prevention ’s second-level biosafety laboratory—outdoor respiratory virus detection, seven sample transfer boxes were lined up on the ground. Some of the samples were just collected by the District Centers for Disease Control and Prevention, and some were sent by car from the local hospital. There were sputum and throat swabs. A total of 19 samples were sealed in transfer boxes and ready to be sent to the laboratory for testing. The owners of these samples are awaiting "sentencing."

The new crown virus is highly contagious, and experiments must be carried out in strict accordance with biosafety regulations. In the locker room ten meters away, virus detection technicians Yu Hong and Wang Zhao'e on duty are hurrying to replace protective clothing. Their mission was to extract all the nucleic acids from the 19 samples. Yu Hong has been in the Microbiology Laboratory of Fengtai District Disease Control Center for 14 years, and Wang Zhao'e is also a veteran with 9 years of work experience. The two sisters have been working together on a regular basis since January 20. That night, the main operator was Yu Hong, and Wang Zhao'e was an assistant, responsible for sample checking and centrifugation.

Hats, shoe covers, disposable isolation clothing, first-layer gloves, N95 masks, disposable medical protective clothing, second-layer gloves, disposable medical boot covers, second-layer shoe covers, splash-proof isolation clothing, goggles ... … Entering the laboratory means there is a risk of being exposed to the virus. Yu Hong and Wang Zhao'e check each other's protective clothing at all times to see if they are in place.

Yu Hong said, "The test results in our hands are not only related to the owner of the sample, but also the life safety of the people around him, as well as the overall situation of the epidemic prevention and control. At the early stage of the epidemic, the understanding of the disease was not so clear. We The psychological burden will be particularly heavy, especially when you make a positive. "At this time, Wang Zhao'e joked:" At the beginning, when you made a negative, you suspected that the experiment was not done well, and you are afraid of being exposed if you make a positive. "At the beginning of the epidemic, the two of them were always in such a state of entanglement and contradiction, so they would always recall every step they had done, whether they did it right, and whether there were any omissions.

Wang Zhao'e used a pen to write the sample number on the cover of each EP tube and collection column, and strictly put the sample number in the sample grid according to the same position.

It takes nearly 20 minutes to remove the sampling tube and disinfect it

After more than ten minutes of preparation, at 17:00, Yu Hong and Wang Zhao'e were all dressed up. The reporter of Beiqing Daily also put on protective clothing and followed them through two protective doors to enter the laboratory. Next to the outer protective door, there is a layer of transparent glass. Wei Xiuxia, a staff member sitting outside, can observe the internal state of the laboratory through this layer of glass, and can respond at any time if there is an accident. On the glass side, there is a small transfer window through which the samples have been sent to the laboratory in turn.

This laboratory is about 20 square meters. The most important equipment inside is the biological safety cabinet with a height of about two meters in the corner. This is also where Yu Hong will extract nucleic acids. This biological safety cabinet only allows experimenters to put their hands into it for operation. The cabinet is equipped with a special internal circulation system and a special filter membrane to ensure the isolation of the air inside and outside the cabinet and prevent viruses from running outside the cabinet.

Ready, Wang Zhao'e took the freshly prepared chlorine-containing disinfectant and spray-disinfected seven boxes containing samples in order. Open the box, take out the yellow 95 kPa sealed can, and sterilize it before handing it to Yu Hong. Yu Hong has been seated in front of the biological safety cabinet. She took the jar, slowly opened the lid, took out the sealed bag, and then carefully sprayed the front and back sides of the bag with disinfectant. Through the sealed bag, you could see the throat swabs and sputum samples inside. The reporter from Beiqing Daily found that it took nearly 20 minutes to remove the 19 samples from the transfer box simply to inactivate the possible new crown virus on the surface of each layer of sample packaging.

After half an hour, Wang Zhao'e took the sample out of the water bath, and Yu Hong took it and put it in the biological safety cabinet.

25 ℃ room temperature plus protective clothing sweat drips down

In order to prevent the virus infection from harming the experimenter, the sample should be inactivated every time before the sampling tube is opened. Wang Zhao'e put the coded samples into a water bath, the time was set to 30 minutes, and the temperature was 56 ° C. Later, she wrote "17: 22-17: 52" in the blank space of the small card on the experimental platform to remind herself of the time. He got up and down, disinfected, and handed samples, and there was a layer of mist on Wang Zhao'e's goggles. At a room temperature of 25 ° C, plus a sealed protective suit, Wang Zhao'e said that the tight-fitting jacket was soaked and he could feel the sweat dripping from his body.

Taking advantage of this half-hour gap, the two began another vital preparation. On the experimental bench on one side, seven white sample boxes with grids have been placed. Each box contains 20 white EP tubes and collection columns in order, 19 for processing samples, and 1 for negative. Control to ensure the accuracy of the experiment.

