Covid-19 continues to course through our country with new variants, requiring our knowledge of the virus to evolve with it. This includes not only understanding the vaccines but also understanding the types of tests available to us. The two standard ones being used are PCR tests and Antigen tests. While all testing is critical to preventing the spread of Covid-19, it’s best to recognize which testing method may be preferable for you and your loved ones. Let’s take a look at the differences between them.
The PCR (Polymerase Chain Reaction) test is considered a molecular test. They are also referred to as diagnostic tests. They are taken via nasal swabs. Some are done as a saliva test; however, this is less common. The collected sample is then converted into DNA, where it can be positively identified if found present in the sample. Standard PCR tests must be sent to a lab for processing and may take 1 – 3 business days to return results. In contrast, Rapid PCR tests can be processed onsite and typically produce results within hours.
Antigen tests are also referred to as viral or rapid tests. An antigen test detects a protein coating the surface of the SARS-CoV-2 virus. Typically, the test samples are collected through nasal swabs and then placed into a solution to identify the virus. These types of tests can produce results in as little as fifteen minutes. Because antigens tests are affordable and don’t need to be sent to a lab, they are ideal for large groups and events, as they allow many individuals to get tested in a short period of time.
What’s the difference?
Both the PCR and Antigen tests detect active cases of Covid-19. Beyond the ways these tests detect the virus, the main difference between the two tests lies in the speed and accuracy.
●While the Antigen Tests are often much quicker, they are not as accurate as a PCR test, especially in the early stages of Covid-19. The Antigen Test has a higher rate of producing “false negatives”. This is because they may have a lower sensitivity, which means they may miss some infections and may require multiple tests to ensure the virus is not present.
● When looking at testing time frames, the PCR tests usually take much longer. This is because results usually must be sent to a lab and the results can be received from 1-3 days. PCR tests are highly accurate and do not often need to be repeated. More recently, rapid PCR tests have become available at select clinics and healthcare providers. These results are typically received the same day