Figure 3
Hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC) and fluorescent PCR (F-PCR) of kidney samples from patient BMF4 showing oncocytosis. (a), H&E staining of 'normal' renal tissue showing numerous oncocytic nodules throughout the renal tissue (arrowheads; magnification: × 100). (b) F-PCR analysis for the mutation m.3571insC (MT-ND1) shows peaks for wild-type and mutant alleles in DNA extracted from tissue with oncocytosis. No mutation is detectable in the microdissected normal tissue (0% mutation), whereas only a very small peak is seen for the wild-type allele in the microdissected tumor tissue (93% mutation). IHC for a respiratory chain complex I subunit (NDUFB8) (c) and complex IV subunit (COXIV) (d, overlap shown in e) shows correlation between abundance of mitochondria, as indicated by CIV staining, and absence of CI in multiple nodules throughout the tissue (indicated with white arrows). Normal renal tissue expresses both CI and CIV proteins (central part of images; magnification: × 200).
