Disclosed is a chromatographic separation column assembly (100) comprising a column cylinder (120) having a cylinder wall (126) including an inner wall surface (124) partially defining a column volume (50), and a column component (110/130) insertable into to the cylinder (120), wherein at least an edge region (113/133) of the column component is intended to be in contact or adjacent a part of the inner wall surface (124) in use, the edge region and the contacting or adjacent part of inner wall surface each being formed from a compatible heat fusible material or materials, and wherein at least the cylinder wall in the area of the contacting or adjacent part of the inner wall is formed from a material which allows transmission of the light energy needed to cause said fusing of the adapter plate edge region to the inner wall surface.