Cell culture process

[0086]Media comprising various concentration of L-Tyrosine (tyrosine 2Na2H2O)), PVA (Sekisui Chemical Co, Selvol™ 203) and Pluronic F68 (Kolliphor P188, Sigma) and fixed concentrations of Ala, Arg, Asn, Asp, Cystine, Glu, Gly, His, Ile, Leu, Lys, Met, Phe, Pro, Ser, Thr, Trp, Tyr and Val, were prepared using feed medium A as starting material. Media were made according to the procedure described in Table 1 for medium comprising 5 g / L PVA and 3 or 12 mM Tyr, Table 2 for medium comprising no PVA, 5 g / L Pluronic F68 and 3 or 12 mM Tyr and Table 3 for medium comprising no PVA, no Pluronic F68 and 3 or 12 mM Tyr. The rest of the media were made by mixing the above 6 media to get the corresponding PVA, Pluronic F68 and Tyr concentrations. All media had a final osmolarity of 1000-1300 mOsm and a pH of 7.1-7.3. All media were sterile filtered through 0.2 μm filter unit and stored in 0.2 μm Nalgen filter bottles at cold (2-8° C.) and protected from light.

TABLE 1Medium with 5 g / L PVA, 3 mM or...