PCR Testing for COVID-19

An Overview

The Life Sciences Testing Center is CAP-accredited and CLIA-certified to perform high-complexity molecular testing for SARS-CoV-2. Considered the gold standard for testing, real time reverse transcriptase polymerase chain reaction (qRT-PCR) testing amplifies DNA strands in order to identify the genome responsible for COVID-19 within a few days of infection, making the test far more sensitive and reliable than antigen testing for COVID-19. Sample collection takes place at designated collection sites, including at Northeastern’s Boston and Burlington campuses. The samples are then transported to the LSTC for testing and analysis, and results are delivered to patients virtually within 12-48 hours.

LSTC scientists swab for daily COVID-19 testing. (Photo by Matthew Modoono/Northeastern University)

An LSTC tech processes samples. (Photo by Matthew Modoono/Northeastern University)

Samples are pipetted during the sample preparation process. (Photo by Matthew Modoono/Northeastern University)

The Testing Process: Step By Step

Step 1: Sample Collection

Nasal swabs are collected at Northeastern’s Cabot Center (for routine tests) and at the Huntington Avenue Testing Clinic (for symptomatic tests). Unlike the notorious “brain ticklers,” these tests are a simple lower nasal swab, painless and easy to self-administer. Members of the Northeastern community in Boston — including students, faculty, and staff — are required to get tested every three days in order to participate in on-campus functions.

Step 2: Receiving

After the samples are collected, they are couriered to the Life Sciences Testing Center at the Burlington campus. Once the samples arrive at the LSTC, they are scanned into the patient management system and individually verified before being prepared for testing and analysis.

Step 3: Extraction

Once the samples have been received and documented, they are prepared for nucleic acid extraction. The samples are run through liquid handlers which automate the procedure to isolate the purified nucleic acids needed for the PCR testing of the samples.

Step 4: Processing

Once the purified nucleic acids have been extracted, the samples can be processed by the PCR machines. First, the reverse transcriptase cycle is run, which builds a nucleotide strand complementary to the single-stranded viral RNA. Then, the PCR thermocycler alternates high heat cycles to denature (“unzip”) the DNA strands, cooling cycles which allow the strands to bind to the primers and probes, and mid-temperature cycles which amplify (extend) the targeted genetic sequences of any viral RNA present in the samples. This process is repeated for multiple cycles, allowing the RNA to be amplified exponentially. As the targeted genetic sequences of SARS-CoV-2 multiply, probes in the mixture fluoresce, signalling the presence of virus in the sample.

Step 5: Resulting

Following PCR analysis, the raw data are uploaded into an interpretive software program designed to determine whether samples are COVID positive, negative, inconclusive, or invalid. A General Supervisor then reviews the interpretive software output for approval of results. Once approved, negative results are reported directly to the patient and provider via the patient results portal, as are any tests which are determined to be inconclusive or invalid after repeat testing. Any positive results are sent to the Technical Supervisor; once reviewed and approved, they are released to the patient and provider, and reported to the Massachusetts Department of Public Health. The full test process takes 12-48 hours, delivering quick and reliable test results to patients.

LSTC Receives Emergency Use Authorization for Home Collection Testing

The Life Sciences Testing Center has received Emergency Use Authorization (EUA) from the FDA to distribute home collection kits for the detection of COVID-19. Have questions about the testing process or the purpose of the test? Click on the applicable fact sheet below to learn more about the LSTC’s home collection kits and the FDA’s EUA.

Disclaimer: This product has not been FDA cleared or approved, but has been authorized for emergency use by FDA under an EUA for use by the authorized laboratory. This product has been authorized only for the detection of nucleic acid from SARS-CoV-2, not for any other viruses or pathogens. The emergency use of this product is 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 Federal Food, Drug, and Cosmetic Act, 21 U.S.C. 360bbb-3(b)(1), unless the declaration is terminated or authorization is revoked sooner.

LSTC Receives Emergency Use Authorization for Home Collection Testing

The Life Sciences Testing Center has received Emergency Use Authorization (EUA) from the FDA to distribute home collection kits for the detection of COVID-19. Have questions about the testing process or the purpose of the test? Click on the applicable fact sheet below to learn more about the LSTC’s home collection kits and the FDA’s EUA.

Disclaimer: This product has not been FDA cleared or approved, but has been authorized for emergency use by FDA under an EUA for use by the authorized laboratory. This product has been authorized only for the detection of nucleic acid from SARS-CoV-2, not for any other viruses or pathogens. The emergency use of this product is 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 Federal Food, Drug, and Cosmetic Act, 21 U.S.C. 360bbb-3(b)(1), unless the declaration is terminated or authorization is revoked sooner.