The Impact of Cell Culture Medium on Cell Line and Process Development Timelines and Strategies - Animal-component free (ACF) medium sped up cell-line development by eliminating the adaptation period
The Impact of Cell Culture Medium on Cell Line and Process Development Timelines and Strategies
Animal-component free (ACF) medium sped up cell-line development by eliminating the adaptation period from serum-containing medium used in early development to ACF medium used for high-titer production.
Table 1. Cloning efficiency of MTCM on recombinant cell lines derived from Expression Systems I and II
CHO-derived HuMAb cell lines were plated at 0.25, 0.5, and 1.0 cell/well and were used to measure the subcloning efficiency
of MTCM first- and second-generation media. Even when plated at 0.25 cell/well, recombinant cell lines generated from both
expression systems were able to grow to 10 to 90% cloning efficiency (Table 1). High-titer cell culture processes can be successfully
developed further from these subclones after appropriate upstream process development. In a case of Expression System I using
MTCM A medium, MTCM medium outperformed two commercially available ACF media when the same parental cell line was subcloned
by limiting dilution. Approximately 227 colonies were obtained from MTCM medium by plating at 1.0 cell/well in 20 x 96 well
plates (Table 1), whereas no colonies appeared in the other two commercial ACF media (not shown). As shown in Table 1, these
two versions of MTCM media supported high efficiency cloning for CHO recombinant cell lines derived from both expression systems.
Preparation of Cell Banks with MTCM Media
Table 2. Use of MTCM for cell bank preparation of different CHO recombinant cell lines from Expression Systems I and II
Cryopreservation of cells for manufacturing was performed with the two versions of MTCM media for different recombinant cell
lines. These banks were periodically monitored to check recovery of the cells for further subculturing and the inoculum expansion
process for upstream manufacturing. Freezing the cells at varying densities, from 1 to 3 x 107 cells/mL, was successful in a freezing mixture containing either MTCM A or MTCM B and dimethyl sulfoxide. These cells were
thawed with >85% viability for all CHO cell lines tested (Table 2). One of the cell banks was evaluated for recovery and propagation
after five years and was found to have the same performance as at the time of banking. To date, more than 20 recombinant CHO
cell banks have been made in MTCM media and used in different manufacturing processes. Inoculum expansion processes for manufacturing
are consistent and robust with the banks prepared and stored in these ACF basal media. Using ACF media from early stages of
cell line development also reduces safety concerns from exogenous contaminants.
