title: A novel true volumetric method for the determination of residual leucocytes in blood components.
abstract: OBJECTIVE
  Accurate determination of residual leucocytes [white blood cells (WBC)] in blood components is of high clinical importance. To date, several labour-intensive, time-consuming or expensive techniques have been used for this purpose.
  
  
  METHODS
  A method for the determination of residual WBC is described using a novel low-cost flow-cytometric cell counter and analyser (CCA). The DNA in WBC was stained using 4'-6-diamidino-2-phenylindole (DAPI) and WBC were automatically analysed by true volumetric counting of 200-microl samples (prepared from a 20-microl undiluted sample).
  
  
  RESULTS
  Dilution experiments over a range of 0.5-50 WBC/microl showed a linearity of r = 0.998. The detection limit of this method was 0.83 WBC/microl of red blood cell concentrate (RCC) and 0.67 WBC/microl of platelet concentrate (PC), with an accuracy of 95.5%.
  
  
  CONCLUSIONS
  Residual WBC (< 1 WBC/microl) can be accurately counted using the CCA within 2 min and at a total cost of less than euro 1 per sample.
authors.affiliation: Institute for Transfusion Medicine/Department for Transplantation Immunology, University Hospital Münster, Germany. cassenu@uni-muenster.de
authors.forename: U
authors.initials: U
authors.lastname: Cassens
authors.forename: B
authors.initials: B
authors.lastname: Greve
authors.forename: K
authors.initials: K
authors.lastname: Tapernon
authors.forename: B
authors.initials: B
authors.lastname: Nave
authors.forename: E
authors.initials: E
authors.lastname: Severin
authors.forename: W
authors.initials: W
authors.lastname: Sibrowski
authors.forename: W
authors.initials: W
authors.lastname: Göhde
mesh_terms: D016913:Blood Component Transfusion; D003363:Cost Control; D005434:Flow Cytometry / Q000379:methods*; D005470:Fluorometry; D006801:Humans; D007958:Leukocyte Count; D007962:Leukocytes