Copyright 2026, Rising Spire
The goal of upstream development is to create a robust cell culture process that maximizes yield (titer) while maintaining CQAs.
Low pH hold (pH 3.6 for 60 minutes) was used. But with A Mab’s sensitivity, they optimized to pH 3.7 for exactly 30 minutes – no longer, no shorter. Validation showed >4 log reduction of model virus (xMuLV).
The initial Protein A step used MabSelect SuReâ„¢ resin. Loading at 30 g A Mab/L resin captured >99% of product, but elution at pH 3.5 caused significant aggregation (from 1.5% to 7%).
The was defined such that any combination within ranges (e.g., Protein A elution pH 3.6–4.0, polishing flow rate 150–250 cm/h) yielded CQA compliance.
The fermentation process was optimized to achieve:
Copyright 2026, Rising Spire