COUNTERFLOW CENTRIFUGAL ELUTRIATION - PRESENT AND FUTURE

Counterflow centrifugal elutriation (CCE) has been proposed as a metho d for separating heterogeneous cell populations into distinct subpopul ations on the basis of different sedimentation characteristics, withou t impairment of cell function or yield. The advantages of this techniq ue are the high recovery and viability of fractionated cells and the r apidity and reproducibility of results. CCE alone or in combination wi th other separation methods can provide homogeneous populations of cel ls for further investigations. Recently, CCE has been employed in clin ical studies aimed at preventing GVHD in BMT recipients by depleting l ymphocytes prior to BM infusion. Furthermore, ongoing studies are conc entrating on the use of negative selection procedures on the fractions currently excluded from the graft with the purpose of adding these de pleted fractions to the graft preparation to augment the number of ste m cells, accessory cells and unselected lymphocyte subsets. In the exp erimental field, CCE combined with negative and positive selection tec hniques may be useful in the study of hematopoiesis by separating 'pur e' stem cell populations from more committed hematopoietic progenitors . We review here the present and possible future applications of elutr iation in the clinical and experimental field.