Development of a serum-free medium for the production of recombinant proteins from CHO cells using statistical design

Abstract

In order to develop serum-free (SF) medium for the propagation of recombinant Chinese hamster ovary (rCHO) cells expressing recombinant proteins, a statistical optimization approach based on Plackett-Burman design was adopted. SF-hu17 for hu17-0.32, SF-LG for CHO-LG and SF-DG for DG44 medium were formulated by supplementing basal medium with components showing positive effects on cell growth and recombinant proteins production. From a seeding density of $1×10^5 cells/ml$, hu17-0.32 cells reached a maximal cell density of $5.6×10^5 cells/ml$ and antibody concentration of 18.4㎍/ml in SF-hu17 medium. From a seeding density of $1.5×10^5 cells/ml$ CHO-LG cells reached the maximal cell density of $7.4×10^5 cells/ml$ and the EPO concentration of 18.36㎍/ml in SF-LG medium. We have developed lineages of DG44 cells adapted to growth in low-serum culture and serum-free medium for these lineages. Growth of adapted DG44 cells maintained robust in SF-DG medium over 5 passages whereas growth of non-adapted cells decreased. It demonstrated their utility as hosts for the DHFR-mediated gene amplification system using serum-free medium. Serum-free media developed using Plackett-Burman design supported cell growth and antibody production comparable to those in 5% dialyzed fetal bovine serum (dFBS) containing media.