Test Quick Guide

Molecular COVID-19 tests are designed to detect an active infection with SARS-CoV-2, the coronavirus that causes COVID-19.

The most well-known molecular test uses a laboratory method known as reverse transcription polymerase chain reaction (RT-PCR), often called PCR.

PCR and molecular tests look for the virus’s genetic material in your test sample, usually taken by swabbing your nose or throat. Molecular tests analyzed by a laboratory are generally considered the most accurate method of diagnosing COVID-19.

About the Test

Purpose of the test

PCR and other molecular tests determine if you have an active infection of SARS-CoV-2. The test may be used for diagnosis, screening, and monitoring.

A molecular test is used for diagnosis when you have signs or symptoms of COVID-19. It is utilized for screening if you are asymptomatic but may have had exposure to the virus, such as through close contact with an infected person.

In some cases, a laboratory-based molecular test confirms the results of other types of tests. For example, a follow-up PCR analyzed by a laboratory may be used after a rapid test, at-home test, or COVID-19 antigen test.

What does the test measure?

Molecular tests are designed to detect the presence of SARS-CoV-2 by measuring very small amounts of the virus’s genetic material.

Genetic material is isolated from your test sample and then copied many times to conduct the test. That genetic material can be analyzed for SARS-CoV-2, and even small amounts can be detected because of the copying process.

Nucleic acids are the genetic material analyzed, and the copying process is known as amplification. For that reason, nucleic acid amplification testing (NAAT) is the technical name for this kind of molecular testing.

There are multiple types of laboratory techniques used to detect COVID-19 and other viruses such as influenza and respiratory syncytial virus (RSV). Some tests are designed to detect the presence of more than one virus in the same sample, for example, a co-infection with SARS-CoV-2 and influenza.

When should I get this test?

There is a range of circumstances in which a molecular COVID-19 test can be appropriate.

If you have symptoms of COVID-19, a PCR test or other molecular test is regarded as the most reliable method to determine whether you have COVID-19. In these cases, the test is used in the process of diagnosis.

A molecular test can also be used for screening. If you have no symptoms, you may get this test if:

  • You have been in close contact with someone diagnosed with COVID-19.
  • You have been in situations at high risk of viral transmission, such as travel or large gatherings.
  • You live or work in an environment like a correctional facility, nursing home, or homeless shelter where there is an elevated risk of viral spread or severe cases of COVID-19.
  • You will have surgery or a medical procedure that generates tiny air particles known as aerosols.
  • You will start taking medication that affects your immune system.
  • You are required to provide a negative test result by your employer to travel or participate in another activity.

Because there are many different applications of molecular COVID-19 tests, your doctor can best explain whether this kind of testing is appropriate in your situation.

It is also important to note getting tested with a PCR or other molecular test can depend on the available testing capacity in your area. When resources for testing are limited, certain testing uses may be prioritized.

Finding a PCR or Other Molecular COVID-19 Test

How can I get a PCR or other molecular COVID-19 test?

Depending on your circumstances, there are different ways to get a PCR or other molecular test for COVID-19.

If you have symptoms of COVID-19, reach out to your doctor, and if they are severe, go to the hospital or call emergency medical services. A doctor can order diagnostic molecular testing. Similarly, if you have tested positive on a rapid, antigen, or at-home test, contact your doctor, who may choose to confirm that result with a PCR or molecular test.

In some cases, such as after close contact with a person with COVID-19, a doctor may order testing to screen for SARS-CoV-2 infection even if you are asymptomatic.

If your doctor recommends a PCR test, they may either take the test sample in their office or refer you to another location, such as a laboratory or drive-through testing site, where a swab can be done in your nose or throat.

Not all PCR tests require a physician’s order. For many types of screening, you can contact a laboratory or health clinic directly for test options. You can order COVID-19 PCR test kits online.

Some molecular tests for COVID-19 have been developed as point-of-care tests, which provide results without sending your sample to a laboratory. These rapid and at-home tests may need confirmation with a repeat molecular test analyzed by a laboratory.

Can I take the test at home?

At-home PCR tests are available both with and without a physician’s order. These molecular COVID-19 tests generally fall within two categories:

  • At-home self-collection tests: You take a swab of your nose or throat or collect a saliva sample and send it by mail to a laboratory. Results are normally available within a few days after your sample is received by the lab.
  • At-home self-tests: These also involve taking your test sample, but that sample is then analyzed at home using a device included in your test kit. This type of tests often provides results within 30 minutes.

