What is COVID-19?

COVID-19 (formally known as 2019-nCoV) is the name for the respiratory syndrome caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The World Health Organization has declared COVID-19 a pandemic.

What are the symptoms of COVID-19?

Symptoms of COVID-19 include fever, loss of smell, coughing (typically dry), sore throat, shortness of breath or difficulty breathing, feeling weak or lethargic, chills, muscle pain, lightheadedness or dizziness, headache, vomiting or diarrhea, slurred speech, and/or seizures. Other unknown or rarer symptoms may also arise. It can take up to 14 days for symptoms to develop but on average patients have developed symptoms within 5-6 days.

How do I get tested for COVID-19?

Appointment for travel testing can be booked online at www.targetdxlab.com. Click Book Your Test and follow the instructions on how to register.

You can also email info@targetdxlab.com to make an appointment or for further details regarding getting tested.

What types of tests are available for COVID-19?

Two types of tests are available for COVID-19 – a molecular test for active infection and an antibody test that might tell you if you have had a past infection.

The molecular test for active infection involves collecting swab specimens from your nose or throat. The antibody test involves collecting a sample of the blood.

What tests does TargetDx Laboratory offer for COVID-19?

TargetDx Laboratory offers both molecular and antibody COVID-19 tests.

For the antibody test (post-infection), TargetDx utilizes an enzyme linked immunoassay for an in-vitro qualitative detection of antibodies (IgM, IgG, and IgA combined) and a colloidal gold (IgM or IgG independent) to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in human serum and plasma. The test is intended to aid in the determination of the immune reaction to SARS-CoV-2.

For the molecular test (active infection), TargetDx utilizes a nucleic acid amplification test (NAAT) using Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR) test intended for the qualitative detection of nucleic acid from SARS-CoV-2. This assay detects ORF1ab, N, and S genes of SARS-CoV-2, plus an MS2 phage control.

These tests are only authorized for Emergency Use Authorization (EUA) in laboratories in the United States, certified under the Clinical Laboratory Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, to perform high complexity tests.

How accurate are COVID-19 tests offered by TargetDx?

Lab test accuracy is measured in two ways—specificity and sensitivity.
The antibody tests currently offered by TargetDx Laboratory have specificity values of 99.5% which keeps false positive results to a minimum. The antibody test sensitivity values are approximately 99.5% to 100%.

The antibody tests provided by TargetDx have met validation standards and have been granted Emergency Use Authorizations (EUA) by the FDA for public health and clinical use.

The active infection (molecular) tests currently performed by TargetDx have been validated for FDA Emergency Use Authorization (EUA) for the current pandemic. Based on a validation study using 20 bronchoalveolar lavage (BAL) and 20 NP (Nasopharyngeal) swabs, the test was able to detect 100% of positive specimens accurately.

How do I know if I’m recovered from COVID-19?

You are considered “recovered” from COVID-19 and no longer infectious if it has been at least 10 days from start of your first symptoms, at least 24 hours without a fever, and all other symptoms have since improved.

An antibody test may also be able to detect if you have previously had an infection and already recovered, even if you never experienced symptoms. Detecting antibodies suggests you may possibly have a lower risk of getting COVID-19 again. However, more research is still needed.

Will I contract COVID-19 again if I test positive for antibodies?

More research is needed on this because it is not yet known how long antibodies will last after infection and whether antibodies offer short- and/or long-term protection against getting infected again. Some studies are showing the SARS-CoV-2 IgG antibodies lasting up to 4 months, with potential to last longer. On the other hand, there have also been cases of patients being reinfected by a new infection after recovering from COVID-19, though these cases are rare. Ultimately more research and longer studies are needed to have an answer on the matter. See more information regarding antibodies in later sections.

Why should I get tested for COVID-19?

If you suspect you have COVID-19 or were recently in contact with someone who had it, a swab test can tell you whether you have an active infection. Knowing if you currently have COVID-19 gives you the information you need to self-isolate and protect everyone around you.

If you suspect that you previously had COVID-19, even if you never showed signs of being sick, you can take an antibody blood test to confirm prior infection. If the test detects antibodies, you may possibly have a lower risk of getting the virus again.

Understanding your antibody status also gives you and your healthcare provider the insight to make an informed decision about returning to activity. Other reasons why it is beneficial to know if you are positive for COVID-19 antibodies include:

  • Encouraging those you were in contact with to talk to their doctor about getting tested
  • Reducing the need to be monitored and retested for COVID-19 infection
  • Donating plasma for those who are seriously ill from COVID-19
  • Doing your part to slow the spread of the virus by being counted in global pandemic statistics
How quickly can I get my COVID-19 test results?

Our current turnaround time is 24-30 hours. We will email a copy of your test result as an encrypted and password protected PDF file, as well as provide you with a patient portal for access.

Can I order this test online for myself?

You can email appt@targetdxlab.com to book an appointment or get more information regarding appointments. For travel testing questions please refer to our FAQs for Travelers.

If you suspect you have active COVID-19 infection or have been exposed to the virus, contact your doctor or an authorized healthcare provider. If testing is right for you, your healthcare provider will direct you to where to get tested.

