Description
Amyl Desoxycholate Agar AM 47 is based on the Hynes1 modification of Leifson’s2 original formulation for the isolation of Salmonella and Shigella spp. from clinical specimens and dairy products. Plates of prepared medium have a pale pink appearance. The higher levels of inhibitory substances ( sodium desoxycholate, sodium citrate ) in DCA are designed to inhibit the growth of gram positive organisms and the majority of the non-pathogenic lactose fermenting coliform bacteria whilst allowing proliferation and recognition of colonies of Salmonella and Shigella. The colonies of those lactose fermenting organisms that will grow on the medium appear red-pink due to acid produced by lactose fermentation altering the pH which, in the presence of the neutral red indicator, changes the colony colour to red.
