Chromatography columns and their operation

A method of operating chromatography column apparatus;

• the apparatus comprising a column tube having first and second ends, and first and second discrete end cell structures which are associated with the respective ends of the column tube and positionable to close off the column tube and thereby define therein a column space for retaining chromatography medium, in use of the apparatus;
• at least the first end cell structure comprising a piston portion fitting slidably in the column tube;
• the operating method comprising separating the second end of the column tube and the second end cell structure to provide an access spacing between them moving a safety plate and blocking movement of the second end of the column tube toward the second end cell structure to maintain the access spacing, advancing the piston portion of the first end cell structure through the column tube to expose it at the open second end of the column tube, and carrying out maintenance of the piston portion thus exposed.