Assays
Reduction of antibody was tested by non-reduced SDS-PAGE using the
NuPAGE 4-12%Bis-Tris Gel (Thermo Fisher). Sample preparation was
carried out as described in the Thremo manual. TrxR activity and NADPH
were determined by Thioredoxin Reductase Activity Assay Kit (BioVision)
and Amplite Colorimetric NADPH Assay Kit (AAT Bioquest), respectively.
The tests were carried out as described in the kit manuals. LDH activity
was determined by Cedex (Roch). The viable cell density (VCD) and the
viability during cell lysis were determined by Vi-cell (Backman
Coulter). For HCCF, a HPLC-based protein A method was used to measure
the titers of antibodies and Fc-Fusion proteins. For the purified
antibodies and Fc-Fusion proteins, the concentration was measured using
UV spectrometry (Thermofisher) at 280nm.