Cystine Heart Agar

Cystine Heart Agar is a solid medium recommended for the cultivation of the tularemia-causing bacteria Francisella tularensis, Gram-negative cocci, and other pathogenic organisms. Penicillin inhibits Gram-positive organisms, while Polymyxin B suppresses the growth of Enterobacteriacea. Beef Heart Infusion, Casein Peptone, and Yeast Extract provide amino acids, peptides, carbohydrates, vitamins, and minerals. Dextrose is the fermentable carbohydrate. L-Cystine is a reducing agent allowing the growth of F. tularensis. Agar is the gelifying agent. Rabit Blood can be added to enrich the medium.