The Petaka® G3 cell culture device uses ducted respiratory chamber technology to provide normal cellular environments for culture in room air. The ducted respiratory chamber limits the diffusion of oxygen into, and carbon dioxide out of, the bioreaction chamber. This allows the normal metabolism of most cell types to autoregulate oxygen and carbon dioxide to levels naturally seen at normal cellular levels, even though the Petaka G3 functions entirely in room air. Because the chamber is isolated from contact with the outside by a silicone injection port and 0.2 micron filter, cell culture takes place in a closed and aseptic environment that reduces evaporation. Each Petaka G3 will culture 25–30 million cells.