title: Liquid Storage of Hematopoietic Stem Cells Versus Proliferative Potential Colony-Forming Unit Granulocyte-Monocytes: Validation of Cell Processing.
abstract: BACKGROUND
  The material for transplantation must be of the highest quality. As far as we know, short-term storage is one of the crucial points of stem cell banking. According to the quality assurance system in a stem cell bank, each step of cell processing must be validated. The aim of this study was to assess the influence of short-term storage conditions into a clonogenic assay.
  
  
  METHODS
  Material was collected from mobilized peripheral blood by means of leukapheresis from 15 patients. Samples were stored at 4°C and 20°C; samples were evaluated on the day of leukapheresis and after 24 hours and after 48 hours of storage. The number of colony-forming unit granulocyte-monocyte (CFU-GM) precursors was analyzed with the use of in vitro culture. The material was evaluated before freezing and after thawing.
  
  
  RESULTS
  The average number of CFU-GM precursors in the material stored at 4°C before freezing on the day of collection was 84/10(5) nuclear cells (nc) and after 24 hours and 48 hours of storage was, respectively, 62/10(5) nc (P = .011719) and 36/10(5) nc (P = .02088). The average of the CFU-GM precursors in material stored at 20°C after 24 hours and 48 hours of storage amounted to 33/10(5) nc (P = .004439) and 2/10(5) nc (P = .00346), respectively.
  
  
  CONCLUSIONS
  In our study, the number of colonies of CFU-GM after 24 hours and 48 hours of storage, both at 4°C and 20°C, was significantly reduced compared with the number of colonies on the day of collection. Significantly greater numbers of CFU-GM precursors were observed in the material stored before freezing at 4°C in comparison with the material stored at 20°C.
authors: Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland. Electronic address: paula.matuszak@skpp.edu.pl.
authors: P
authors: P
authors: Matuszak
authors: Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland.
authors: E
authors: E
authors: Bembnista
authors: Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland.
authors: A
authors: A
authors: Kubiak
authors: Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland.
authors: M
authors: M
authors: Kozlowska-Skrzypczak
mesh_terms: D000094902:Blood Banking / Q000379:methods*; D002454:Cell Differentiation; D049109:Cell Proliferation; D015925:Cryopreservation / Q000379:methods*; D006098:Granulocytes / Q000166:cytology*; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D009000:Monocytes / Q000166:cytology*