Bile Esculin Azide Agar Plate

This medium is recommended as a selective medium used for isolation and presumptive identification of faecal Streptococci. Bile and sodium azide inhibits most of the other accompanying bacteria. Esculin in the medium is hydrolysed to esculetin and dextrose. Esculetin reacts with ferric citrate to form a dark brown or black complex, visualized as a zone of black precipitate around the colonies.