Cultivation of frozen mouse bone marrow cells in agar.

The authors attempted to cultivate frozen mouse bone marrow cells in a semisolid medium. They demonstrated that the stem haematopoietic cells of frozen mouse bone marrow were capable of proliferation and of colony formation on agar. The much smaller number of colonies from frozen mouse bone marrow (about 80% fewer) compared with fresh marrow is evidence that part of the stem haematopoietic cell population retains proliferative capacity even after freezing.