This broth is made in 4 variations: with lysine, ornithine, arginine and the control broth without amino acids. Broth uses for differentiating microorganisms by the possibility of decarboxylating a particular amino acid.

The environment indicator is bromocresol purple, which changes its color from purple (above a pH of 6.8) to yellow (below pH of 5.2). The composition of the medium includes glucose, after its fermentation, acid products are formed, through which the medium turns yellow. After carbon starts amino acids decarboxylate, formed as a result of alkaline products that increase the pH and changing the color of the medium to purple - this indicates a positive reaction for the decarboxylation. If the medium remains yellow, then the microorganisms do not decarboxylate amino acid, which is part of the environment.

Table №1. With lysine

Table №2. With ornithine

Table №3. With arginine

Table №4. Control