Enterococcus Differential Agar Base (TITG Agar Base) is a selective medium recommended for the differentiation of Enterococcus faecalis and Enterococcus faecium.The differentiation is based depending upon the reduction of tetrazolium. Enterococcus faecalis produces colonies with a deep red centre and a narrow white periphery, whereas Enterococcus faecium produces white or pale pink coloured colonies.