Expanded Bed Chromatography: Hydrodynamics And Protein Adsorption

In this article, we focused on the changes of local particle size distribution and bed voidage of an expanded bed during the changes in bed expansion and the visualization and modeling of intraparticle protein distributions during the protein adsorption to porous particles: 1. Using a glass column modified with three side sampling ports and Streamline AC as the solid phase, the transient changes of local particle size distribution and bed voidage of an expanded bed were found first occurred in the bed bottom and then progressed from bottom to top along the axial direction. However, the changes of bed voidage at different axial positions were not unidirectional, which is ascribed to the compression effect caused by the upward movement of the lower part particles. 2. The dynamic uptake process of the porous media DEAE Sepharose Fast Flow on the progress of BSA adsorption have been visualized and studied by CLSM. A mathematical model for expanded bed protein adsorption was employed to predict the protein breakthrough of both the bed effluent and the solid phase at different position in the bed. Using independently determined parameters, the model prediction of the bed effluent agreed reasonably well to the experimental data. While, obvious lag in the breakthrough of in-bed particles were observed, comparing with the simulation data at corresponding bed heights due to the unexpected difference between the adsorption characteristics of BSA-FITC and unlabeled BSA to the anion exchanger.