Temperature-dependence of the proliferation of mouse bone marrow cells cultured in H2O- and D2O-media.

In an attempto to optimize and standardize the in vitro culture conditions of mouse bone marrow cells for assaying growth regulating factors, we studied the effects of incubation at low temperatures and of a nutrient medium containing deuteriumoxide instead of water. It was found that (1) the proliferative capacity of the cells is significantly increased by pre-incubation for 1-2 h at 0 degrees C rather than at 37 degrees C, measured by both a colony-forming and a 3H-thymidine (3H-tdr) uptake assay. A similar temperature effect on the colony-forming and 3H-tdr uptake ability is apparent after pre-incubation in D2O-medium, yet significantly lower than in H2O-medium. It was concluded that the previously observed protective effects of D2O on ascites tumor cell proliferation and viability and for hemolysis of human erythrocytes is not apparent in proliferating and colony-forming mouse bone marrow cells in vitro.