ABSTRACT
I. INTRODUCTION In consideration of the recent advances in the field of hematopoietic stem cell transplantation, it is important to recognize the critical contributions that certain technologies have made to the significant progress of the field. To this end, CD34 selection culminates a line of graft engineering strategies designed to prepare the hematopoietic stem cell product for transplantation. In effect, the evolution from technologies based on the exploitation of broad differences in cell size (centrifugation and elutriation) and surface characteristics (soybean agglutination and E rosetting) to specific surface antigens [monoclonal antibody (mAb)–based approaches] has represented a progressive refinement in cell processing expectations. Such development makes possible a nontoxic, passive removal of cells considered to act as contaminants of the hematopoietic stem cell product, has opened the doors to cellular therapeutics through gene therapy and immunotherapy, and has advanced these experimental technologies to within the realm of possibility.
