Conditions of adherent cell growth from murine bone marrow in liquid cultures, and partial characterization of function.

The number of adherent colonies grown and the type of their growth were influenced by both the serum and the medium used for the culture. The test results were obtained using either Dulbecco MEM, TC-199 or NCTC-109 together with 10% fetal calf serum and 10% horse serum (FCS/HS). Murine marrow cultures made in these conditions gave the linear relationship between the number of cells explanted (in the range 5 X 10(3) cells/ml to 5 X 10(6) cells/ml) nd the number of macroscopic adherent colonies grown. The number of colonies reached plateau by day 9 of culture and did not increase for up to 90 days of culture. Adherent colony forming cells disappeared from the liquid phases of such cultures within 3 days. Adherent layer formed had the capacity to support maintenance of spleen colony forming units and produced colony stimulating factor (CSF). This CSF supported 4-day granulocyte and macrophage colony formation in liquid cultures but not 7-day granulocyte-macrophage colony formation in semisolid medium. Therefore, the described culture system allowed to quantitatively grow cells responsible for some properties attributed to hemopoietic microenvironment (HM), possessed defined growth characteristics and may be utilized for further in vitro studies of HM.