Experimental characterization of the transport phenomena, adsorption, and elution in a protein A affinity monolithic medium.

A commercially available convective interaction media (CIM) Protein A monolithic column was fully characterized in view of its application for the affinity capture of IgG in monoclonal antibody production processes. By means of moment analysis, the interstitial porosity and axial dispersion coefficient were determined. The frontal analysis method of characteristic points was employed, for the first time with monolithic media, to determine the dynamic binding capacity. The effects of the flow rate and pH on the total recovery of polyclonal IgG and elution profile were evaluated. A comparison with literature data for Protein A chromatography beads demonstrate the superior bed utilization of monolithic media, which gave better performance at lower residence times.

Transport and binding characterization of a novel hybrid particle impregnated membrane material for bioseparations.

The transport and binding properties of a novel hybrid particle-nonwoven membrane medium are described. In this construct, a polymeric chromatographic resin is entrapped between two layers of a nonwoven polypropylene membrane. The membrane-supported resin medium offers the advantage of increased interstitial pore diameter to allow passage of cells and other debris in the feed, while providing sufficiently high surface area for product capture within the resin particles. Columns packed with PIM displayed excellent flow distribution and had interstitial porosities of 0.48 ± 0.01, 25-60% larger than those typical of a packed bed. These columns were able to pass over 95% of E. coli cells and human red blood cell concentrate in 30 column volumes while maintaining a pressure drop significantly lower than that of a packed bed with a similar amount of resin. The dynamic binding capacity of bovine serum albumin (BSA) to the chromatographic resin entrapped in the PIM packed column was essentially the same as that observed with the same volume of resin in a packed bed. The General Rate (GR) model of chromatography was used to analyze experiments indicating the breakthrough behavior of the PIM columns is predictable, and very similar to those of a normal packed bed. These results suggest that PIM constructs can be designed to process viscous mobile phases containing particulates while retaining the desirable binding characteristics of the embedded chromatographic resin and could find uses in adsorption separation processes from complex feed streams such as whole blood, cell culture, and food processing.