ABSTRACT
Most industrial processes involve processing very large lots of materials of relatively low unit cost. The numbers and types of contaminants to be removed from these systems do not require chromatographic separations, which would increase unit cost significantly without providing a corresponding increase in purity. In biopharmaceutics, the lot sizes are relatively small and the unit costs are relatively high. In addition, the purification challenges presented can be formidable and can only be addressed chromatographically. Use of other techniques such as precipitation and recrystallization may not be possible. It has been estimated that more than half the costs of processing a recombinant protein arise from downstream processing rather than fermentation.
