noun

A test used to determine if an organism is able to form acetoin and/or diacetyl in a phosphate buffered glucose peptone medium. The test consists of inoculating phosphate buffered glucose peptone medium and subsequent incubation at 37°C (for 48 hrs) or 30°C (for 5 days). Then α-naphtol and KOH are added and the medium is observed for red coloration (which indicates a positive reaction). Part of the IMViC tests.