Development of a serum-free medium for growth of NS-1 mouse myeloma cells and its application to the isolation of NS-1 hybridomas.

In this study, we have devised a hormone-supplemented, lipid-enriched serum-free medium, designated KSLM, that supports the growth of NS-1 mouse myeloma cells and have studied its applicability to the efficient isolation of antibody-producing hybridomas formed from the fusion of NS-1 myeloma cells and spleen cells from immunized mice. Our results show that KSLM medium, when used in conjunction with our hybridization protocol, allowed for the isolation, in a reproducible manner, of antibody-secreting hybridomas. Moreover, the yield of antibody-producing hybridomas was similar in KSLM medium and serum-supplemented medium. Here, we also report on the adaptation of NS-1 myeloma cells to growth in lipid-deficient KSLM medium. The use of the adapted myeloma cells (NS-1-503), instead of NS-1 myeloma cells, in fusion experiments not only permitted the isolation of antibody-secreting hybridomas in lipid-free KSLM medium but also resulted in a higher yield of antibody-producing hybridomas in both complete KSLM medium and serum-supplemented medium.