Variation of Dihydrofolate Reductase Activity During In Vitro and In Vivo Growth of Sublines of L1210 Lymphoma

Summary

Three cloned strains of L1210 lymphoma were isolated and studied in suspension culture and mice. All lines doubled more slowly in vivo (24 hr) than in vitro (19 hr) and differed in their lethal effect on mice, in their chromosomes, and their sensitivity to growth inhibition by methotrexate. However, no significant difference occurred in enzyme behavior in any one cell during in vitro and in vivo growth. The transfer of cells from culture to mice can be used to increase significantly the yield of cells available for enzyme studies.