There are a total of 19 samples on the seven sample delivery sheets, which have indicated the information of the unit, the sample person's name, the type of throat swab or sputum, and the corresponding sample number for each sample. The two men used a pen to write the sample number on the cover of each EP tube and collection column, and strictly put the sample number in the sample grid according to the same position. For example, Wang Moumou's throat swab sample number is fixed at 1011, and the position of the sample box is fixed, which is fixed at the first number in the first row.

At this point, there were more than ten minutes before the inactivation was completed, and the two sat in the corners to rest. "Here is a closed laboratory, and wearing N95 masks will cause a lot of resistance, so most of us rely on eye contact." Wang Zhao'e calmed herself down, expecting the mist on the goggles to quickly dissipate.

The risk of removing the outer packaging layer by layer is increased slightly

After half an hour, Wang Zhao'e took the sample out of the water bath, and Yu Hong took it and put it in the biological safety cabinet. The sealed bag was still hot. After standing for 10 minutes, they were disinfected, opened the sealed bag, removed the sampling tube, disinfected, labeled with numbers, and placed in the sample holder. It took another 20 minutes for these throat swabs and sputum samples to be removed and stacked. neat.

The outer packaging is removed layer by layer, and the risk is increasing. If there is a new crown virus in the sample and it has not been completely inactivated before, this next step is the most dangerous. Six of the samples were sputum. Because the sputum was thick, it had to be diluted for further processing. Yu Hong first added sputum digestion to these six samples. She pinched the lower part of the sampling tube with her left hand, and squeezed the lid with her right hand, turning the tube carefully, slowly, about three or four times, opening the lid, adding the sputum and digestive juice in proportion, and then Close the lid and let the sputum stand and dilute it sufficiently.

Yu Hong said that although it has been inactivated, no one can guarantee whether there is any inactivated virus attached to the lid. In order to avoid the generation of aerosols, it must be careful and the action must be small.

Subsequently, the sample must be moved from the sampling tube to a white EP tube dedicated to the experiment before the next step of cell lysis. Gently open the lid of the sampling tube, pipette a 140 microliter sample into the EP tube, and close the cap. At each step, Yu Hong's movements are very slow and careful. In her own words, "I can hardly feel my heartbeat and feel out of breath when I do the experiment. It is a very calm state. "

A sample is related to a life, and each step must be carefully checked. Wang Zhao'e stands on the right side of Yu Hong, holding the list in his hand. For each sample, Wang Zhao'e reads the position where the sample should be placed: "pharyngeal swab, 1015- 1, four rows in one; throat swabs, 1016-1, four rows in two; 1017-2, four rows in three ... "

The biological safety cabinet is the most important equipment in the laboratory. Yu Hong stretches her hands into it to extract nucleic acids.

Translate the liquid to avoid contamination on other sample surfaces

To extract nucleic acids, lysates must be added to lyse viruses that may be present. Yu Hong explained that this process is the process of opening the virus capsid of the sample, and the nucleic acids in the sample, that is, DNA, RNA and other substances are all released. Yu Hong picked up the pipette, connected the tip, and sucked back some of the liquid in the EP tube containing the sample and put it back again. After coagulating for five or six times, the liquid was more uniform. After 10 minutes, the cells had been lysed by adding lysate to the sample. The next step is to collect viral RNA.

At this point, all the liquid in the EP tube needs to be translated into the collection column. The reporter from Beiqing Daily noticed that Yu Hong was very slow in translating the liquid. When she sucked the liquid with a pipette, she deliberately bypassed the surface of other samples in order to prevent other samples from being contaminated. After the sample was translated, Wang Zhao'e put these collection columns into the centrifuge in turn, and centrifuged for one minute, and the RNA in the sample was completely absorbed in the white membrane. This process requires two passes to remove all the lysate and adsorb the RNA to the collection membrane. Wang Zhao'e handed the extracted RNA liquid to Wei Xiuxia, who was already waiting outside the transmission window, and sent it to another laboratory for RNA amplification and detection of the new crown virus. It took another three hours, which means that a total of seven It takes hours to know the results.

Yu Hong (left) and Wang Zhao'e have been working together since the outbreak. That night, the main operator was Yu Hong, and Wang Zhao'e was an assistant who was responsible for sample checking and centrifugation.

"Sanshan Town Demon" on the card

On the workbench in the laboratory, a reporter from the Beijing Youth Daily also found a small card that read: "Vulcan Mountain, Thunder God Mountain, Zhong Nanshan Sanshan Town Demon, Hahaha", with a monster head painted next to it, "Ha Haha "and three smiley faces. After seeing this card found by a reporter from Beiqing Newspaper, Wang Zhao'e hurried over to grab the card, buckled it on the table, and said shyly, "Oh, don't read this, it was a blind draw when I waited for the experiment last time. "Yu Hong said that while waiting for the samples, they would occasionally paint time on the paper to pass the time. Writing these words, they also hoped that the epidemic would end sooner.

After the nucleic acid extraction is completed, it is necessary to "clean up the battlefield": clean and sterilize the biological safety cabinet, clean up the experimental items and protective supplies, put in garbage bags, autoclave, sterilize the table and the ground, turn on the ultraviolet disinfection lamp ... the two have completed all The work left the laboratory at exactly 9 pm. Taking off their protective clothing, their faces and hands were scratched. The skin of the cheekbones on both sides of Yu Hong has been reddened by the N95 mask. When asked about her feelings, she sorted her clothes and said lightly, "Nothing, I'm used to it."

