title: Laboratory evaluation of a flow cytometric BCR-ABL immunobead assay.
abstract: BACKGROUND
  A new flow cytometric (FC) BCR-ABL immunobead assay has been developed recently. Here we present the laboratory evaluation of the commercially available kit.
  
  
  METHODS
  Mononuclear cells were isolated, lysed and processed according to the instructions of the manufacturer. Anti-BCR antibodies adsorbed to capture beads bind the BCR-ABL fusion proteins of the lysed cells, a phycoerythrin (PE)-conjugated anti-ABL antibody is the detector reagent and mean fluorescence intensity (MFI) signals were recorded by flow cytometry. Detection of t(9;22)(q34;q11) translocation was carried out with a quantitative PCR assay.
  
  
  RESULTS
  MFI results of 20 normal peripheral blood samples were 88±8 (mean±SD), CV 9%. K562 cells were used as positive control. Within-batch imprecision was excellent (3.7% in the normal and 10% in the pathological range). Cut-off was chosen at MFI 112, where both sensitivity and specificity were 100%. Altogether 17 chronic myeloid leukemia (CML) and 16 acute leukemia samples were analyzed. All PCR positive samples (n=14) were positive with the FC method and negative results were also concordant (n=15). Frozen cell lysates can be stored up to 4 weeks without significant decrease of MFI signal.
  
  
  CONCLUSIONS
  The FC BCR-ABL assay is a fast, reproducible and reliable method that may be incorporated into standard flow cytometric protocols to help clinical decision-making.
authors.affiliation: Department of Laboratory Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Hevessy
authors.forename: Renáta
authors.initials: R
authors.lastname: Hudák
authors.forename: Valéria
authors.initials: V
authors.lastname: Kiss-Sziráki
authors.forename: Péter
authors.initials: P
authors.lastname: Antal-Szalmás
authors.forename: Miklós
authors.initials: M
authors.lastname: Udvardy
authors.forename: László
authors.initials: L
authors.lastname: Rejtő
authors.forename: László
authors.initials: L
authors.lastname: Szerafin
authors.forename: János
authors.initials: J
authors.lastname: Kappelmayer
mesh_terms: D005434:Flow Cytometry / Q000379:methods* / Q000592:standards; D016044:Fusion Proteins, bcr-abl / Q000097:blood* / Q000235:genetics; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D007753:Laboratories; D007938:Leukemia / Q000097:blood; D008863:Microspheres; D016133:Polymerase Chain Reaction; D012015:Reference Standards
chemical_list: D016044:Fusion Proteins, bcr-abl