HiChromogenicâ„¢ Coliform Agar is a selective medium recommended for the simultaneous detection of Escherichia coli and total coliforms in water samples. HiCromeâ„¢ Chromogenic Coliform HiCynthâ„¢ Agar is a modification prepared by replacing animal peptones with chemically defined peptones to avoid BSE/TSE risks associated with animal peptones.