Cell suspensions from human and mouse bone marrow, heterogeneous with respect to size, were physically separated by a technique of velocity sedimentation at unit gravity. Fractions were collected, cell counts performed, and a sedimentation "profile" obtained. Fractions were assayed in culture for response to phytohemagglutinin and to allogeneic irradiated leukocytes. The peak activity in these assays occurred in fractions taken from the region of small, slowly sedimenting, nucleated cells, which in humans have an average sedimentation velocity at 4°C of approximately 3.5 mm/hr. The results suggest that velocity sedimentation can be used to separate human stem cells from cells that cause graft-vs.-host disease.

This content is only available as a PDF.
Sign in via your Institution