Combined Real Time PCR Test & Antibody Testing

COVID Testing Options

Promus Diagnostics offers a comprehensive CFR real-time PCR as well as QNAT, a quantitative neutralizing antibody test.


COVID, Flu & RSV (CFR) Test

The Promus Diagnostics’ CFR panel is a real-time RT-PCR test designed for the qualitative detection SARS-CoV-2, Influenza A/B, and Human Respiratory Syncytial Virus A/B.

Promus qNAT quantitative neutralizing antibody test logo

Quantitative Neutralizing Antibody Test

Promus Diagnostics’ qNAT is a semi-quantitative COVID-19 Antibody Test that can measure immune response from prior infection or vaccination.

Combined COVID, Flu & RSV (CFR) Panel

The Promus Diagnostics’ CFR panel is a real-time RT-PCR test designed for the qualitative detection of RNA from the SARS-CoV-2, Influenza A/B (Flu A/B), and Human Respiratory Syncytial Virus A/B (RSV A/B) in respiratory specimens (nasopharyngeal swab and oropharyngeal swab) from individuals suspected of respiratory infections by their healthcare provider.

The CFR panel detects the presence of Influenza and RSV, but does not differentiate between types A or B. In one convenient test, healthcare providers can quickly diagnose the underlying cause of a respiratory infection, relying on the accuracy of RT-PCR technology that examines the presence of SARS-CoV-2, Flu, and RSV at the RNA level of the virus.

CFR is a Laboratory Developed Test (LDT) using Real-Time PCR amplification of defined targets. This test has not been cleared or approved by the FDA, however, approval/clearance is not required as Promus Diagnostics LLC is certified under CLIA to perform high-complexity clinical laboratory testing. CFR is used for clinical purposes and should not be regarded as investigational or for research.

Young nurse with protective face shield administering a nasal swab for COVID testing
  • Rapid turn-around times (24 – 48 hours)
  • Same-day service available
  • 99.99% accuracy rate for true results
  • HIPAA Compliant secure electronic reporting
  • High complexity CAP Accredited & CLIA Certified infectious disease lab

Promus qNAT quantitative neutralizing antibody test logo

Quantitative Neutralizing Antibody Test

Promus Diagnostics SARS-CoV-2 Quantitative Neutralizing Antibody Test (qNAT) is a semi-quantitative COVID-19 Antibody Test that can measure immune response from prior infection or vaccination and provides an individualized level of neutralizing antibody activity.

COVID-19 (SARS-CoV-2) had an enormous impact worldwide. Tests that aid in the identification of SARS-CoV-2 infection, such as RT-PCR testing, have been a valuable tool in slowing the spread of the virus.

However, PCR testing for COVID-19 is only useful if the patient has an active SARS-CoV-2 infection. If a person takes a PCR test after recovering from the virus, the PCR test likely will show a negative result, leaving them wondering if they had COVID-19 or a different virus with shared symptoms.

In addition, research is indicating that the effectiveness of the vaccine wanes over time making it difficult for vaccinated individuals to know their current level of protection against COVID-19 and if it may be time to consider a booster.

Measuring SARS-CoV-2 neutralizing antibody levels is the solution to these problems. When a person is exposed to a virus or receives a vaccine, their immune system produces proteins called antibodies in response to protect the body. Promus Diagnostics’ SARS-CoV-2 Quantitative Neutralizing Antibody Test (qNAT) is a semi-quantitative COVID-19 antibody test that can detect and numerically measure neutralizing antibodies in the blood that are specific to COVID-19 infection or vaccination. The qNAT report provides not only a positive or negative indication of whether antibodies are present, but gives an individualized numerical value that can show the level of immune response.

The importance of COVID-19 neutralizing antibody testing
  • Monitoring Vaccine Efficacy
  • Monitor antibody count from a previous SARS-CoV-2 infection
  • Considering if you are in need of a booster shot
  • Provide actionable information to people in populations of mixed vaccinated and non-vaccinated individuals

Neutralizing Antibodies

SARS-CoV-2 neutralizing antibodies block virus from attaching to cell
  • Specific to fighting the pathogen
  • SARS-CoV-2 Neutralizing Antibodies block the binding of ACE 2 receptor
  • Stops the virus from working and stops replication

  • Sample Type: Blood

  • Results Detected: Provides an estimate on the level of immune response
  • Test Utility – Estimate of level and neutralizing activity of immune response

Non-neutralizing Antibodies

SARS-CoV-2 non-neutralizing antibodies fail to stop virus from binding to cell
  • Non-specific
  • Allows virus to bind to the ACE 2 receptor
  • Virus can replicate inside the cell
  • Sample Type: Swab or Blood

  • Results Detected: Provides yes or no answer to previous infection

Why choose qNAT by Promus Diagnostics?

