cobas® Strep A Assay

Fast results without compromising performance

Product image for cobas® Strep A Assay
Sore throat, fever, could it be strep A?

Strep A is responsible for over 600 million global cases of acute pharyngitis annually.1 On a global scale, group A Streptococcus (GAS) is a leading cause of morbidity and mortality.2 Clinical symptoms of GAS infection overlap with other diseases. Providing an early and accurate diagnosis enables appropriate prescription of antibiotics which can aid in reducing further complications of Strep A.3

The cobas® Strep A Nucleic acid test for use on the cobas® Liat® System is a real-time polymerase chain reaction (PCR) test for the detection of Strep A in throat swab specimens from patients with signs and symptoms of pharyngitis 

® Strep A offers:

  • Definitive Strep A PCR results in 15 minutes, for confident treatment decisions
  • No confirmation needed, enabling optimized patient workflow
  • Informed prescribing to support antibiotic stewardship and patient confidence

Help patients get the treatment and relief they need faster with the reliable accuracy of the cobas® Strep A Test for use on the cobas® Liat® System. A growing menu of assays, together with the small, swift, simple and secure analyzer, and the cobas® infinity POC solution, form the total point-of-care PCR solution—a revolution in POC efficiency and patient satisfaction.

cobas® Strep A performance4



Strep A


LOD: 5 – 20 CFU/mL



(95% CI: 93.4%-99.2%)



(95% CI: 89.9%-95.6%)

*Compared to culture; PCR/sequencing shows that cobas® Liat® System positive samples were actually positive for Strep A and that all cobas® Liat® System negative culture positive specimens were proven positive by PCR/Sequencing.


CI=confidence intervals. LOD=limit of detection. CFU=colony-forming unit.

The cobas® Liat® PCR System vs. conventional methods

Signs & Symptoms


Strep score based on clinical manifestations


Could lead to incorrect antibiotic treatment

Unnecessary antibiotics for empirical
treatment based on clinical suspicion.

Not prescribing antibiotics because
clinical suspicion was not high enough,
but it was in fact Strep A

Conventional methods


Strep score based on clinical manifestations


Take throat swab sample


Perform a rapid test and confirm with culture


Negative result needs confirmation5


Send for culture


Wait for results (2-5 days)

cobas® Strep A test


Strep score based on clinical manifestations


Specimen collected


Perform cobas® Strep A Test
(Definitive results in ~15 minutes)

Learn more about the expanding menu of assays

cobas® Liat® System


Rapidly test, triage, and treat your patients with the accuracy, simplicity, and security needed at the point of care.

Learn more
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The cobas® Strep A nucleic acid test for use on the cobas® Liat® System (cobas® Strep A) is a qualitative in vitro diagnostic test for the detection of Streptococcus pyogenes (Group A β-hemolytic Streptococcus, Strep A) in throat swab specimens from patients with signs and symptoms of pharyngitis.

The cobas® Strep A assay utilizes nucleic acid purification and polymerase chain reaction (PCR) technology to detect Streptococcus pyogenes by targeting a segment of the Streptococcus pyogenes  genome.

CE-IVD, FDA 510(k) cleared, CLIA waived


The cobas® Liat® System is commercially available in select markets. This product is not registered as an in vitro diagnostic (IVD) in all countries; additional information may be available from your Roche sales representative.

Access package inserts through your country’s Roche Diagnostics Website.

young girls diagnosed with influenza

Test for it. Don’t ignore it.


Respiratory tract infections

The non-specific clinical presentation of respiratory infections poses a considerable challenge to the differential diagnosis of pathogens. What impact can a timely and accurate diagnosis have on patient management?

Learn more
Healthcare associated infections

Healthcare-associated infections (HAIs)

From prolonging institutional stays to creating long-term disability, healthcare-associated infections place a tremendous financial burden on health systems.

Learn more
Antimicrobial resistance

Antibiotic resistance and diagnostic testing

As mankind continues its widespread use of antibiotics, antimicrobial resistance will continue to pose a threat to the global healthcare system.

Learn more


  1. DeWyer A, Scheel A, Webel AR, et al. Prevalence of group A β-hemolytic streptococcal throat carriage and prospective pilot surveillance of streptococcal sore throat in Ugandan school children. Int J Infect Dis. 2020;93:245-251.
  2. Carapetis JR, Steer AC, Mulholland EK, Weber, M. The global burden of group A streptococcal diseases. Lancet Infect Dis. 2005:5(11);685-694.
  3. Cunningham MW. Pathogenesis of group A streptococcal infections. Clin Microbiol Rev. 2000;13(3):470-511
  4. cobas® Strep A [package insert]. Pleasanton, CA: Roche Molecular Systems, Inc., 2016.
  5. Shulman ST, et al. Clin Infect Dis. 2012;55(10):1279-82.