Use of a Disposable Syringe as a Novel Economic Breath-Collection Chamber for Mice

We modified commercially available 50-ml syringes to allow their use as breath-collection chambers for mice. By drilling holes at the flanged end and applying 3-way valves to the opposite (tip) end, a syringe can be ventilated, then quickly and simply converted to a closed chamber for collection of breath samples. We evaluated the influence of sample collection time on CO2 content of breath samples and found that 30 sec was required to obtain a CO2 concentration of 3 to 5%. We believe this is an economic, simple, and safe alternative to conventional breath-collection chambers.