title: Properties of ras-amplified recombinant BHK-21 cells in protein-free culture.
abstract: We compared serum and protein-free cultures ofa ras-amplified recombinant BHK-21 cell line(ras-rBHK-IgG), which hyperproduces a lungcancer specific recombinant human monoclonal antibody. Ras-rBHK-IgG cells were shown to grow well, evenin protein-free medium and to be morphologicallysimilar to cells cultured in serum containing medium. However, the growth rate of ras-rBHK-IgG cellswas considerably slower in protein-free medium, whichresults in a longer maintenance period compared with cells cultured in serum containing medium. In addition, it was found that antibody production in protein-free culture had a ten times higher maximum than cells cultured in serum containing medium. On theother hand, in high density culture, using the hollowfiber bioreactor system, ras-rBHK-IgG cellscould be maintained for a month in protein-freeculture in contrast with serum culture, which onlylasted for half a month. However, the markedincrease of antibody production was not observed. A total amount of about 15 mg of the recombinantantibody, obtained in protein-free culture, was abouttwo times of that obtained in serum culture, and wasshown to be reactive to lung cancer cells in tissue. From these properties in protein-free medium, it isconcluded that protein-free culture of ras-rBHK-IgG cells is suitable for middle scaleproduction of recombinant human monoclonal antibody.
authors.affiliation: Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan, inoue@chem.agri.kagoshima-u.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Kawamoto
authors.forename: M
authors.initials: M
authors.lastname: Shoji
authors.forename: S
authors.initials: S
authors.lastname: Hashizume
authors.forename: K
authors.initials: K
authors.lastname: Teruya
authors.forename: Y
authors.initials: Y
authors.lastname: Katakura
authors.forename: S
authors.initials: S
authors.lastname: Shirahata