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.