A technique for isolation of bone marrow cells using hydroxyethyl starch (HES) sedimentation agent.

Various methods have been investigated to concentrate hemopoietic stem cells before in vitro treatment and cryopreservation. Each procedure requires various degrees of cell manipulation; moreover, the extent of purification of the stem cell fraction depends on the further use of bone marrow. Fifty four bone marrows were treated with hydroxyethyl starch (HES) to isolate the mononuclear cell population. The manipulation with HES permitted to concentrate marrow stem cells in a small volume with removal of unwanted granulocytes, red blood cells and the donor isohemagglutinins in the major ABH incompatibility. We describe here a manual method which permits the transfusion of a very few number of red cells without depletion of progenitor cells and thus delay of engraftment.