Azide Blood Agar Base is a selective medium intended to detect and isolateStreptococciandStaphylococcifrom a variety of different samples including food and sewage. ‘Lab-Lemco’ Powder and Tryptose supply nitrogenous compounds, carbohydrates, and vitamins. Sodium Chloride maintains the osmotic balance. Sodium Azide is a bacteriostatic agent suppressing the growth of most Gram-negative bacteria but allowing that of Gram-positive microorganisms likeStreptococcusandStaphylococcusspp. Agar is the gelifying agent. Addition of blood allows for the detection of hemolytic reactions