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RTube Exhaled Breath Condensate Collection

Rtube

About

The RTube is a non-invasive, hand-held device for the collection of Exhaled Breath Condensate (EBC). Manufactured by Respiratory Research, it has been used more than 230,000 times across academic, pharmaceutical and government research over 25 years, making it one of the most established EBC collection systems available.

EBC is obtained by cooling exhaled air, which condenses aerosolised particles and volatile compounds from the airway lining fluid. The resulting sample provides a non-invasive window into the biochemical and inflammatory state of the airways, and is used to measure biomarkers including pH, hydrogen peroxide, nitric oxide derivatives, and a range of cytokines, proteins and metabolites associated with oxidative stress and airway inflammation.

The RTube is a non-rebreathing device. Two one-way valves maintain unidirectional flow throughout the breathing cycle. As the subject breathes normally through the mouthpiece, saliva is separated from the exhalate in the blue ‘T’ section and drained away through a one-way disc valve, preventing salivary contamination of the sample. The exhaled stream passes through a one-way duckbill valve into the condensation tube, which is enclosed by a pre-chilled cooling sleeve. Turbulence created by the nozzle drives impaction of suspended particles against the tube wall and enhances heat transfer, maximising condensate yield. A syringe-style aluminium plunger then consolidates even minute droplets from the tube walls into a single sample for analysis.

Because the device is self-contained, portable and requires no supervision, EBC can be collected consistently across clinics, hospitals, homes and field or occupational settings. Each unit is supplied sterile for single-patient, single-use, eliminating cross-contamination risk and removing any need for cleaning or reprocessing between subjects.

Applications: airway inflammation and oxidative stress monitoring; asthma, COPD and cystic fibrosis research; lung cancer and breathomics studies; metabolomics and proteomics; and occupational and environmental exposure research.

Training

The RTube is designed for straightforward operation and can be used by subjects without clinical supervision, but consistent technique is important for reproducible sample volumes and reliable biomarker measurement.

Before collection

  • Store the cooling sleeve in a freezer until immediately before use. The sleeve must be adequately chilled to condense breath efficiently.
  • Confirm the device is within its use-by date and the sterile packaging is intact. Do not use a device that has been opened or damaged.
  • Assemble the mouthpiece, condensation tube and cooling sleeve as directed, and ensure the one-way valves are correctly seated.

During collection

  • The subject breathes tidally (normal, relaxed breathing) through the mouthpiece while seated. A nose clip may be used to standardise breathing where required by the protocol.
  • Collection time is typically set by the study protocol; longer collection periods yield larger condensate volumes.
  • Keep the device upright so that saliva drains away from the sample through the ‘T’ section.

After collection

  • Use the aluminium plunger to draw the condensate to the top of the tube for retrieval.
  • Seal the condensation tube for storage or transport. The tube is designed to be sealable and suitable for mailing.
  • Handle, aliquot, freeze and store samples according to your assay requirements, as biomarker stability varies.

For standardised temperature-controlled collection, refer to the manufacturer’s protocol. BMedical can arrange product training and application support for research teams — contact us to discuss.

Research

Please follow these links to access a range of RTube research articles and papers.

ACCESS RESEARCH

Warranty

Please follow this link to access the warranty claim procedures documents

Service Warranty Form

The RTube is a single-patient, single-use disposable device. Warranty terms and conditions to be confirmed. 

FAQs

EBC is the liquid recovered when exhaled air is cooled and condensed. It contains aerosolised droplets and volatile compounds from the airway lining fluid, and is used as a non-invasive sample for studying the biochemical and inflammatory state of the airways.

Commonly measured markers include pH and hydrogen peroxide (a reactive oxygen species linked to oxidative stress and disease severity), along with nitric oxide derivatives, cytokines, proteins and metabolites. The specific panel depends on your assay and research question.

No. It is a single-patient, single-use disposable device, supplied sterile. This eliminates cross-contamination risk and removes any need for cleaning or reprocessing.

Yes. The cooling sleeve must be pre-chilled (typically stored in a freezer) before use. Adequate cooling is necessary for efficient condensate collection.

The device’s large ‘T’ section separates saliva from the exhaled stream and drains it through a one-way disc valve, so saliva does not compromise the condensate.

Yield depends on collection time, breathing pattern and cooling. Longer tidal-breathing periods produce larger volumes. Follow your study protocol for standardised collection.

Yes. The condensation tube is sealable and suitable for transport and mailing. Store and freeze samples according to your assay’s stability requirements.

No. The hand-held design allows unsupervised use, including at home, though standardised technique improves reproducibility.

The RTube is manufactured by Respiratory Research and distributed in Australia and New Zealand by BMedical. Contact us for pricing, training and application support.

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