BATON ROUGE, La (BRPROUD) – There are many reasons why you might need to take a COVID-19 test. Whether you were in contact with someone who has the virus or if you have any of the known symptoms. But which test is the best option for you?

Dr. Lucio Miele, Cancer Crusaders Professor and Chair, Department of Genetics, Assistant Dean for Translational Science for Louisiana State University Health Sciences Center New Orleans explains the difference between a PCR molecular test and the antigen or rapid test.

“The most commonly used tests are so-called PCR based, they are molecular tests,” Miele said.

PCR testing is considered the “gold standard” according to Memorial Health Care.

The PCR test detects RNA that is unique to the COVID-19 virus. This test can take a few days because of the high demand for the test. The rapid test works by detecting the protein fragments specific to the virus. This test works best if you are showing symptoms, and need results fast.

“You should take it because that gives you a rapid answer that you can use to prevent yourself from spreading the disease,” said Miele. “If you do not have symptoms but you believe you’ve been exposed then you need to go to your doctor and get a molecular test.”

But, there are concerns that rapid tests don’t pick up every case.

“What you don’t have in absolute accuracy you gain in speed,” Miele said.

False positives are very rare, according to Harvard Health.

Most false-positive results are thought to be due to lab contamination or other problems with how the lab has performed the test, not limitations of the test itself.

Take-home COVID tests are available at participating stores. The test takes 15-minutes to yield results and is simple to use.

“This is very worth doing if you are having any type of symptoms, no matter how small, even if you have the sniffles, the advantage of that is that it gives you an answer quickly,” Miele said.

Miele said if you get a positive result with the home test, it’s important to tell a medical professional.

“If you are positive you need to isolate yourself and go to the doctor and confirm that what you have is in fact COVID-19 with a longer molecular test,” Miele said.

Experts advise that testing and reporting are key to fighting the pandemic.

“The only way we have to get out of this pandemic is to stop the spread of this virus. We won’t know how to stop it unless we know where the cases are,” Miele said.

Miele says because the Delta variant has a larger viral load, the virus is much easier to detect, making these tests even more accurate.