Diagnostic test kit cobas®

COVID-19for respiratory diseasesfor respiratory infections

Overview
cobas® Respiratory flex is an automated, multiplex, qualitative nucleic acid test for use on the cobas® 5800/6800/8800 systems that utilizes real-time PCR and Roche's TAGS (Temperature Activated Generation of Signal) technology to enable simultaneous detection and differentiation of multiple respiratory viral targets from a single well. The assay provides up to 12 viral results plus an RNA Internal Control per well and is intended for in vitro diagnostic (IVD) use in nasopharyngeal swab specimens from individuals with signs and symptoms of respiratory tract infection in conjunction with clinical and epidemiological risk factors.

Intended use / Clinical application
Qualitative detection and differentiation of respiratory viral nucleic acids to aid diagnosis of respiratory infection when used together with clinical and epidemiological information. Negative results do not exclude infection; positive results do not rule out coinfection and may not indicate the definitive cause of disease. Due to genetic similarity between human rhinovirus and enterovirus, the assay cannot reliably differentiate them.

Key features and process

• Fully automated sample preparation (nucleic acid extraction and purification) followed by PCR amplification and detection on cobas® 5800/6800/8800 systems.
• Simultaneous extraction of nucleic acid and RNA Internal Control (RNA IC); nucleic acid released by proteinase and lysis reagent, bound to magnetic glass particles, washed and eluted.
• TAGS technology enables differentiation of multiple targets per fluorescence channel by combining 5 fluorescence channels with 3 thermal detection channels (T1, T2, T3), allowing detection/differentiation of up to 15 targets per well in future implementations and up to 12 respiratory viral results plus the RNA IC with this kit.
• Master mix contains thermostable DNA polymerase, TAGS probes, and dUTP plus AmpErase (uracil-N-glycosylase) for carryover contamination control.

Target panel (target — targeted gene)
Target — Target gene
Influenza A — Matrix protein 1 (M1)
Influenza B — Non-structural protein NS-1/2 (NS1/NEP)
Respiratory Syncytial Virus (RSV) — Matrix protein (M)
SARS-CoV-2 — ORF1ab polyprotein and ORF1a polyprotein (ORF1ab / ORF1a)
Adenovirus (species B, E) — Terminal protein precursor (E2B)
Adenovirus (species C) — Capsid protein precursor (L3)
Human Metapneumovirus — Matrix protein (M)
Enterovirus / Rhinovirus — 5' untranslated region (5'UTR)
Coronavirus OC43 — Replicase polyprotein 1a/1b (ORF1ab)
Coronavirus HKU1 — Replicase polyprotein 1a/1b (ORF1ab)
Coronavirus 229E — Replicase polyprotein 1a/1b (ORF1ab)
Coronavirus NL63 — Replicase polyprotein 1a/1b (ORF1ab)
Human Parainfluenza Virus 1 — L polymerase protein (L)
Human Parainfluenza Virus 2 — Large protein (L)
Human Parainfluenza Virus 3 — Nucleocapsid protein (N)
Human Parainfluenza Virus 4 — Large protein (L)

Analytical / operational notes

• Uses target-specific forward/reverse primers and fluorescently labeled probes; TAGS probe signal requires nuclease cleavage plus an increase in reaction temperature to activate fluorescence.
• Fluorescence is captured across multiple fluorescence channels and at three defined temperatures per cycle to enable multiplex differentiation.
• External positive and negative controls are processed the same way as patient samples.

Limitations

• Negative results do not preclude respiratory infection and should not be used as the sole basis for patient management.
• Positive results do not exclude coinfections and detected agent may not be the definite cause of disease.
• Cannot reliably distinguish human rhinovirus from enterovirus due to genetic similarity.

Benefits / Highlights

• Flexibility to select targets and obtain additional results (digital reflex) from the same kit/run.
• Enables consolidation of multiple respiratory targets into one customizable solution on existing cobas® x800 family systems without hardware or software upgrades.
• Designed to help simplify laboratory logistics, reduce duplicate testing and support efficient PCR diagnosis with fast turnaround.

Technical specifications

• Targets: Influenza A, Influenza B, RSV, SARS-CoV-2, adenovirus (B, C, E), human metapneumovirus, enterovirus/rhinovirus, common human coronaviruses (229E, HKU1, NL63, OC43), parainfluenza viruses 1–4.
• Sample type: Nasopharyngeal swab samples collected in Copan UTM-RT® or BD™ Universal Viral Transport (UVT) or equivalent.
• Minimum sample volume: 0.4 mL.
• Technology: Real-time PCR with Roche TAGS (Temperature Activated Generation of Signal) multiplexing.
• Kit size: 192 tests per kit.
• Open kit stability: 90 days with 40 re-uses.
• Internal control: RNA Internal Control included and co-extracted.