Performance comparison of protein A affinity resins for the purification of monoclonal antibodies

During the selection of protein A affinity resin for the purification of monoclonal antibodies, dynamic binding capacity (Qdyn10%), volumetric production rate (Prvol) and ‘process robustness’ are essential parameters to be evaluated. In this article, empirical mathematical models describe these parameters as a function of antibody concentration in load (C0), load flow rate (uload) and bed height (L). These models allow us to select optimal process conditions for each of the evaluated protein A affinity resins. C0, uload and L largely affect dynamic binding capacity (Qdyn10%) and volumetric production rate (Prvol). Maximum Qdyn10% is generally obtained at high C0 and at low uload. Maximum Prvol is obtained at high C0 and at lowest L, run at high uload. All evaluated resins have a relatively high robustness against variations in C0. |δQdyn10%/δC0| ranges from 0.0 to 7.8. It is clear that Qdyn10%, Prvol and ‘process robustness’ cannot be maximized all at the same time. Furthermore, some other aspects like IgG recovery, protein A leaching, easiness to pack, easiness to clean, number of re-uses and cost of production might be important to be taken into the equation. Certain evaluation parameters may be more important than others, depending on the specific situation. Therefore, a case-by-case evaluation is recommended.