Are COVID-19 test covered by my insurance?
  • If the patient has insurance, the patient’s health plan is required to pay for approved COVID-19 tests in the State of California. Providing your insurance information allows for billing the cost of the test to the insurance.
  • If the patient does not have insurance, the federal government through the Families First Coronavirus Response Act, the Coronavirus Aid, Relief, and Economic Security (CARES) Act and other legislation will be assisting in covering the cost.
  • The patient can also pay for the test out-of-pocket
  • Travel testing is not covered by insurance.
  • Antibody testing is also not covered by insurance unless deemed medically necessary by your physician.
What if I do not have health insurance and I need screening or treatment for COVID⁠-⁠19?
  • Check with your local community health center or hospital to see if fees for testing can be waived
  • See if you are eligible for Medi-Cal
  • See if you are eligible for Covered California
Can someone test negative and later test positive of COVID-19?

Yes, it is possible. You may test negative if the sample was collected early in your infection and test positive later during this illness. You could also be exposed to COVID-19 after the test and get infected then. Even if you test negative, you still should take steps to protect yourself and others.

Important information about COVID-19 antibody testing

The test is designed to detect antibodies specific to SARS-CoV-2, the virus that causes COVID-19. Antibodies are proteins that the body produces in response to infections. The antibodies can be produced even if a person has few or no symptoms during the infection.

It generally takes some time after infection for antibodies to be produced and become detectable in blood (sometimes up to 3 weeks). It is important to remember that we do not yet know whether having antibodies to SARS-CoV-2 will prevent against getting the infection again or if you are totally free of the virus. Antibodies are generally detectable in the blood for a period after a person has recovered from the infection and after the virus that caused the infection is no longer detectable by laboratory methods.

Sometimes the antibodies developed in response to an infection protect us from getting that same infection again. However, it is important to know that we do not yet know whether this is true for COVID-19. Even if you have recovered and have antibodies, there is a chance that you still have the virus and can infect others. It is still critical to keep taking measures to avoid getting infected again and/or spreading infection.

Our body produces 3 types of antibodies: Immunoglobins G, A, and M. When fighting an infection, your body produces IgM antibodies as a first defense. IgA antibodies are produced to protect mucosal membranes. IgG antibodies hold potential to keep us immune from the same infection in the future. If IgA and IgM’s are being detected, it is possible it is from a recent infection, but still should not be used to diagnose an active infection.

The antibody test is not meant for detecting an active infection.

The swab test (sometimes also known as a molecular, RNA or PCR test) should be used to test for active infection.
A negative antibody test result means that antibodies were not detected in your blood sample. This can have several possible meanings, including:

  • You have not been infected with SARS-CoV-2
  • You have been infected with SARS-CoV-2, but your antibodies have not reached a sufficient level to be detected
  • You have been infected with SARS-CoV-2, but there has not been enough time for antibodies to develop (it can take up to one to three weeks to develop antibodies after someone is infected, sometimes longer).

A positive antibody test result means that antibodies were detected in your blood sample. This can have a couple of possible meanings, including:

  • You have potentially been exposed to SARS-CoV-2 in the past.
  • A false positive result may have occurred due to cross reactivity from pre-existing antibodies or other possible causes.
  • It is important to note:
    • A positive result does not exclude recently infected individuals who are still contagious.
    • It is unknown how long antibodies to SARS-CoV-2 will remain present in the body after infection and if they confer immunity to infection.
Vaccine Interference in Antibody Testing – Will the vaccine cause me to test positive?
  • Our antibody testing detects antibodies specific to the SARS-CoV-2 nucleocapsid protein (also referred to as the N protein)
  • Current U.S. vaccines elicit a response to the SARS-CoV-2 spike protein, resulting in antibodies specific to the S protein, not the N protein.
Mutation Interference in Testing – What about SARS-CoV-2 Variants?

We expect the new variant from the UK, B.1.1.7, to be detected by our test because it screens for three regions of interest:
• S Gene (Spike protein)
• N Gene (Nuclear Capsid protein; at virus’ core)
• ORF Gene
The variant has most its mutations in the S protein, so even if the RT-PCR does not detect the variant’s S gene, it still checks for both N & ORF genes.

COVID-19 testing statements

The antibody test and the molecular test (together “All tests”) have not been FDA cleared or approved.

1- All tests have been authorized by FDA under Emergency Use Authorization (EUA) for use by authorized laboratories.

2- The antibody test has been authorized only for the detection of IgG antibodies against SARS-CoV-2, not for any other viruses or pathogens.

3- The molecular test has been authorized only for the detection of nucleic acid from SARS-CoV-2, not for any other viruses, pathogens.

4- All tests are only authorized for the duration of the declaration that circumstances exist justifying the authorization of emergency use of in vitro diagnostics for detection and/or diagnosis of COVID-19 under Section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner.


1) Centers for Disease Control and Prevention. 2020. Coronavirus Disease 2019 (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html. Accessed 13 July 2020.
2) Questdiagnostics.com. 2020. Faqs. [online] Available at: https://www.questdiagnostics.com/home/Covid-19/Patients/FAQs/. Accessed 12 July 2020.
3) https://virological.org/t/preliminary-genomic-characterisation-of-an-emergent-sars-cov-2-lineage-in-the-uk-defined-by-a-novel-set-of-spike-mutations/563
4) https://directorsblog.nih.gov/2020/10/20/two-studies-show-covid-19-antibodies-persist-for-months/
5) https://www.cdc.gov/coronavirus/2019-ncov/more/science-and-research/scientific-brief-emerging-variants.html