Gas permeable culture flask and method for culturing mammalian cells

Claim 1

A gas permeable culture flask adapted for use in growing cell cultures in incubators having controlled atmospheres with selected levels of one or more gases, said flask comprising: a flask having a unitary body including gas impermeable walls with a surface area defining a culturing zone having an atmosphere containing one or more gases; a neck connected to said flask body having an opening for introducing mammalian cells and culture fluids into said culturing zone to form a cell culture within said culturing zone; a gas permeable insert located in said flask wall defining a gas permeable opening through which said gases from the atmosphere in said incubator can communicate with the gases in the atmosphere in said flask to thereby allow equilibration between the two atmospheres while the flask is in said incubator to form an equilibrated atmosphere in said flash which is substantially equivalent to the atmosphere in said incubator having said selected levels of one or more of said gases, said selected levels of gases being chosen to provide the desired growth of said cell culture, said gas permeable insert being made from material having a sufficiently large pore size to allow passage of said gases therethrough while having a sufficiently small pore size to prevent microorganisms from passing therethrough; means associated with said flask for selectively occluding said gas permeable insert, said occluding means being movable repeatedly between an open position when said flask is placed within said incubator to allow exchange of gases through said gas permeable insert and a closed position when said flask is removed form said incubator atmosphere to prevent the escape of gases from said culturing zone through said gas permeable insert to thereby increase the amount of time said flask may be left outside said incubator atmosphere while still maintaining the desired selected levels of gases within the atmosphere of said flask; a cap for covering said opening in said neck; and means for removably mounting said cap to said neck whereby said cap may be removed from said neck when said cells and culturing fluids are to be introduced into or removed from said culturing zone.