Tryptic soy broth or Trypticase soy broth (frequently abbreviated as TSB) is used in microbiology laboratories as a culture broth to grow aerobic bacteria. It is a complex, general purpose medium that is routinely used to grow certain pathogenic bacteria, which tend to have high nutritional requirements (i.e., they are fastidious). Its agar counterpart is tryptic soy agar (TSA). One of the components of Tryptic soy broth is Phytone, which is an enzymatic digest of soybean meal.