oxidase reaction

ox·i·dase re·ac·tion

1. the formation of indol blue when a blood smear containing myeloid leukocytes is treated with a mixture of α-naphthol and p-dimethylaniline sulfate; the myeloid leukocytes contain an oxidase that catalyzes this reaction, and the lymphoid leukocytes do not; 2. in bacteriology, a reaction that depends on the presence of certain oxidases in some bacteria that catalyze the transport of electrons between electron donors in the bacteria and an oxidation reduction dye, such as tetramethyl-p-phenylenediamine; the dye is reduced to a blue or black color.