FAQs Regarding SARS-CoV-2 PCR Testing

The FAQs below provide information and guidance for the University and are based on the May 4, 2020 guidance and FAQs issued by NewYork-Presbyterian Hospital. This FAQ guidance describes the polymerase chain reaction (PCR) test for SARS-CoV-2, the virus that causes COVID-19, and our current understanding of the meaning of positive and negative PCR results in individuals with (symptomatic) and without (asymptomatic) symptoms.

Individuals who are SARS-CoV-2-positive, even without any symptoms, should self-isolate at home as described below. Guidance for return to work is also described below.

SARS-CoV-2 is the new coronavirus that causes COVID-19 illness.

There are two different types of tests for COVID-19, one determines whether you have it now (being the time the test was collected) and the other determines if you have had it at some point in the past.

  • To detect a SARS-CoV-2 infection now, a nasopharyngeal (NP) or nasal swab is used to detect the RNA of SARS-CoV-2 virus.
  • To detect that an infection occurred at some point in the past, a serology blood test is done to detect antibodies to SARS-CoV-2

It will take between 24-72 hours to get the PCR test results back.  If individuals are on Connect, the patient portal associated with Columbia’s electronic medical record, or sign up for Connect anywhere during the scheduling and testing process, the results will be available in Connect as soon as the lab finalizes the results. To sign up for Connect, go to myconnectnyc.org. For individuals not on Connect, and if the result is positive for the presence of the virus, individuals will be called as soon as the result is available. For individuals who test at Columbia University Morningside, negative results will be emailed on the day the results are finalized. If the test is done at an NYP testing site, NYP Workforce Health and Safety (WH&S) will call or send a letter when the results are available.

To do the NP or nasal test to detect SARS-CoV-2 virus or parts of the virus, a sterile, small, cotton-tipped swab is gently passed into the nose back to the nasopharynx or the anterior part of the nose (in the case of nasal swabs) to obtain respiratory tract secretions. It is rotated, removed, and placed in a viral transport media and sent to the clinical microbiology laboratories.

The NYP clinical microbiology laboratories that analyze the tests perform PCR assays on the NP or nasal swab specimens to detect the SARS-CoV-2 viral genetic material (RNA). PCR assays can detect live virus, dead virus, or fragments of virus.

  • Individuals with symptoms to see if their symptoms are from SARS-CoV-2. Symptoms of COVID-19 include documented fever or fever to touch, cough, shortness of breath, sore throat, chills or shaking chills, congestion/runny nose, diarrhea, alterations of taste, or loss of smell.
  • Individuals without symptoms who have had close contact with someone with laboratory-confirmed COVID-19 or with symptoms consistent with COVID-19.

Columbia University has also chosen to require initial testing for asymptomatic individuals who are returning to campus.

Columbia University employees and students who are returning to work are required to get tested. Clinical researchers, providers, or trainees as well as other essential employees who have been consistently on campus since March may get the testing but are not required to do so.

A positive PCR test from an individual with symptoms means that a person has COVID-19 and can infect others. These individuals need to be isolated at home. In order to return to work, all of the following criteria must be met:

  • At least 10 days have passed since the onset of symptoms
  • At least 72 hours have passed without fever without the use of antipyretic medications, e.g., acetaminophen (Tylenol), ibuprofen (Advil, Motrin)
  • Marked improvement in symptoms

*Note: When these individuals return to work, they need to continue to use all protective measures against COVID-19 (e.g., use of face covering, adherence to physical distancing) because we do not know yet if someone can be re-infected with SARS-CoV-2.

The PCR test can detect both live and dead virus, or viral RNA fragments.

A positive PCR result in someone without symptoms could mean any of the following:

  • A person has recovered from the virus, but is still shedding the virus and could transmit SARS-CoV-2 to others.
  • A person has recovered from COVID-19  but the PCR is detecting dead virus or viral RNA fragments, and SARS-CoV-2 cannot be transmitted to others.
  • A person is pre-symptomatic or asymptomatic, meaning they may or may not develop symptoms, but is shedding the virus. Asymptomatic or pre-symptomatic people who are PCR-positive can sometimes transmit SARS-CoV-2 to others, although less frequently than those with symptoms.

This is why asymptomatic individuals who are SARS-CoV-2-positive will need to self-isolate at home. They can return to work as long as they remain symptom free after 10 days have passed since the date that their NP or nasal swab was obtained. The NP of nasal swab does not need to be repeated before the individual can return to work.

Individuals with positive PCR tests should obtain guidance regarding their health and how to protect their close contacts from their primary care provider.

*Note: When these individuals return to work, they need to continue to use all protective measures against COVID-19 because we do not know yet if someone can be re-infected with SARS-CoV-2.

No, individuals can return to work as described above. No further PCR testing is required to return to work.

