CHT ceramic hydroxyapatite media require specific considerations during process-scale chromatography packing due to high specific gravity, rapid settling rate, and sensitivity to mechanical shear. CHT ceramic hydroxyapatite has a free settling velocity of 35–125 cm/hr for 40 µm particles and 125–275 cm/hr for 80 µm particles. If subjected to mechanical shear, CHT media particles can fracture, creating fines. This article describes straightforward best practices for successful and reproducible CHT media column packing at process scale.
- For 40 µm CHT, equip the column with frits that have a pore size of ≤10 µm. Although the median particle size is 40 µm, a small population down to 16 µm exists. These smaller particles can clog frits with larger pore sizes and cause increased backpressure
- Ensure that the column is level in all directions
- Know the functional column height, defined as the usable height of the column tube with the adaptor in place
- Calculate appropriate slurry percentage and slurry volume based on functional column height; consult the tables in section 7 of the CHT Ceramic Hydroxyapatite Instruction Manual (Bio-Rad bulletin LIT611)