2.6. Virus filter and filtration
The virus filter used was 0.0003 m2 Planova BioEX
filter (Asahi Kasei Medical Co., Ltd., Tokyo, Japan).
To prepare for filtration through the virus filter, the feed solution
was filtered through a 0.2 µm microfilter (Minisart RC 25 mm, Sartorius)
to remove potential precipitates and placed in a feed vessel. The feed
solution was then filtered with the Planova BioEX filter under constant
pressure at 0.3 or 0.35 MPa. The mass of permeate was recorded manually
during the filtration run to determine flow rate, and throughput
(L/m2) and flux (LMH) were calculated.