Ethyl Violet Azide Broth is recommended for selective, confirmatory detection of Enterococci as an indicator of faecal pollution in water and other specimens. Combination of ethyl violet dye and of azide favours the selectivity for the growth of Streptococci (Enterococci) while it inhibits gram-positive bacilli and gram-positive cocci other than Enterococci. Enterococcus faecalis grows luxuriantly on this media and appears as purple button at the bottom of tube.