x
Breaking News
More () »

What are the different types of COVID-19 tests?

An expert from Cleveland Clinic is here to explain the difference between a molecular test and antigen test.

CLEVELAND — Editor's Note: The above video is from December 16, 2020

As COVID-19 continues to spread across the country, and specifically in Ohio, it is important to understand the different testing available.

According to a recent post on Cleveland Clinic's Health Essentials blog, understanding the different types of tests being used is a key factor in understanding your results - whether that means the chance of a false negative or positive, symptomatic timeline and how the test works.

RELATED: Cleveland Clinic immunizes first frontline healthcare workers with Pfizer COVID-19 vaccine

There are currently two primary COVID-19 tests available to patients: molecular testing and rapid antigen testing. 

There is a third type of testing that looks for antibodies that combat the virus, but it is only administered occasionally and can only tell if you've had the virus in the past. 

Cleveland Clinic pathologist Brian Rubin, MD, PhD, explains that the molecular tests are "more sensitive and specific" than antigen tests, thus making them more accurate. The molecular test is often performed by a nasal swab. "What molecular tests do is it looks for and detects the RNA (or nucleic acid) component of the virus," Dr. Rubin explains. "That's opposed to the antigen tests where are looking for the proteins from the virus."

If you have heard about PCR COVID-19 testing, these are the most commonly used and a subset of molecular tests. "PCR" stands for "polymerase chain reaction" which is a way of amplifying nucleic acids in your test sample. "According to the  FDA, the polymerase chain reaction converts any virus RNA in your sample into DNA and 'amplifies' it by making millions of copies of the DNA which the molecular test can then detect," the post continues. Dr. Rubin adds that the amplification allows labs to detect the virus more easily.

As far as which test is more accurate, Dr. Rubin says the molecular test is more accurate than the antigen test. Though, that comes at a cost. While the antigen test may be less accurate, it can give results in as little as 15 minutes and don't require being sent to a lab. The molecular test may take 24 hour hours or longer depending on if they are being sent to an outside lab and how backed-up the lab is with other tests. 

"So, for now, the PCR tests remain the gold standard of COVID-19 tests," the post concludes. 

Related Stories:

Editor's Note: The below video aired on December 15, 2020

Before You Leave, Check This Out