Methods Cord blood was collected seperately from cord vein and artery.CD34+ cells were detected by FACs, CFU-GM semisolid agar culture, and hematopoietic growth factors(HGFs) by ELISA.

• 方法分别测定脐动脉和脐静脉血中CD34+细胞、粒-区噬系细胞集落(CFU-GM)及造血生长因子含量;