Platinum-Diaminobenzidine Reaction and Its Contribution to the Quantitation of Cytochrome Oxidase Activity.

The platinum-diaminobenzidine (Pt-DAB) reaction, which yields a black, electron-dense, insoluble, Pt-containing reaction product at the active site of cytochrome oxidase without postosmification, has been developed. This reaction permits us to quantitate the oxidase activity in an individual mitochondrion or in its constituent part by the energy dispersive X-ray analysis (EDAX), based on the platinum atoms incorporated in the product. [ABSTRACT FROM PUBLISHER]