Utility of bag segment and cryovial samples for quality control and confirmatory HLA typing in umbilical cord blood banking

Abstract

Many cord blood (CB) banks have been established worldwide as a response to the increasing number of CB transplantations. In this study, we describe a quality control program in which the utility of an integral bag segment and cryovial containing aliquots of cryopreserved product as haematopoietic content control and HLA typing confirmation for CB units has been evaluated. For this purpose, every month one stored CB unit and its satellite cryovials were thawed and washed. Nucleated cell counts, viability and clonogenic assays were performed from the bag and cryovial before washing. After washing, total nucleated cell, CD34+ counts, viability, and clonogenic assays were performed from the bag. In order to assure the ability of bag segments to confirm hematopoietic potential of CB units, clonogenic assays and viability were performed from attached segments of 10 CB units and the results were compared with those from bags and cryovials. When comparing all variables between thawed bag and cryovial samples, they showed similar results. Mean colony-forming unit (CFU) content of segment samples was 118.8 +/- 93.72 x 10(4) that resulted similar to bags and cryovials haematopoietic content. In conclusion, the quality control system described in this paper demonstrates that CB units are processed preserving the quantity and quality of the progenitor cells. The contiguous segment haematopoietic content is representative of the final product.