HPL-donor age is associated with activity of senescence-associated β-galactosidase.

MSC were cultivated for 5–6 days in HPL media of younger (<35 years; n = 8) or older donors (>45 years, n = 7). C₁₂FDG, a fluorogenic substrate of SA-βgal was subsequently analyzed by flow cytometry. A representative histogram of fluorescence intensity is demonstrated (grey line: autofluorescence; blue line: youngest HPL donor; red line: oldest HPL donor). Comparison of mean fluorescence intensity between the age-groups revealed higher SA-βgal activity with HPL of older donors (B). *P<0.05.