SF (Streptococcus faecalis) Broth is a selective medium for the identification and differentiation of Enterococci from other cocci. Casein Enzymatic Hydrolysate provides amino acids, peptides, carbohydrates, vitamins, and trace elements. Dextrose is the fermentable carbohydrate. Sodium Azide inhibits Gram-negative organisms, thus making it selective for Enterococci. Phosphates serve as pH buffers. Sodium chloride maintains the osmotic equilibrium. Bromocresol Purple is the pH indicator that turns yellow upon Dextrose fermentation by Enterococci.