You have, of course, asked multiple questions about multiple passages. (redeeminggod.com)
Mesenchymal stem cells can be expanded through multiple passages in medium containing high concentrations of fetal bovine serum (FBS); only a fraction of the cells will remain clonogenic through propagation. (discovery.lifemapsc.com)
Evidence of infection and replication of the two principal viral groups that infect humans was demonstrated for multiple passages of viruses through cell culture (Figure 1). (pnnl.gov)