Fig. 2

Comparison of histological sections for the H- (left column), HI- (middle column) and AT1-tumor (right column). Structural changes and differentiation level are detected by Hematoxylin / Eosin (H&E) staining (upper row). For visualization of hypoxic areas, pimonidazole was used (brown staining, 2^nd row) and cell nuclei were counterstained with Hematoxylin. Vessel endothelium was stained with CD31 antibody in red (3^rd row). The maturity of vessels was proven by a pericyte staining using a smooth muscle actin antibody. Magnification: 100× (1^st and 2^nd row) or 200× (3^rd and 4^th row). Scale bars are 100 μm