Histochemical demonstration of type IV collagen in the renal glomerulus.

Disulfide-groups are demonstrated in the basement membranes of glomerular capillaries, proximal convoluted tubules, and collecting ducts by means of a thiosulfathion/Alcian Blue +0.8 Mol MgCl2-staining sequence. It is suggested that the reaction shows type IV collagen of basal lamina material, which is characterized by a relatively high cystine content (8 half-cystine residues/1000).