A Polymerase Chain Reaction (PCR) test can be performed at any time, regardless of whether there are any symptoms or not. The test can also be performed before the onset of the disease. The PCR test is a more sensitive method of detecting the coronavirus than the antigen test. The results of the test are available approximately within 1–2 days. An antigen test can be done if there are symptoms and it has been under five days since the onset of symptoms. The antigen test is not as sensitive as the PCR test, but it is faster than the PCR test, as its results are available in about 30 minutes from testing. The antigen test is ideal for situations where quick results are required and the symptoms have just begun. If you receive a referral to a test from a health care professional, they will determine which method of testing is appropriate for you. You do not need to request a specific type of coronavirus test. Both tests are performed by taking a sample from the nasal cavity with a cotton swab.