Promus Diagnostics’ SARS-CoV-2 Quantitative Neutralizing Antibody Test (qNAT) test gives an exact number of the total SARS-CoV-2 neutralizing antibodies from a blood sample that can be collected with a simple finger prick. These neutralizing antibodies are responsible for preventing SARS-CoV-2 from infecting healthy cells. There is growing evidence correlating the presence of neutralizing antibodies to protective immunity, disease severity, and overall survival.

Many different antibodies are elicited from SARS-CoV-2 (COVID-19) immune response or vaccination, but only a subset handcuff the virus so it cannot attach to healthy cells and spread throughout the body. Most commercially available antibody testing for SARS-CoV-2 only detects “Antigen Binding” antibodies, but qNAT can detect “Neutralizing Antibodies” which act as the special forces of the immune response, disarming the virus at just the right point before it can attack our cells.

An antibody test needs to be able to differentiate between “antigen-binding antibodies” and “neutralizing antibodies” because these two types of antibodies serve two distinct purposes in the body’s immune response. The job of antigen-binding antibodies is to attach to the disease-causing pathogen to alert the immune system to produce the needed response to combat the pathogen. Neutralizing antibodies attached to a pathogen in a way that actively prevents the pathogen from entering healthy cells and replicating.

SARS-CoV-2 Neutralizing Antibody is testing for functional antibody response or immunity by detecting SARS-CoV-2 neutralizing antibodies that block how the virus invades the cell. This is the most effective method since the SARS-CoV-2 Neutralizing Antibodies protect against the SARS-CoV-2 virus and aid in the destruction of the virus. Hence, the SARS-CoV-2 Neutralizing Antibody is an important indicator of your immune status against Covid-19.

The qNAT report contains three important results to help you understand your overall protection against COVID-19.


Neutralizing Activity

A quantitative percentile determination of the quantity of virus neutralizing antibodies in a patient’s serum.


Neutralizing Anitbody Titer Value

An exact titer value indicating the amount of antibodies in the blood. If the value exceeds 1500, the individual shows signs of virus neutralization.


qNAT Score

Both the neutralizing activity and titer value determine the semi-quantitative qNAT score. If antibody activity is detected, the interpretation will indicate level of neutralization ranging from low to high. 

The future of COVID-19 protection

Promus Diagnostics’ SARS-CoV-2 Quantitative Neutralizing Antibody Test (qNAT) is a functional Enzyme-Linked Immunosorbent Assay (ELISA) intended for qualitative or semi-quantitative detection of total neutralizing antibodies in human serum, K2-EDTA plasma, peripheral blood, and blood plasma that block the binding of SARS-CoV-2 to the human ACE2 receptor of host cells.

There is growing evidence correlating the presence of SARS-CoV-2 infection or vaccination-induced neutralizing antibodies to protective immunity, disease severity, and survival, which has also been observed for numerous other viral infections. The treatment of SARS CoV-2 with purified neutralizing antibodies correlates to reduced viral load.

Vaccine-induced neutralizing antibodies have also been shown to protect against the newly emerged SARS-CoV-2 variants. Neutralization antibodies to natural SARS-CoV-2 infections are generally detectable in the blood several days after initial infection or vaccination — similar to the time frame for the production of IgG binding antibodies. Post-vaccination, functional neutralization antibodies have been shown to be less abundant and are more closely correlated with vaccine efficacy than total IgG binding antibodies.

Although SARS-CoV-2 infected individuals may have detectable antibodies present for several months following seroconversion and the temporal persistence of neutralization antibodies has been shown to decline, there is no evidence supporting their total duration. qNAT is intended for use as an aid in the identification, semi-quantification, and longitudinal monitoring of the neutralizing antibody response to SARS-CoV-2 post-infection and vaccination. This test was developed by GenScript and has been granted Emergency Use Authorization (EUA) by the FDA.

“Ultimately, neutralization assays are the gold standard for determining if a patient has effective antibodies and protective immunity against SARS-CoV-2.”

— Johns Hopkins University National Strategy for Serology Report

“Neutralizing antibodies are the gold standard for protective immunity.”

— Dr. Anthony Fauci, Chief Medical Advisor to the President

COVID Testing for Your Business

Promus Diagnostics’ delivers comprehensive COVID-19 testing strategies for businesses, organizations, and nursing homes. We provide science-based results that enable organizations to create healthy working environments and protect their customers and staff by implementing proactive testing schedules and early testing intervention for symptomatic persons. 

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Maintain a healthy workforce during your return-to-work strategy

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Long Term Care

Protect your residents from outbreaks and provide timely care

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Schools & Universities

Keep your students, employees and communities safer

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Medical Practices

Rely on rapid and reliable results for your patients and staff

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Sports Teams

Keep your players healthy and your team in league compliance

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Film & Media

Significantly reduce risk outbreaks and production shutdowns