The various COVID-19 tests on the market are definitely NOT the same thing. It’s important to understand these differences to ensure the lab result is interpreted correctly. Especially if the results are yours or belong to someone you care about.

The main three tests on the market are (1) molecular tests, (2) antigen tests and (3) antibody tests. From now on we’ll refer to SARS-CoV-2, the virus that causes the disease called COVID-19.

MOLECULAR VS. ANTIGEN VS. ANTIBODY

SARS-CoV-2 (COVID-19) MOLECULAR TESTS EXPLAINED

Of the 3 main types of testing, molecular is the most common.

These tests use a nasal, nasopharyngeal (the super deep and uncomfortable one) or saliva sample to look for the genetic blueprint of the SARS-CoV-2 virus. The blueprint is its RNA or ribonucleic acid.

These molecular, or nucleic acid tests are the gold standard. The greater medical community considers them the best because they can take a very tiny amount of RNA and amplify it with a process that makes tons of copies. These duplicates help identify if SARS-CoV-2 is present or not.

This amplification process is called Polymerase Chain Reaction (PCR). Don’t be fooled by the media – PCR technology is not new. It’s been used for many years to diagnose infectious diseases. Due to the complexity of the PCR method, these tests are usually sent off to a laboratory.

Molecular testing is the gold standard.

ADVANTAGES & DISADVANTAGES OF PCR TESTING FOR SARS-COV-2

PCR’s increased complexity offers some serious advantages. Here’s why it’s worth the extra time in the lab.

The PCR method is considered highly accurate. You can trust that a positive or negative result is correct. All clinical tests come with a certain sensitivity, and these top the list.

What’s the major limitation, you ask? PCR tests are SO good at detecting the virus that you may continue to have a positive SARS-CoV-2 test for weeks after you’re infected – even though you’re not contagious anymore.

To cut a short story long, it is crucial that you consult a physician if you have COVID-19 symptoms or a positive test. And I’m not just saying that because I’m a doctor.

PCR tests are also the most sensitive type of COVID-19 test on the market. PCR tests such as the at-home test from empowerDX have a limit of detection (LoD) as low as 180 NDU/mL. What’s the limit of detection, you ask? The LoD is essentially the lowest amount of a given substance that the test needs in order to detect the virus.

SARS-COV-2 ANTIGEN TESTS EXPLAINED

Antigen tests are the most common rapid tests. Results come back in a matter of minutes. But is faster actually better?

These tests look for the virus capsid, which functions as an envelope or shell around the SARS-CoV-2 virus. While this method is appealing because of the super fast turnaround time, there are critical trade-offs to understand.

Consider this: most antigen testing performs well only in the first few days after symptoms begin. A positive antigen test is considered highly accurate, but a negative test is not considered accurate.

Negative tests should be followed up with a molecular PCR test to confirm a truly negative result. Particularly if you’re putting others at risk around you.

SARS-COV-2 ANTIBODY TESTS EXPLAINED

Do you ever wonder if you were previously infected with COVID-19? With an antibody test, you can see if your immune system has responded to the SARS-CoV-2 virus in the past – regardless of if you experienced symptoms.

Your immune system produces different kinds of antibodies in response to any viral infection. In the case of SARS-CoV-2, IgG antibodies have been shown to last for up to 8 months, according to two studies from the NIH.

However, these antibodies do not stay in the body permanently, and another study found that while IgG antibodies lasted longer than IgA and IgM antibodies, they did decrease in the second and third month after infection, especially in those who had mild cases of COVID-19.

While testing for IgG antibodies can’t reveal if you’re currently infected with COVID-19 (it takes 1-3 weeks after getting infected for antibodies to develop), they can show if your body has built up possible immunity against COVID-19. If you’ve been vaccinated against COVID-19, you can even use an IgG antibody test to test how your vaccine measures up against its claims of effectiveness.

WHAT SARS-COV-2 (COVID-19) TEST SHOULD I ORDER?

Overall, the best way to get an accurate result is to order a molecular PCR test. Both positive and negative results are trustworthy.

Antigen and antibody testing certainly play an important role in fighting this pandemic. But do your homework before purchasing.

First, cut through the marketing jargon. Be sure you can differentiate PCR, antigen and antibody testing.
Second, read up on the clinician, company or laboratory selling you the product. Is the test FDA authorized? Is the lab CLIA certified? Does the brand have credibility?
Third, compare turnaround time, eligibility and price. After your sample has shipped, does it take 2 days to get results or up to 7 days? Will they let you get SARS-CoV-2 testing even if you don’t have symptoms? Is the price comparable to similar tests on the market?

No matter what route you take, testing will always bring you one step closer to thriving. What one step are you planning to take?