COVID-19 testing 101
EDITOR’S NOTE: This story was updated on Jan. 13, 2022 to note new close contact testing recommendations and the new drop-off testing option on select campuses.
At this point in the pandemic, it’s likely that you or someone close to you has wanted or needed to be tested for COVID-19. But what type of test is best for your situation, and what do the different types of tests mean?
Let us help you sort it out.
Types of tests
The three most common types of tests for COVID-19 are PCR tests, antigen tests and antibody tests.
This test will tell you if you have an active case of COVID-19. PCR tests can use either saliva or a nasal swab to gather a sample.
From the collected sample, a lab determines whether it contains genetic material from the virus. If genetic material is detected, the test is positive.
IU uses saliva-based PCR tests for all on-campus COVID-19 testing (COVID Check, voluntary asymptomatic, symptomatic). Results are typically back in 24 to 48 hours.
PCR tests are highly accurate. They are both sensitive and specific, with false positives being rare.
This test may sometimes be called a rapid test and will also tell you if you have an active case of COVID-19. Antigen tests can also use either saliva or a nasal swab to get a sample.
This test looks for specific proteins on the surface of the virus. A positive test result from an antigen test also means it is very likely that you have an active case of COVID-19.
Antigen test results are typically available in less than an hour.
Unlike PCR and antigen tests, which let you know about an active COVID-19 infection, antibody tests tell you about old infections with coronaviruses. There are still a lot of unknowns about antibody testing, however.
These tests don’t tell the whole story in terms of our immune cells and our overall ability to respond to infection. In addition, we don’t know the amount of antibodies needed for protection against COVID-19 like we do with other diseases, so these tests are of limited help at this time.
False positives may occur after exposure to other non-COVID-19 coronaviruses. False negatives may occur early in a disease or a few months after true infection. IU does not currently use antibody testing.
Where and how to get tested at IU
All IU campuses, including IUPUI, offer COVID-19 testing for faculty, staff and students. All tests are saliva-based PCR tests with results back in 24 to 48 hours. Appointments are required for all types of testing.
COVID Check testing is required for any IU faculty, staff or student who is not fully vaccinated. Appointments are scheduled via a link sent to these individuals’ IU email addresses each Friday.
Asymptomatic testing is available for all IU faculty, staff and students who want to know their COVID-19 status as well as vaccinated close contacts five days after their exposure. Appointments are made online. This testing should not be used if you have any COVID-19 symptoms.
Symptomatic testing is also available for all IU faculty, staff and students on all campuses. If you’re having any symptoms of COVID-19, start with IU’s symptom checker to let us know what symptoms you’re experiencing. You’ll then receive an email to your IU email address with a link and instructions for scheduling your appointment.
Drop-off testing is available on the IU Bloomington, IUPUI and IU Southeast campuses. Drop-off testing should especially be used for symptomatic testing, but may also be used for required COVID Check testing and voluntary asymptomatic testing. This option involves picking up a test kit on campus, providing your saliva sample at your convenience and then dropping it back off in your campus’s designated location(s).
Learn more about COVID-19 testing in our FAQ on iu.edu/covid.
Amanda Roach is a senior communications consultant in the Office of the Vice President for Communications and Marketing.