The new crown antigen detection kit has been used as a supplementary means for nucleic acid detection by the Comprehensive Group of the Joint Prevention and Control Mechanism of the State Council as a new epidemic prevention method in 2022. We know that antigen kits cannot be compared with nucleic acid testing in terms of sensitivity and specificity, so residents may miss tests when using the COVID-19 antigen kits to self-test. So is there any way to improve the sensitivity and specificity of the antigen detection kit. Today we will take a look at the reasons why the new crown antigen test may cause missed tests and remedies.
Antigen kits can cause missed tests
Antigen detection does not have a nucleic acid amplification process like nucleic acid detection technology, which results in antigen detection methods that are less sensitive and specific than nucleic acid detection. In other words, antigen detection kits such as latex and colloidal gold methods increase the risk of "false negatives" due to their relatively low sensitivity and specificity. In particular, some patients may miss tests due to long infection times and low viral loads. Similarly, in people with low prevalence of the epidemic, the use of latex or colloidal gold antigen detection kits may even have a "false positive" number of people far more than the number of "true positives", which is more likely to have "false positive" misinspectives.
How to reduce the probability of missed misexamination of antigenic reagent test kits?
At present, there are actually three technical solutions for antigen detection kits, common latex method and colloidal gold method mentioned above, which are similar in technical routes, and the detection sensitivity and specificity are almost the same. The third antigen detection kit uses fluorescent immunochromatography, which increases the detection sensitivity by 10 times and greatly improves the specificity of the previous two. In terms of ease of operation, fluorescence immunochromatography kits often require the use of immunofluorescence analyzers to read the fluorescence signal on the reagent card, which is not as good as the previous two detection methods.
Are there other options to make up for it? The answer is yes.
A protocol that preserves the sensitivity and specificity of the fluorescence immunochromatography antimetry in balance with ease of use
Detection lamps such as UV340 using specialized portable UV reagents excite antigen-antibody complexes labeled with fluorescent microspheres. The ultraviolet light waves radiated by this UV lamp allow fluorescent bead markers to fluorescently react and present on the antigen reagent card. This is a relatively "perfect" solution at the moment.