Tetramer analysis of HM1.24 peptide–specific T cells. CD8⁺ T cells from normal PBMCs (HLA-A2⁺, A24^-) or PBSC harvests of patient no. 3 (HLA-A2⁺, A24^-) were stimulated with autologous DCs pulsed with HM1.24-126 or MAGE-3-195 peptides 3 times. Normal PBMCs (A), MAGE-3–stimulated CD8⁺ cells (B), HM1.24-126–stimulated CD8⁺ cells (C), PBSC harvests (D), MAGE-3–stimulated PBSC harvests (E), and HM1.24-126–stimulated PBSC harvests (F) were stained with FITC-labeled anti-CD8 MoAb and PE-labeled HM1.24-126/A2 tetramer and were analyzed by 2-color flow cytometry. The numbers represent the percentage of CD8⁺/tetramer⁺ cells. Negative control staining showed less than 0.1% of CD8⁺/tetramer⁺ cells in each experiment.