Processing and cryopreservation for 1963 units of human umbilical cord blood.

The study was aimed to establish a standard procedure for human umbilical cord blood bank. The hematopoietic nucleated cells in cord blood were processed by using sedimentation and centrifugation method. After finishing CD34(+) cell counting, hematopoietic progenitor cell assay, microbial culture, infectious disease test and HLA typing, cord blood units were stored in the liquid nitrogen for further application. The results showed that nucleated cells of cord blood were (10.94 +/- 2.74) x 10(8) per unit; recovery rate of nucleated cells was (79.82 +/- 17.76)%. CD34(+) cells in cord blood were counted as (51.62 +/- 30.53) x 10(5) per unit. Eight units of cord blood were thawed after two years of cryopreservation, the recovery rate of nucleated cells, CD34(+) cells and CFU-GM were (91.4 +/- 6.0)%, (84.6 +/- 20.0)% and (85.8 +/- 14.9)% respectively. It is suggested that the methods and procedure reported for processing and cryopreservation of hematopoietic stem/progenitor cells in the human umbilical cord blood is effective.