Serum-free medium for long-term growth, freezing, cloning and fusion of myelomas and hybridomas

Dear Editor: A number of laboratories and companies have reported on the development of serum-free media for the growth of myelomas and hybridomas in tissue culture (1-4,6-9). Due to the different growth requirements of different cell lines, these serum-free media generally have not been broadly applicable. For example, HB101 (Hana Biologies) supported the growth of SP2/0 cells, SP2/O-derived hybridomas, human-human hybridomas, etc., but not NS-I and NS-l-derived hybridomas (6); the SFH medium described by Kovar and Franek (4) was suitable for the growth of F0 myeloma cells and T3-03 cells (F0-derived hybridomas) but not X63-Ag8.653 cells and PGG-05 cells (X63-Ag8.653-derived hybridomas); the SSF medium of Chang et al. (1) supported five hybridoma cells but not P3X63Ag8 and 653 myeloma cells; the SFFD/ITES medium of Murakami et al. (7) supported MPC11or SP2/0-derived hybridomas but not sufficiently NS-l-derived hybridomas; and the media of Cleveland et al. (2) supported P3X63-Ag8.653 myelomas and some of hybridomas but not M1/75.16.4 rat-mouse hybridomas. Our experimental findings indicated that DMI serum-free medium supported the growth of all tested cell lines which covered human, rat and mouse myelomas, rat-mouse heterohybridomas, mousemouse homohybridomas, K562 cells etc. (Table 1) (5). It was shown that successful growth of hybridoma in a serum-free medium in short-term culture did not mean successful adaptation to longterm cultivation in the serum-free medium (4). In the present study it was confirmed that DMI could be successfully used to long-term