Isolation of hemopoietic pluripotent stem cells from spleens of thiamphenicol-pretreated mice

The present report describes the bulk isolation of pluripotent stem cells (PSC) (assayed as day-9 CFU-S, colony-forming-units-spleen). As starting material, spleens, highly enriched with PSC, were used from mice that were bled and treated with thiamphenicol (TAP). In subjecting the spleen cells to a two-stage centrifugal elutriation procedure and a subsequent Percoll gradient centrifugation stage a 30-fold enrichment in the CFU-S concentration was achieved. The splenic PSC seeded with a characteristic low efficiency in the spleens of irradiated mice (f = 2%). Correcting the colony number for this, we obtained a cell mixture consisting of 88% PSC, contaminated with 4% committed precursor cells and about 10% ganuloid cells.