Priority Research Paper Volume 1, Issue 7 pp 608—621

Figure 5. ISG15 is increased in human skin with aging. (A) Immunofluorescence staining of ISG15 in BJ cells at different population doublings. The negative sample was treated identically except no primary antibody was added. Nuclei were stained with DAPI. Staining intensity increases in cells with short telomeres. (B) Immunochemical staining illustrating an age-dependent up-regulation of ISG15 expression in the dermis of human skin tissues. 2-4 cases were examined in each group. Infant, 0-1 year old; young adult, 20-24 year old; older adult, 53-68 year old. No primary antibody was added to the negative control. (C) Quantitation of the results of all the samples described above. 8-10 random fields were counted for each sample.