Abstract: Systems include a chromatography column tube having an inlet and outlet and port assembly arranged in a wall of the column tube between flow distributors that together form a chamber within the tube that is filled with packing medium are described. The port assembly facilitates the removal of resin from the pre-packed column and the port assembly does not affect fluid flow in the normal use of the column for chromatographic separation or ability to maintain sanitary conditions within the column. Also described are methods that include attaching tubing to a pump and to a column inlet and a column outlet, opening the port assembly, attaching tubing to the port assembly and to a second reservoir, and pumping aqueous solution from a reservoir into the chamber and out through the port assembly into the second reservoir, thereby removing packing medium from the column along with the flowing aqueous solution.