cobas® Strep A

Nucleic acid test for use on the cobas® liat system

IVD For in vitro diagnostic use.
<b>cobas</b><sup>®</sup> Strep A
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

cobas® 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. The cobas® liat system enables definitive and rapid diagnosis, combining powerful PCR technology with fast turnaround time, 15 minutes or less, allowing sample to answer while patients wait.

cobas® Strep A performance4

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cobas® Strep A performance4

  Sensitivity* Specificity*
Strep A
LOD: 5 - 20 CFU/mL
97.7 %
(95% CI: 93.4% - 99.2%)
93.3 %
(95% CI: 89.9% - 95.6%)
*Compared to culture; PCR/sequencing of specimens that yielded discordant results shows that all cobas liat-positive culture-negative specimens were positive for Strep A, and that all cobas liat-negative culture-positive specimens were also positive for Strep A; CLIA data. CI=confidence intervals. LOD=limit of detection. CFU=colony-forming unit.
cobas® liat system

cobas® liat system

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

The cobas® liat 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)

Intended use

The 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.

Registration status

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.

Package inserts

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


  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 V4], Pleasanton, CA; Roche Molecular Systems, Inc., 2020.
  5. Shulman ST, et al. Clin Infect Dis. 2012;55(10):1279-82.


COBAS and LIAT are trademarks of Roche.


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