Methods and systems for removing gases and/or pressure formed during the sterilization, e.g., the gamma irradiation, of prepacked chromatography systems (column plus attached tube and valve set) are described. The methods include purging the gas and/or pressure through specially designed tube and valve sets without breaching the sterility of the prepacked sterile chromatography system. The systems include a sterile or aseptic pre-packed chromatography column including a column having an inlet and an outlet, a tubing and valve set attached to the inlet and the outlet, and a pump configured to pump sterile or aseptic liquid from the fluid source along the tubing and valve set, into the column tube inlet and out of the column tube outlet along a first flow path, thereby removing any entrapped gas and/or pressure from the chamber.