From: Grein TA, Loewe D, Dieken H, Weidner T, Salzig D and Czermak P (2019) Aeration and Shear Stress Are Critical Process Parameters for the Production of Oncolytic Measles Virus. Front. Bioeng. Biotechnol. 7:78. doi: 10.3389/fbioe.2019.00078

Vero cells were adapted to grow in serum-free medium VP-SFM (ThermoFisher Scientific) by increasing the VP-SFM content in four steps (25, 50, 75, and 100%). Vero cells growing in serum-free medium therefore had a higher passage number (P174) than the cells in serum-containing medium. The cells were detached and re-suspended using the procedure described above for cells in serum-containing medium, except the trypsinization step lasted only 5 min and was stopped by adding 0.02 mL cm⁻² trypsin inhibitor (Sigma-Aldrich).