Enrichment of naive CD8⁺ T cells by Fab-streptamer technology. (A) Flow cytometry analyses of fresh human PBMCs from a healthy donor (HD) prior to and after sequential enrichment of CD8⁺, CD62L⁺, and CD45RA⁺ cells with Fab multimers conjugated with Strep-Tactin–functionalized magnetic beads. Living lymphocytes in the respective positive and negative fractions of each selection step are shown. Data are shown after gating on live cells. Numbers indicate the percentage of cells in each gate. (B) Percentage of CD8⁺CD62L⁺CD45RA⁺ T cells prior to and after each selection step from 6 HDs; mean value ± standard error of the mean (SEM) is indicated. (C) Percentage yields of the target CD8⁺CD62L⁺CD45RA⁺ T cells from 6 HD; mean value ± SEM is indicated.