With either type of at-home test, it is essential to follow the test kit’s instructions for properly collecting your sample and avoiding potential sources of contamination.

While at-home tests are generally accurate, they are not considered to be as reliable as standard laboratory testing. Rapid tests are more likely to produce an inaccurate result than tests processed in a lab.

If you test positive, contact your doctor, who may want to perform a confirmatory PCR. You or your doctor may also need to contact your state health department that is responsible for tracking the number of COVID-19 cases.

How much does the test cost?

The cost of a PCR or other molecular test depends on where the sample is collected, how the sample is analyzed, whether a doctor orders the test, and whether you have health insurance.

Potential components of testing costs include office visits, technician fees for taking a nasal or throat swab, and charges for molecular analysis by the laboratory. When prescribed by a doctor, most of these costs are covered by insurance, but you may be charged a copay or deductible. In some cases, government programs are covering the full costs of COVID-19 testing.

Talk with your doctor and insurance provider to determine which test is most appropriate for you and what out-of-pocket costs you will be required to pay for testing.

Taking a PCR or Other Molecular COVID-19 Test

Molecular COVID-19 tests are typically conducted on samples collected from the respiratory tract. In most cases, the sample is taken with a nose or throat swab. Some tests can be done with a saliva sample.

Depending on the specific molecular test, the sample can be collected in many different places, including a hospital, doctor’s office, health clinic, drive-through testing site, pharmacy, laboratory, or even at home.

Before the test

No special steps are required to prepare for a molecular COVID-19 test other than possibly abstaining from eating or drinking for 30 minutes before taking a saliva sample.

For at-home tests, it is important to follow any suggested steps to clean the area where you will prepare the test kit so that you can avoid contamination that might affect your test sample.

During the test

Your experience during the test can vary based on the type of sample required. Swabs may be needed from your nose or throat. To obtain the sample, a swab is inserted into your nose or throat, left in place for a few seconds, and then turned a few times. A sample may be taken from both nostrils.

You may find the procedure uncomfortable, especially if it requires inserting the swab deeper into your nostril to reach the nasopharynx, which is behind the nose. Your eyes may water, or the test may cause you to gag or flinch. The entire process is usually finished within minutes and normally does not cause any lasting pain.

Saliva can be used for certain molecular tests. This requires spitting into a tube until you have collected a sufficient amount of saliva.

After the test

Once your test sample is collected, you can leave the testing site and should not expect any side effects.

While the test does not require any restrictions on activity, if you are being tested because of symptoms or potential exposure to the SARS-CoV-2 virus, follow appropriate precautions to prevent the potential spread of the virus to others. This includes avoiding close contact with other people and large gatherings, wearing a mask, and washing your hands frequently.

PCR and Molecular COVID-19 Test Results

Receiving test results

If your test sample is sent to a laboratory to be analyzed, results are usually available in one to three business days. Turnaround time can depend on the demand for testing and available laboratory resources. You may get a phone call with your test result or receive a test report either electronically or by mail.

Rapid PCR test options can provide results in less than 30 minutes. These are also known as point-of-care tests because the sample is analyzed on-site and does not need to be sent to a laboratory. Some at-home tests are point-of-care options with rapid results.

Interpreting test results

The test result is generally listed as either detected or not detected.

A positive result means that SARS-CoV-2 virus genetic material was found in the test sample. This is sufficient to diagnose COVID-19, although you may not have any symptoms.

If you test positive, it is essential to take steps to avoid spreading the virus to other people even if you don’t have any symptoms. Please speak with your physician and refer to the Centers for Disease Control and Prevention (CDC) guidelines for isolation and quarantine.

A negative test indicates that no genetic material of the virus was present in your sample. In most cases, this means that you do not have COVID-19. However, a false negative result can occur if the level of the virus is too low to detect when testing is done shortly after being infected.

Your doctor is in the best position to review your test report and explain what it means for your health.

The following questions may be helpful to bring up when you discuss your COVID-19 test result with your doctor:

  • Which type of molecular test did I have, and how accurate is that testing method?
  • Based on my test result, do I need to take any special precautions related to COVID-19?
  • Is there any benefit to repeating the test?
  • Are there other types of tests that might be helpful in my situation?


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