A hypoxic pressure chamber or incubator for cell culture comprises an air tight plastic box that has: at least one gas inlet； and a gas outlet, the gas outlet being closed with an adjustable one way valve (i.e. a check or pressure relief valve) that is configured to allow a desired increased pressure level inside the box (preferably up to 20 cm H2O, 49.82 mbar). Preferably, a medical positive end expiratory pressure valve (PEEP valve) is conveniently utilised as the one way valve and the incubator preferably portable. In some embodiments the incubator may comprise a more than one gas inlet, i.e. a tri-gas hypoxic incubator to allow culture gas mixing.
