Initial evaluation of protein A modified capillary-channeled polymer fibers for the capture and recovery of immunoglobulin G.

A novel protein A affinity chromatography stationary phase has been developed from polypropylene capillary-channeled polymer fibers modified with a recombinant protein A ligand for the capture and recovery of immunoglobulin G (IgG) with high specificity and yield. An SPE micropipette tip format was employed so that solvent, protein, and antibody consumption was minimized. The adsorption modification of the fiber surfaces with protein A was evaluated as a function of feed concentration and volume. Optimal modification of the fiber surface with protein A yielded a 5.7 mg/mL (bed volume) ligand capacity with the modified fibers showing stability across numerous solvent environments. Performance was evaluated through exposure to human IgG and myoglobin, individually and as a mixture. Myoglobin was used as a surrogate for host cell proteins common to growth media. The efficacy of the selective binding to the ligand is demonstrated by the 2.9:1 (IgG/protein A) binding stoichiometry. Elution with 0.1 M acetic acid yielded an 89% recovery of the captured IgG based on absorption measurements of the collected eluents. Regeneration was possible with 10 mM NaOH. Protein A modified polypropylene capillary-channeled polymer fibers show promising initial results as an affinity phase for efficient capture and purification of IgG.