Influence of flow-rate on the chromatographic performance of agarose- and cellulose-based anion-exchange media

The influence of flow-rate on the separation of hen egg-white proteins was investigated using Whatman Express-Ion Exchanger Q and Pharmacia Q-Sepharose Fast Flow. Using 25-ml columns, breakthrough studies demonstrated that Express-Ion Q had an ovalbumin capacity of ca. 70 mg/ml, ca. 20% (w/w) greater than Q-Sepharose Fast Flow. Breakthrough for each exchanger was rapid. Using 25-I columns ca. 3.9 kg of protein was loaded on to each exchanger with Express-Ion Q having a capacity of ca. 2.1 kg compared with ca. 1.8 kg for Q-Sepharose Fast Flow. The desorption kinetics of the agarose were slower than those of the cellulose, as indicated by reduced chromatographic resolution with increasing flow-rate. Express-Ion Q was shown to give consistent chromatography over 100 chromatographic cycles with periodic clean-in-place.