TABLE 1.

Properties of different feed streams used in this study.

Feed stream	Physicochemical properties of particulate matter
Pichia pastoris cell broth for HSA production	NTU 3500, mean particle size 4–6 μm w/w
Pichia pastoris cell broth centrate	NTU 300, mean particle size < 100 nm, unstable, becomes hazy in 12–15 h
CHO cell culture harvest	NTU 1785, cell viability 85%
CHO cell culture centrate	NTU 200–400, unstable, becomes hazy in 12–15 h
Refolding output of GCSF (quenched)	NTU 1600, white precipitate due to HCP while quenching from 9.5–4 using acetic acid, 50–100 nm size
Drug product GCSF	Clear solution
Drug product mAb	Clear solution