How does the PCR test work?

The test consists of inserting a soft cotton swab (swab) into each nostril up to the nasopharynx for a few minutes. This process is unpleasant but not painful. The sample is then analyzed in the laboratory using a method called “polymerase chain reaction” (PCR). This technique makes it possible to detect the RNA of the virus, its genome, which characterizes it in a way. The best time to detect SARS-CoV-2 RNA is 1-7 days after symptom onset. Before or after this period, the PCR test would no longer be optimal. Learn more
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First of all

You should have your head tilted back.


The sampler will insert the swab 5 to 6 cm into the back of the nose, to optimize the chances of collecting the virus. The swab may touch the walls of your nose which is made up of many blood and nerve vessels. It is therefore possible, in some cases, to notice discomfort.


The sampler will rotate the swab to collect as much secretion as possible to find viral particles. Duration: 5-15 seconds
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After collection, the swab will be placed in a tube to be analyzed by a specialized laboratory.