Fig. 3.

Immunoperoxidase localization of kAE1 and vH-ATPase in kidney sections from dRTA patient III:3. (A and C) Non-representatative regions of tissue in which AE1 staining (diaminobenzidine substrate, Vector Laboratories) is evident in diffuse distribution in occasionally encountered intercalated cells (asterisks). Less frequently encountered are candidate intercalated cells with basal-apical or apical enhancement of kAE1 staining (arrows in A). Red blood cells are evident in interstitial spaces. (B and D) Near-consecutive sections showing intercalated cells with diffuse vH⁺-ATPase staining (NovaRed substrate, Vector Laboratories) with occasional apical enhancement. Asterisks indicate kAE1-positive cells in (A) and (B). Apical enhancement of vH⁺-ATPase staining is also evident in other collecting duct cells. (E) Unaffected ‘control’ kidney stained for vH⁺-ATPase. Scale bars: 20 µm (A–D) and 50 µm (E).