Erythropoietic Capacity of Short-Term Mouse Marrow Cultures 1.2

SUMMARY-Maintenance of erythropoietic activity of mouse bone marrow cells In short-term culture was investigated as part of a study of postradiation environment. Erythropoietic activity was measured by Fe59 uptake by spleens of lethally irradiated mice given injections of normal or cultured marrow cells. Medium composition and physical factors of marrow culture were investigated. Best maintenance at 37 ° C was obtained with TC 199 + 25 percent mammalian serum, and there was a broad pH optimum (6.6-8.0). There was an inverse relation between maintenance of erythropoietic activity and culture temperature from 30 to 45 ° C. Maintenance was improved at temperatures of 2 to 30 ° C. De-cline of activity in culture reRects inability of the stem cell compartment to maintain and replenish Itself.-J Nat Cancer Inst 35: 573-577, 1965r DESPITE advances made in culture techniques, long-term maintenance of normal mammalian hematopoietic cells in vitro continues to be a chal