Todd-Hewitt Broth is a liquid medium used for the cultivation ofStreptococci,Pneumococciand other fastidious organisms. Heart Infusion provides a source of amino acids, peptides, carbohydrates, vitamins, and trace elements. Peptone provides essential vitamins and minerals. Dextrose is the fermentable carbohydrate. Disodium Phosphate and Sodium Carbonate serve as pH buffers. Sodium Chloride maintains the osmotic equilibrium.