High-dose cytotoxic chemotherapy can be supported with autologous haemopoietic cells. Cryopreserved bone marrow has conventionally been used for this but blood stem cells are now in common use. We have examined different storage conditions for haemopoietic cells from bone marrow, leukapheresis product and whole blood primed with chemotherapy and filgrastim. The mean number of GM-CFC surviving cryopreservation was 80% in leukapheresis product (95% CI 66-96). At 4 degrees C, GM-CFC viability in all three sources of haemopoietic progenitors declined at the same rate, with mean recovery at 24 h of 90% (95% CI 82-98), at 48 h of 68% (95% CI 61-75) and at 72 h of 47% (95% CI 40-53). Progenitors remained viable for longer in autologous serum and citrate phosphate dextrose or Iscove's medium than in phosphate buffered saline. There was no significant difference in GM-CFC recovery from whole blood or whole blood buffy layer at 4 degrees C. The capacity to generate and sustain haemopoiesis in long-term culture is a feature of the more primitive progenitor cells. This capacity was similar in cryopreserved bone marrow and leukapheresis product, cryopreserved or stored for up to 5 days at 4 degrees C, suggesting that long-term culture-initiating cells are more resilient than colony-forming cells when cryopreserved or stored at 4 degrees C. These data indicate that primed whole blood, in addition to leukapheresis product and bone marrow, could be stored at 4 degrees C and used to support multicyclic high-dose chemotherapy.