What is the Difference Between the Types of Tests Available for COVID-19?

Testing for COVID-19 remains one of the most important strategies for preventing outbreaks and the spread of such a pervasive, volatile virus. It’s how we identify those who could infect others, and it’s also the primary way we learn how the virus spreads and evolves. 

When COVID outbreaks escalated into a pandemic, testing was not nearly as widespread and available as it is today. In the early stages, many were generally confused about testing due to conflicting reports on where to get tested, how testing was conducted, how long before a patient could receive results, and how much it would cost. The tests and types of COVID tests have narrowed to those most accurate, most timely, and—very importantly—most accessible. 

Luckily, we have a better grasp on a lot of those issues, but questions remain about the types of tests available for COVID-19, and why testing remains a critical tool in fighting and preventing additional spread. 

What Types of Tests are there? 

COVID testing involves the analysis of biological samples from a patient to identify evidence of a current infection—or if there was a prior infection, and antibodies are present. There are two main types of testing for COVID: molecular (or PCR) identifies the presence of the virus’ DNA, and antigen detects pieces of a protein on the outside of the virus that indicates infection. 

How the testing is completed, its accuracy, and its application is dependent on the way the test identifies the presence of the virus. For example, antigen tests are faster and easier to process than molecular—testing for proteins instead of DNA—but they tend to be somewhat less accurate. While more sensitive and requiring laboratory analysis, molecular tests tend to provide the most sensitive and specific results. 

The other type of testing brought up often surrounding COVID-19 is the serology test: different from molecular or antigen which look for current infection, serology tests analyze for antibodies. The body creates antibodies in response to an infection, and the ones specifically related to COVID-19 can be identified. 

Serology testing is the only test conducted as a blood test for COVID-19, because it measures the antibodies found in your blood. Molecular (PCR) and antigen tests are typically done with a nasal swab to collect samples, but these can also be done as a mouth swab COVID test. While serology can be helpful with providing data about who has had COVID, it is still unknown if the possession of antibodies creates immunity against COVID. 

What is the Antigen Test for COVID 19?

Antigen tests for COVID-19 try to identify a specific protein that is produced as part of the immune response when a person is infected with the virus. So the antigen test involves swabbing an infected area—generally a nasal or saliva sample—and looks to identify those proteins, usually from surface spikes like those seen in popular COVID-19 pictures. 

Antigen tests are unique because they can detect the virus prior to symptoms. And, they are easily conducted and distributed, cheap, and only require a few minutes before you receive a result. Keep in mind the reason testing is important: not only does it help diagnose individuals, but mass testing effectively reduces the spread as more contagious people are identified and quarantined. So rapid response tests are especially useful for large-scale, quick testing. 

What does PCR Stand for?

The PCR is the most accurate and reliable of all COVID-19 tests. The PCR in molecular testing stands for polymerase chain reaction, and this references the lab technique used to detect genetic material of COVID, signifying infection. By understanding what is being tested, we can define a PCR COVID test meaning and know why this test is different from antigen or serology testing. In this case, testing the genetic material differentiates it from other tests. By doing so they achieve a more accurate, decisive diagnosis. 

The PCR test will produce either a positive or negative result. However, a negative result might mean that the PCR test was conducted early-on in the infection and did not have enough of the virus in your body to be detected.

COVID testing has come a long way since it became widely needed due to the pandemic. And despite the introduction of vaccines and the decreasing numbers of infections, it remains one of the most important health care tools to prevent and contain further sickness. 

That’s why companies like BioCollections Worldwide, a leading diagnostics and testing provider, remain vigilant in keeping up to date with developments in testing and work to provide accurate, available testing—especially for COVID. With over twenty years’ experience, BioCollections was already looking into COVID-related testing developments prior to the pandemic. 
Click here for information and hours at our many rapid COVID-19 testing sites located throughout the United States and around the world.