Salmonella Differential Agar is modification of original formulation of Rambach used for differentiation of Salmonella species from Proteus species and other enteric bacteria. Production of acid from propylene glycol is a novel characteristic of Salmonella species and is utilized in these media. Salmonella Differential HiCynthâ„¢ Agar is prepared by replacing animal and vegetable peptones with chemically defined peptones to avoid BSE/TSE risks associated with animal peptones.