An argyrophil-III method for the selective demonstration of mitochondria in aldehyde-fixed rat brain

Based on recent achievements in physicochemical aspects of histological silver staining, a selective and reliable method was elaborated for the demonstration of mitochondria in frozen sections of aldehyde-fixed rat brain. Areas of similar architecture were stained with comparable intensity both within one section or in serial sections. The distribution patterns of mitochondria can be examined at low magnification or even with the unaided eye. At high magnifications, rounded and elongated profiles with the size and shape of mitochondria clearly stand out against a pale background. Electron microscopy revealed a high degree of selectivity and completeness of the mitochondrial staining.