Yu Hong had lunch at 11.30 noon that day, and the experiment ended at 9 pm without eating anything. "I didn't dare to drink more water before I went in. I was afraid I wanted to go to the toilet and I didn't feel hungry. I concentrated on the experiment." To cope with it, Yu Hong returned her 7-year-old son to his hometown in Hebei before the Spring Festival. "I miss him so much and hope to see him soon after the epidemic is over."

Each member of this testing team is an ordinary hero. They have a common name, called "Technical Group for the Prevention and Control of New-type Coronary Pneumonia in Fengtai District". The members include: Dong Xiaogen, Qin Meng, Zhang Ling, Feng Huiru, Xing Hongguang, Yu Hong, Wang Zhao'e, Wei Xiuxia, Zhang Zhimin, Yan Tao, Meng Zhiming, Li Lijun, Cao Jiaqi, Chi Xiuping, Liu Xiaoling.

According to the Beijing Youth Daily reporter, the sample testing in Beijing is divided into two levels in the urban area. At present, the Beijing Centers for Disease Control and Prevention is responsible for the detection of some key samples, and the Centers for Disease Control and Prevention in each district is responsible for detecting the samples submitted within its jurisdiction. In addition, there are 16 hospital laboratories with testing capabilities in the city, which are responsible for the testing of samples in this hospital. Text / Reporter Jiang Ruojing

dialogue

Worry about affecting your family

Did not dare to enter the house for more than 40 days

Dialogue: Dong Xiaogen, Section Chief, Microbiology Laboratory, Fengtai CDC

Beiqing Daily: As far as the test just was performed, you stared at the test all the way and saw the final test result, did you feel relieved?

Dong Xiaogen: Yes, it shows that the situation is improving.

Beiqing Daily: Now that machine inspection is relatively mature, it can also save time. Why use manual inspection?

Dong Xiaogen: Manual testing is a relatively primitive method. Machine testing is indeed more mature and can be an hour faster than manual testing. However, this epidemic came quickly and violently. Every sample is important. For security reasons, we can use manual testing. Try to use manual testing to control every link.

Beiqing Newspaper: In addition to the new crown epidemic, do you usually detect other viruses manually? Will the level of protection be so high?

Dong Xiaogen: When detecting common and common diseases such as norovirus, influenza virus, and enterovirus, the detection methods are relatively mature. Machine testing is usually used, and secondary protection is used in the laboratory. However, in the face of new coronary pneumonia, the epidemic situation is special and it is an emerging disease. We must be responsible for each sample and our laboratory staff. To adopt three levels of protection, we must wear N95 masks and monkey clothes.

Beiqing Daily: When you detect a positive result, how do you feel?

Dong Xiaogen: Can't find the exact word to describe it. From the perspective of prevention and control, it can prevent proliferation, and will have a greater sense of accomplishment than usual detection work. But I am also worried about this patient, not only about the patient's body, but also whether the patient will be discriminated against by people around him. As a team leader, I also worry about my team members, especially when the epidemic is just out, they are afraid of being infected.

Beiqing Newspaper: What kind of methods would you use to ensure their safety?

Dong Xiaogen: Usually I always remind them to protect themselves. Before I started my job on the 20th, I specially trained them to put on and take off protective clothing. I also sent a colleague to check their protective clothing daily to see if they were wearing standards. The time required to work in the laboratory is now strictly controlled to 4 hours.

Beiqing News: I heard that you have just finished helping Xinjiang, and you have come to work before your vacation. How long have you been working on the job?

Dong Xiaogen: Yes, I assisted Xinjiang for one year and returned on January 3. I could have taken a month long vacation, but the epidemic suddenly came back to work on January 20. Including our entire team, it also started to rotate from the moment when the first case was found in Fengtai District on January 20. Until now, it is 7 × 24 hours a week without stopping, and everyone is basically in the unit. Our testing team has 15 people. Samples come and go at any time. The room temperature at 25 ° C is in closed protective clothing. At the beginning, it took up to five or six hours.

Beiqing Daily: Have you been home this time?

Dong Xiaogen: Because I was worried that I would affect my family, I did n’t dare to enter the house for more than 40 days, so I went back to the gate of the community to pick up clothes twice. I stayed for less than two minutes each time, and I was sent by my lover. The last time I went back to get my clothes, my lover cried when she saw me at the gate of the community. The neighbors around me knew the disease control I did, and I dealt with the virus every day. I was afraid that they would worry about going back home to live, so I wouldn't go back and sleep in the office every day.

Now I dare not turn off my phone every day, and I have n’t slept in a sense of stability. No matter day or night, I have to process information at any time. I especially hope that I can shut down and sleep for a few days. Text / Reporter Jiang Ruojing

This edition of photography / our reporter Fu Ding