Optimum inorganic ion concentrations for hematopoiesis cultures

Current limitations in the ability to culture hematopoietic cells may be due to the use of ion concentrations that reflect those in the general circulation rather than those expected at hematopoietic sites. Expected changes in calcium, phosphate and hydroxyl ion are calculated indirectly using published data. Results indicate doubling of normal concentrations for the first week, followed by 2 weeks of smaller elevations as the osteon undergoes resorption and replacement. The period of 3 weeks fits the expected time of the three stages of differentiation and proliferation of erythrocytes to the maturation phase. Mimicking the high concentrations of these ions in vitro may require the development of dynamic flow cultures because of problems with precipitation of calcium phosphate crystals. After 3 weeks 10% less than normal concentrations is expected as the bone mineral is replaced over a period of months, allowing a static system for maturation.