Repetitive maturation cycles in a cultured mouse myeloma.

Abstract

. In general, these cell lines grow as stationary suspension cultures with few cells attaching to the growing surface . Exponential growth in these cultures continues indefinitely as long as cell density is kept below 1-2 X 10 6per milliliter . Cultures with more than 2 X 10 6cells per milliliter have been reported to undergo rapid deterioration . Considerable morphologicvariation, especiallyin nuclearcytoplasmic ratios, among the various cell lines has been observed . However, within a given cell line little morphologic variation in regard to the stage of plasma cell maturation has been described . We report here the establishment of a mouse myeloma cell line which undergoes typical plasma cell morphological differentiation . Shortly after the fully mature stage is reached, greater than 99% of the cells die ; the few viable cells remaining initiate a new cycle of replication and maturation . At the time of this writing, these cells have continued to cycle in this fashion for over I yr. The underlying nature of the observed cycling does not appear to be related to cell density or to depletion of medium components .