Foetal stem cells of Umbilical Cord Blood

After cord blood collection by an obstetrician, stem cell purification has been performed either with a combination of monoclonal antibodies, using the negative selection Stem Sep method, or with a positive cell selection based on their surface CD34 antigens, using the Mini Macs system. An excellent recovery of hematopoietic progenitors: Burst Forming Unit Erythroid; Colony Forming Unit Granulocyte and Macrophage; and Colony Forming Unit Granulocyte, inversely related to the rising of clamping time, have been achieved with the Mini Macs system (54% of colonies, with 90%purity). With the Stem Sep method, recovery of hematopoietic progenitors was 35% (with 80% purity). By early clamping of umbilical cord blood, we obtained a greater number of CD34+ cells whose clonogenic activity increased with enrichment. This is particularly useful considering that the number of CD34+ stem cells contained in a unit of placental blood is enough for transplantation to a child, but not for an adult engraftment. Thus, using these methods, we can obtain a larger number of CD34+ stem cells which increases the possibility of reducing graft-versus-host disease in adult patients, producing survival rates similar to those with transplantation of bone marrow.