You've probably seen pictures of people waiting outside a clinic for a COVID-19 test by now. They are awaiting the results of a polymerase chain reaction (PCR) test.

Rapid antigen tests (RATs) are a unique type of test. The good news is that they're rapid, easy to use, and can for the most time detect COVID-19 even before symptoms appear. You can perform the exam at home or wherever you are most comfortable. They are not, however, as precise as PCR tests.

Both types of tests use a swab sample collected from your throat or nose, nasal secretions ('snot,'), or sometimes saliva to detect COVID-19 in your body.

Here's everything you should know about RATs.

There are two types of tests available to the general public. One being a saliva test, the other being nasal. 

Nasal rapid antigen tests require a  nasal swab to be inserted about 3/5 to 1 of an inch into your nose and swirled around at least 5 times. This may take about 15 seconds. After that, place the swab in a solution, rotate about 10 seconds, and finally read the result in 10-15 minutes.

A saliva test requires you to usually place the saliva on top, under, or side of the tongue. After 2 minutes push the collector to the base of the test kit. The result will appear within 15 minutes.

A study comparing the performance of saliva-based PCR testing to nasal fast antigen tests in 30 patients who tested positive as part of a screening programme was published.

The saliva rapid test results agreed 100% of the time with a normal laboratory-based PCR test for the presence of the Omicron variation, but only 86 percent of the time with the nasal rapid test results.

According to the authors, the findings may indicate that standard diagnostic testing for suspected COVID-19 patients should be reconsidered.

Nevertheless, it is recommended to get PCR tested if you have been in close contact with someone who has symptoms, after taking a rapid. Whether taking a nasal or saliva is up to the individual to decide based on health requirements and personal preference.