Patent ID: 8177082

Claim:
A vent cap assembly for a cell culture apparatus, comprising: a cap housing member having a generally cylindrical side wall and an end wall extending across one end of the side wall to form a major cavity within the cylindrical side wall and the end wall, wherein the end wall has a first major surface facing the major cavity, an opposing second major surface, and an opening extending through the end wall from the first major surface to the second major surface; a flexible membrane having first and second opposing major surfaces and a slit extending through the membrane from the first major surface to the second major surface, wherein the flexible membrane is disposable within the major cavity such that the membrane sealingly divides the major cavity into (i) a chamber formed between the first major surface of the end wall and the first major surface of the membrane and (ii) a minor cavity formed by the second major surface of the membrane and a portion of the side wall, wherein the slit is biased in a closed position to prevent fluid from passing from the minor cavity into the chamber and is configured to open to allow gas to pass from the minor cavity into the chamber when the pressure differential across the membrane is above a threshold; and a microbial filter disposed between the membrane and the opening such that air flowing through the opening in the end wall into the chamber passes through the filter.