Method for continuous purification of biological material using immunosorbent

Moving adsorption belt system for continuous bioproduct recovery utilizing composite fibrous adsorbents

A continuous protein recovery and purification system based on the true moving bed concept is presented. A novel adsorbent material, in the form of an elastic and robust woven fabric, served as a moving belt following the general designs observed in known belt conveyors. The composite fibrous material that forms the said woven fabric showed high protein binding capacity, reaching a static binding capacity equal to 107.3 mg/g, as determined via isotherm experiments. Moreover, testing the same cation exchange fibrous material in a packed bed format resulted in excellent dynamic binding capacity values (54.5 mg/g) even when operating at high flow rates (480 cm/h). In a subsequent step, a benchtop prototype was designed, constructed, and tested. Results indicated that the moving belt system could recover a model protein (hen egg white lysozyme) with a productivity up to 0.5 mg/cm²/h. Likewise, a monoclonal antibody was directly recovered from unclarified CHO_K1 cell line culture with high purity, as judged by SDS-PAGE, high purification factor (5.8), and in a single step, confirming the suitability and selectivity of the purification procedure.

Isolation of antigens and antibodies by affinity chromatography

Antibody-antigen binding constants are commonly strong enough for an effective affinity purification of antibodies (by immobilized antigens) or antigens (by immobilized antibodies) to work out a straightforward purification method. A drawback is that antibodies are large protein molecules and subject to denaturation under conditions required for the elution from the complex. Structures of antigens can vary but usually antigens are also equally subject to similar problems. The lability of the components can sometimes make the procedure sophisticated, but usually in all cases it is possible to find a satisfactory approach. In certain cases, specific interactions of the Fc part of antibodies are more facile to exploit for their purification.

A method for the continuous purification of proteins by affinity adsorption

A method was conceived for the purification of biomolecules on a continuous-flow basis using affinity adsorption. The affinity ligand was bound to a nylon belt which was passed sequentially through four chambers to which flows of feedstock, wash medium, eluent and regeneration medium were applied. The target compound was thus removed from the feedstock stream and desorbed into a continuous flow of eluent. Prototype laboratory-scale apparatus was designed and constructed and the technical feasibility of this method was demonstrated using soybean trypsin inhibitor as a ligand for the adsorption of trypsin. The effects of various operational parameters on apparatus function were investigated using this model system. In addition, continuous removal of trypsin from a bovine pancreatic extract was carried out during an 8 h experiment.

An overview of continuous protein purification processes

As the sphere of influence of recombinant technology moves away from the laboratory bench, towards product commercialization, development of manufacturing and large scale process technology is becoming a major challenge and determinant for commercial success. The challenge is particularly acute for protein purification process development where protein purification costs tend to dominate overall process economics. The primary objective for process scale purification is to minimize cost for a purified product which meets specifications. Continuous processes may be used to facilitate achievement of the overall objectives. This review critically examines the use of continuous processing for protein purification and recovery operations. The processes have been divided into three general areas: adsorptive and chromatographic, electrophoretic, and extractive. Consideration is given to the operational advantages and limitations of the reviewed processes.