Performance comparison of suspended bed and batch contactor chromatography

In some applications, the purification and recovery of biomolecules is perf ormed via a cascade of batch adsorption and desorption stages using agitate d contactors and related filtration devices. Suspended bed chromatography i s a recent process-scale innovation that is applicable to these separations . This hybrid technique exploits the benefits of combining batch adsorption in an agitated contactor with elution in an enclosed column system. To som e extent, the process is similar to batch contactor chromatography but can be fully contained and significantly quicker. The process has two steps; fi rst the fluid containing the sample is mixed with the adsorbent in a stirre d tank. Second, the slurry suspension is transferred directly into a specia lized column, such as an IsoPak column. The media with the adsorbed product is formed as a packed bed, whilst the suspension liquid is passed out of t he column. The product is then eluted from the packed bed utilizing standar d column-chromatography techniques. The performance of the suspended bed an d the agitated contactor operations are demonstrated both by full-scale exp erimental results and process simulations. The purification of ovalbumin fr om a hen-egg white feedstock by anion-exchange chromatography was used as a case study in order to prove the concept. With the availability of both pu mp-packed systems and shear-resistant media, suspended bed chromatography i s a better alternative for a range of applications than the traditional bat ch separations using agitated contactors. (C) 2001 Elsevier Science B.V. Al l rights reserved.