High turbidity in the load causes column fouling and pressure spikes >3 bar.
Mab-X binds to a strong cation exchanger (Poros 50 HS) at pH 5.5. The team runs a shallow salt gradient (0 to 150 mM NaCl over 30 column volumes). This resolves the main peak from the deamidated variant, which elutes slightly earlier. Collection windows are narrowed to 70-85% of peak height, discarding tails. A Mab A Case Study In Bioprocess Development
Lowering the pH during harvest. As the culture ages, CO2 builds up, lowering pH to 6.7. Mab-X has a unique hydrophobic patch in the Fc region that is prone to unfolding at pH <6.8. High turbidity in the load causes column fouling