Purification of proteins by adsorption chromatography in expanded beds

Adsorption in stable expanded beds enables proteins to be recovered directly from particulate-containing feedstocks, such as fermentation broths and preparations of disrupted cells, without the need for prior removal of the suspended solids, which would normally result in the blockage of packed beds. The adoption of this technique will greatly reduce the complexity of downstream processing by eliminating certain filtration, centrifugation and concentration steps. Factors that are critical to the success of the procedure include the correct choice of adsorbent, together with careful design of the apparatus in which the separation is performed. The design, optimization and scale-up of appropriate operating protocols for expanded-bed procedures are very similar to those used for the operation of packed beds.