Quantification of TREC content in highly purified peripheral T-cell subsets from healthy adults. gDNA of sorted subpopulations from 7 healthy adults was isolated from freshly isolated DN (▪), CD4⁺ (□), and CD8⁺ (▦) T cells and the number of TRECs was determined by QRT-PCR. TREC counts per 1000 cells in individual samples; 1-7 indicate the number of the individual healthy donor.