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 immunoglobulin, 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 fusion partners in the production of rat x rat hybridomas. Y0 has also been used in recombinant gene technology. Y0 cells grown in shake flask culture, using RPMI 1640 medium with 4mM l-glutamine and 5% foetal bovine serum, reached a maximal cell density of 1.5×10(6) cells ml(-1) with 86% viability. Y0 cells which has been adapted to grow in ABC protein-free medium reached a maximal density, in shake flask culture, of 8.75×10(5) cells ml(-1) with 79% viability. An improved protein-free medium, designated W38 medium, was developed. In shake flask culture, W38 medium supported Y0 cell growth to a density of 2.02×10(6) cells 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 hybridomas, cell growth and product yield in shake flask culture using W38 medium was superior to that obtained with serum-containing RPMI 1640 medium.