A nutrient medium formulated by Todd and Hewitt for the production of antigenic streptococcal haemolysin. The broth is also used for the cultivation of streptococci before serological grouping. Dextrose breakdown leads to the production of acid that would normally inactivate the haemolysin. The acids produced are neutralized by the presence of sodium carbonate and sodium phosphate. The prepared material has a light golden to amber color and is clear. Expected culture results appear after 18 – 48 hours of incubation at 35-37C°.