title: Methods for measuring a 6 log10 white cell depletion in red cells.
abstract: Methodology is presented for enumerating very low concentrations of white cells (WBCs) in red cells (RBCs) by two separate measurement techniques. Both techniques rely on the method of harvesting WBCs from a 300- to 350-mL unit of RBCs and concentrating them to a volume of approximately 0.5 to 1.0 mL, which is equivalent to a WBC concentration of approximately 550 to 1. The WBC separation and concentration steps require less than 3 hours to complete, and multiple RBC units can be processed in parallel. Cell counting is carried out in a fluorescence hemocytometer or by a modified cytospin technique. As few as 1000 WBCs in a unit of RBCs, which corresponds to a more than 6 log10 WBC depletion, can be measured without reaching the sensitivity limit of either technique (800 and 200 WBC/unit, respectively). The harvesting method and counting techniques are relatively simple and inexpensive.
authors.affiliation: Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland.
authors.forename: B J
authors.initials: BJ
authors.lastname: Sadoff
authors.forename: D C
authors.initials: DC
authors.lastname: Dooley
authors.forename: V
authors.initials: V
authors.lastname: Kapoor
authors.forename: P
authors.initials: P
authors.lastname: Law
authors.forename: L I
authors.initials: LI
authors.lastname: Friedman
authors.forename: R R
authors.initials: RR
authors.lastname: Stromberg
mesh_terms: D000165:Acridine Orange; D001781:Blood Component Removal; D002463:Cell Membrane Permeability; D002469:Cell Separation; D002498:Centrifugation; D017707:Erythrocyte Transfusion; D005456:Fluorescent Dyes; D006648:Histocompatibility; D006801:Humans; D007958:Leukocyte Count / Q000379:methods*; D007962:Leukocytes / Q000166:cytology; D017830:Octoxynol; D011092:Polyethylene Glycols; D011419:Propidium
chemical_list: D005456:Fluorescent Dyes; D011419:Propidium; D011092:Polyethylene Glycols; D017830:Octoxynol; D000165:Acridine Orange