Evaluation of affinity membrane adsorbers for antibody purification

Recent development of therapeutics based on monoclonal antibodies has lead biotech industry to look at alternatives to chromatography in view of the increased production needs and affinity membrane adsorbers are among the process considered. A2P mimetic (Prometic Biosciences, UK) has been coupled to Sartobind epoxy (Sartorius AG, Germany) pre-activated cellulose membranes and characterised with pure polyclonal human IgG and MAbs from a cell culture supernatant. Membrane capacity and selectivity towards the target proteins have been measured together with all the relevant kinetic parameters, which characterise adsorption and elution. The membranes were also studied with respect to stability of the stationary phase and ligand leakage and compared to affinity chromatography resins. A2P-Sartobind epoxy affinity membranes were extensively tested in dynamic experiments. The effects of feed concentration and flow rate were investigated in order to find the better conditions for binding and elution steps. The equilibrium and kinetic parameters measured experimentally were used in a mathematical model developed to describe the behaviour of affinity membrane systems in binding and elution steps. The influence of different adsorption kinetics as well as the effects of dead end volumes, lag times and analysis of flow distribution were used to assess the use of the model for scale-up purposes.