No abstract

Expanded bed adsorption is a technique for recovery of biomolecules directly from unclarified feedstocks. The work described here demonstrates that expanded bed adsorption is a scaleable technique. The methods used to test scaleability were ''determination of degree of bed expansion'', ''determination of axial dispersion'' and ''determination of protein breakthrough capacity''. The performance of a production scale expanded bed column with 600 mm diameter was tested using these methods and the results were found to be consistent with the results obtained from lab scale and pilot scale expanded bed columns.The scaleability and function of the expanded bed technique was also tested by performing a ''process example'': a purification mimicking a real process using a yeast culture spiked with bovine serum albumin as feedstock. The results show that the 600 mm diameter production scale column was as efficient as a 25 mm diameter lab scale column in recovering bovine serum albumin from the unclarified yeast culture. The production scale runs were fully automated using a software controlled system containing an adaptor position sensor and an adsorbent sensor.A cleaning study was performed which showed that after use of a proper cleaning protocol, no surviving microorganisms could be detected in the column or in the adsorbent.