TCR repertoire of naive and EM_CD45RA+ IL-7Rα^high and IL-7Rα^low CD8⁺ T cells in elderly and young subjects. PBMCs from healthy young and elderly subjects were stained with antibodies to CD8, CD45RA, CCR7, and IL-7Rα and sorted into naive, EM_CD45RA+ IL-7Rα^high, and IL-7Rα^low CD8⁺ T cells. Total RNA was isolated from sorted cells and used for measuring the TCR repertoire using spectratyping, as described in “Experimental procedures.” Results are representative data from 2 young and 2 elderly subjects.