Figure 3. Construction of a hypoxic chamber.
A. The lid of the chamber is a flat piece of acrylic (purchased from Plymor, 1 cm thick) with a groove sculpted about 1 mm into the underside of the lid. The lid also contains two holes (1 cm in diameter) as an inlet and an outlet for flowing gases. Tubing adapters can be secured into these holes using epoxy or silicone glue. B. The hypoxic chamber is an acrylic cylinder with a flat bottom (purchased from Plymor). The cylinder is 7 cm in diameter, 3.5 cm in height and has a total volume of 140 cm3. C. The groove in the lid of the chamber nicely slots into the rim of the cylindrical hypoxic chamber to ensure an airtight fit.