The reporter visited the scene——
How to perform nucleic acid detection in the mobile P3 laboratory
Focus on the frontline of science and technology
At 6 o'clock in the morning, Yang Xiaowen, an assistant researcher of the Center for Disease Control and Prevention of the Chinese Center for Disease Control and Prevention (hereinafter referred to as the China Center for Disease Control and Prevention), Beijing Fengtai District Center for Disease Control and Prevention, and colleagues are preparing to enter the mobile P3 laboratory to start a day of new coronavirus nucleic acid testing jobs.
Yang Xiaowen is already used to these jobs. From Wuhan to Mudanjiang, and then to Jilin and Beijing, since the outbreak of the New Coronary Pneumonia, she and her colleagues have followed the mobile P3 laboratory across half of China, helping all over the world and protecting all living beings.
What does the mobile P3 laboratory look like? How does the staff operate inside? Many people are full of curiosity. On June 20, a reporter from the Science and Technology Daily visited the mobile P3 laboratory of the Chinese Center for Disease Control and Prevention to get close contact and experience, and unveiled its mysterious veil for you.
Negative pressure laboratory prevents contaminants from leaking
The mobile P3 laboratory is white in appearance, large in size, and looks like a container.
"The vehicle is 12.67 meters long, 2.5 meters wide, and has an area of about 30 square meters. It is like a small home, divided into a buffer zone and a core operation area." Zhao Hongqun, deputy team leader of the mobile P3 laboratory testing team of China CDC, told Science and Technology Daily Reporter introduction.
The car is equipped with all kinds of advanced instruments required for the experimental process, such as biological safety cabinets, nucleic acid extraction instruments, membrane sealing instruments, and small centrifuges. "So the space left for the staff to operate is very small, 12 square meters, which can be operated by 4 people at a time. Its biggest advantage is that it can be moved, maneuvered, and flexible, and it can be opened where needed." Zhao Hongqun said.
Kan Biao, deputy director of the Infectious Disease Prevention and Control Institute of the Chinese Center for Disease Control and Prevention, and the leader of the mobile P3 laboratory testing team, introduced that P3 laboratory is the abbreviation of Level 3 laboratory for biological safety protection. The entire laboratory is completely sealed and the room is under negative pressure. So that the internal gas will not leak to the outside and cause pollution. "We usually use the "three streams" to summarize it, that is, the flow of people, logistics, and airflow in one direction, to ensure that the contaminants inside will not leak to the outside to cause pollution, and ensure the safety of the core area operators to the greatest extent." Kan Biao said.
It takes about one hour to enter and exit the laboratory to change clothing and protective equipment
Yang Xiaowen and colleagues first came to the buffer zone, which was divided into two. The first buffer zone is on the right side of the entrance door, about one square meter. Here, they are going to change the experimental liner and white coat, change the experimental shoes, wear a medical protective hat and N95 mask, and then enter the negative pressure mobile test vehicle buffer room (second buffer zone) and put on Biological safety level Ⅲ experimental Siamese protective clothing, wear double gloves, protective shoe covers, disposable isolation clothing, goggles or protective face screen, after checking each other correctly, enter the core area of the mobile laboratory for experiments.
This process takes about 20-30 minutes, that is to say, it takes about an hour for them to go in and out to change the experimental clothes and protective equipment after doing an experiment.
The intense nucleic acid detection work is about to begin.
First, after the sample receiving staff registers and inspects the samples sent to the testing vehicle, the infectious sample transfer box is sent to the delivery window. "It is worth mentioning that the door of the transfer window is an interlocking device. It has double doors that cannot be opened at the same time, ensuring that the air brought in when transferring samples is isolated in the double door, so that the environment outside the laboratory is not polluted. "Yang Xiaowen explained.
Then, the staff in the core area disinfected the surface of the sample transfer box and opened the box in the core operation area to take out the biosafety transport tank. After disinfecting the surface of the biosafety transport tank, place it in the biosafety cabinet, open the tank in the biosafety cabinet, and after the surface disinfection, take out the sample sampling tube and sort it according to the experimental sample number. Take an appropriate amount of the sample and add it to the viral nucleic acid extraction kit, and use the nucleic acid extraction instrument to extract the sample nucleic acid.
"Opening the lid and adding the sample is the key to the operation. Because it wears double gloves, it looks awkward. Coupled with the double barrier of goggles or protective screens and the glass window of the biological safety cabinet, all movements appear slow, and the hands will also Shivering from time to time, you need to be extra careful." Yang Xiaowen said.
Next, according to the instructions of the dual real-time fluorescent PCR detection kit, prepare a PCR reaction system according to the number of samples tested, add the extracted nucleic acid, and use a real-time fluorescent PCR instrument to detect, according to the CT value output by the instrument, determine whether the sample is negative, positive or Suspected.
"This step is commonly referred to as an amplification reaction. Due to the large number of equipment and the limited space in the P3 laboratory, we will proceed in the P2 laboratory next to it." Yang Xiaowen said.
"We can operate up to 32 people at a time, and multiple rounds are required when the sample volume is large. In addition, the time for extracting nucleic acids and manually counting samples is generally 8 hours. If the amplification curve of some samples is abnormal, it needs to be reviewed. That time will be longer." Lu Xin, a member of the testing team, said that in Jilin, they had been working continuously for 36 hours because of sequencing.
Finally, after the test is completed, the sample is checked, then disinfected by ultraviolet radiation and disinfectant surface, and then transported out of the mobile testing laboratory for autoclaving. The mobile laboratory sample receiving staff is responsible for the final laboratory sorting and cleaning, and if necessary, terminal disinfection treatment.
"With the existing staff and staff, the laboratory has a daily testing capacity of more than 1,000 copies. In Jilin, it has tested more than 1,600 copies a day. It will adjust its strength at any time according to the needs of the epidemic situation and do a good job in testing," Kan Biao said.
Only stayed at home for 6 days since early February
At 9 a.m. on June 17, the mobile P3 laboratory testing team of the Chinese Center for Disease Control was assembled. They consisted of 14 members of the Institute of Infectious Diseases. Prior to this, three of them had participated in the front line epidemic prevention in Wuhan, Mudanjiang and Jilin, and eight of them had fought in the front lines in Wuhan and Northeast respectively.
"This is an iron team, don't look at most girls, but the combat effectiveness is particularly strong." Kan Biao is particularly proud of the team's performance. Due to the large number of sample tubes to be unscrewed, some players even worn their fingers with double gloves, and their skins were worn off.
"Since February 4, I have been at home for 6 days, and my family is used to it." Zhao Hongqun said that since 2004, he has been responsible for the operation and management of the P3 laboratory for 16 years. Wherever the car arrives, the person will be there. From Wuhan to Mudanjiang, and then to Jilin, he returned to Beijing on June 6. After 10 days of isolation in the hotel, he and his team members fought again.
Outside of work, he rarely contacts his family. "No news is the best news." When saying this, Zhao Hongqun choked a little. In less than a month, his daughter was about to take the entrance exam. When he was withdrawn from Jilin to Beijing, he was most afraid of going home to isolate the children from going to school. Later, he knew that it was concentrated isolation, so he let go of his suspended heart. At a critical moment, you can't cheer on your children, Zhao Hongqun said: "The child is older, I believe she will understand."
An epidemic is an order, and prevention and control is a responsibility. In the face of the call of the country, they did not hesitate at all. At that moment, they were soldiers, guarding the safety of the people with selflessness and fearlessness.
May the mountains and rivers be unharmed and the heroes return home as soon as possible.
Our reporter Fu Lili Zhou Weihai