A technique for the concentration of nucleated bone marrow cells for in vitro manipulation or cryopreservation using the IBM 2991 blood cell processor.

27 bone marrow aspirates were processed on the IBM 2991 Blood Cell Processor to achieve a reduction in volume (greater than 80%) and in red blood cell contamination (greater than 75%), without loss (less than 20%) of nucleated cells. The procedure was used to concentrate nucleated bone marrow cells either prior to cryopreservation for subsequent autologous transplantation, or prior to incubation with a murine monoclonal antibody (OKT3) for allogeneic transplantation. We conclude that the procedures used for the concentration, cryopreservation, thawing and infusion do not adversely affect the viability of cells as assessed by in vitro culture (CFU-GM). Of the marrows processed, 12 have been reinfused and resulted in successful engraftment.