Recommended for detection of Escherichia coli and coliforms in water .The composition and performance criteria of this medium are as per the specifications laid down in ISO 9308-1:2014. The medium contains a mixture of three chromogens - 6-chloro-3-indoxyl β-D-galactopyranoside, 5-bromo-4-chloro-3-indoxyl- β-D-glucuronic acid cyclohexamine ammonium salt, monohydrate and IPTG. E.coli give dark blue to violet coloured colonies due to cleavage of both the chromogens while other coliform form pale pink to pink coloured colonies. Tergitol-7 inhibits gram-positive as well as some gram-negative bacteria other than coliforms. Available in scored plate . Grids for easy counting.