Collection, processing and cryopreservation of umbilical cord blood for unrelated transplantation

Umbilical cord blood (UCB) transplantation is being used as an alternative source of hematopoietic stem cells for bone marrow reconstitution, Separati on and processing of UCB samples in large numbers for storage in cord blood banks ideally needs to be partially automated. The aim of this study was t o establish and standardize a method for unrelated cord blood banking as we ll as the biological characterization of the samples. Up to October 1999, a total of 938 UCB units (mean volume 84.6 +/- 23.6 ml, nucleated cell (NC) count 0.90 +/- 0.37 x 10(9), total CFU-GM 79 +/- 72 x 10(-4), CD34(+) cell count 2.46 +/- 2.72 x 10(6)) had been collected. Twenty-three per cent of a ll UCB samples had a NC count below 0.4 x 10(9) and were discarded. The ini tial bacterial contamination rate was reduced to less than 5% as a result o f extensive training in collection procedures. Using a modification of a tr iple bag system and adding a solution of 6% hydroxyethyl starch, the UCB wa s separated by two centrifugation steps into three components: huffy coat, red cell and plasma fractions. The overall recoveries for NC, CFU-GM and CD 34(+) cells were 87.4 +/- 8.5%, 88.8 +/- 6.6% and 90.3 +/- 12.4%, respectiv ely, in a mean final volume of 27 +/- 4.2 ml.