Fig. 3
From: Carbonic anhydrase IX is a pH-stat that sets an acidic tumour extracellular pH in vivo
CAIX is expressed in all viable CA9 tumour tissue (a) but only at the hypoxic necrotic/viable interface in EV tumours (b). For both (a) and b: upper parts i, ii and iii show close-cut whole tumour sections, scale bar: 3 mm; lower parts iv, v and vi show higher magnification of the area indicated by the black rectangle, scale bar: 800 µm. Parts i and iv: haematoxylin and eosin staining; viable areas are dark purple; necrotic areas are pale. Parts ii and v: CAIX staining in brown, showing staining in all viable areas in CA9 tumours but absence of staining in the viable areas of EV tumours. Parts iii and vi: Ki67 staining (for proliferating cells) in brown, which confirms the proliferative areas and further defines the hypoxic periphery of viable tissue, adjacent to necrosis. Necrotic areas are non-perfused and so do not give an ISUCA signal
