Figure 1. Immunohistochemistry of Ku80, human mitochondria and Alu biomarkers in organs from human, mouse and rat origins.

All three biomarkers are expressed in human liver, pancreas, brain, testis, lung, hematopoietic bone marrow and lymph node (upper panels) but not in mouse (lower left panels) or rat (lower right panels) tissue counterpart. Ku80 and Alu strongly label the nucleus while hMito is confined to the cytoplasmic compartment. In most of the human organs, more than 99% of the cells, regardless of their tissular origin (epithelial, muscular, connective), are immunoreactive for Alu and Ku80 biomarkers. hMito is less broadly expressed and for instance does not label all types of human pneumocytes. A detailed analysis of biomarker expression is shown in Table 2. Scale bar represents 50 μm.

hMito: Human mitochondria.