s a nonselective, enriched medium used for the isolation and identification of fastidious pathogens. Chocolate agar is prepared by heating blood agar, which in turn ruptures the red blood cell (RBC) and releases nutrients that aid in the growth of fastidious bacteria, most notably Haemophilus and Neisseria species. The name is derived from the fact that the lysis of RBC gives the medium a chocolate-brown color.