Microtopography of growth of normal and leukemic murine cells in diffusion-chamber cultures.

Histologic examination of "suspension" diffusion-chamber (DC) cultures of normal murine bone marrow cells demonstrates that hemopoietic cell growth in this system takes place in clonal form. Soon after implantation, marrow cells are arrayed on the filter membranes in a circumferential fashion adjacent to the surrounding lucite ring. Colonies of granulocytic cells soon form in this location and increase in size and number with increasing time of culture. Eventually cells begin to approach confluence over the entire filter membrane. Growth of C1498 murine acute myelogenous leukemic cells in DC cultures also takes place on the filter membranes and begins in a circumferential pattern. However, the leukemic cells grow diffusely and soon overspread the entire filter membrane, often growing several layers thick. Thus, although normal marrow cells are implanted into and are harvested from DC cultures in liquid-suspension form, they grow in a clonal pattern similar to that observed with the plasma-clot and fibrin-clot DC culture methods.