Enterococcus selective agar allows to develop enterococci and to identify the reduction of TTX (triphenyltetrazolium chloride). The selective effect is achieved due to the presence of the sodium azide in the medium, which inhibits the growth of gram-negative and some gram-positive bacteria. Bacteria capable of reduction of TTX accumulate inside the cells Freemason which gives the colonies a red color. The cultivation is conducted at 37 ° C for 48 hours.