PYREX Gas Washing BottleGas Washing Humidifier Bubbler Bottle These bottles are a very effective way to humidify carbon dioxide air mixtures for maintaining high humidity in gassed cell culture incubators. The gas enters the bottle through the top of the central vertical tube, the lower end of which is fritted and below the surface of the washing medium. After bubbling through the medium, the gas is removed via the sidearm of the bottle stopper. The Standard Taper stopper