Description

Oxidase reagent is a liquid ready-to-use reagent that is used in procedures to detect cytochrome oxidase activity in bacteria.

Cytochrome containing organisms produce an intracellular oxidase enzyme. This oxidase enzyme catalyzes the oxidation of cytochrome c. Organisms which contain cytochrome c as part of their respiratory chain are oxidasepositive and turn the reagent blue/purple. Organisms lacking cytochrome c as part of their respiratory chain do not oxidize the reagent, leaving it colorless within the limits of the test, and are oxidase-negative.

The oxidase test is based on bacterial production of an intracellular oxidase enzyme and some organisms may produce more than one type of oxidase enzyme. These enzymes participate in the cellular respiration process and catalyze removal of hydrogen from a substrate using oxygen as a hydrogen acceptor. The active substrate in oxidase reagent, N,N,N,Ntetramethyl-p-phenylenediamine dihydrochloride, acts as an artificial electron acceptor for the enzyme oxidase and is oxidized to form the colored compound Wurster’s blue. Wurster’s blue is a purple compound that is readily visible and signifies a positive reaction.