Figure 5.

Results of fluorescence in situ hybridization using flow cytometry (flow FISH) of purified CD45RO⁺ cutaneous lymphocyte antigen (CLA)-negative and -positive T cells from healthy individuals. (a) Isolated CD45RO⁺ CLA⁻ and CLA⁺ T cells from a young and an old individual were analyzed after hybridization with or without fluorescein isothiocyanate (FITC)-labelled peptide nucleic acid (shaded and open histograms, respectively). (b) The bar chart shows the mean ± standard error of the mean (SEM) relative telomere length (RTL) in cells of young and old donors. Note that the RTL of CLA⁺ T cells is lower than the RTL of CD45RO⁺ CLA⁻ T cells. A moderate increase of the RTL in aged CLA⁺ T cells is evident.