The domestic self-test box builds a "fence" for the prevention and control of the world epidemic

There are many listed companies involved in home-use COVID-19 testing business in China, but only a few COVID-19 antigen testing products have been approved
.

Starting from January 9, Tianjin has launched three rounds of nucleic acid testing for all employees in the city
.

The detection of the new coronavirus is an important part of the fight against the epidemic
.

Home self-testing is also one of the means to control the epidemic

Zhang Yan, a professor at the School of Pharmacy of Tianjin University, said that the real-time fluorescence quantitative polymerase chain reaction nucleic acid detection technology currently used in screening patients with new coronary pneumonia, as well as the constant temperature detection technology that relies on DNA amplification, require professionals and professional equipment, including many Novel coronavirus antigen detection methods based on specific antibodies also need to use fluorescent labels to ensure the accuracy of detection
.

Zhang Yan introduced that the home new crown self-test reagent uses antigen detection reagents, not nucleic acid detection reagents
.

"Antigen reagent combines the characteristics of nucleic acid reagents with high early diagnosis accuracy and antibody reagents for rapid detection.
It can be detected on the first day of infection with the new coronavirus.
It is easy to operate and does not require special equipment or instruments
.

The use of nucleic acid testing (diagnosis) + home self-testing (screening) can more effectively block the spread of Omicron, and is a public health and epidemic prevention method to effectively control the epidemic
.

As early as November 2020, the United Kingdom piloted the first universal COVID-19 test in Liverpool by means of antigen reagents and other methods
.

New home self-test system is more efficient and cheaper

At present, the home new crown self-testing agent mainly adopts the traditional colloidal gold test strip method that can distinguish the color with the naked eye
.

Therefore, scientists from all over the world are looking for more efficient, lower-cost and safer home self-testing methods for the new coronavirus
.

A few days ago, Zhang Yan cooperated with scientific research institutions such as Harvard University in the United States to develop a home new crown self-test system that does not require any training in electronics, optics, equipment and operating skills
.
The system can detect the results within 5 minutes at the fastest, and provide the results visible to the naked eye with intuitive color contrast.
A single microfluidic chip can be used repeatedly for more than 50 times, which greatly reduces the detection cost and is very suitable for ordinary families.
and personal testing use
.
The results were recently published in the international journal "Small"
.

According to reports, the research team innovatively used a microfluidic chip instead of capillary chromatography test strips, which increased the sample load by dozens of times compared to traditional test strips
.
At the same time, it also avoids the risk that the conventional method using colloidal gold test strips is easy to miss the detection of low viral load samples
.

Zhang Yan said that using the microfluidic chip method for detection, in the double-blind clinical test of more than 100 users, the detection accuracy rate for the common new coronavirus and delta variant strains was as high as 95.
4% and 100%, respectively
.

"This detection chip uses two kinds of microspheres and nanospheres modified by different antibodies, and the colors are white and red respectively
.
" Zhang Yan said that when there is no virus antigen in the sample, the red nanospheres can be quickly removed by a specific interception pore size.
The barrier filter makes the detection window appear white as microspheres, and when the new coronavirus exists, the microspheres and nanospheres form a complex mediated by the virus antigen through the antibodies on the surface, and the red nanospheres achieve surface coverage on the white microspheres.
Thus, the detection window displays a red color that is visible to the naked eye
.

Because the chip is designed with a reverse flow function, after the detection is completed, the microspheres can be returned from the original path under the flushing of physiological saline or water to clear the detection window, so that they can be used repeatedly for dozens or even hundreds of times
.

In addition, the home new crown self-test system is easy to operate and can be guided by video, suitable for adult-assisted collection of children aged 2 and above, as well as all adult self-test use
.
Test results can be displayed within 20 minutes without leaving home
.

Domestic promotion of new crown family self-assessment remains to be studied

At present, there are many domestic listed companies involved in the domestic new crown virus detection business, including Jiu'an Medical, Oriental Bio, Rejing Bio, Wanfu Bio, and Aotai Bio
.
However, at present, China has only approved a few new crown antigen detection products
.

However, due to the particularly developed domestic nucleic acid detection, sampling points are everywhere, and the time for results is relatively fast, the method of antigen detection has not been widely used
.
On the contrary, due to the lack of overseas nucleic acid detection capabilities, a large number of new crown antigen detection methods have been used, and most of the new crown antigen reagents produced by Chinese companies are sold abroad
.
According to China's customs data, in November 2021, China's new crown antigen detection reagents were mainly sold to Germany, the United Kingdom, the United States, Canada and Greece
.

According to industry insiders, due to the small number of new cases in China and relatively scattered cases, it is difficult for reagent manufacturers to raise enough clinical trial cases in accordance with the current regulations of the State Food and Drug Administration
.
However, according to the EUA registration requirements of the U.
S.
Food and Drug Administration (FDA), the certified Jiu’an Medical, Oriental Bio and Aikang Technology have completed clinical trials of new crown antigen detection reagents in the United States
.
For example, the iHealth new crown antigen home self-test OTC kit produced by Jiu'an Medical is one of the public health and epidemic prevention products widely used in the United States
.

Zhang Yan pointed out that China still faces a difficult problem in promoting the new crown home self-test, that is, the problem of supervision
.
How to report the test results, how to avoid concealment, how to verify the authenticity and effectiveness of the test results in the background, and how to conduct big data statistics are all issues that need to be solved before the promotion of the new crown home self-test
.
However, with the normalization of new crown virus prevention and control, the promotion and popularization of new crown home self-testing still has certain value
.