Enhanced Tangential Flow Filtration of Precipitated Proteins Using Screened Membrane Cassettes.

BACKGROUND

Recent advances in cell culture have led to significant increases in monoclonal antibody (mAb) titers, opening a new window of opportunity for developing a fully continuous downstream purification process based on the selective precipitation of the mAb from harvested cell culture fluid, with the precipitate dewatered and washed using single-pass tangential flow filtration (SPTFF) with microfiltration membranes.

METHODS

Experiments were performed with precipitates of human serum immunoglobulin G formed using ZnCl and polyethylene glycol, both with and without added disodium malonate. SPTFF was conducted in both hollow fiber and screened cassette modules, with the critical flux identified using flux-stepping experiments.

RESULTS

Critical fluxes as high as 250 L/m/h were obtained in the screened cassette, significantly higher than what was possible in hollow fiber modules. A two-stage system was designed that provided up to 85% conversion in a single pass. This system could be operated continuously for 24 h with 80% conversion at a filtrate flux of 144 L/m/h without any significant fouling.

CONCLUSIONS

The results demonstrate the potential of using screened membrane cassettes for the continuous/intensified processing of precipitated proteins like monoclonal antibodies.