Coronavirus (COVID-19) testing: What you should know
Updated Nov. 23, 2020

At UC Davis Health, we test patients as part of diagnosing an illness, while they are in our hospital, or as part of a medical procedure they're having with us. We've also partnered with Sacramento County to open five community testing sites across the county:

Monday – 1-5 p.m.
La Familia Maple Neighborhood Center
3301 37th Ave., Room 7
Sacramento, CA 95824 (park on 36th Ave.)
Appointments: 916-990-1311

Tuesday – 8 a.m.-12 p.m.
Natomas Unified School District
1931 Arena Blvd.
Sacramento, CA 95934
Appointments: 916-561-5253

Wednesday – 1-5 p.m.
Tetteh Pediatric Health
7248 S Land Park Dr., Suite 118
Sacramento, CA 95831
Click here for appointments.

Thursday – 1-5 p.m.
Robertson Community Center
3525 Norwood Ave.
Sacramento, CA 95838
Appointments: 916-567-9567

Friday – 8 a.m.-12 p.m.
South Sacramento Christian Center
7710 Stockton Blvd.
Sacramento, CA 95823
Appointments: 916-681-6791

Get more information on COVID-19 testing sites in Sacramento County

Find a COVID-19 testing site in California near you 

The diagnostic test, known as a molecular PCR test, uses a nasal swab and collects samples of cells and fluids from your respiratory system. It enables the identification of specific genes for the SARS-CoV-2 virus that causes COVID-19. The specimen is collected using a long nasal swab that is inserted into the passageway between the nose and the back of the throat.

Antigen tests account for most of the rapid diagnostic tests. It's done with a nasal or throat swab and looks for a protein that’s part of the novel coronavirus (COVID-19). Antigen tests are less expensive and have a generally quicker turnaround time. However, they can be less accurate because if a person is not near peak infection, but still contagious, the tests may come back negative. The CDC advises people who show COVID-19 symptoms but test positive with an antigen test to get a PCR test to confirm results.

An antibody test, also known as a serology test, is done with a blood sample that may identify past infection of the virus that causes COVID-19. It’s a test that looks for evidence of the body’s immune response to the virus. Antibodies are detected in the blood after an infection. However, with COVID-19, we don’t fully know what the presence of its antibodies means yet.

Learn more about novel coronavirus (COVID-19) testing

Antigen tests are known to be less sensitive than viral tests. These COVID tests perform best with people in the early stages of COVID-19 infection, when viral load is the highest. No test is completely accurate, which means that some cases will be missed (false negatives) and some people will be told they have the virus when they don’t (false positives). Positive tests tend to be accurate, but negative tests need to be interpreted with caution, especially in a high-risk setting or when used on asymptomatic individuals. However, some experts argue that widespread testing, even when it’s less accurate, can still help contain the COVID-19 pandemic.

Learn more about COVID rapid tests

UC Davis Health has rolled out a groundbreaking, highly accurate test that can check for both COVID-19 and flu viruses at the same time, returning results in 20 minutes. We are the first in the region and among the first in the nation to use these rapid, combined molecular tests at the point of care.

For now, the combined COVID-19 and flu tests will be limited to the emergency department or situations when speed is critical to understand a patient’s condition. Fast, accurate flu and COVID-19 results can help with management and treatment of both viruses. They can also eliminate hours or sometimes days of anxiety for patients.

Read more about the rapid test for flu and COVID-19

Learn more about COVID rapid testing

Yes. Our clinical laboratory began internal testing in March, using CDC assays (tests to determine the presence of infectious agents like the novel coronavirus).

At the same time, we developed high-throughput assays on the Roche Diagnostics cobas® 6800 System to meet an expected surge in cases. The commercial device has the capacity to perform more than 1,000 tests per day, if the need arises. Since we began testing in March, we have performed more than 10,000 molecular tests.

Clinical pathologists, infectious disease physicians and scientists at UC Davis Health are now collaborating on new reagents (substances used for chemical analysis), diagnostic tests and a possible vaccine for COVID-19 in the hopes of preventing and treating the infection.

We don’t really know what the presence of coronavirus antibodies means. It doesn’t necessarily mean that you’re immune to the novel coronavirus (COVID-19). Medical science has yet to determine what level of antibodies confirm immunity, if immunity is possible, or how long immunity might last. The virus that causes COVID-19 was only discovered in December 2019. The result of a positive antibody test means nothing given the current gaps in knowledge about COVID-19. Until there is more definitive information, we should assume, even with positive antibodies, that a person may still be susceptible to the novel coronavirus.

The worldwide COVID-19 pandemic involves information that is continually evolving as public health officials and scientists collect more data and develop a better understanding of coronavirus. We have information and resources for health professionals, including information for community providers and COVID-19 FAQs for health professionals.

Get the latest information for health care professionals from UC Davis Health