The secret of the universal new crown nucleic acid rapid test - the principle of mixed detection

This Liu'an screening is divided into three levels: first, from the key population spread all single test or 1:5 mixed test, close contact, sub-close contact, isolation places isolation staff, confirmed cases and asymptomatic infected people living in the community residents, the city hospital medical staff, patients and escorts and all close contact samples all implement single test; second, sub-close contact residents living in the building, all medical institutions staff samples all according to In addition, the general population by 1:10 mixed test.

See here you may have some questions, why the new crown nucleic acid rapid test will have a single test, 1:5 mixed test and 1:10 mixed test this classification method? Don't worry, next, I will answer for you one by one.

Let's take 1:5 mixed test as an example, the mixed test is carried out as follows.

Suppose the New Crown Nucleic Acid Rapid Test Laboratory collects samples, such as nasopharyngeal swab samples, from five people. The lab takes a portion of each sample and mixes it together to make a mixed sample. The New Corona Nucleic Acid Rapid Test staff then performs a diagnostic test on this mixed sample instead of doing a diagnostic test on each of the five samples.

If the results of the New Corona Nucleic Acid Rapid Test for the mixed samples: one is negative, it is inferred that all patients are nucleic acid negative. If the second is positive, then you need to go back and perform separate New Coronary Nucleic Acid Rapid Test tests on each of the five samples to find out which one(s) are positive.

What are the advantages and limitations of the mixed test compared to the single sample rapid nucleic acid test?

The biggest advantage of mixed testing is that more people can be detected in the same amount of time with less manpower and material resources. It is because of the mixed testing method that Wuhan completed the rapid testing of 6.5 million people for new coronary nucleic acid in only 9 days.

When conducting mass screening in a country (region) with a large population, it is not feasible to test everyone consistently because there are simply not enough resources and time to support it. The manpower for the New Crown Nucleic Acid Rapid Test is one aspect and the reagents needed for the New Crown Nucleic Acid Rapid Test are another.

Since the hybrid test method has such great advantages, why don't countries adopt this strategy from the very beginning? That is because the mixed test method has one of the biggest drawbacks: the false negative rate will increase and the accuracy decreases.

Therefore, in order to avoid cross-contamination during the sampling process, one person needs to implement one-person disinfection; the mixing room should be disinfected after each batch of sample dilution and mixing operation. Swabs should be completely infiltrated with virus preservation solution, and samples should be fully shaken (on an oscillator for 30 seconds) before and after mixing. It is recommended that the sensitivity of the new crown nucleic acid rapid test reagents should be evaluated and the new crown nucleic acid rapid test reagents with higher sensitivity and accuracy should be selected.