Immunoperoxidase localisation of fibronectin in glomeruli of formalin fixed paraffin processed renal tissue.

An indirect immunoperoxidase technique was used to demonstrate fibronectin in sections of routine formalin fixed paraffin embedded renal tissue. Previous exposure of the sections to a solution of pepsin (4 mg/ml) in 0.01 N HCl for 2 h at 37 degrees C was essential in order to demonstrate antigenicity of fibronectin previously masked by fixation and embedding procedures.