[Clonal growth of granulocytic progenitor cells in diffusion chambers in vivo]

Investigations on colony forming ability of committed granulocytic progenitors from bone marrow were carried out. In all, 85 cultures were performed. The bone marrow was obtained from 12 subjects without evident haematological abnormalities. Cultures were carried on for 9 days in 0.2% agar medium in diffusion chambers implanted into the peritoneal cavity of irradiated mice. It was found that committed granulocytic stem cells produced on the average 132 colonies (70--240), which were divided into four types according to their size and morphology. All types of colonic consisted of granulocytes, including polymorphonuclears. In cultures also were observed aggregations of cells containing monocytes.