Comparison of two culture media types used to grow Neisseria gonorrhoeae bacteria. Known as overgrowth, the nonselective chocolate agar medium on the left, due to its composition, allowed for the growth of organismal colonies other than those of N. gonorrhoeae, while the selective Thayer–Martin medium on the right, containing antimicrobials that inhibit the growth of organisms other than N. gonorrhoeae, shows no overgrowth, but is positive for N. gonorrhoeae bacteria. (Enlarge image to see N. gonorrhoeae colonies) | Public Domain, https://commons.wikimedia.org/w/index.php?curid=2740645