Separation processes in biotechnology are of increasing industrial importance since they entail the major costs of bioprocessing especially when high purity is required. Chromatography and membranes are two of the most important technologies used for direct treatment of fermentation broths as well as for high resolution steps in product purification. The theoretical foundations of chromatographic and membrane processes are well understood for the case of small molecules. Nevertheless there is a need to adapt and further develop that knowledge to the processing of large biological molecules....