Processing and manipulation of human hemopoietic stem cells

In this paper, we reviewed the basic principles and methods of collection, processing and manipulation of marrow and peripheral haemopoietic progenitor cells. The advances in cell separation are due to the progress in blood bank technology and to the introduction of more sophisticated devices. This allows to process larger amounts of blood or marrow and to obtain a final single cell suspension. For this purpose, several procedures have been employed, including the unit gravity sedimentation, the centrifugal elutriation, the isopyknic sedimentation and the positive selection on columns of CD34+ cells. As expected, the emerging problems are the extreme heterogeneity of the methods employed and the unreliability of the quality control. The proposal for standardized protocols for each step of the various procedures is urgent, and the institution of multicenter studies is recommended.