Neisseria meningitidis
Thayer-Martin agar (or Thayer-Martin medium, or VPN agar) is a Mueller-Hinton agar with 5% chocolate sheep blood and antibiotics. It is used for culturing and primarily isolating pathogenic "Neisseria" bacteria, including "Neisseria gonorrhoeae" and "Neisseria meningitidis", as the medium inhibits the growth of most other microorganisms. When growing "Neisseria meningitidis", one usually starts with a normally sterile body fluid (blood or CSF), so a plain chocolate agar is used. Thayer-Martin agar was initially developed in 1964, with an improved formulation published in 1966.