Plasma protein fractionation with advanced membrane adsorbents

High capacity membrane adsorbents have been used as a stationary phase for the preparative chromatographic purification of human serum albumin. A two-step ion exchange fractionation scheme yields albumin with 98% purity from clarified, microfiltrated, and desalted human plasma. Experiments with laboratory and pilot scale membrane modules are compared to literature data obtained with conventional Fast Flow Sepharose in a similar purification protocol. Increased productivity in combination with excellent reproducibility and stability was found using the membrane adsorbents. Scale-up of the process based on standard microfiltration equipment was successful but resulted in reduced capacity and productivity due to deteriorated flow characteristics of the module. This was attributed to the effects of substantial axial dispersion in the pilot scale module. Methods to reduce this limitation were identified. The concept of membrane adsorption chromatography for the fast purification of proteins is illustrated and engineering aspects important for the process design are discussed.