Eating oranges and drinking Coca -Cola can make antigen detection positive? The truth is here

Original title: Eating oranges and drinking cola can make antigen detection positive? The truth is here. Recently, a wave of brains’ clear operations caused onlookers -dripping orange juice or cola in the small holes of the new crown antigen detection board, and the test results can also show "two lines" … There are rumors to eat oranges. Drinking Cola will affect the test results, and some netizens call directly. Is it too easy for false positive? However, from the perspective of R & D personnel, these so -called "false positives" are completely out of nothing.

  "In the final analysis, if any test product wants to get exact results, it should be used according to the instructions. This is a basic common sense.

"Xu Lei, director of R & D director of Huada Yinyuan, told a reporter from the Science and Technology Daily that although some antigen detection products have stepped out of the laboratory, the test and verification link is in the final analysis. Zhu Yuqing, a professor of clinical immune room at the Shanghai Clinical Inspection Center, conducted verification tests on the above operations. She found that some testing kits could identify "bad tests" and displayed invalid. The line is normal and shows weak positive.

  For the reason, different base components were used in the antigening kit approved for listing.

  So why does orange juice and cola make some antigen detection show false positive? The real positive color rendering is because the antigen detection captures the protein of the virus. The antibody and the viral protein reaction occurs at the detection line, and the color control line and the detection line are colorful. Orange juice and cola can also make the detection line color rendering because the two acidic solutions directly stimulate the color reaction, so that the presence of viral protein can be displayed. In chemical reactions, the pH value in the solution system is crucial, determining the dissipation and combination of ions. Imagine that adding white vinegar to hot milk in daily life will cause flocculent precipitation, and it is not difficult to understand the protein degeneration caused by the pH value (the antibody combined with the detection board is also a protein). Due to the changes in the acidity and alkali, the chemical structure has changed, and then the chemical structure is changed. Then As a result, the color reactions were further occurred, causing false positives.

Zhu Yuqing explained in his popular science article: dripping orange juice into the reagent plate, the pH value of the solution is too low, and there is vitamin C in the orange juice. Report false positive.

  In the design of the kit, there is a special design that avoids the pH value, which is the buffer solution. This solution plays a "buffer" effect on the small amount of pH value brought by sweat, air, etc., to avoid severe changes in the entire reaction system due to small changes, and then affect the results.

Even so, the buffer solution cannot "buffer" the destructive effects of the entire experimental result by the addition of a large amount of acidic substances.

  Refusing to fake positive, the antigen detection is to be dismantled. In order to detect the convenience, the reaction and color reaction of the antigen antibody reaction and color reaction are condensed on a thin detection board to complete. However, due to the method of physical adsorption in collagen gold immune layer, antigen/antibodies are easily separated from the surface of the gold particles, and the markers are unstable, which will cause orange juice and cola to make the reaction environment change and bring false positives. As of April 27, the State Drug Administration has approved 30 new crown virus antigen test agent products. The detection principles of all approved products can be divided into three latex method, colloidal gold method, and fluorescent immunization layer method.

  The principles of the three methods are dual -resistant sandwiches, but the signal of color rendering is different.

The signal of the colloidal gold method is nano -gold particles, which is a visible light color signal, which usually observes the results of the naked eye; the latex method is painted with color sources, and it is also visible light. , Need to be given the appropriate lavage to launch the corresponding fluorescence, so usually requires specific instruments to observe the test results, but the fluorescent substances are higher than the stability of the colloidal gold, which is suitable for semi -quantitative detection. Therefore The first two are higher.

  "The more stable color signal signal will avoid some false positive occurrences brought about by the operation.

"Xu Lei said that in order to increase the stability of the color rendering signal, Huada’s antigen detection products use nano -micro -ball as the carrier technology and combined with the fluorescent alignment probe, which greatly improves the stability of color rendering in terms of carrier and light emitting. In addition, the detection signal does not rely on the naked eye observation, but is quantitative through the fluorescent identification device. Therefore, the information provided is more diagnostic value, and it is about 10 times higher than that of the traditional colloidal golden layer detection technology.

  It can be seen that it is not easy to "fake positive" by antigen detection. It is obviously unique. Don’t let orange and cola back. (Responsible editor: Yan Yuan, Xuan Zhaoqiang) Share let more people see it.