Background

As part of the platform process, a low pH viral inactivation step was performed with the target protein at a pH below 3.8. The target protein is sensitive to low pH environment and has a tendency to aggregate. Using the platform buffers, the protein aggregated from 3% to 40% in 2 hours.

Challenge

Minimize protein aggregation while maintain high viral inactivation kinetics.

Experiments

Screening buffer parameters in the Protein A elution buffer to evaluate the effect of buffer species, conductivity, and pH on protein stability.

Result

The change in aggregates was less than 1% after incubating at pH 3.6 with the selected buffer for two hours.