THE CULTURE OF RAT MYELOMA AND RAT HYBRIDOMA CELLS IN A PROTEIN-FREE MEDIUM

Y0 is a rat x rat hybridoma cell line, which does not secrete immunogl obulin, produced using a fusion partner derived from the Y3 (Y3,Ag.1.2 .3) rat myoloma cell line. Y0 and Y3 have both been widely used as fus ion partners in the production of rat x rat hybridomas. Y0 has also be en used in recombinant gene technology. Y0 cells grown in shake flask culture, using RPMI 1640 medium with 4mM l-glutamine and 5% foetal bov ine serum, reached a maximal cell density of 1.5 x 10(6) cells ml(-1) with 86% viability. Y0 cells which had been adapted to grow in ABC pro tein-free medium reached a maximal density, in shake flask culture, of 8.75 x 10(5) cells ml(-1) with 79% viability. An improved protein-fre e medium, designated W38 medium, was developed. In shake flask culture , W38 medium supported Y0 cell growth to a density of 2.02 x 10(6) cel ls ml(-1) with 96% viability. Two Y3 hybridomas, YID 13.9.4 cells and SAM 618 cells were adapted to growth in W38 medium. For both hybridoma s, cell growth and product yield in shake flask culture using W38 medi um was superior to that obtained with serum-containing RPMI 1640 mediu m.