A: Relative antibody ratios in pMCBs generated by mixing two ECHO cell lines at five different ratios. The antibody ratios were determined once a week by CIEX (from week 1 to 6 of cultivation) and in the harvest of a 14-day fed batch cultivation initiated after 6 weeks of cultivation. Red lines represent antibody 1 (Ab 1) and blue lines represent antibody 2 (Ab 2). B: Expected percentages plotted against measured percentages of Ab 1 in the five different mixes after 6 weeks seed train. C: Antibody compositions in pWCB in fed batch shaker experiments after 14, 21 and 28 days seed train, respectively. D:Antibody distributions in harvest from seven different 5 L bioreactor processes. Four pWCB-1 ampoules (blue columns) and three pWCB-2 ampoules (green columns) were used for seed train. The lighter colored columns represent mean ± sdev.