Types of TestsYou can order free self-test kits at COVIDtests.gov or purchase tests online, in pharmacies, and retail stores.You can also visit FDA's website to see a list of authorized tests.
This COVID-19 test detects certain proteins in the virus. Using a long nasal swab to get a fluid sample, some antigen tests can produce results in minutes. Others may be sent to a lab for analysis.
Accuracy: The BinaxNOW test correctly gave a positive result 84.6% of the time compared to PCR. In the same study, the test correctly gave a negative result 98.5% of the time.
“PCR tests are more reliable and accurate due to testing the specific genetic material of the virus, eliminating the interference from other viruses,” said Heather Seyko, a Laboratory Services manager for OSF HealthCare.
However, at-home COVID-19 antigen tests are generally expected to detect the SARS-CoV-2 virus at least 80% of the time when someone is infected.
“PCR would be chosen where there is a low likelihood of having the virus, but we want to be certain the patient doesn't have it. Antigen would be chosen if there is a high probability the patient has the virus (i.e. is experiencing symptoms), and we need to screen the patient as positive or negative,” Heather said.
PCR tests are more accurate than antigen tests. "PCR tests are the gold standard for detecting SARS-CoV-2," says Dr. Broadhurst. "It is the most accurate testing modality that we have.
There is a very small chance that this test can give a positive result that is wrong (a false positive result). Your healthcare provider will work with you to determine how best to care for you based on your test result(s) along with your medical history, and your symptoms.
Reverse transcription polymerase chain reaction (RT-PCR)-based diagnostic tests (which detect viral nucleic acids) are considered the gold standard for detecting current SARS-CoV-2 infection.
PCR tests are very accurate when properly performed by a health care professional, but the rapid test can miss some cases.
The good news is that, according to the World Health Organization (WHO), PCR and rapid antigen tests can still detect Omicron as well as previous variants.
RT-PCR tests are not perfect, Alland said. “After the first week of infection, there is a decline in virus shedding in the respiratory tract, where tests can become falsely negative,” he said.
In people who did not have COVID-19, antigen tests correctly ruled out infection in 99.6% of people with symptoms and 99.7% of people without symptoms.
PCR tests are more accurate than antigen tests. "PCR tests are the gold standard for detecting SARS-CoV-2," says Dr. Broadhurst. "It is the most accurate testing modality that we have.
A single antigen test may only be able to correctly identify the virus 60% of the time in patients who have the omicron variant and who display symptoms of the disease, Tim Stenzel, director of the Food and Drug Administration's Office of In Vitro Diagnostics and Radiological Health, said during a Wednesday meetin.
Antigen tests typically give results in just 15 minutes, can be done at home by yourself, and are much less expensive than PCR tests.