Erythropoietin, thrombopoietin and colony stimulating factor in fetal mouse liver culture media.

Fetal mouse livers, days 13 to 19 of gestation, were cultured for 21 days and the culture media tested for erythropoietin (Ep), thrombopoietin (TSF) and colony stimulating factor (CSF). High levels of both Ep and CSF were released into the culture media. However, no detectable TSF was found. Maximum Ep culture activity was detected in day 14 and day 15 fetal liver cultures while maximum CSF was found in the day 16 fetal liver culture. These studies indicate that fetal liver cells in culture are capable of producing and/or releasing both Ep and CSF but not TSF.