The quantity and quality of hematoblast in umbilical cord blood ( ucb ) can be compared with bone marrow . furthermore , it has other advantages : widely sourced , no contamination of pathogeny , weakly antigenicity , and no mature lymphocyte , et al 脐血中造血细胞的数量和质量都与骨髓相近,而且,具有来源丰富、无病原体污染、抗原性弱、淋巴细胞不成熟等优点。