  • Contact health provider to seek advice and care

Before seeking care, an individual should call their provider to help coordinate care.

  • Individuals should put a face mask on before entering a health care facility.
  • Call 911 if there is a medical emergency like significant shortness of breath.

People with COVID-19-like symptoms can have a negative test for several reasons. 

  • A negative test from an individual who previously had symptoms and is now well may mean that a person has cleared the virus and can’t spread the virus to others. 
  • This may be a false negative test meaning that the person does have COVID-19, but that the PCR test did not detect the virus because the level of viral RNA was below the limit of detection. Levels of viral RNA are usually highest in the first 5 days of illness. 
  • False negative tests can also occur due to inadequate or improper NP or nasal swab collection or problems in the transport of the specimen.
  • Sometimes people with symptoms can have a negative test because they have other reasons for their symptoms such as other respiratory viruses, seasonal allergies or asthma.

It is highly likely that a person without symptoms with a negative NP or nasal PCR test does not have COVID-19 at this point in time. These individuals should observe all preventive measures and  and self-monitor for symptoms of COVID-19.

If an individual has a negative NP or nasal PCR test result but has had close contact with a person who is known to be positive, this individual should self-quarantine and continue to self-monitor for symptoms of COVID-19 for 14 days from the time of exposure as there is continued risk of transmission.

Yes. The asymptomatic individual can continue to work while waiting for their test result. They should continue to physically distance and wear a face covering according to University policy. If asymptomatic individuals with close contact of a COVID-19 case get tested, such individuals should self-quarantine for 14 days from the time of exposure.

*Note: For individuals in patient-facing positions, self-quarantine of close contacts is not required, consistent with NewYork-Presbyterian Hospital policies for health care workers.

Not at this time. The laboratory that performs the test is required to notify the NYC Department of Health. New York City or State is responsible for identifying and tracing the contacts of the case and informing individuals who have had contacts that put them at risk of infection, advising them regarding self-quarantine and testing, and providing the necessary support, in addition to maintaining confidentiality.

In the future, Columbia will be developing a Contact Tracing Program to assist the city or state in their contact tracing activities.

Occasionally a person will have an indeterminate NP PCR test result. This is considered a positive result and represents a low level of virus. It does NOT need to be repeated.  The individual with an indeterminate result should follow the guidance described above for a positive test result.

Occasionally, a person will have an invalid NP PCR test result, which is the result of excessive mucus in the sample, which interferes with the test. This person SHOULD have a repeat NP swab sent for SARS-CoV-2 testing.

There will not be a charge for the visit or for the swabbing to obtain a sample, and costs will be covered in full by the individual’s health plan or the University.  

The current SARS-CoV-2 testing strategy at Columbia University includes the following: 

  1. Individuals with symptoms consistent with COVID-19 and those with history of contact with presumed or confirmed COVID-19 case are strongly encouraged to test for SARS-CoV-2.
  2. Individuals who will be returning to campus as of June 22 as part of the first research ramp-up phase are required to have initial SARS-CoV-2 testing within 14 days of return to campus (either before or after date of return). These individuals are likely to be returning from other parts of the country, including possibly from communities with active SARS-CoV-2 transmission, and will be re-entering a closed community of individuals who have been on campus.  The goal of initial testing for individuals returning to campus as of June 22 is to estimate the prevalence of infection among those individuals. Initial testing will help us estimate prevalence among those newly returning to campus and how that compares to prevalence in NYC. It will also assist in design of further testing strategies.  We will continue to evaluate and adjust the testing strategy going forward.
  3. Individuals who have been consistently on campus prior to June 22 are not required to get SARS-CoV-2 testing. These individuals have been in the New York City area, which has experienced a substantial decrease in burden of COVID-19 cases. However, such individuals can obtain SARS-CoV-2 testing, if they desire to do so.

It should be noted that public health measures such as consistent face covering, physical distancing, hand washing, staying home when sick among others, remain the most important measures for prevention of transmission of SARS-CoV-2.



The information provided herein is based on current knowledge and is subject to change as new information becomes available. 

The term PCR testing is used to indicate tests for the diagnosis of infection with SARS-CoV-2, the virus that causes COVID-19. These tests detect viral nucleic acid utilizing the common methodology referred to as reverse transcriptase (RT) – polymerase chain reaction (PCR) amplification (Rt-PCT). Tests which detect viral proteins by immunoassay (antigen detection tests) are under development and some were recently made available. 

Serological tests are another type of COVID-19 related test. Serological tests detect antibodies which are developed by an individual’s immune system. They indicate previous SARS-CoV-2 infection. Additional information on testing can be found at the following:
https://covid19.columbia.edu/content/testing-and-treatment and https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html

The information provided herein is based on current knowledge and is subject to change as new information becomes available.