Fig. 1.

Virus seed adaptation to Vero cells. a Maximum HA titer of each passage during adaptation of human influenza A/PR/8/34 H1N1 supplied by NIBSC from a MDCK cell-derived virus seed to Vero cells in ΔSC medium (dilution error of HA, ±0.3 log₁₀ HA units/100 μL). b Capillary gel electrophoresis—laser-induced fluorescence (CGE-LIF) N-glycan fingerprint of the HA protein fraction from the MDCK cell-derived virus seed (human influenza A/PR/8/34 H1N1_ma supplied by NIBSC) and of each adaptation step in Vero cells (Schwarzer et al. 2009) (RFU: relative fluorescence units over migration time (t _mig))