If you have had a recent exposure to someone with COVID-19, are experiencing symptoms, or are planning to travel, testing for COVID-19 is recommended (and sometimes required) to keep yourself and your community safe. Testing is a powerful tool to slow the spread of COVID-19 among both vaccinated and unvaccinated persons.
With all of the options for testing–at a testing site, at home, rapid result, mail-in, nasal swab, throat swab, Emergency Use Authorization, FDA approved–it can be difficult to know which test will give the most accurate results.
This post will provide clarity on the differences between COVID-19 molecular tests–also known as polymerase chain reaction (PCR) tests–and antigen tests, which are commonly referred to as rapid tests.
Two of the most common options for COVID-19 testing are PCR tests and rapid tests. Each test has a different wait time and accuracy, and either one could be the right choice depending on your situation.
A molecular test, or PCR test, uses your body’s natural ability to replicate cells to test for COVID-19. When you send a mucus or saliva sample to a lab, the technicians can trigger the polymerase chain reaction to replicate the virus’ DNA if it’s present. Because this test essentially increases the sample size, it can detect a positive result from only a small trace.
COVID-19 and its emerging variants are still recent developments in scientific terms, so data is still being gathered on the accuracy of each type of test. At the time of writing, PCR Covid test accuracy is still considered to be the highest among COVID-19 tests, according to Yale Medicine.
Because PCR tests need to be analyzed by lab equipment, they take longer to get results back than from a rapid test.
At BioCollections, we can deliver lab-quality PCR test results in 24 hours or less through our secure, online portal.
PCR tests have higher accuracy and longer wait time than rapid tests. They should be taken whenever you are able to quarantine while waiting for results (such as when you are experiencing symptoms) or you know you’ll need the test ahead of time (such as when planning to travel).
Antigen tests look for the presence of the virus’ proteins to determine a positive or negative result.
Test kits typically come with a nasal swab, a solution, and a testing strip. The patient, or their healthcare provider, uses the swab to collect a sample from about three-quarters of an inch up the patient’s nostril. That sample is then mixed with the solution and dripped onto the test strip. When the test is complete, many will resemble a pregnancy test—one line for negative and two lines for positive.
Rapid tests require a larger trace of the virus to detect it than a PCR test, so there is a greater chance of a false negative. This is especially true in the early days after getting exposed to COVID-19 because the virus is still replicating in your system.
Remember to exercise caution when acting on results. While no test is 100% accurate, false positives are rarer than false negatives.
Many rapid tests can give results in as little as 15 to 30 minutes.
Rapid tests make the most sense when you need to know your result quickly, or would like to take a preliminary test before sending a PCR test to a lab. This can include when you find out that someone you spent time with just tested positive for COVID-19 or when arriving at a place of employment, like a nursing home, that requires daily testing.
When keeping yourself and those around you safe from COVID-19, testing that is both proactive and accurate can be one of your best tools. BioCollections meets you where you’re at with lab-accurate PCR tests—whether you prefer onsite, offsite, or at-home testing. Contact us to learn about our 24 hour turnaround time.