 The samples prepared as described above were analyzed on a fluorescence activated cytometer EPICS ELITE; Coultronics; Louton, UK. The lymphocytes were tightly gated by volume and complexity on a forward 0o and side light scattering 90o mode. Phycocyanate-conjugated anti-human CD45 monoclonal antibodies DAKO; Ely, UK will be used as pan-leukocyte stain to exclude non leukocyte events by logical gating. The percentage of one-color, two-color, and three-color positive cells will be measured and the mean channel value as well as the relative fluorescence intensity RFI corresponding to the antigen density wii be estimated. QC-Combo Kit FCSC; San Jun, Puerto Rico will be used for the quantification of antibody binding. 