Cross evaluation of three flow cytometric F cell counting methods performed by different laboratories.
Three flow cytometric methods of counting F cells were evaluated in the settings of an external laboratory assessment scheme. The laboratories to participate with a different method were located in Oxford (method O), Athens (method A) and Jerusalem, (method J). Two monoclonal anti-gamma chain antibodies were used: monoclonal antibody produced by P. Beverley (Oxford) (BEV) and an antibody provided by Bioatlantic S.A.R.L. (France) (BIO). The specimens tested were mixtures in five predefined ratios of a sample with homozygous deltabeta-thalassemia with 100% F cells with a sample with no F cells. A central independent laboratory prepared and distributed the aliquots (at room temperature) to the participating centers within 2 (O), 3 (A), and 6 (J) days. The performance of the three methods was evaluated by: 1) deviation indices, 2) relative accuracy, as percent difference of the counts from the target values, and 3) bias and linearity by linear regression of the counts versus the target values [parameters: slope (s), y-intercept (y), R squared (Rs), and F ratio]. The highest score of performance was obtained by method A with both monoclonal antibodies.
Paterakis
G S
GS
Immunology Department and National Histocompatibility Center General District Hospital of Athens G. Gennimatas, Greece.
Thein
S L
SL
Fibach
E
E
Cappellini
M D
MD
D004906:Erythrocyte Count / Q000379:methods*; D005069:Evaluation Studies as Topic; D005319:Fetal Hemoglobin / Q000032:analysis* / Q000276:immunology; D005434:Flow Cytometry / Q000379:methods*; D005455:Fluorescent Antibody Technique; D006801:Humans; D017086:beta-Thalassemia / Q000097:blood / Q000276:immunology
D005319:Fetal Hemoglobin