Detection and characterization by flow cytometry of CD30+ T cells in postnatal thymus. Freshly isolated thymic MNC were resuspended in PBS containing 0.5% BSA and 0.02% sodium azide at the concentration of 1 × 10⁶ cells/mL. Cells were then assessed for CD30, CD4, and CD8 expression (A), as well as for CD30, CD45RO, and IL-4R expression (B) by three-color flow cytometry. IL-4R+ were then separated from IL-4R− thymocytes by incubation of thymic MNC with biotin-conjugated anti–IL-4R MoAb, followed by addition of streptavidin-coated MACS colloidal supermagnetic microbeads, and the two subsets were then assessed for CD30 expression (C). A representative experiment is shown.